| /***************************************************************************/ |
| /* */ |
| /* ftimage.h */ |
| /* */ |
| /* This file defines the glyph image formats recognized by FreeType, as */ |
| /* well as the default raster interface. */ |
| /* */ |
| /* 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. */ |
| /* */ |
| /***************************************************************************/ |
| |
| #ifndef FTIMAGE_H |
| #define FTIMAGE_H |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Type> */ |
| /* FT_Pos */ |
| /* */ |
| /* <Description> */ |
| /* The type FT_Pos is a 32-bit integer used to store vectorial */ |
| /* coordinates. Depending on the context, these can represent */ |
| /* distances in integer font units, or 26.6 fixed float pixel */ |
| /* coordinates. */ |
| /* */ |
| typedef signed long FT_Pos; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Struct> */ |
| /* FT_Vector */ |
| /* */ |
| /* <Description> */ |
| /* A simple structure used to store a 2d vector; coordinates are of */ |
| /* the FT_Pos type. */ |
| /* */ |
| /* <Fields> */ |
| /* x :: The horizontal coordinate. */ |
| /* y :: The vertical coordinate. */ |
| /* */ |
| typedef struct FT_Vector_ |
| { |
| FT_Pos x; |
| FT_Pos y; |
| |
| } FT_Vector; |
| |
| |
| /************************************************************************* |
| * |
| * <Enum> |
| * FT_Pixel_Mode |
| * |
| * <Description> |
| * An enumeration type used to describe the format of pixels |
| * in a given bitmap. Note that additional formats may be added |
| * in the future. |
| * |
| * <Fields> |
| * ft_pixel_mode_mono :: a monochrome bitmap (1 bit/pixel) |
| * |
| * ft_pixel_mode_grays :: an 8-bit gray-levels bitmap. Note that |
| * the total number of gray levels is given |
| * in the `num_grays' field of the FT_Bitmap |
| * structure. |
| * |
| * ft_pixel_mode_pal2 :: a 2-bit paletted bitmap. |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_pal4 :: a 4-bit paletted bitmap. |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_pal8 :: an 8-bit paletted bitmap. |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_rgb15 :: a 15-bit RGB bitmap. Uses 5:5:5 encoding |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_rgb16 :: a 16-bit RGB bitmap. Uses 5:6:5 encoding |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_rgb24 :: a 24-bit RGB bitmap. |
| * currently unused by FreeType. |
| * |
| * ft_pixel_mode_rgb32 :: a 32-bit RGB bitmap. |
| * currently unused by FreeType. |
| * |
| * <Note> |
| * Some anti-aliased bitmaps might be embedded in TrueType fonts |
| * using formats pal2 or pal4, though no fonts presenting those |
| * have been found to date.. |
| * |
| *************************************************************************/ |
| |
| typedef enum FT_Pixel_Mode_ |
| { |
| ft_pixel_mode_none = 0, |
| ft_pixel_mode_mono, |
| ft_pixel_mode_grays, |
| ft_pixel_mode_pal2, |
| ft_pixel_mode_pal4, |
| ft_pixel_mode_pal8, |
| ft_pixel_mode_rgb15, |
| ft_pixel_mode_rgb16, |
| ft_pixel_mode_rgb24, |
| ft_pixel_mode_rgb32, |
| |
| ft_pixel_mode_max /* do not remove */ |
| |
| } FT_Pixel_Mode; |
| |
| |
| |
| /************************************************************************* |
| * |
| * <Enum> |
| * FT_Palette_Mode |
| * |
| * <Description> |
| * An enumeration type used to describe the format of a bitmap |
| * palette, used with ft_pixel_mode_pal4 and ft_pixel_mode_pal8 |
| * |
| * <Fields> |
| * ft_palette_mode_rgb :: the palette is an array of 3-bytes RGB records |
| * |
| * ft_palette_mode_rgba :: the palette is an array of 4-bytes RGBA records |
| * |
| * <Note> |
| * As ft_pixel_mode_pal2, pal4 and pal8 are currently unused by |
| * FreeType, these types are not handled by the library itself. |
| * |
| *************************************************************************/ |
| |
| typedef enum FT_Palette_Mode_ |
| { |
| ft_palette_mode_rgb = 0, |
| ft_palette_mode_rgba, |
| |
| ft_palettte_mode_max /* do not remove */ |
| |
| } FT_Palette_Mode; |
| |
| |
| /************************************************************************* |
| * |
| * <Struct> |
| * FT_Bitmap |
| * |
| * <Description> |
| * A structure used to describe a bitmap or pixmap to the raster. |
