| /***************************************************************************/ |
| /* */ |
| /* ftraster.c */ |
| /* */ |
| /* The FreeType glyph rasterizer (body). */ |
| /* */ |
| /* Copyright 1996-2000 by */ |
| /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
| /* */ |
| /* This file is part of the FreeType project, and may only be used */ |
| /* modified and distributed under the terms of the FreeType project */ |
| /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
| /* this file you indicate that you have read the license and */ |
| /* understand and accept it fully. */ |
| /* */ |
| /***************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The `raster' component implements FreeType's scan-line converter, the */ |
| /* one used to generate bitmaps and pixmaps from vectorial outline */ |
| /* descriptions. */ |
| /* */ |
| /* It has been rewritten entirely for FreeType 2.0, in order to become */ |
| /* completely independent of the rest of the library. It should now be */ |
| /* possible to include it more easily in all kinds of libraries and */ |
| /* applications, which do not necessarily need the font engines and API. */ |
| /* */ |
| /* This version contains the following features: */ |
| /* */ |
| /* - Support for third-order Bezier arcs. */ |
| /* */ |
| /* - Improved performance of the 5-levels anti-aliasing algorithm. */ |
| /* */ |
| /* - 17-levels anti-aliasing for smoother curves, though the difference */ |
| /* isn't always noticeable, depending on your palette. */ |
| /* */ |
| /* - An API to decompose a raster outline into a path (i.e., into a */ |
| /* a series of segments and arcs). */ |
| /* */ |
| /* Planned additions: */ |
| /* */ |
| /* - Getting rid of the second pass for horizontal drop-out detection. */ |
| /* I've got a few ideas, but I'll have to experiment in Pascal with */ |
| /* them. to avoid damaging of the rendering of glyphs at small sizes. */ |
| /* */ |
| /* - Adding a `composition' callback, which should be invoked during */ |
| /* anti-aliased rendering. In short, it will allow line-by-line */ |
| /* composition (i.e., transparencies, etc.) of the output in a fairly */ |
| /* portable way. Of course, a single sweep is required there. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| #include <ftraster.h> |
| #ifndef _STANDALONE_ |
| #include <ftconfig.h> |
| #endif |
| |
| #ifndef EXPORT_FUNC |
| #define EXPORT_FUNC /* nothing */ |
| #endif |
| |
| #undef FT_COMPONENT |
| #define FT_COMPONENT trace_raster |
| |
| #ifdef _STANDALONE_ |
| |
| /*************************************************************************/ |
| /* */ |
| /* The following defines are used when the raster is compiled as a */ |
| /* stand-alone object. Each of them is commented, and you're free to */ |
| /* toggle them to suit your needs. */ |
| /* */ |
| /*************************************************************************/ |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_INT_IS_32 */ |
| /* */ |
| /* Set this configuration macro to the unsigned type which has 32 */ |
| /* bits. */ |
| /* */ |
| #define FT_RASTER_INT_IS_32 |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_OPTION_ANTI_ALIAS */ |
| /* */ |
| /* Define this configuration macro if you want to support */ |
| /* anti-aliasing. */ |
| /* */ |
| #define FT_RASTER_OPTION_ANTI_ALIAS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_OPTION_CONIC_BEZIERS */ |
| /* */ |
| /* Define this configuration macro if your source outlines contain */ |
| /* second-order Bezier arcs. Typically, these are TrueType outlines. */ |
| /* */ |
| #define FT_RASTER_CONIC_BEZIERS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_OPTION_CUBIC_BEZIERS */ |
| /* */ |
| /* Define this configuration macro if your source outlines contain */ |
| /* third-order Bezier arcs. Typically, these are Type1 outlines. */ |
| /* */ |
| #define FT_RASTER_CUBIC_BEZIERS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_ANTI_ALIAS_5 */ |
| /* */ |
| /* Define this configuration macro if you want to enable the 5-grays */ |
| /* anti-aliasing mode. Ignored if FT_RASTER_OPTION_ANTI_ALIAS isn't */ |
| /* defined. */ |
| /* */ |
| #define FT_RASTER_ANTI_ALIAS_5 |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_ANTI_ALIAS_17 */ |
| /* */ |
| /* Define this configuration macro if you want to enable the 17-grays */ |
| /* anti-aliasing mode. Ignored if FT_RASTER_OPTION_ANTI_ALIAS isn't */ |
| /* defined. */ |
| /* */ |
| /* #define FT_RASTER_ANTI_ALIAS_17 */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_LITTLE_ENDIAN */ |
| /* FT_RASTER_BIG_ENDIAN */ |
| /* */ |
| /* The default anti-alias routines are processor-independent, but */ |
| /* slow. Define one of these macros to suit your own system, and */ |
| /* enjoy greatly improved rendering speed. */ |
| /* */ |
| |
| /* #define FT_RASTER_LITTLE_ENDIAN */ |
| /* #define FT_RASTER_BIG_ENDIAN */ |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_CONSTANT_PRECISION */ |
| /* */ |
| /* Define this configuration macro if you want to use a constant */ |
| /* precision for the internal sub-pixel coordinates. Otherwise, the */ |
| /* precision is either 64 or 1024 units per pixel, depending on the */ |
| /* outline's "high_precision" flag.. */ |
| /* */ |
| /* This results in a speed boost, but the macro can be undefined if */ |
| /* it results in rendering errors (mainly changed drop-outs).. */ |
| /* */ |
| #define FT_RASTER_CONSTANT_PRECISION |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_PRECISION_BITS */ |
| /* */ |
| /* When the macro FT_RASTER_CONSTANT_PRECISION is defined, this */ |
| /* constant holds the number of bits used for the internal sub-pixels */ |
| /* */ |
| /* This number should be at least 6, but use at least 8 if you */ |
| /* intend to generate small glyph images (use 6 for a printer, for */ |
| /* example..) */ |
| /* */ |
| #define FT_PRECISION_BITS 8 |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_DYNAMIC_BEZIER_STEPS */ |
| /* */ |
| /* Set this macro to enable the bezier decomposition to be */ |
| /* dynamically computed. This is interesting when the precision is */ |
| /* constant, as it speeds things a bit while keeping a very good */ |
| /* accuracy on the bezier intersections.. */ |
| /* */ |
| #define FT_DYNAMIC_BEZIER_STEPS |
| |
| |
| #else /* _STANDALONE_ */ |
| |
| #include <freetype.h> |
| #include <ftconfig.h> |
| |
| /*************************************************************************/ |
| /* */ |
| /* The following defines are used when the raster is compiled within the */ |
| /* FreeType base layer. Don't change these unless you really know what */ |
| /* you're doing. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| #ifdef FT_CONFIG_OPTION_ANTI_ALIAS |
| #define FT_RASTER_OPTION_ANTI_ALIAS |
| #endif |
| |
| #define FT_RASTER_CONIC_BEZIERS |
| #define FT_RASTER_CUBIC_BEZIERS |
| |
| #define FT_RASTER_ANTI_ALIAS_5 |
| /* #define FT_RASTER_ANTI_ALIAS_17 */ |
| |
| #ifdef FT_CONFIG_OPTION_LITTLE_ENDIAN |
| #define FT_RASTER_LITTLE_ENDIAN |
| #endif |
| |
| #ifdef FT_CONFIG_OPTION_BIG_ENDIAN |
| #define FT_RASTER_BIG_ENDIAN |
| #endif |
| |
| #define FT_RASTER_CONSTANT_PRECISION |
| #define FT_DYNAMIC_BEZIER_STEPS |
| #define FT_PRECISION_BITS 8 |
| |
| #endif /* _STANDALONE_ */ |
| |
| |
| /* to keep the compiler happy */ |
| #ifndef PTRACE2 |
| #define PTRACE2(x) /*void*/ |
| #endif |
| |
| /*************************************************************************/ |
| /* */ |
| /* FT_RASTER_ANY_ENDIAN indicates that no endianess was defined by one */ |
| /* of the configuration macros. */ |
| /* */ |
| #if !defined( FT_RASTER_LITTLE_ENDIAN ) && !defined( FT_RASTER_BIG_ENDIAN ) |
| #define FT_RASTER_ANY_ENDIAN |
| #endif |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The rasterizer is a very general purpose component. Please leave the */ |
| /* following redefinitions here (you never know your target */ |
| /* environment). */ |
| /* */ |
| /*************************************************************************/ |
| |
| #ifndef TRUE |
| #define TRUE 1 |
| #endif |
| |
| #ifndef FALSE |
| #define FALSE 0 |
| #endif |
| |
| #ifndef NULL |
| #define NULL (void*)0 |
| #endif |
| |
| |
| #ifndef UNUSED |
| #define UNUSED( arg ) ( (void)(arg) ) |
| #endif |
| |
| |
| #undef FAILURE |
| #define FAILURE TRUE |
| |
| #undef SUCCESS |
| #define SUCCESS FALSE |
| |
| #ifndef ABS |
| #define ABS(x) ( (x) < 0 ? -(x) : (x) ) |
| #endif |
| |
| /*************************************************************************/ |
| /* */ |
| /* Please don't touch the following macros. Their importance is */ |
| /* historical to FreeType, but they have some nice effects, like getting */ |
| /* rid of all `->' symbols when accessing the raster object (replacing */ |
| /* them with a simple `.'). */ |
| /* */ |
| /*************************************************************************/ |
| |
| /* used in function signatures to define the _first_ argument */ |
| #define RAS_ARG_ FT_Raster raster, |
| #define RAS_ARG FT_Raster raster |
| |
| /* used to call a function within this component, first parameter */ |
| #define RAS_VAR_ raster, |
| #define RAS_VAR raster |
| |
| /* used to access the current raster object, with a `.' instead of a */ |
| /* `->' */ |
| #define ras (*raster) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Error codes returned by the scan-line converter/raster. */ |
| /* */ |
| #define ErrRaster_Ok 0 |
| #define ErrRaster_Uninitialized_Object 1 |
| #define ErrRaster_Overflow 2 |
| #define ErrRaster_Negative_Height 3 |
| #define ErrRaster_Invalid_Outline 4 |
| #define ErrRaster_Invalid_Map 5 |
| #define ErrRaster_AntiAlias_Unsupported 6 |
| #define ErrRaster_Invalid_Pool 7 |
| #define ErrRaster_Unimplemented 8 |
| #define ErrRaster_Bad_Palette_Count 9 |
| |
| |
| #define Flow_Up 1 |
| #define Flow_Down -1 |
| |
| #define SET_High_Precision( p ) Set_High_Precision( RAS_VAR_ p ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Fast MulDiv, as `b' is always < 64. Don't use intermediate */ |
| /* precision. */ |
| /* */ |
| #define FMulDiv( a, b, c ) ( (a) * (b) / (c) ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Define DEBUG_RASTER if you want to generate a debug version of the */ |
| /* rasterizer. This will progressively draw the glyphs while all the */ |
| /* computation are done directly on the graphics screen (the glyphs will */ |
| /* will be shown inverted). */ |
| /* */ |
| /* Note that DEBUG_RASTER should only be used for debugging with b/w */ |
| /* rendering, not with gray levels. */ |
| /* */ |
| /* The definition of DEBUG_RASTER should appear in the file */ |
| /* `ftconfig.h'. */ |
| /* */ |
| #ifdef DEBUG_RASTER |
| extern char* vio; /* A pointer to VRAM or display buffer */ |
| #endif |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The maximum number of stacked Bezier curves. Setting this constant */ |
| /* to more than 32 is a pure waste of space. */ |
| /* */ |
| #define MaxBezier 32 |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The number fractional bits of *input* coordinates. We always use the */ |
| /* 26.6 format (i.e, 6 bits for the fractional part), but hackers are */ |
| /* free to experiment with different values. */ |
| /* */ |
| #define INPUT_BITS 6 |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* An unsigned type that is exactly 32 bits on your platform. This */ |
| /* means `unsigned long' on 16-bit machines, and `unsigned int' on */ |
| /* others. */ |
| /* */ |
| #ifdef _STANDALONE_ |
| #if defined( FT_RASTER_INT_IS_32 ) |
| typedef unsigned int FT_Word32; |
| #elif defined( FT_RASTER_LONG_IS_32 ) |
| typedef unsigned long FT_Word32; |
| #else |
| #error "no 32bit type found - please check your configuration" |
| #endif |
| #endif |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* A pointer to an unsigned char. */ |
| /* */ |
| typedef unsigned char Byte, *PByte; |
| typedef int TResult; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The type of the pixel coordinates used within the render pool during */ |
| /* scan-line conversion. We use longs to store either 26.6 or 22.10 */ |
| /* fixed float values, depending on the `precision' we want to use */ |
| /* (i.e., low resp. high precision). These are ideals in order to */ |
| /* subdivise Bezier arcs in halves by simple additions and shifts. */ |
| /* */ |
| /* Note that this is an 8-bytes integer on 64 bits systems. */ |
| /* */ |
| typedef long TPos, *PPos; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The type of a scanline position/coordinate within a map. */ |
| /* */ |
| typedef int TScan, *PScan; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* States and directions of each line, arc, and profile. */ |
| /* */ |
| typedef enum _TDirection |
| { |
| Unknown, |
| Ascending, |
| Descending, |
| Flat |
| |
| } TDirection; |
| |
| |
| struct _TProfile; |
| typedef struct _TProfile TProfile; |
| typedef TProfile* PProfile; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The `master' structure used for decomposing outlines. */ |
| /* */ |
| struct _TProfile |
| { |
| TPos X; /* current coordinate during sweep */ |
| PProfile link; /* link to next profile - various purpose */ |
| PPos offset; /* start of profile's data in render pool */ |
| int flow; /* Profile orientation: Asc/Descending */ |
| TScan height; /* profile's height in scanlines */ |
| TScan start; /* profile's starting scanline */ |
| |
| TScan countL; /* number of lines to step before this */ |
| /* profile becomes drawable */ |
| |
| PProfile next; /* next profile in same contour, used */ |
| /* during drop-out control */ |
| }; |
| |
| typedef PProfile TProfileList; |
| typedef PProfile* PProfileList; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* A simple record used to implement a stack of bands, required by the */ |
| /* sub-banding mechanism. */ |
| /* */ |
| typedef struct _TBand |
| { |
| TScan y_min; /* band's minimum */ |
| TScan y_max; /* band's maximum */ |
| |
| } TBand; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The size in _TPos_ of a profile record in the render pool. */ |
| /* */ |
| #define AlignProfileSize \ |
| ( (sizeof ( TProfile ) + sizeof ( TPos ) - 1) / sizeof ( TPos ) ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Prototypes used for sweep function dispatch. */ |
| /* */ |
| typedef void (*Function_Sweep_Init)( RAS_ARG_ int* min, |
| int* max ); |
| |
| typedef void (*Function_Sweep_Span)( RAS_ARG_ TScan y, |
| TPos x1, |
| TPos x2 ); |
| |
| typedef int (*Function_Test_Pixel)( RAS_ARG_ TScan y, |
| int x ); |
| |
| typedef void (*Function_Set_Pixel)( RAS_ARG_ TScan y, |
| int x, |
| int color ); |
| |
| typedef void (*Function_Sweep_Step)( RAS_ARG ); |
| |
| typedef struct Raster_Render_ |
| { |
| Function_Sweep_Init init; |
| Function_Sweep_Span span; |
| Function_Sweep_Step step; |
| Function_Test_Pixel test_pixel; |
| Function_Set_Pixel set_pixel; |
| |
| } Raster_Render; |
| |
| |
| #ifdef FT_RASTER_CONSTANT_PRECISION |
| |
| #define PRECISION_BITS FT_PRECISION_BITS |
| #define PRECISION (1 << PRECISION_BITS) |
| #define PRECISION_MASK (-1L << PRECISION_BITS) |
| #define PRECISION_HALF (PRECISION >> 1) |
| #define PRECISION_JITTER (PRECISION >> 5) |
| #define PRECISION_STEP PRECISION_HALF |
| |
| #else |
| |
| #define PRECISION_BITS ras.precision_bits |
| #define PRECISION ras.precision |
| #define PRECISION_MASK ras.precision_mask |
| #define PRECISION_HALF ras.precision_half |
| #define PRECISION_JITTER ras.precision_jitter |
| #define PRECISION_STEP ras.precision_step |
| |
| #endif |
| |
| /*************************************************************************/ |
| /* */ |
| /* Compute lowest integer coordinate below a given value. */ |
| /* */ |
| #define FLOOR( x ) ( (x) & PRECISION_MASK ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Compute highest integer coordinate above a given value. */ |
| /* */ |
| #define CEILING( x ) ( ((x) + PRECISION - 1) & PRECISION_MASK ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Get integer coordinate of a given 26.6 or 22.10 `x' coordinate -- no */ |
| /* rounding. */ |
| /* */ |
| #define TRUNC( x ) ( (signed long)(x) >> PRECISION_BITS ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Get the fractional part of a given coordinate. */ |
| /* */ |
| #define FRAC( x ) ( (x) & (PRECISION-1) ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Scale an `input coordinate' (as found in FT_Outline structures) into */ |
| /* a `work coordinate' which depends on current resolution and render */ |
| /* mode. */ |
| /* */ |
| #define SCALED( x ) ( ((x) << ras.scale_shift) - ras.scale_delta ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* DEBUG_PSET is used to plot a single pixel in VRam during debug mode. */ |
| /* */ |
| #ifdef DEBUG_RASTER |
| #define DEBUG_PSET Pset() |
| #else |
| #define DEBUG_PSET |
| #endif |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* This structure defines a point in a plane. */ |
| /* */ |
| typedef struct _TPoint |
| { |
| TPos x, y; |
| |
| } TPoint; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The most used variables are at the beginning of the structure. Thus, */ |
| /* their offset can be coded with less opcodes which results in a */ |
| /* smaller executable. */ |
| /* */ |
| struct FT_RasterRec_ |
| { |
| PPos cursor; /* Current cursor in render pool */ |
| |
| PPos pool; /* The render pool base address */ |
| PPos pool_size; /* The render pool's size */ |
| PPos pool_limit; /* Limit of profiles zone in pool */ |
| |
| int bit_width; /* target bitmap width */ |
| PByte bit_buffer; /* target bitmap buffer */ |
| PByte pix_buffer; /* target pixmap buffer */ |
| |
| TPoint last; |
| long minY, maxY; |
| |
| int error; |
| |
| #ifndef FT_RASTER_CONSTANT_PRECISION |
| int precision_bits; /* precision related variables */ |
| int precision; |
| int precision_half; |
| long precision_mask; |
| int precision_shift; |
| int precision_step; |
| int precision_jitter; |
| #endif |
| |
| FT_Outline* outline; |
| |
| int n_points; /* number of points in current glyph */ |
| int n_contours; /* number of contours in current glyph */ |
| int n_extrema; /* number of `extrema' scanlines */ |
| |
| TPoint* arc; /* current Bezier arc pointer */ |
| |
| int num_profs; /* current number of profiles */ |
| |
| char fresh; /* signals a fresh new profile which */ |
| /* `start' field must be completed */ |
| char joint; /* signals that the last arc ended */ |
| /* exactly on a scanline. Allows */ |
| /* removal of doublets */ |
| PProfile cur_prof; /* current profile */ |
| PProfile start_prof; /* head of linked list of profiles */ |
| PProfile first_prof; /* contour's first profile in case */ |
| /* of impact */ |
| TDirection state; /* rendering state */ |
| |
| FT_Bitmap target; /* description of target bit/pixmap */ |
| |
| int trace_bit; /* current offset in target bitmap */ |
| int trace_pix; /* current offset in target pixmap */ |
| int trace_incr; /* sweep's increment in target bitmap */ |
| |
| /* dispatch variables */ |
| |
| Raster_Render render; |