| * Note that we now manage pixmaps of various depths through the |
| * `pixel_mode' field. |
| * |
| * <Fields> |
| * rows :: The number of bitmap rows. |
| * |
| * width :: The number of pixels in bitmap row. |
| * |
| * pitch :: The pitch's absolute value is the number of bytes |
| * taken by one bitmap row, including padding. However, |
| * the pitch is positive when the bitmap has a `down' |
| * flow, and negative when it has an `up' flow. In all |
| * cases, the pitch is an offset to add to a bitmap |
| * pointer in order to go down one row. |
| * |
| * buffer :: A typeless pointer to the bitmap buffer. This value |
| * should be aligned on 32-bit boundaries in most cases. |
| * |
| * num_grays :: this field is only used with ft_pixel_mode_grays, |
| * it gives the number of gray levels used in the |
| * bitmap. |
| * |
| * pixel_mode :: the pixel_mode, i.e. how pixel bits are stored |
| * |
| * palette_mode :: this field is only used with paletted pixel modes, |
| * it indicates how the palette is stored |
| * |
| * palette :: a typeless pointer to the bitmap palette. only used |
| * for paletted pixel modes. |
| * |
| * <Note> |
| * When using pixel modes pal2, pal4 and pal8 with a void `palette' |
| * field, a gray pixmap with respectively 4, 16 and 256 levels of gray |
| * is assumed. This, in order to be compatible with some embedded bitmap |
| * formats defined in the TrueType spec. |
| * |
| * Note that no font was found presenting such embedded bitmaps, so this |
| * is currently completely unhandled by the library. |
| * |
| * |
| *************************************************************************/ |
| |
| typedef struct FT_Bitmap_ |
| { |
| int rows; |
| int width; |
| int pitch; |
| void* buffer; |
| short num_grays; |
| char pixel_mode; |
| char palette_mode; |
| void* palette; |
| |
| } FT_Bitmap; |
| |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Struct> */ |
| /* FT_Outline */ |
| /* */ |
| /* <Description> */ |
| /* This structure is used to describe an outline to the scan-line */ |
| /* converter. It's a copy of the TT_Outline type that was defined */ |
| /* in FreeType 1.x. */ |
| /* */ |
| /* <Fields> */ |
| /* n_contours :: The number of contours in the outline. */ |
| /* */ |
| /* n_points :: The number of points in the outline. */ |
| /* */ |
| /* points :: A pointer to an array of `n_points' FT_Vector */ |
| /* elements, giving the outline's point */ |
| /* coordinates. */ |
| /* */ |
| /* tags :: A pointer to an array of `n_points' chars, */ |
| /* giving each outline point's type. If bit 0 is */ |
| /* unset, the point is 'off' the curve, i.e. a */ |
| /* Bezier control point, while it is `on' when */ |
| /* unset. */ |
| /* */ |
| /* Bit 1 is meaningful for `off' points only. If */ |
| /* set, it indicates a third-order Bezier arc */ |
| /* control point; and a second-order control point */ |
| /* if unset. */ |
| /* */ |
| /* contours :: An array of `n_contours' shorts, giving the end */ |
| /* point of each contour within the outline. For */ |
| /* example, the first contour is defined by the */ |
| /* points `0' to `contours[0]', the second one is */ |
| /* defined by the points `contours[0]+1' to */ |
| /* `contours[1]', etc. */ |
| /* */ |
| /* flags :: a set of bit flags used to characterize the */ |
| /* outline and give hints to the scan-converter */ |
| /* and hinter on how to convert/grid-fit it.. */ |
| /* see FT_Outline_Flags.. */ |
| /* */ |
| typedef struct FT_Outline_ |
| { |
| short n_contours; /* number of contours in glyph */ |
| short n_points; /* number of points in the glyph */ |
| |
| FT_Vector* points; /* the outline's points */ |
| char* tags; /* the points flags */ |
| short* contours; /* the contour end points */ |
| |
| int flags; /* outline masks */ |
| |
| } FT_Outline; |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Enum> */ |
| /* FT_Outline_Flags */ |
| /* */ |
| /* <Description> */ |
| /* A simple type used to enumerates the flags in an outline's */ |
| /* "outline_flags" field. */ |
| /* */ |
| /* <Fields> */ |
| /* ft_outline_owner :: */ |
| /* when set, this flag indicates that the outline's field arrays */ |
| /* (i.e. "points", "flags" & "contours") are "owned" by the */ |
| /* outline object, and should thus be freed when it is destroyed. */ |