| |
| int scale_shift; /* == 0 for bitmaps */ |
| /* == 1 for 5-levels pixmaps */ |
| /* == 2 for 17-levels pixmaps */ |
| |
| int scale_delta; /* ras.precision_half for bitmaps */ |
| /* 0 for pixmaps */ |
| |
| char dropout_mode; /* current drop_out control method */ |
| |
| char second_pass; /* indicates whether a horizontal pass */ |
| /* should be performed to control drop-out */ |
| /* accurately when calling Render_Glyph. */ |
| /* Note that there is no horizontal pass */ |
| /* during gray rendering. */ |
| |
| char flipped; /* this flag is set during the rendering to */ |
| /* indicate the second pass. */ |
| |
| TBand band_stack[16]; /* band stack used for sub-banding */ |
| int band_top; /* band stack top */ |
| |
| TPoint arcs[2 * MaxBezier + 1]; /* The Bezier stack */ |
| }; |
| |
| |
| |
| #ifdef DEBUG_RASTER |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Pset */ |
| /* */ |
| /* <Description> */ |
| /* Used for debugging only. Plots a point in VRAM during rendering */ |
| /* (not afterwards). */ |
| /* */ |
| /* <Note> */ |
| /* This procedure relies on the value of cProfile->start, which may */ |
| /* not be set when Pset() is called sometimes. This will usually */ |
| /* result in a dot plotted on the first screen scanline (far away */ |
| /* from its original position). */ |
| /* */ |
| /* This `feature' reflects nothing wrong in the current */ |
| /* implementation, and the bitmap is rendered correctly, so don't */ |
| /* panic if you see `flying' dots in debugging mode. */ |
| /* */ |
| static |
| void Pset( RAS_ARG ) |
| { |
| long o; |
| long x; |
| |
| |
| x = ras.cursor[-1]; |
| |
| switch ( ras.cur_prof->flow ) |
| { |
| case FT_Flow_Up: |
| o = Vio_ScanLineWidth * |
| ( ras.cursor - ras.cur_prof->offset + ras.cur_prof->start ) + |
| ( x / (PRECISION * 8) ); |
| break; |
| |
| case FT_Flow_Down: |
| o = Vio_ScanLineWidth * |
| ( ras.cur_prof->start - ras.cursor + ras.cur_prof->offset ) + |
| ( x / (PRECISION * 8) ); |
| break; |
| } |
| |
| if ( o > 0 ) |
| Vio[o] |= (unsigned)0x80 >> ( (x/PRECISION) & 7 ); |
| } |
| |
| |
| static |
| void Clear_Band( RAS_ARG_ TScan y1, |
| TScan y2 ) |
| { |
| MEM_Set( Vio + y1*Vio_ScanLineWidth, (y2-y1+1)*Vio_ScanLineWidth, 0 ); |
| } |
| |
| #endif /* DEBUG_RASTER */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Set_High_Precision */ |
| /* */ |
| /* <Description> */ |
| /* Sets precision variables according to the parameter flag. */ |
| /* */ |
| /* <Input> */ |
| /* High :: Set to True for high precision (typically for ppem < 18), */ |
| /* false otherwise. */ |
| /* */ |
| static |
| void Set_High_Precision( RAS_ARG_ char High ) |
| { |
| #ifdef FT_RASTER_CONSTANT_PRECISION |
| (void)High; |
| (void)&ras; |
| #else |
| if ( High ) |
| { |
| ras.precision_bits = 10; |
| ras.precision_step = 128; |
| ras.precision_jitter = 24; |
| } |
| else |
| { |
| ras.precision_bits = 6; |
| ras.precision_step = 32; |
| ras.precision_jitter = 2; |
| } |
| |
| ras.precision = 1L << ras.precision_bits; |
| ras.precision_half = ras.precision / 2; |
| ras.precision_shift = ras.precision_bits - INPUT_BITS; |
| ras.precision_mask = -ras.precision; |
| #endif |
| } |
| |
| /*************************************************************************/ |
| /* */ |
| /* A simple technical note on how the raster works: */ |
| /* */ |
| /* Converting an outline into a bitmap is achieved in several steps */ |
| /* which are: */ |
| /* */ |
| /* 1 - Decomposing the outline into successive `profiles'. Each */ |
| /* profile is simply an array of scanline intersections on a given */ |
| /* dimension. A profile's main attributes are */ |
| /* */ |
| /* o its scanline position boundaries, i.e. `Ymin' and `Ymax'. */ |
| /* */ |
| /* o an array of intersection coordinates for each scanline */ |
| /* between `Ymin' and `Ymax'. */ |
| /* */ |
| /* o a direction, indicating wether is was built going `up' or */ |
| /* `down', as this is very important for filling rules. */ |
| /* */ |
| /* 2 - Sweeping the target map's scanlines in order to compute segment */ |
| /* `spans' which are then filled. Additionaly, this pass performs */ |
| /* drop-out control. */ |
| /* */ |
| /* The outline data is parsed during step 1 only. The profiles are */ |
| /* built from the bottom of the render pool, used as a stack. The */ |
| /* following graphics shows the profile list under construction: */ |
| /* */ |
| /* ____________________________________________________________ _ _ */ |
| /* | | | | | */ |
| /* | profile | coordinates for | profile | coordinates for |--> */ |
| /* | 1 | profile 1 | 2 | profile 2 |--> */ |
| /* |_________|___________________|_________|_________________|__ _ _ */ |
| /* */ |
| /* ^ ^ */ |
| /* | | */ |
| /* start of render pool cursor */ |
| /* */ |
| /* The top of the profile stack is kept in the `cursor' variable. */ |
| /* */ |
| /* As you can see, a profile record is pushed on top of the render */ |
| /* pool, which is then followed by its coordinates/intersections. If */ |
| /* a change of direction is detected in the outline, a new profile is */ |
| /* generated until the end of the outline. */ |
| /* */ |
| /* Note that when all profiles have been generated, the function */ |
| /* Finalize_Profile_Table() is used to record, for each profile, its */ |
| /* bottom-most scanline as well as the scanline above its upmost */ |
| /* boundary. These positions are called `extrema' because they (sort */ |
| /* of) correspond to local extrema. They are stored in a sorted list */ |
| /* built from the top of the render pool as a downwards stack: */ |
| /* */ |
| /* _ _ _______________________________________ */ |
| /* | | */ |
| /* <--| sorted list of | */ |
| /* <--| extrema scanlines | */ |
| /* _ _ __________________|____________________| */ |
| /* */ |
| /* ^ ^ */ |
| /* | | */ |
| /* pool_limit end of render pool */ |
| /* */ |
| /* This list is later used during the sweep phase in order to */ |
| /* optimize performance (see technical note on the sweep below). */ |
| /* */ |
| /* Of course, the raster detects whether the two stacks collide and */ |
| /* handles the situation propertly. */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* New_Profile */ |
| /* */ |
| /* <Description> */ |
| /* Creates a new Profile in the render pool. */ |
| /* */ |
| /* <Input> */ |
| /* aState :: The state/orientation of the new profile. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult New_Profile( RAS_ARG_ TDirection direction ) |
| { |
| if ( ras.start_prof == NULL ) |
| { |
| ras.cur_prof = (PProfile)ras.cursor; /* current profile */ |
| ras.start_prof = ras.cur_prof; /* first profile in pool */ |
| ras.cursor += AlignProfileSize; /* record profile in buffer */ |
| } |
| |
| /* check for overflow */ |
| if ( ras.cursor >= ras.pool_limit ) |
| { |
| ras.error = ErrRaster_Overflow; |
| return FAILURE; |
| } |
| |
| /* record profile direction */ |
| switch ( direction ) |
| { |
| case Ascending: |
| ras.cur_prof->flow = Flow_Up; |
| break; |
| |
| case Descending: |
| ras.cur_prof->flow = Flow_Down; |
| break; |
| |
| default: |
| ras.error = ErrRaster_Invalid_Map; |
| return FAILURE; |
| } |
| |
| /* initialize a few fields */ |
| { |
| PProfile cur = ras.cur_prof; |
| |
| |
| cur->start = 0; /* current start scanline */ |
| cur->height = 0; /* current height */ |
| cur->offset = ras.cursor; /* address of first coordinate */ |
| cur->link = (PProfile)0; /* link to next profile in pool */ |
| cur->next = (PProfile)0; /* link to next profile in contour */ |
| } |
| |
| /* record the first profile in a contour */ |
| if ( ras.first_prof == NULL ) |
| ras.first_prof = ras.cur_prof; |
| |
| ras.state = direction; |
| ras.fresh = TRUE; /* this profile has no coordinates yet */ |
| ras.joint = FALSE; |
| |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* End_Profile */ |
| /* */ |
| /* <Description> */ |
| /* Finalizes the current Profile and computes its height. If it is */ |
| /* not 0, the profile's fields are updated and a new profile is */ |
| /* pushed on top of its coordinates. Otherwise the current profile */ |
| /* is kept and the recording of intersections is restarted. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult End_Profile( RAS_ARG ) |
| { |
| int h; |
| |
| |
| h = ras.cursor - ras.cur_prof->offset; |
| |
| if ( h < 0 ) |
| { |
| /* This error should _never_ occur unless the raster is buggy */ |
| ras.error = ErrRaster_Negative_Height; |
| return FAILURE; |
| } |
| |
| if ( h > 0 ) |
| { |
| PProfile old, new; |
| |
| /* record scanline height in current profile, create a new one */ |
| /* and set a link from the old one to it */ |
| old = ras.cur_prof; |
| old->height = h; |
| ras.cur_prof = new = (PProfile)ras.cursor; |
| |
| ras.cursor += AlignProfileSize; |
| |
| new->height = 0; |
| new->offset = ras.cursor; |
| old->next = new; |
| |
| ras.num_profs++; |
| } |
| |
| /* check for overflow */ |
| if ( ras.cursor >= ras.pool_limit ) |
| { |
| ras.error = ErrRaster_Overflow; |
| return FAILURE; |
| } |
| |
| ras.joint = FALSE; |
| |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Insert_Extrema */ |
| /* */ |
| /* <Description> */ |
| /* Records that a given scanline contains at least one local */ |
| /* extremum. The table of extrema is placed at the end of the render */ |
| /* pool and grows downwards. It is used during the sweep phase. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The coordinate of the scanline containing an extremum. */ |
| /* */ |
| static |
| TResult Insert_Extrema( RAS_ARG_ TScan y ) |
| { |
| PPos extrema; |
| TScan y2; |
| int n; |
| |
| |
| PTRACE2(( "EXTREMA += %d", y )); |
| n = ras.n_extrema - 1; |
| extrema = ras.pool_size - ras.n_extrema; |
| |
| /* look for first y extremum that is <= */ |
| while ( n >= 0 && y < extrema[n] ) |
| n--; |
| |
| /* if it is <, simply insert it, ignore if == */ |
| if ( n >= 0 && y > extrema[n] ) |
| while ( n >= 0 ) |
| { |
| y2 = extrema[n]; |
| extrema[n] = y; |
| y = y2; |
| n--; |
| } |
| |
| if ( n < 0 ) |
| { |
| ras.pool_limit--; |
| ras.n_extrema++; |
| ras.pool_size[-ras.n_extrema] = y; |
| |
| if ( ras.pool_limit <= ras.cursor ) |
| { |
| ras.error = ErrRaster_Overflow; |
| return FAILURE; |
| } |
| } |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Finalize_Profile_Table */ |
| /* */ |
| /* <Description> */ |
| /* Adjusts all links in the profiles list. Called when the outline */ |
| /* parsing is done. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Finalize_Profile_Table( RAS_ARG ) |
| { |
| int n, bottom, top; |
| PProfile p; |
| |
| |
| n = ras.num_profs; |
| |
| if ( n > 1 ) |
| { |
| p = ras.start_prof; |
| while ( n > 0 ) |
| { |
| if ( n > 1 ) |
| p->link = (PProfile)( p->offset + p->height ); |
| else |
| p->link = NULL; |
| |
| switch ( p->flow ) |
| { |
| case Flow_Down: |
| PTRACE2(( "FLOW DOWN (start = %d, height = %d)", |
| p->start, p->height )); |
| bottom = p->start - p->height+1; |
| top = p->start; |
| p->start = bottom; |
| p->offset += p->height-1; |
| break; |
| |
| case Flow_Up: |
| default: |
| PTRACE2(( "FLOW UP (start = %d, height = %d)", |
| p->start, p->height )); |
| bottom = p->start; |
| top = p->start + p->height-1; |
| } |
| |
| if ( Insert_Extrema( RAS_VAR_ bottom ) || |
| Insert_Extrema( RAS_VAR_ top+1 ) ) |
| return FAILURE; |
| |
| p = p->link; |
| n--; |
| } |
| } |
| else |
| ras.start_prof = NULL; |
| |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Line_Up */ |
| /* */ |
| /* <Description> */ |
| /* Computes the scan-line intersections of an ascending line segment */ |
| /* and stores them in the render pool. */ |
| /* */ |
| /* <Input> */ |
| /* x1 :: The start x coordinate. */ |
| /* y1 :: The start y coordinate. */ |
| /* x2 :: The end x coordinate. */ |
| /* y2 :: The end y coordinate. */ |
| /* miny :: The minimum vertical grid coordinate. */ |
| /* maxy :: The maximum vertical grid coordinate. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Line_Up( RAS_ARG_ TPos x1, TPos y1, |
| TPos x2, TPos y2, |
| TPos miny, TPos maxy ) |
| { |
| TPos Dx, Dy; |
| int e1, e2, f1, f2, size; |
| TPos Ix, Rx, Ax; |
| |
| PPos top; |
| |
| |
| Dx = x2 - x1; |
| Dy = y2 - y1; |
| |
| if ( Dy <= 0 || y2 < miny || y1 > maxy ) |
| return SUCCESS; |
| |
| /* clip to higher scanline when necessary */ |
| if ( y2 > maxy ) |
| { |
| /* x2 += FMulDiv( Dx, maxy-y2, Dy ); UNNECESSARY */ |
| e2 = TRUNC( maxy ); |
| f2 = 0; |
| } |
| else |
| { |
| e2 = TRUNC( y2 ); |
| f2 = FRAC( y2 ); |
| } |
| |
| /* clip to lower scanline when necessary */ |
| if ( y1 < miny ) |
| { |
| TPos x, y; |
| |
| /* we use a binary search to compute the lower |
| // clipping intersection. That's because we don't |
| // want to use an external function like FT_MulDiv |
| // to compute it directly. |
| */ |
| if ( y2 == miny ) goto Exit; |
| do |
| { |
| x = (x1 + x2) >> 1; |
| y = (y1 + y2) >> 1; |
| |
| if (y <= miny) |
| { |
| x1 = x; |
| y1 = y; |
| } |
| else |
| { |
| x2 = x; |
| y2 = y; |
| } |
| } |
| while ( y1 < miny ); |
| |
| e1 = TRUNC( miny ); |
| f1 = 0; |
| } |
| else |
| { |
| e1 = TRUNC( y1 ); |
| f1 = FRAC( y1 ); |
| } |
| |
| /* adjust start point so that we begin on an integer scanline position */ |
| if ( f1 > 0 ) |
| { |
| if ( e1 == e2 ) goto Exit; |
| else |
| { |
| x1 += FMulDiv( Dx, PRECISION - f1, Dy ); |
| e1 += 1; |
| } |
| } |
| else |
| if ( ras.joint ) |
| { |
| ras.cursor--; |
| ras.joint = FALSE; |
| } |
| |
| ras.joint = ( f2 == 0 ); |
| |
| /* if this is a `fresh' profile, record its starting scanline */ |
| if ( ras.fresh ) |
| { |
| ras.cur_prof->start = e1; |
| ras.fresh = FALSE; |
| } |
| |
| /* check for overflow */ |
| size = e2 - e1 + 1; |
| if ( ras.cursor + size >= ras.pool_limit ) |
| { |
| ras.error = ErrRaster_Overflow; |
| return FAILURE; |
| } |
| |
| /* compute decision variables and push the intersections on top */ |
| /* of the render pool */ |
| Dx <<= PRECISION_BITS; |
| Ix = Dx / Dy; |
| Rx = Dx % Dy; |
| if (Rx < 0) |
| { |
| Ix --; |
| Rx += Dy; |
| } |
| |
| Ax = -Dy; |
| Rx <<= 1; |
| Dy <<= 1; |
| |
| top = ras.cursor; |
| |
| while ( size > 0 ) |
| { |
| *top++ = x1; |
| |
| DEBUG_PSET; |
| |
| x1 += Ix; |
| Ax += Rx; |
| if ( Ax >= 0 ) |
| { |
| Ax -= Dy; |
| x1 ++; |
| } |
| size--; |
| } |
| |
| ras.cursor = top; |
| Exit: |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Line_Down */ |
| /* */ |
| /* <Description> */ |
| /* Computes the scan-line intersections of a descending line segment */ |
| /* and stores them in the render pool. */ |
| /* */ |
| /* <Input> */ |
| /* x1 :: The start x coordinate. */ |
| /* y1 :: The start y coordinate. */ |
| /* x2 :: The end x coordinate. */ |
| /* y2 :: The end y coordinate. */ |
| /* miny :: The minimum vertical grid coordinate. */ |
| /* maxy :: The maximum vertical grid coordinate. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Line_Down( RAS_ARG_ TPos x1, TPos y1, |
| TPos x2, TPos y2, |
| TPos miny, TPos maxy ) |
| { |
| TResult result, fresh; |
| |
| |
| /* simply invert the coordinates and call Line_Up */ |
| fresh = ras.fresh; |
| result = Line_Up( RAS_VAR_ x1, -y1, x2, -y2, -maxy, -miny ); |
| |
| /* if this was a fresh profile, invert the recorded start position */ |
| if ( fresh && !ras.fresh ) |
| ras.cur_prof->start = -ras.cur_prof->start; |
| |
| return result; |
| } |
| |
| |
| |
| |
| /* A function type describing the functions used to split bezier arcs */ |
| typedef void (*TSplitter)( TPoint* base ); |
| |
| #ifdef FT_DYNAMIC_BEZIER_STEPS |
| static |
| TPos Dynamic_Bezier_Threshold( RAS_ARG_ int degree, TPoint* arc ) |
| { |
| TPos min_x, max_x, min_y, max_y, A, B; |
| TPos wide_x, wide_y, threshold; |
| TPoint* cur = arc; |
| TPoint* limit = cur + degree; |
| |
| /* first of all, set the threshold to the maximum x or y extent */ |
| min_x = max_x = arc[0].x; |
| min_y = max_y = arc[0].y; |
| cur++; |
| for ( ; cur < limit; cur++ ) |
| { |
| TPos x = cur->x; |
| TPos y = cur->y; |
| |
| if ( x < min_x ) min_x = x; |
| if ( x > max_x ) max_x = x; |
| |
| if ( y < min_y ) min_y = y; |
| if ( y > max_y ) max_y = y; |
| } |
| wide_x = (max_x - min_x) << 4; |
| wide_y = (max_y - min_y) << 4; |
| |
| threshold = wide_x; |
| if (threshold < wide_y) threshold = wide_y; |
| |
| /* now compute the second and third order error values */ |
| |
| wide_x = arc[0].x + arc[1].x - arc[2].x*2; |
| wide_y = arc[0].y + arc[1].y - arc[2].y*2; |
| |
| if (wide_x < 0) wide_x = -wide_x; |
| if (wide_y < 0) wide_y = -wide_y; |
| |
| A = wide_x; if ( A < wide_y ) A = wide_y; |
| |
| if (degree >= 3) |
| { |
| wide_x = arc[3].x - arc[0].x + 3*(arc[2].x - arc[3].x); |
| wide_y = arc[3].y - arc[0].y + 3*(arc[2].y - arc[3].y); |
| |
| if (wide_x < 0) wide_x = -wide_x; |
| if (wide_y < 0) wide_y = -wide_y; |
| |
| B = wide_x; if ( B < wide_y ) B = wide_y; |
| } |
| else |
| B = 0; |
| |
| while ( A > 0 || B > 0 ) |
| { |
| threshold >>= 1; |
| A >>= 2; |
| B >>= 3; |
| } |
| |
| if (threshold < PRECISION_STEP) |
| threshold = PRECISION_STEP; |
| |
| return threshold; |
| } |
| #endif |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Bezier_Up */ |
| /* */ |
| /* <Description> */ |
| /* Computes the scan-line intersections of an ascending second-order */ |
| /* Bezier arc and stores them in the render pool. The arc is taken */ |
| /* from the top of the stack. */ |
| /* */ |
| /* <Input> */ |
| /* miny :: The minimum vertical grid coordinate. */ |
| /* maxy :: The maximum vertical grid coordinate. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Bezier_Up( RAS_ARG_ int degree, |
| TSplitter splitter, |
| TPos miny, |
| TPos maxy ) |
| { |
| TPos y1, y2, e, e2, e0, threshold; |
| int f1; |
| |
| TPoint* arc; |
| TPoint* start_arc; |
| |
| PPos top; |
| |
| |
| arc = ras.arc; |
| y1 = arc[degree].y; |
| y2 = arc[0].y; |
| top = ras.cursor; |
| |
| if ( y2 < miny || y1 > maxy ) |
| goto Fin; |
| |
| e2 = FLOOR( y2 ); /* integer end y */ |
| |
| if ( e2 > maxy ) |
| e2 = FLOOR(maxy); |
| |
| e0 = CEILING(miny); |
| |
| if ( y1 < miny ) |
| { |
| e = e0; /* integer start y == current scanline */ |
| } |
| else |
| { |
| e = CEILING( y1 ); /* integer start y == current scanline */ |
| f1 = FRAC( y1 ); /* fractional shift of start y */ |
| e0 = e; /* first integer scanline to be pushed */ |
| |
| if ( f1 == 0 ) /* do we start on an integer scanline? */ |
| { |
| if ( ras.joint ) |
| { |
| top--; |
| ras.joint = FALSE; |
| } |
| |
| *top++ = arc[degree].x; /* write directly start position */ |
| |
| DEBUG_PSET; |
| |
| e += PRECISION; /* go to next scanline */ |
| } |
| } |
| |
| /* record start position if necessary */ |
| if ( ras.fresh ) |
| { |
| ras.cur_prof->start = TRUNC( e0 ); |
| ras.fresh = FALSE; |
| } |
| |
| /* exit if the current scanline is already above the max scanline */ |
| if ( e2 < e ) |
| goto Fin; |
| |
| /* check for overflow */ |
| if ( ( top + TRUNC( e2 - e ) + 1 ) >= ras.pool_limit ) |
| { |
| ras.cursor = top; |
| ras.error = ErrRaster_Overflow; |
| return FAILURE; |
| } |
| |
| #ifdef FT_DYNAMIC_BEZIER_STEPS |
| /* compute dynamic bezier step threshold */ |