| /* */ |
| /* ft_outline_even_odd_fill :: */ |
| /* by default, outlines are filled using the non-zero winding */ |
| /* rule. When set to 1, the outline will be filled using the */ |
| /* even-odd fill rule.. (XXX: unimplemented) */ |
| /* */ |
| /* ft_outline_reverse_fill :: */ |
| /* By default, outside contours of an outline are oriented in */ |
| /* clock-wise direction, as defined in the TrueType specification. */ |
| /* This flag is set when the outline uses the opposite direction, */ |
| /* (typically for Type 1 fonts). This flag is ignored by the */ |
| /* scan-converter. However, it is very important for the */ |
| /* auto-hinter.. */ |
| /* */ |
| /* ft_outline_ignore_dropouts :: */ |
| /* By default, the scan converter will try to detect drop-outs */ |
| /* in an outline and correct the glyph bitmap to ensure consistent */ |
| /* shape continuity. When set, this flag hints the scan-line */ |
| /* converter to ignore such cases. */ |
| /* */ |
| /* ft_outline_high_precision :: */ |
| /* this flag indicates that the scan-line converter should try */ |
| /* to convert this outline to bitmaps with the highest possible */ |
| /* quality. It is typically set for small character sizes. Note */ |
| /* that this is only a hint, that might be completely ignored */ |
| /* by a given scan-converter. */ |
| /* */ |
| /* ft_outline_single_pass :: */ |
| /* this flag is set to force a given scan-converter to only */ |
| /* use a single pass over the outline to render a bitmap glyph */ |
| /* image. Normally, it is set for very large character sizes. */ |
| /* It is only a hint, that might be completely ignored by a */ |
| /* given scan-converter. */ |
| /* */ |
| typedef enum FT_Outline_Flags_ |
| { |
| ft_outline_none = 0, |
| ft_outline_owner = 1, |
| ft_outline_even_odd_fill = 2, |
| ft_outline_reverse_fill = 4, |
| ft_outline_ignore_dropouts = 8, |
| ft_outline_high_precision = 256, |
| ft_outline_single_pass = 512 |
| |
| } FT_Outline_Flags; |
| |
| |
| |
| #define FT_CURVE_TAG( flag ) (flag & 3) |
| |
| #define FT_Curve_Tag_On 1 |
| #define FT_Curve_Tag_Conic 0 |
| #define FT_Curve_Tag_Cubic 2 |
| |
| #define FT_Curve_Tag_Touch_X 8 /* reserved for the TrueType hinter */ |
| #define FT_Curve_Tag_Touch_Y 16 /* reserved for the TrueType hinter */ |
| |
| #define FT_Curve_Tag_Touch_Both ( FT_Curve_Tag_Touch_X | \ |
| FT_Curve_Tag_Touch_Y) |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Outline_MoveTo_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function pointer type used to describe the signature of a `move */ |
| /* to' function during outline walking/decomposition. */ |
| /* */ |
| /* A `move to' is emitted to start a new contour in an outline. */ |
| /* */ |
| /* <Input> */ |
| /* to :: A pointer to the target point of the `move to'. */ |
| /* user :: A typeless pointer which is passed from the caller of the */ |
| /* decomposition function. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| typedef int (*FT_Outline_MoveTo_Func)( FT_Vector* to, |
| void* user ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Outline_LineTo_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function pointer type used to describe the signature of a `line */ |
| /* to' function during outline walking/decomposition. */ |
| /* */ |
| /* A `line to' is emitted to indicate a segment in the outline. */ |
| /* */ |
| /* <Input> */ |
| /* to :: A pointer to the target point of the `line to'. */ |
| /* user :: A typeless pointer which is passed from the caller of the */ |
| /* decomposition function. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| typedef int (*FT_Outline_LineTo_Func)( FT_Vector* to, |
| void* user ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Outline_ConicTo_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function pointer type use to describe the signature of a `conic */ |
| /* to' function during outline walking/decomposition. */ |
| /* */ |
| /* A `conic to' is emitted to indicate a second-order Bezier arc in */ |
| /* the outline. */ |
| /* */ |
| /* <Input> */ |
| /* control :: An intermediate control point between the last position */ |
| /* and the new target in `to'. */ |
| /* */ |
| /* to :: A pointer to the target end point of the conic arc. */ |
| /* */ |
| /* user :: A typeless pointer which is passed from the caller of */ |
| /* the decomposition function. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| typedef int (*FT_Outline_ConicTo_Func)( FT_Vector* control, |
| FT_Vector* to, |
| void* user ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Outline_CubicTo_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function pointer type used to describe the signature of a `cubic */ |
| /* to' function during outline walking/decomposition. */ |
| /* */ |
| /* A `cubic to' is emitted to indicate a third-order Bezier arc. */ |
| /* */ |
| /* <Input> */ |
| /* control1 :: A pointer to the first Bezier control point. */ |
| /* control2 :: A pointer to the second Bezier control point. */ |
| /* to :: A pointer to the target end point. */ |
| /* user :: A typeless pointer which is passed from the caller of */ |
| /* the decomposition function. */ |
| /* */ |
| /* <Return> */ |
| /* Error code. 0 means success. */ |
| /* */ |
| typedef int (*FT_Outline_CubicTo_Func)( FT_Vector* control1, |
| FT_Vector* control2, |
| FT_Vector* to, |
| void* user ); |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Struct> */ |
| /* FT_Outline_Funcs */ |
| /* */ |
| /* <Description> */ |
| /* A structure to hold various function pointers used during outline */ |
| /* decomposition in order to emit segments, conic, and cubic Beziers, */ |
| /* as well as `move to' and `close to' operations. */ |
| /* */ |
| /* <Fields> */ |
| /* move_to :: The `move to' emitter. */ |
| /* line_to :: The segment emitter. */ |
| /* conic_to :: The second-order Bezier arc emitter. */ |
| /* cubic_to :: The third-order Bezier arc emitter. */ |
| /* */ |
| typedef struct FT_Outline_Funcs_ |
| { |
| FT_Outline_MoveTo_Func move_to; |
| FT_Outline_LineTo_Func line_to; |
| FT_Outline_ConicTo_Func conic_to; |
| FT_Outline_CubicTo_Func cubic_to; |
| |
| int shift; |
| FT_Pos delta; |
| |
| } FT_Outline_Funcs; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Macro> */ |
| /* FT_IMAGE_TAG */ |
| /* */ |
| /* <Description> */ |
| /* This macro converts four letter tags which are used to label */ |
| /* TrueType tables into an unsigned long to be used within FreeType. */ |
| /* */ |
| #define FT_IMAGE_TAG( _x1, _x2, _x3, _x4 ) \ |
| (((unsigned long)_x1 << 24) | \ |
| ((unsigned long)_x2 << 16) | \ |
| ((unsigned long)_x3 << 8) | \ |
| (unsigned long)_x4) |
| |
| |
| /*********************************************************************** |
| * |
| * <Enum> |
| * FT_Glyph_Format |
| * |
| * <Description> |
| * An enumeration type used to describethe format of a given glyph |
| * image. Note that this version of FreeType only supports two image |
| * formats, even though future font drivers will be able to register |
| * their own format. |
| * |
| * <Fields> |
| * ft_glyph_format_composite :: the glyph image is a composite of several |
| * other images. This glyph format is _only_ |
| * used with the FT_LOAD_FLAG_NO_RECURSE flag |
| * (XXX: Which is currently iunimplemented) |
| * |
| * ft_glyph_format_bitmap :: the glyph image is a bitmap, and can |
| * be described as a FT_Bitmap |
| * |
| * ft_glyph_format_outline :: the glyph image is a vectorial image |
| * made of bezier control points, and can |
| * be described as a FT_Outline |
| * |
| * ft_glyph_format_plotter :: the glyph image is a vectorial image |
| * made of plotter lines (some T1 fonts like |
| * Hershey contain glyph in this format). |
| * |
| ***********************************************************************/ |
| |
| typedef enum FT_Glyph_Format_ |
| { |
| ft_glyph_format_none = 0, |
| ft_glyph_format_composite = FT_IMAGE_TAG('c','o','m','p'), |
| ft_glyph_format_bitmap = FT_IMAGE_TAG('b','i','t','s'), |
| ft_glyph_format_outline = FT_IMAGE_TAG('o','u','t','l'), |
| ft_glyph_format_plotter = FT_IMAGE_TAG('p','l','o','t') |
| |
| } FT_Glyph_Format; |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** R A S T E R D E F I N I T I O N S *****/ |
| /***** *****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /************************************************************************** |
| * |
| * |
| * |
| * |
| * |
| * |
| * |
| * |
| **************************************************************************/ |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Type> */ |