| threshold = Dynamic_Bezier_Threshold( RAS_VAR_ degree, arc ); |
| #else |
| threshold = PRECISION_STEP; |
| #endif |
| |
| start_arc = arc; |
| |
| /* loop while there is still an arc on the bezier stack */ |
| /* and the current scan line is below y max == e2 */ |
| while ( arc >= start_arc && e <= e2 ) |
| { |
| ras.joint = FALSE; |
| |
| y2 = arc[0].y; /* final y of the top-most arc */ |
| |
| if ( y2 > e ) /* the arc intercepts the current scanline */ |
| { |
| y1 = arc[degree].y; /* start y of top-most arc */ |
| |
| if ( y2 >= e + PRECISION || y2 - y1 >= threshold ) |
| { |
| /* if the arc's height is too great, split it */ |
| splitter( arc ); |
| arc += degree; |
| } |
| else |
| { |
| /* otherwise, approximate it as a segment and compute */ |
| /* its intersection with the current scanline */ |
| *top++ = arc[degree].x + |
| FMulDiv( arc[0].x-arc[degree].x, |
| e - y1, |
| y2 - y1 ); |
| |
| DEBUG_PSET; |
| |
| arc -= degree; /* pop the arc */ |
| e += PRECISION; /* go to next scanline */ |
| } |
| } |
| else |
| { |
| if ( y2 == e ) /* if the arc falls on the scanline */ |
| { /* record its _joint_ intersection */ |
| ras.joint = TRUE; |
| *top++ = arc[0].x; |
| |
| DEBUG_PSET; |
| |
| e += PRECISION; /* go to next scanline */ |
| } |
| arc -= degree; /* pop the arc */ |
| } |
| } |
| |
| Fin: |
| ras.cursor = top; |
| ras.arc -= degree; |
| return SUCCESS; |
| } |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Bezier_Down */ |
| /* */ |
| /* <Description> */ |
| /* Computes the scan-line intersections of a descending second-order */ |
| /* Bezier arc and stores them in the render pool. The arc is taken */ |
| /* from the top of the stack. */ |
| /* */ |
| /* <Input> */ |
| /* miny :: The minimum vertical grid coordinate. */ |
| /* maxy :: The maximum vertical grid coordinate. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Bezier_Down( RAS_ARG_ int degree, |
| TSplitter splitter, |
| TPos miny, |
| TPos maxy ) |
| { |
| TPoint* arc = ras.arc; |
| TResult result, fresh; |
| |
| arc[0].y = -arc[0].y; |
| arc[1].y = -arc[1].y; |
| arc[2].y = -arc[2].y; |
| if (degree > 2) |
| arc[3].y = -arc[3].y; |
| |
| fresh = ras.fresh; |
| |
| result = Bezier_Up( RAS_VAR_ degree, splitter, -maxy, -miny ); |
| |
| if ( fresh && !ras.fresh ) |
| ras.cur_prof->start = -ras.cur_prof->start; |
| |
| arc[0].y = -arc[0].y; |
| return result; |
| } |
| |
| |
| #ifdef FT_RASTER_CONIC_BEZIERS |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Split_Conic */ |
| /* */ |
| /* <Description> */ |
| /* Subdivides one second-order Bezier arc into two joint sub-arcs in */ |
| /* the Bezier stack. */ |
| /* */ |
| /* <Note> */ |
| /* This routine is the `beef' of the component. It is one of _the_ */ |
| /* inner loops that should be optimized like hell to get the best */ |
| /* performance. */ |
| /* */ |
| static |
| void Split_Conic( TPoint* base ) |
| { |
| TPos a, b; |
| |
| |
| base[4].x = base[2].x; |
| b = base[1].x; |
| a = base[3].x = ( base[2].x + b + 1 ) >> 1; |
| b = base[1].x = ( base[0].x + b + 1 ) >> 1; |
| base[2].x = ( a + b + 1 ) >> 1; |
| |
| base[4].y = base[2].y; |
| b = base[1].y; |
| a = base[3].y = ( base[2].y + b + 1 ) >> 1; |
| b = base[1].y = ( base[0].y + b + 1 ) >> 1; |
| base[2].y = ( a + b ) / 2; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Push_Conic */ |
| /* */ |
| /* <Description> */ |
| /* Clears the Bezier stack and pushes a new arc on top of it. */ |
| /* */ |
| /* <Input> */ |
| /* p2 :: A pointer to the second (control) point. */ |
| /* p3 :: A pointer to the third (end) point. */ |
| /* */ |
| /* <Note> */ |
| /* The first point is taken as `raster->last', so it doesn't appear */ |
| /* in the signature. */ |
| /* */ |
| static |
| void Push_Conic( RAS_ARG_ FT_Vector* p2, |
| FT_Vector* p3 ) |
| { |
| #undef STORE |
| #define STORE( _arc, point ) \ |
| { \ |
| TPos x = SCALED( point->x ); \ |
| TPos y = SCALED( point->y ); \ |
| \ |
| \ |
| if ( ras.flipped ) \ |
| { \ |
| _arc.x = y; \ |
| _arc.y = x; \ |
| } \ |
| else \ |
| { \ |
| _arc.x = x; \ |
| _arc.y = y; \ |
| } \ |
| } |
| |
| TPoint* arc; |
| |
| |
| ras.arc = arc = ras.arcs; |
| |
| arc[2] = ras.last; |
| STORE( arc[1], p2 ); |
| STORE( arc[0], p3 ); |
| #undef STORE |
| } |
| |
| #endif /* FT_RASTER_CONIC_BEZIERS */ |
| |
| |
| |
| #ifdef FT_RASTER_CUBIC_BEZIERS |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> Split_Cubic */ |
| /* */ |
| /* <Description> */ |
| /* Subdivides a third-order Bezier arc into two joint sub-arcs in */ |
| /* the Bezier stack. */ |
| /* */ |
| /* <Note> */ |
| /* This routine is the `beef' of the component. It is one of _the_ */ |
| /* inner loops that should be optimized like hell to get the best */ |
| /* performance. */ |
| /* */ |
| static |
| void Split_Cubic( TPoint* base ) |
| { |
| TPos a, b, c, d; |
| |
| |
| base[6].x = base[3].x; |
| c = base[1].x; |
| d = base[2].x; |
| base[1].x = a = ( base[0].x + c + 1 ) >> 1; |
| base[5].x = b = ( base[3].x + d + 1 ) >> 1; |
| c = ( c + d + 1 ) >> 1; |
| base[2].x = a = ( a + c + 1 ) >> 1; |
| base[4].x = b = ( b + c + 1 ) >> 1; |
| base[3].x = ( a + b + 1 ) >> 1; |
| |
| base[6].y = base[3].y; |
| c = base[1].y; |
| d = base[2].y; |
| base[1].y = a = ( base[0].y + c + 1 ) >> 1; |
| base[5].y = b = ( base[3].y + d + 1 ) >> 1; |
| c = ( c + d + 1 ) >> 1; |
| base[2].y = a = ( a + c + 1 ) >> 1; |
| base[4].y = b = ( b + c + 1 ) >> 1; |
| base[3].y = ( a + b + 1 ) >> 1; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Push_Cubic */ |
| /* */ |
| /* <Description> */ |
| /* Clears the Bezier stack and pushes a new third-order Bezier arc on */ |
| /* top of it. */ |
| /* */ |
| /* <Input> */ |
| /* p2 :: A pointer to the second (control) point. */ |
| /* p3 :: A pointer to the third (control) point. */ |
| /* p4 :: A pointer to the fourth (end) point. */ |
| /* */ |
| /* <Note> */ |
| /* The first point is taken as `raster->last', so it doesn't appear */ |
| /* in the signature. */ |
| /* */ |
| /* This is the same as Push_Conic(), except that it deals with */ |
| /* third-order Beziers. */ |
| /* */ |
| static |
| void Push_Cubic( RAS_ARG_ FT_Vector* p2, |
| FT_Vector* p3, |
| FT_Vector* p4 ) |
| { |
| #undef STORE |
| #define STORE( _arc, point ) \ |
| { \ |
| TPos x = SCALED( point->x ); \ |
| TPos y = SCALED( point->y ); \ |
| \ |
| if ( ras.flipped ) \ |
| { \ |
| _arc.x = y; \ |
| _arc.y = x; \ |
| } \ |
| else \ |
| { \ |
| _arc.x = x; \ |
| _arc.y = y; \ |
| } \ |
| } |
| |
| TPoint* arc; |
| ras.arc = arc = ras.arcs; |
| |
| arc[3] = ras.last; |
| STORE( arc[2], p2 ); |
| STORE( arc[1], p3 ); |
| STORE( arc[0], p4 ); |
| |
| #undef STORE |
| } |
| |
| #endif /* FT_RASTER_CUBIC_BEZIERS */ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Check_Contour */ |
| /* */ |
| /* <Description> */ |
| /* Performs some checks at contour closure. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Check_Contour( RAS_ARG ) |
| { |
| PProfile lastProfile; |
| |
| /* Sometimes, the first and last profile in a contour join on */ |
| /* an integer scan-line; we must then remove the last intersection */ |
| /* from the last profile to get rid of doublets */ |
| if ( ( FRAC( ras.last.y ) == 0 && |
| ras.last.y >= ras.minY && |
| ras.last.y <= ras.maxY ) ) |
| { |
| if ( ras.first_prof && ras.first_prof->flow == ras.cur_prof->flow ) |
| ras.cursor--; |
| } |
| |
| lastProfile = ras.cur_prof; |
| if ( End_Profile( RAS_VAR ) ) |
| return FAILURE; |
| |
| /* close the `next profile in contour' linked list */ |
| lastProfile->next = ras.first_prof; |
| |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Move_To */ |
| /* */ |
| /* <Description> */ |
| /* This function injects a new contour in the render pool. */ |
| /* */ |
| /* <Input> */ |
| /* to :: A pointer to the contour's first point. */ |
| /* raster :: A pointer to the current raster object. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* This function is used as a `FTRasterMoveTo_Func' by the outline */ |
| /* decomposer. */ |
| /* */ |
| static |
| int Move_To( FT_Vector* to, |
| FT_Raster raster ) |
| { |
| TPos scaled_x, scaled_y; |
| |
| |
| /* if there was already a contour being built, perform some checks */ |
| if ( ras.start_prof ) |
| if ( Check_Contour( RAS_VAR ) ) |
| return FAILURE; |
| |
| /* set the `current last point' */ |
| scaled_x = SCALED( to->x ); |
| scaled_y = SCALED( to->y ); |
| |
| if ( ras.flipped ) |
| { |
| ras.last.x = scaled_y; |
| ras.last.y = scaled_x; |
| } |
| else |
| { |
| ras.last.x = scaled_x; |
| ras.last.y = scaled_y; |
| } |
| |
| ras.state = Unknown; |
| ras.first_prof = NULL; |
| |
| return SUCCESS; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Line_To */ |
| /* */ |
| /* <Description> */ |
| /* This function injects a new line segment in the render pool and */ |
| /* adjusts the profiles list accordingly. */ |
| /* */ |
| /* <Input> */ |
| /* to :: A pointer to the target position. */ |
| /* raster :: A pointer to the current raster object. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* This function is used as a `FTRasterLineTo_Func' by the outline */ |
| /* decomposer. */ |
| /* */ |
| static |
| int Line_To( FT_Vector* to, |
| FT_Raster raster ) |
| { |
| TPos x, scaled_x; |
| TPos y, scaled_y; |
| |
| |
| scaled_x = SCALED( to->x ); |
| scaled_y = SCALED( to->y ); |
| |
| if ( ras.flipped ) |
| { |
| x = scaled_y; |
| y = scaled_x; |
| } |
| else |
| { |
| x = scaled_x; |
| y = scaled_y; |
| } |
| |
| /* First, detect a change of direction */ |
| if ( y != ras.last.y ) |
| { |
| TDirection new_state = ( (y > ras.last.y) ? Ascending : Descending ); |