| /* FT_Raster */ |
| /* */ |
| /* <Description> */ |
| /* A handle (pointer) to a raster object. Each object can be used */ |
| /* independently to convert an outline into a bitmap or pixmap. */ |
| /* */ |
| typedef struct FT_RasterRec_* FT_Raster; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Struct> */ |
| /* FT_Span */ |
| /* */ |
| /* <Description> */ |
| /* A structure used to model a single span of gray (or black) pixels */ |
| /* when rendering a monocrhome or anti-aliased bitmap. */ |
| /* */ |
| /* <Fields> */ |
| /* x :: the span's horizontal start position */ |
| /* len :: the span's length in pixels */ |
| /* coverage :: the span color/coverage, ranging from 0 (background) */ |
| /* to 255 (foreground). Only used for anti-aliased */ |
| /* rendering.. */ |
| /* */ |
| /* <Note> */ |
| /* This structure is used by the span drawing callback type */ |
| /* named FT_Raster_Span_Func, which takes the y coordinate of the */ |
| /* span as a paremeter.. */ |
| /* */ |
| /* The coverage value is always between 0 and 255, even if the */ |
| /* number of gray levels have been set through FT_Set_Gray_Levels() */ |
| /* */ |
| typedef struct FT_Span_ |
| { |
| short x; |
| unsigned short len; |
| unsigned char coverage; |
| |
| } FT_Span; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Raster_Span_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function used as a call-back by the anti-aliased renderer in */ |
| /* order to let client applications draw themselves the gray pixel */ |
| /* spans on each scan line. */ |
| /* */ |
| /* <Input> */ |
| /* y :: the scanline's y coordinate */ |
| /* count :: the number of spans to draw on this scanline */ |
| /* spans :: a table of 'count' spans to draw on the scanline */ |
| /* user :: user-supplied data that is passed to the callback */ |
| /* */ |
| /* <Note> */ |
| /* This callback allows client applications to directly render the */ |
| /* gray spans of the anti-aliased bitmap to any kind of surfaces. */ |
| /* */ |
| /* This can be used to write anti-aliased outlines directly to a */ |
| /* given background bitmap, and even perform translucency.. */ |
| /* */ |
| /* Note that the "count" field cannot be greater than a fixed value */ |
| /* defined by the FT_MAX_GRAY_SPANS configuration macro in ftoption.h */ |
| /* */ |
| /* By default, this value is set to 32, which means that if there are */ |
| /* more than 32 spans on a given scanline, the callback will be called */ |
| /* several times with the same "y" parameter in order to draw all */ |
| /* callbacks.. */ |
| /* */ |
| /* Otherwise, the callback is only called once per scan-line, and */ |
| /* only for those scanlines that do have "gray" pixels on them.. */ |
| /* */ |
| typedef void (*FT_Raster_Span_Func)( int y, |
| int count, |
| FT_Span* spans, |
| void* user ); |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Raster_BitTest_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function used as a call-back by the monochrome scan-converter */ |
| /* to test wether a given target pixel is already set to the drawing */ |
| /* "color". These tests are crucial to implement drop-out control */ |
| /* per-se the TrueType spec.. */ |
| /* */ |
| /* <Input> */ |
| /* y :: the pixel's y coordinate */ |
| /* x :: the pixel's x coordinate */ |
| /* user :: user-supplied data that is passed to the callback */ |
| /* */ |
| /* <Return> */ |
| /* 1 if the pixel is "set", 0 otherwise */ |
| /* */ |
| typedef int (*FT_Raster_BitTest_Func)( int y, |
| int x, |
| void* user ); |
| |
| /*************************************************************************/ |
| /* */ |
| /* <FuncType> */ |
| /* FT_Raster_BitSet_Func */ |
| /* */ |
| /* <Description> */ |
| /* A function used as a call-back by the monochrome scan-converter */ |
| /* used to set an individual target pixel. This is crucial to */ |
| /* implement drop-out control per-se the TrueType spec.. */ |
| /* */ |
| /* <Input> */ |
| /* y :: the pixel's y coordinate */ |
| /* x :: the pixel's x coordinate */ |
| /* user :: user-supplied data that is passed to the callback */ |
| /* */ |
| /* <Return> */ |
| /* 1 if the pixel is "set", 0 otherwise */ |
| /* */ |
| typedef void (*FT_Raster_BitSet_Func)( int y, |
| int x, |
| void* user ); |
| |
| |
| /************************************************************************** |
| * |
| * <Enum> |
| * FT_Raster_Flag |
| * |
| * <Description> |
| * An enumeration used to list the bit flags used in the "flags" |
| * field of a FT_Raster_Params function. |
| * |
| * <Fields> |
| * ft_raster_flag_default :: this value is 0 |
| * |
| * ft_raster_flag_aa :: resquests the rendering of an anti-aliased |
| * glyph bitmap. If unset, a monchrome bitmap |
| * will be rendered. |
| * |
| * ft_raster_flag_direct :: requests direct rendering over the target |
| * bitmap. Direct rendering uses user-provided |
| * callbacks in order to perform direct |
| * drawing or composition over an existing |
| * bitmap. If this bit is unset, the content |
| * of the target bitmap **must be zeroed** ! |
| * |
| **************************************************************************/ |
| typedef enum { |
| |
| ft_raster_flag_default = 0, |
| ft_raster_flag_aa = 1, |
| ft_raster_flag_direct = 2 |
| |
| } FT_Raster_Flag; |
| |
| /************************************************************************** |
| * |
| * <Struct> |
| * FT_Raster_Params |
| * |
| * <Description> |
| * A structure used to hold the arguments used by a raster's render |
| * function. |
| * |
| * <Fields> |
| * target :: the target bitmap |
| * source :: pointer to the source glyph image (e.g. a FT_Outline) |
| * flags :: rendering flags |
| * gray_spans :: gray span drawing callback |
| * black_spans :: black span drawing callback |
| * bit_test :: bit test callback |
| * bit_set :: bit set callback |
| * user :: user-supplied data that is passed to each drawing |
| * callback.. |
| * |
| * <Note> |
| * An anti-aliased glyph bitmap is drawn if the ft_raster_flag_aa bit |
| * flag is set in the "flags" field, otherwise a monochrome bitmap will |
| * be generated. |
| * |
| * When the ft_raster_flag_direct bit flag is set in "flags", the raster |
| * will call the "gray_spans" callback to drawn gray pixel spans, in the |
| * case of an aa glyph bitmap, or "black_spans", "bit_test" and "bit_set" |
| * in the case of a monochrome bitmap. |
| * |
| * This allows direct composition over a pre-existing bitmap through |
| * user-provided callbacks to perform the span drawing/composition. |
| * |
| * Note that the "bit_test" and "bit_set" callbacks are required when |
| * rendering a monochrome bitmap, as they are crucial to implement correct |
| * drop-out control per-se the TrueType specification.. |
| * |
| **************************************************************************/ |
| |
| typedef struct FT_Raster_Params_ |
| { |
| FT_Bitmap* target; |
| void* source; |
| int flags; |
| FT_Raster_Span_Func gray_spans; |
| FT_Raster_Span_Func black_spans; |
| FT_Raster_BitTest_Func bit_test; |
| FT_Raster_BitSet_Func bit_set; |
| void* user; |
| |
| } FT_Raster_Params; |
| |
| |
| |
| /************************************************************************** |
| * <FuncType> |
| * FT_Raster_New_Func |
| * |
| * <Description> |
| * A function used to create a new raster object. |
| * |
| * <Input> |
| * memory :: handle to memory allocator. |
| * |
| * <Output> |
| * raster :: handle to new raster object |
| * |
| * <Return> |
| * Error code. 0 means success |
| * |
| * <Note> |
| * the "memory" parameter is a typeless pointer in order to avoid |
| * un-wanted dependencies on the rest of the FreeType code. |
| * |
| * in practice, it is a FT_Memory, i.e. a handle to the standard |
| * FreeType memory allocator. However, this field can be completely |
| * ignored by a given raster implementation.. |
| * |
| **************************************************************************/ |
| |
| typedef int (*FT_Raster_New_Func)( void* memory, |
| FT_Raster *raster ); |
| |
| |
| /************************************************************************** |
| * <FuncType> |
| * FT_Raster_Done_Func |
| * |
| * <Description> |
| * A function used to destroy a given raster object. |
| * |
| * <Input> |
| * raster :: handle to new raster object |
| * |
| **************************************************************************/ |
| |
| typedef void (*FT_Raster_Done_Func)( FT_Raster raster ); |