| |
| |
| if ( ras.state != new_state ) |
| { |
| if ( ras.state != Unknown && |
| End_Profile( RAS_VAR ) ) |
| goto Fail; |
| |
| if ( New_Profile( RAS_VAR_ new_state ) ) |
| goto Fail; |
| } |
| } |
| |
| /* Then compute the lines */ |
| switch ( ras.state ) |
| { |
| case Ascending: |
| if ( Line_Up ( RAS_VAR_ ras.last.x, ras.last.y, |
| x, y, ras.minY, ras.maxY ) ) |
| goto Fail; |
| break; |
| |
| case Descending: |
| if ( Line_Down( RAS_VAR_ ras.last.x, ras.last.y, |
| x, y, ras.minY, ras.maxY ) ) |
| goto Fail; |
| break; |
| |
| default: |
| ; |
| } |
| |
| ras.last.x = x; |
| ras.last.y = y; |
| |
| return SUCCESS; |
| |
| Fail: |
| return FAILURE; |
| } |
| |
| |
| #ifdef FT_RASTER_CONIC_BEZIERS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Conic_To */ |
| /* */ |
| /* <Description> */ |
| /* Injects a new conic Bezier arc and adjusts the profile list */ |
| /* accordingly. */ |
| /* */ |
| /* <Input> */ |
| /* control :: A pointer to an intermediate control point. */ |
| /* to :: A pointer to the end point. */ |
| /* raster :: A handle to the current raster object. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* This function is used as a `FTRasterConicTo_Func' by the outline */ |
| /* decomposer. */ |
| /* */ |
| static |
| int Conic_To( FT_Vector* control, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| TPos y1, y2, y3, x3, ymin, ymax; |
| TDirection state_bez; |
| |
| |
| Push_Conic( RAS_VAR_ control, to ); |
| |
| do |
| { |
| y1 = ras.arc[2].y; |
| y2 = ras.arc[1].y; |
| y3 = ras.arc[0].y; |
| x3 = ras.arc[0].x; |
| |
| /* first, categorize the Bezier arc */ |
| |
| if ( y1 <= y3 ) |
| { |
| ymin = y1; |
| ymax = y3; |
| } |
| else |
| { |
| ymin = y3; |
| ymax = y1; |
| } |
| |
| if ( y2 < ymin || y2 > ymax ) |
| { |
| /* this arc has no given direction, split it !! */ |
| Split_Conic( ras.arc ); |
| ras.arc += 2; |
| } |
| else if ( y1 == y3 ) |
| { |
| /* this arc is flat, ignore it and pop it from the bezier stack */ |
| ras.arc -= 2; |
| } |
| else |
| { |
| /* the arc is y-monotonous, either ascending or descending */ |
| /* detect a change of direction */ |
| state_bez = y1 < y3 ? Ascending : Descending; |
| if ( ras.state != state_bez ) |
| { |
| /* finalize current profile if any */ |
| if ( ras.state != Unknown && |
| End_Profile( RAS_VAR ) ) |
| goto Fail; |
| |
| /* create a new profile */ |
| if ( New_Profile( RAS_VAR_ state_bez ) ) |
| goto Fail; |
| } |
| |
| /* now call the appropriate routine */ |
| if ( state_bez == Ascending ) |
| { |
| if ( Bezier_Up( RAS_VAR_ 2, Split_Conic, ras.minY, ras.maxY ) ) |
| goto Fail; |
| } |
| else |
| if ( Bezier_Down( RAS_VAR_ 2, Split_Conic, ras.minY, ras.maxY ) ) |
| goto Fail; |
| } |
| |
| } while ( ras.arc >= ras.arcs ); |
| |
| ras.last.x = x3; |
| ras.last.y = y3; |
| |
| return SUCCESS; |
| |
| Fail: |
| return FAILURE; |
| } |
| |
| #else /* FT_RASTER_CONIC_BEZIERS */ |
| |
| |
| static |
| int Conic_To( FT_Vector* control, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| UNUSED( control ); |
| UNUSED( to ); |
| UNUSED( raster ); |
| |
| return ErrRaster_Invalid_Outline; |
| } |
| |
| |
| #endif /* FT_RASTER_CONIC_BEZIERS */ |
| |
| |
| #ifdef FT_RASTER_CUBIC_BEZIERS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Cubic_To */ |
| /* */ |
| /* <Description> */ |
| /* Injects a new cubic Bezier arc and adjusts the profile list */ |
| /* accordingly. */ |
| /* */ |
| /* <Input> */ |
| /* control1 :: A pointer to the first control point. */ |
| /* control2 :: A pointer to the second control point. */ |
| /* to :: A pointer to the end point. */ |
| /* raster :: A handle to the current raster object. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* This function is used as a `FTRasterCubicTo_Func' by the outline */ |
| /* decomposer. */ |
| /* */ |
| static |
| int Cubic_To( FT_Vector* control1, |
| FT_Vector* control2, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| TPos y1, y2, y3, y4, x4, ymin1, ymax1, ymin2, ymax2; |
| TDirection state_bez; |
| |
| |
| Push_Cubic( RAS_VAR_ control1, control2, to ); |
| |
| do |
| { |
| y1 = ras.arc[3].y; |
| y2 = ras.arc[2].y; |
| y3 = ras.arc[1].y; |
| y4 = ras.arc[0].y; |
| x4 = ras.arc[0].x; |
| |
| /* first, categorize the Bezier arc */ |
| |
| if ( y1 <= y4 ) |
| { |
| ymin1 = y1; |
| ymax1 = y4; |
| } |
| else |
| { |
| ymin1 = y4; |
| ymax1 = y1; |
| } |
| |
| if ( y2 <= y3 ) |
| { |
| ymin2 = y2; |
| ymax2 = y3; |
| } |
| else |
| { |
| ymin2 = y3; |
| ymax2 = y2; |
| } |
| |
| if ( ymin2 < ymin1 || ymax2 > ymax1 ) |
| { |
| /* this arc has no given direction, split it! */ |
| Split_Cubic( ras.arc ); |
| ras.arc += 3; |
| } |
| else if ( y1 == y4 ) |
| { |
| /* this arc is flat, ignore it and pop it from the bezier stack */ |
| ras.arc -= 3; |
| } |
| else |
| { |
| state_bez = ( y1 <= y4 ) ? Ascending : Descending; |
| |
| /* detect a change of direction */ |
| if ( ras.state != state_bez ) |
| { |
| if ( ras.state != Unknown && |
| End_Profile( RAS_VAR ) ) |
| goto Fail; |
| |
| if ( New_Profile( RAS_VAR_ state_bez ) ) |
| goto Fail; |
| } |
| |
| /* compute intersections */ |
| if ( state_bez == Ascending ) |
| { |
| if ( Bezier_Up ( RAS_VAR_ 3, Split_Cubic, ras.minY, ras.maxY ) ) |
| goto Fail; |
| } |
| else |
| if ( Bezier_Down ( RAS_VAR_ 3, Split_Cubic, ras.minY, ras.maxY ) ) |
| goto Fail; |
| } |
| |
| } while ( ras.arc >= ras.arcs ); |
| |
| ras.last.x = x4; |
| ras.last.y = y4; |
| |
| return SUCCESS; |
| |
| Fail: |
| return FAILURE; |
| } |
| |
| |
| #else /* FT_RASTER_CUBIC_BEZIERS */ |
| |
| |
| int Cubic_To( FT_Vector* control1, |
| FT_Vector* control2, |
| FT_Vector* to, |
| FT_Raster raster ) |
| { |
| UNUSED( control1 ); |
| UNUSED( control2 ); |
| UNUSED( to ); |
| UNUSED( raster ); |
| |
| return ErrRaster_Invalid_Outline; |
| } |
| |
| |
| #endif /* FT_RASTER_CUBIC_BEZIERS */ |
| |
| |
| /********************************************************************/ |
| /* */ |
| /* The following function is compiled in the raster only when it is */ |
| /* compile as a stand-alone module.. */ |
| |
| /* It can, otherwise, be found in the FreeType base layer */ |
| |
| #ifdef _STANDALONE_ |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* FT_Outline_Decompose */ |
| /* */ |
| /* <Description> */ |
| /* Walks over an outline's structure to decompose it into individual */ |
| /* segments and Bezier arcs. This function is also able to emit */ |
| /* `move to' and `close to' operations to indicate the start and end */ |
| /* of new contours in the outline. */ |
| /* */ |
| /* <Input> */ |
| /* outline :: A pointer to the source target. */ |
| /* */ |
| /* interface :: A table of `emitters', i.e,. function pointers called */ |
| /* during decomposition to indicate path operations. */ |
| /* */ |
| /* user :: A typeless pointer which is passed to each emitter */ |
| /* during the decomposition. It can be used to store */ |
| /* the state during the decomposition. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means sucess. */ |
| /* */ |
| static |
| int FT_Outline_Decompose( FT_Outline* outline, |
| FT_Outline_Funcs* interface, |
| void* user ) |
| { |
| typedef enum _phases |
| { |
| phase_point, |
| phase_conic, |
| phase_cubic, |
| phase_cubic2 |
| |
| } TPhase; |
| |
| FT_Vector v_first; |
| FT_Vector v_last; |
| FT_Vector v_control; |
| FT_Vector v_control2; |
| FT_Vector v_start; |
| |
| FT_Vector* point; |
| char* flags; |
| |
| int n; /* index of contour in outline */ |
| int first; /* index of first point in contour */ |
| int index; /* current point's index */ |
| |
| int error; |
| |
| char tag; /* current point's state */ |
| TPhase phase; |
| |
| |
| first = 0; |
| |
| for ( n = 0; n < outline->n_contours; n++ ) |
| { |
| int last; /* index of last point in contour */ |
| |
| |
| last = outline->contours[n]; |
| |
| v_first = outline->points[first]; |
| v_last = outline->points[last]; |
| |
| v_start = v_control = v_first; |
| |
| tag = FT_CURVE_TAG( outline->flags[first] ); |
| index = first; |
| |
| /* A contour cannot start with a cubic control point! */ |
| |
| if ( tag == FT_Curve_Tag_Cubic ) |
| return ErrRaster_Invalid_Outline; |
| |
| |
| /* check first point to determine origin */ |
| |
| if ( tag == FT_Curve_Tag_Conic ) |
| { |
| /* first point is conic control. Yes, this happens. */ |
| if ( FT_CURVE_TAG( outline->flags[last] ) == FT_Curve_Tag_On ) |
| { |
| /* start at last point if it is on the curve */ |
| v_start = v_last; |
| } |
| else |
| { |
| /* if both first and last points are conic, */ |
| /* start at their middle and record its position */ |
| /* for closure */ |
| v_start.x = ( v_start.x + v_last.x ) / 2; |
| v_start.y = ( v_start.y + v_last.y ) / 2; |
| |
| v_last = v_start; |
| } |
| phase = phase_conic; |
| } |
| else |
| phase = phase_point; |
| |
| |
| /* Begin a new contour with MOVE_TO */ |
| |
| error = interface->move_to( &v_start, user ); |
| if ( error ) |
| return error; |
| |
| point = outline->points + first; |
| flags = outline->flags + first; |
| |
| /* now process each contour point individually */ |
| |
| while ( index < last ) |
| { |
| index++; |
| point++; |
| flags++; |
| |
| tag = FT_CURVE_TAG( flags[0] ); |
| |
| switch ( phase ) |
| { |
| case phase_point: /* the previous point was on the curve */ |
| |
| switch ( tag ) |
| { |
| /* two succesive on points -> emit segment */ |
| case FT_Curve_Tag_On: |
| error = interface->line_to( point, user ); |
| break; |
| |
| /* on point + conic control -> remember control point */ |