| |
| |
| |
| /************************************************************************** |
| * |
| * <FuncType> |
| * FT_Raster_Reset_Func |
| * |
| * <Description> |
| * FreeType provides an area of memory called the "render pool", |
| * available to all registered rasters. This pool can be freely |
| * used during a given scan-conversion but is shared by all rasters. |
| * Its content is thus transient. |
| * |
| * This function is called each time the render pool changes, or |
| * just after a new raster object is created. |
| * |
| * <Input> |
| * raster :: handle to new raster object |
| * pool_base :: address in memory of render pool |
| * pool_size :: size in bytes of render pool |
| * |
| * <Note> |
| * Rasters can ignore the render pool and rely on dynamic memory |
| * allocation if they want to (a handle to the memory allocator is |
| * passed to the raster constructor). However, this is not recommended |
| * for efficiency purposes.. |
| * |
| **************************************************************************/ |
| |
| typedef void (*FT_Raster_Reset_Func)( FT_Raster raster, |
| const char* pool_base, |
| long pool_size ); |
| |
| |
| /************************************************************************** |
| * |
| * <FuncType> |
| * FT_Raster_Set_Mode_Func |
| * |
| * <Description> |
| * This function is a generic facility to change modes or attributes |
| * in a given raster. This can be used for debugging purposes, or |
| * simply to allow implementation-specific "features" in a given |
| * raster module. |
| * |
| * <Input> |
| * raster :: handle to new raster object |
| * mode :: a 4-byte tag used to name the mode or property |
| * args :: a pointer to the new mode/property to use |
| * |
| **************************************************************************/ |
| |
| typedef int (*FT_Raster_Set_Mode_Func)( FT_Raster raster, |
| unsigned long mode, |
| void* args ); |
| |
| /************************************************************************** |
| * |
| * <FuncType> |
| * FT_Raster_Render_Func |
| * |
| * <Description> |
| * Invokes a given raster to scan-convert a given glyph image into |
| * a target bitmap. |
| * |
| * <Input> |
| * raster :: handle to raster object |
| * params :: pointer to a FT_Raster_Params structure used to store |
| * the rendering parameters. |
| * |
| * <Return> |
| * Error code. 0 means success |
| * |
| * <Note> |
| * The exact format of the source image depends on the raster's |
| * glyph format defined in its FT_Raster_Funcs structure. It can be |
| * an FT_Outline or anything else in order to support a large array |
| * of glyph formats. |
| * |
| * Note also that the render function can fail and return a |
| * FT_Err_Unimplemented_Feature error code when the raster used does |
| * not support direct composition. |
| * |
| * XXX: For now, the standard raster doesn't support direct composition |
| * but this should change for the final release (see the files |
| * demos/src/ftgrays.c and demos/src/ftgrays2.c for examples of |
| * distinct implementations which support direct composition). |
| * |
| **************************************************************************/ |
| |
| typedef int (*FT_Raster_Render_Func)( FT_Raster raster, |
| FT_Raster_Params* params ); |
| |
| |
| /************************************************************************** |
| * |
| * <Struct> |
| * FT_Raster_Funcs |
| * |
| * <Description> |
| * A structure used to describe a given raster class to the library. |
| * |
| * <Fields> |
| * glyph_format :: the supported glyph format for this raster |
| * raster_new :: the raster constructor |
| * raster_reset :: used to reset the render pool within the raster |
| * raster_render :: renders a glyph into a given bitmap |
| * raster_done :: the raster destructor |
| * |
| **************************************************************************/ |
| |
| |
| typedef struct FT_Raster_Funcs_ |
| { |
| FT_Glyph_Format glyph_format; |
| FT_Raster_New_Func raster_new; |
| FT_Raster_Reset_Func raster_reset; |
| FT_Raster_Set_Mode_Func raster_set_mode; |
| FT_Raster_Render_Func raster_render; |
| FT_Raster_Done_Func raster_done; |
| |
| } FT_Raster_Funcs; |
| |
| #endif /* FTIMAGE_H */ |
| |
| |