| case FT_Curve_Tag_Conic: |
| v_control = point[0]; |
| phase = phase_conic; |
| break; |
| |
| /* on point + cubic control -> remember first control */ |
| default: |
| v_control = point[0]; |
| phase = phase_cubic; |
| break; |
| } |
| break; |
| |
| case phase_conic: /* the previous point was a conic control */ |
| |
| switch ( tag ) |
| { |
| /* conic control + on point -> emit conic arc */ |
| case FT_Curve_Tag_On: |
| error = interface->conic_to( &v_control, point, user ); |
| phase = phase_point; |
| break; |
| |
| /* two successive conics -> emit conic arc `in between' */ |
| case FT_Curve_Tag_Conic: |
| { |
| FT_Vector v_middle; |
| |
| |
| v_middle.x = (v_control.x + point->x)/2; |
| v_middle.y = (v_control.y + point->y)/2; |
| |
| error = interface->conic_to( &v_control, |
| &v_middle, user ); |
| v_control = point[0]; |
| } |
| break; |
| |
| default: |
| error = ErrRaster_Invalid_Outline; |
| } |
| break; |
| |
| case phase_cubic: /* the previous point was a cubic control */ |
| |
| /* this point _must_ be a cubic control too */ |
| if ( tag != FT_Curve_Tag_Cubic ) |
| return ErrRaster_Invalid_Outline; |
| |
| v_control2 = point[0]; |
| phase = phase_cubic2; |
| break; |
| |
| |
| case phase_cubic2: /* the two previous points were cubics */ |
| |
| /* this point _must_ be an on point */ |
| if ( tag != FT_Curve_Tag_On ) |
| error = ErrRaster_Invalid_Outline; |
| else |
| error = interface->cubic_to( &v_control, &v_control2, |
| point, user ); |
| phase = phase_point; |
| break; |
| } |
| |
| /* lazy error testing */ |
| if ( error ) |
| return error; |
| } |
| |
| /* end of contour, close curve cleanly */ |
| error = 0; |
| |
| tag = FT_CURVE_TAG( outline->flags[first] ); |
| |
| switch ( phase ) |
| { |
| case phase_point: |
| if ( tag == FT_Curve_Tag_On ) |
| error = interface->line_to( &v_first, user ); |
| break; |
| |
| case phase_conic: |
| error = interface->conic_to( &v_control, &v_start, user ); |
| break; |
| |
| case phase_cubic2: |
| if ( tag == FT_Curve_Tag_On ) |
| error = interface->cubic_to( &v_control, &v_control2, |
| &v_first, user ); |
| else |
| error = ErrRaster_Invalid_Outline; |
| break; |
| |
| default: |
| error = ErrRaster_Invalid_Outline; |
| break; |
| } |
| |
| if ( error ) |
| return error; |
| |
| first = last + 1; |
| } |
| |
| return SUCCESS; |
| } |
| #endif |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Convert_Glyph */ |
| /* */ |
| /* <Description> */ |
| /* Converts a glyph into a series of segments and arcs and makes a */ |
| /* profiles list with them. */ |
| /* */ |
| /* <InOut> */ |
| /* outline :: The glyph outline. */ |
| /* */ |
| /* <Return> */ |
| /* SUCCESS or FAILURE. */ |
| /* */ |
| static |
| TResult Convert_Glyph( RAS_ARG_ FT_Outline* outline ) |
| { |
| static |
| FT_Outline_Funcs interface = |
| { |
| (FT_Outline_MoveTo_Func)Move_To, |
| (FT_Outline_LineTo_Func)Line_To, |
| (FT_Outline_ConicTo_Func)Conic_To, |
| (FT_Outline_CubicTo_Func)Cubic_To |
| }; |
| |
| /* Set up state in the raster object */ |
| ras.start_prof = NULL; |
| ras.joint = FALSE; |
| ras.fresh = FALSE; |
| |
| ras.pool_limit = ras.pool_size - AlignProfileSize; |
| |
| ras.n_extrema = 0; |
| |
| ras.cur_prof = (PProfile)ras.cursor; |
| ras.cur_prof->offset = ras.cursor; |
| ras.num_profs = 0; |
| |
| /* Now decompose curve */ |
| if ( FT_Outline_Decompose( outline, &interface, &ras ) ) |
| return FAILURE; |
| /* XXX: the error condition is in ras.error */ |
| |
| /* Check the last contour if needed */ |
| if ( Check_Contour( RAS_VAR ) ) |
| return FAILURE; |
| |
| /* Finalize profiles list */ |
| return Finalize_Profile_Table( RAS_VAR ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Init_Linked */ |
| /* */ |
| /* Inits an empty linked list. */ |
| /* */ |
| static |
| void Init_Linked( TProfileList* l ) |
| { |
| *l = NULL; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* InsNew */ |
| /* */ |
| /* Inserts a new Profile in a linked list. */ |
| /* */ |
| static |
| void InsNew( PProfileList list, |
| PProfile profile ) |
| { |
| PProfile *old, current; |
| TPos x; |
| |
| |
| old = list; |
| current = *old; |
| x = profile->X; |
| |
| while ( current ) |
| { |
| if ( x < current->X ) |
| break; |
| old = ¤t->link; |
| current = *old; |
| } |
| |
| profile->link = current; |
| *old = profile; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* DelOld */ |
| /* */ |
| /* Removes an old Profile from a linked list. */ |
| /* */ |
| static |
| void DelOld( PProfileList list, |
| PProfile profile ) |
| { |
| PProfile *old, current; |
| |
| |
| old = list; |
| current = *old; |
| |
| while ( current ) |
| { |
| if ( current == profile ) |
| { |
| *old = current->link; |
| return; |
| } |
| |
| old = ¤t->link; |
| current = *old; |
| } |
| |
| /* We should never reach this place, unless the Profile was not */ |
| /* part of the list. */ |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Update */ |
| /* */ |
| /* Updates all X offsets of a drawing list. */ |
| /* */ |
| static |
| void Update( PProfile first ) |
| { |
| PProfile current = first; |
| |
| |
| while ( current ) |
| { |
| current->X = *current->offset; |
| current->offset += current->flow; |
| current->height--; |
| current = current->link; |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* Sort */ |
| /* */ |
| /* Sorts a trace list. In 95%, the list is already sorted. We need */ |
| /* an algorithm which is fast in this case. Bubble sort is enough */ |
| /* and simple to implement. */ |
| /* */ |
| static |
| void Sort( PProfileList list ) |
| { |
| PProfile *old, current, next; |
| |
| |
| /* First, set the new X coordinate of each profile */ |
| Update( *list ); |
| |
| /* Then sort them */ |
| old = list; |
| current = *old; |
| |
| if ( !current ) |
| return; |
| |
| next = current->link; |
| |
| while ( next ) |
| { |
| if ( current->X <= next->X ) |
| { |
| old = ¤t->link; |
| current = *old; |
| |
| if ( !current ) |
| return; |
| } |
| else |
| { |
| *old = next; |
| current->link = next->link; |
| next->link = current; |
| |
| old = list; |
| current = *old; |
| } |
| |
| next = current->link; |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /******** ********/ |
| /******** Vertical Bitmap Sweep Routines ********/ |
| /******** ********/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Sweep_Init */ |
| /* */ |
| /* <Description> */ |
| /* Initializes the vertical bitmap sweep. Called by the generic */ |
| /* sweep/draw routine before its loop. */ |
| /* */ |
| /* <Input> */ |
| /* min :: The address of the current minimum scanline. */ |
| /* max :: The address of the current maximum scanline. */ |
| /* */ |
| static |
| void Vertical_Sweep_Init( RAS_ARG_ int* min, int* max ) |
| { |
| long pitch; |
| |
| UNUSED( max ); |
| |
| pitch = ras.target.pitch; |
| |
| /* start from the bottom line, going up !! */ |
| ras.trace_bit = - *min * pitch; |
| ras.trace_incr = -pitch; |
| |
| if (pitch > 0) |
| ras.trace_bit += pitch*(ras.target.rows-1); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Sweep_Span */ |
| /* */ |
| /* <Description> */ |
| /* Draws a single horizontal bitmap span during the vertical bitmap */ |
| /* sweep. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x1 :: The left span edge. */ |
| /* x2 :: The right span edge. */ |
| /* */ |
| static |
| void Vertical_Sweep_Span( RAS_ARG_ TScan y, |
| TPos x1, |
| TPos x2 ) |
| { |
| TPos e1, e2; |
| int c1, c2; |
| Byte f1, f2; |
| PByte target; |
| |
| UNUSED( y ); |
| |
| /* Drop-out control */ |
| e1 = TRUNC( CEILING( x1 ) ); |
| if ( x2 - x1 - PRECISION <= PRECISION_JITTER ) |
| e2 = e1; |
| else |
| e2 = TRUNC( FLOOR( x2 ) ); |
| |
| if ( e1 <= e2 && e2 >= 0 && e1 < ras.bit_width ) |
| { |
| if ( e1 < 0 ) e1 = 0; |
| if ( e2 >= ras.bit_width ) e2 = ras.bit_width - 1; |
| |
| c1 = e1 >> 3; |
| c2 = e2 >> 3; |
| |
| f1 = ((unsigned char)0xFF >> (e1 & 7)); |
| f2 = ~((unsigned char)0x7F >> (e2 & 7)); |
| |
| target = ras.bit_buffer + ras.trace_bit + c1; |
| c2 -= c1; |
| |
| if ( c2 > 0 ) |
| { |
| target[0] |= f1; |
| |
| /* memset() is slower than the following code on many platforms. */ |
| /* This is due to the fact that, in the vast majority of cases, */ |
| /* the span length in bytes is relatively small. */ |
| c2--; |
| while ( c2 > 0 ) |
| { |
| *(++target) = 0xFF; |
| c2--; |
| } |
| target[1] |= f2; |
| } |
| else |
| *target |= ( f1 & f2 ); |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Test_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Tests a pixel `light' during the vertical bitmap sweep. Used */ |
| /* during drop-out control only. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x :: The current x coordinate. */ |
| /* */ |
| static |
| int Vertical_Test_Pixel( RAS_ARG_ TScan y, |
| int x ) |
| { |
| int c1 = x >> 3; |
| |
| |
| UNUSED( y ); |
| |
| return ( x >= 0 && x < ras.bit_width && |
| ras.bit_buffer[ras.trace_bit + c1] & (0x80 >> (x & 7)) ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Set_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Sets a single pixel in a bitmap during the vertical sweep. Used */ |
| /* during drop-out control. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x :: The current x coordinate. */ |
| /* color :: Ignored by this function. */ |
| /* */ |
| static |
| void Vertical_Set_Pixel( RAS_ARG_ int y, |
| int x, |
| int color ) |
| { |
| UNUSED( color ); |
| UNUSED( y ); |
| |
| if ( x >= 0 && x < ras.bit_width ) |
| ras.bit_buffer[ras.trace_bit+(x >> 3)] |= (char)(0x80 >> (x & 7)); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Sweep_Step */ |
| /* */ |
| /* <Description> */ |
| /* Called whenever the sweep jumps to another scanline. Only updates */ |
| /* the pointers in the vertical bitmap sweep. */ |
| /* */ |
| static |
| void Vertical_Sweep_Step( RAS_ARG ) |
| { |
| ras.trace_bit += ras.trace_incr; |
| } |
| |
| |
| static |
| const Raster_Render vertical_render_mono = |
| { |
| &Vertical_Sweep_Init, |
| &Vertical_Sweep_Span, |
| &Vertical_Sweep_Step, |
| &Vertical_Test_Pixel, |
| &Vertical_Set_Pixel |
| }; |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /******** ********/ |
| /******** Horizontal Bitmap Sweep Routines ********/ |
| /******** ********/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Sweep_Init */ |
| /* */ |
| /* <Description> */ |
| /* Initializes the horizontal bitmap sweep. Called by the generic */ |
| /* sweep/draw routine before its loop. */ |
| /* */ |
| /* <Input> */ |
| /* min :: The address of the current minimum pixel column. */ |
| /* max :: The address of the current maximum pixel column. */ |
| /* */ |
| static |
| void Horizontal_Sweep_Init( RAS_ARG_ int* min, |
| int* max ) |
| { |
| UNUSED( ras ); |
| UNUSED( min ); |
| UNUSED( max ); |
| |
| /* nothing, really */ |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Sweep_Span */ |
| /* */ |
| /* <Description> */ |
| /* Draws a single vertical bitmap span during the horizontal bitmap */ |
| /* sweep. Actually, this function is only used to check for weird */ |
| /* drop-out cases. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current pixel column. */ |
| /* x1 :: The top span edge. */ |
| /* x2 :: The bottom span edge. */ |
| /* */ |
| static |
| void Horizontal_Sweep_Span( RAS_ARG_ TScan y, |
| TPos x1, |
| TPos x2 ) |
| { |
| TPos e1, e2; |
| PByte bits; |
| Byte f1; |
| |
| UNUSED( y ); |
| |
| /* During the horizontal sweep, we only take care of drop-outs */ |
| if ( x2 - x1 < PRECISION ) |
| { |
| e1 = CEILING( x1 ); |
| e2 = FLOOR( x2 ); |
| |
| if ( e1 == e2 ) |
| { |
| bits = ras.bit_buffer + (y >> 3); |
| f1 = (Byte)(0x80 >> (y & 7)); |
| |
| e1 = TRUNC( e1 ); |
| |
| if ( e1 >= 0 && e1 < ras.target.rows ) |
| { |
| long pitch = ras.target.pitch; |
| long offset = - pitch * e1; |
| |
| if (pitch > 0) |
| offset += (ras.target.rows-1)*pitch; |
| |
| bits[offset] |= f1; |
| } |
| } |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Test_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Tests a pixel `light' during the horizontal bitmap sweep. Used */ |
| /* during drop-out control only. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current pixel column. */ |
| /* x :: The current row/scanline. */ |
| /* */ |
| static |
| int Horizontal_Test_Pixel( RAS_ARG_ int y, |
| int x ) |
| { |
| char* bits = (char*)ras.bit_buffer + (y >> 3); |
| int f1 = (Byte)(0x80 >> (y & 7)); |
| long pitch = ras.target.pitch; |
| long offset = - pitch * x; |
| |
| if (pitch > 0) |
| offset += (ras.target.rows-1)*pitch; |
| |
| return ( x >= 0 && x < ras.target.rows && (bits[0] & f1) ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Set_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Sets a single pixel in a bitmap during the horizontal sweep. Used */ |
| /* during drop-out control. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current pixel column. */ |
| /* x :: The current row/scanline. */ |
| /* color :: Ignored by this function. */ |
| /* */ |
| static |
| void Horizontal_Set_Pixel( RAS_ARG_ int y, |
| int x, |
| int color ) |
| { |
| char* bits = (char*)ras.bit_buffer + (y >> 3); |
| int f1 = (Byte)(0x80 >> (y & 7)); |
| |
| |
| UNUSED( color ); |
| |
| if ( x >= 0 && x < ras.target.rows ) |
| { |
| long pitch = ras.target.pitch; |
| long offset = - x*pitch; |
| |
| if (pitch > 0) |
| offset += (ras.target.rows-1)*pitch; |
| |
| bits[offset] |= f1; |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Sweep_Step */ |
| /* */ |
| /* <Description> */ |
| /* Called whenever the sweep jumps to another pixel column. */ |
| /* */ |
| static |
| void Horizontal_Sweep_Step( RAS_ARG ) |
| { |
| UNUSED( ras.target ); |
| |
| /* Nothing, really */ |
| } |
| |
| |
| static |
| const Raster_Render horizontal_render_mono = |
| { |
| &Horizontal_Sweep_Init, |
| &Horizontal_Sweep_Span, |
| &Horizontal_Sweep_Step, |
| &Horizontal_Test_Pixel, |
| &Horizontal_Set_Pixel |
| }; |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /******** ********/ |
| /******** Anti-Aliased Vertical Bitmap Sweep Routines ********/ |
| /******** ********/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| #ifdef FT_RASTER_OPTION_ANTI_ALIAS |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Gray_Sweep_Init */ |
| /* */ |
| /* <Description> */ |
| /* Initializes the vertical bitmap sweep. Called by the generic */ |
| /* sweep/draw routine before its loop. */ |
| /* */ |
| /* <Input> */ |
| /* min :: The address of the current minimum scanline. */ |
| /* max :: The address of the current maximum scanline. */ |
| /* */ |
| static |
| void Vertical_Gray_Sweep_Init( RAS_ARG_ int* min, int* max ) |
| { |
| long pitch; |
| |
| UNUSED( max ); |
| |
| pitch = ras.target.pitch; |
| |
| /* start from the bottom line, going up */ |
| ras.trace_incr = -pitch; |
| ras.trace_bit = - *min * pitch; |
| |
| if (pitch > 0) |
| ras.trace_bit += (ras.target.rows-1)*pitch; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Gray_Sweep_Span */ |
| /* */ |
| /* <Description> */ |
| /* Draws a single horizontal bitmap span during the vertical bitmap */ |
| /* sweep. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x1 :: The left span edge. */ |
| /* x2 :: The right span edge. */ |
| /* */ |
| static |
| void Vertical_Gray_Sweep_Span( RAS_ARG_ TScan y, |
| TPos x1, |
| TPos x2 ) |
| { |
| TPos e1, e2; |
| int shift = PRECISION_BITS - 6; |
| PByte target; |
| |
| UNUSED( y ); |
| |
| x1 += PRECISION_HALF; |
| x2 += PRECISION_HALF; |
| |
| #ifdef FT_RASTER_OPTION_CONTRAST |
| if ( x2-x1 < PRECISION ) |
| { |
| x1 = ((x1+x2) >> 1) - PRECISION_HALF; |
| x2 = x1 + PRECISION; |
| } |
| #endif |
| |
| e1 = TRUNC( x1 ); |
| e2 = TRUNC( x2 ); |
| |
| if ( e1 <= e2 && e2 >= 0 && e1 < ras.bit_width ) |
| { |
| x1 = FRAC(x1) >> shift; |
| x2 = FRAC(x2) >> shift; |
| |
| if ( e1 < 0 ) |
| { |
| e1 = 0; |
| x1 = 0; |
| } |
| |
| if ( e2 > ras.bit_width ) |
| { |
| e2 = ras.bit_width-1; |
| x2 = 0; |
| } |
| |
| target = ras.bit_buffer + ras.trace_bit + e1; |
| e2 -= e1; |
| |
| if ( e2 > 0 ) |
| { |
| if (x1 > 0) target[0] += (Byte)(64-x1) << 1; |
| else target[0] = 127; |
| e2--; |
| while (e2 > 0) |
| { |
| *(++target) = 127; |
| e2--; |
| } |
| if (x2) |
| target[1] += (Byte)x2 << 1; |
| } |
| else |
| { |
| target[0] += (Byte)(x2-x1) << 1; |
| } |
| } |
| } |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Gray_Test_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Tests a pixel `light' during the vertical bitmap sweep. Used */ |
| /* during drop-out control only. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x :: The current x coordinate. */ |
| /* */ |
| static |
| int Vertical_Gray_Test_Pixel( RAS_ARG_ TScan y, |
| int x ) |
| { |
| UNUSED( y ); |
| |
| #if 0 |
| /* as a rule of thumb, do not add a drop-out if the current */ |
| /* gray level is over 0.5 */ |
| |
| return ( x >= 0 && x < ras.bit_width && |
| ras.bit_buffer[ras.trace_bit + x] >= 64 ); |
| #else |
| UNUSED(x); |
| return 0; |
| #endif |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Gray_Set_Pixel */ |
| /* */ |
| /* <Description> */ |
| /* Sets a single pixel in a bitmap during the vertical sweep. Used */ |
| /* during drop-out control. */ |
| /* */ |
| /* <Input> */ |
| /* y :: The current scanline. */ |
| /* x :: The current x coordinate. */ |
| /* color :: Ignored by this function. */ |
| /* */ |
| static |
| void Vertical_Gray_Set_Pixel( RAS_ARG_ int y, |
| int x, |
| int color ) |
| { |
| UNUSED( y ); |
| |
| if ( x >= 0 && x < ras.bit_width ) |
| { |
| unsigned char* pixel; |
| |
| pixel = ras.bit_buffer + ras.trace_bit + x; |
| |
| /* do not add too much to the pixel gray level */ |
| color += *pixel; |
| if (color < 64) |
| color = 64; |
| |
| *pixel = ( color >= 127 ? 127 : (unsigned char)color ); |
| } |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Vertical_Sweep_Step */ |
| /* */ |
| /* <Description> */ |
| /* Called whenever the sweep jumps to another scanline. Only updates */ |
| /* the pointers in the vertical bitmap sweep. */ |
| /* */ |
| static |
| void Vertical_Gray_Sweep_Step( RAS_ARG ) |
| { |
| ras.trace_bit += ras.trace_incr; |
| } |
| |
| |
| |
| static |
| const Raster_Render vertical_render_gray = |
| { |
| &Vertical_Gray_Sweep_Init, |
| &Vertical_Gray_Sweep_Span, |
| &Vertical_Gray_Sweep_Step, |
| &Vertical_Gray_Test_Pixel, |
| &Vertical_Gray_Set_Pixel |
| }; |
| |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /******** ********/ |
| /******** Horizontal Bitmap Sweep Routines ********/ |
| /******** ********/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Horizontal_Sweep_Init */ |
| /* */ |
| /* <Description> */ |
| /* Initializes the horizontal bitmap sweep. Called by the generic */ |
| /* sweep/draw routine before its loop. */ |
| /* */ |
| /* <Input> */ |
| /* min :: The address of the current minimum pixel column. */ |
| /* max :: The address of the current maximum pixel column. */ |
| /* */ |
| static |
| void Horizontal_Gray_Sweep_Init( RAS_ARG_ int* min, |
| int* max ) |
| { |
| UNUSED( ras ); |
| UNUSED( min ); |
| UNUSED( max ); |
| |
| /* nothing, really */ |
| } |
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