| /***************************************************************************/ | |
| /* */ | |
| /* ftrgb.h */ | |
| /* */ | |
| /* RGB color filtering support for FreeType 2 (specification only). */ | |
| /* */ | |
| /* Copyright 2005 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 __FT_RGB_H__ | |
| #define __FT_RGB_H__ | |
| #include <ft2build.h> | |
| #include FT_FREETYPE_H | |
| FT_BEGIN_HEADER | |
| /** | |
| * @type: FT_RgbFilter | |
| * | |
| * @description: | |
| * an opaque handle to an object modelling an RGB color filter. | |
| * this is used to process LCD-decimated bitmaps in order to reduce | |
| * color fringes during display | |
| */ | |
| typedef struct FT_RgbFilterRec_* FT_RgbFilter; | |
| /** | |
| * @func: FT_RgbFilter_ApplyARGB | |
| * | |
| * @description: | |
| * apply a given color filter to a given bitmap. This function does | |
| * nothing if the bitmap's pixel_mode field is not FT_PIXEL_MODE_LCD | |
| * or FT_PIXEL_MODE_LCD_V | |
| * | |
| * @input: | |
| * filter_or_null :: handle to RGB filter object, or NULL to use the | |
| * default one provided with this library | |
| * | |
| * inverted :: boolean. Set to true if BGR or VBGR filtering is | |
| * needed. | |
| * | |
| * in_mode :: input bitmap pixel mode. must be either | |
| * @FT_PIXEL_MODE_LCD or @FT_PIXEL_MODE_LCD_V | |
| * | |
| * in_bytes :: first byte of input bitmap data in memory | |
| * in_pitch :: number of bytes in a row of input pixels. | |
| * can be negative | |
| * | |
| * out_width :: width in pixels of output bitmap | |
| * out_height :: width in pixels of output bitmap | |
| * | |
| * out_bytes :: first byte of output bitmap data in memory, this | |
| * is an array of 32-bit unsigned integer, storing | |
| * pixels values in ARGB8888 format | |
| * | |
| * out_pitch :: number of _bytes_ in a row of output pixels. can | |
| * be negative. Its absolute value must be greater | |
| * than 4*out_width | |
| * | |
| * @return: | |
| * error code. 0 means success | |
| * | |
| * @note: | |
| * this function returns an error if 'in_mode' isn't set to either | |
| * @FT_PIXEL_MODE_LCD or @FT_PIXEL_MODE_LCD_V, or if the values of | |
| * the parameters are incorrect. | |
| * | |
| * when 'in_mode' is @FT_PIXEL_MODE_LCD, this function assumes that the | |
| * width of the input bitmap is three times the output's one. otherwise, | |
| * it is identical. | |
| * | |
| * when 'in_mode' is @FT_PIXEL_MODE_LCD_V, this function assumes that | |
| * the height of the input bitmap is three times the output's one. otherwise | |
| * it is identical | |
| * | |
| * the absolute value on 'in_bytes' should always match the number of | |
| * _bytes_ in a row of input pixels. It can be negative however to | |
| * indicate "inverted" bitmap. See the description of the 'pitch' | |
| * field in @FT_Bitmap | |
| */ | |
| FT_EXPORT( FT_Error ) | |
| FT_RgbFilter_ApplyARGB( FT_RgbFilter filter_or_null, | |
| FT_Bool inverted, | |
| FT_Pixel_Mode in_mode, | |
| FT_Byte* in_bytes, | |
| FT_Long in_pitch, | |
| FT_Int out_width, | |
| FT_Int out_height, | |
| FT_UInt32* out_bytes, | |
| FT_Long out_pitch ); | |
| /** | |
| * @func: FT_RgbFilter_ApplyInPlace | |
| * | |
| * @description: | |
| * a variant of @FT_RgbFilter_ApplyARGB that performs filtering | |
| * within the input bitmap. It's up to the caller to convert the | |
| * result to a suitable color format. | |
| * | |
| * @input: | |
| * filter_or_null :: handle to RGB filter object, or NULL to use the | |
| * default one provided with this library | |
| * | |
| * inverted :: boolean. Set to true if BGR or VBGR filtering is | |
| * needed. | |
| * | |
| * in_mode :: input bitmap pixel mode. must be either | |
| * @FT_PIXEL_MODE_LCD or @FT_PIXEL_MODE_LCD_V | |
| * | |
| * in_bytes :: first byte of input bitmap data in memory | |
| * in_pitch :: number of bytes in a row of input pixels. can be negative | |
| * | |
| * org_width :: width in pixels of original glyph | |
| * org_height :: height in pixels of original glyph | |
| * | |
| * @return: | |
| * error code. 0 means success | |
| * | |
| * @note: | |
| * this function returns an error if 'in_mode' isn't set to either | |
| * @FT_PIXEL_MODE_LCD or @FT_PIXEL_MODE_LCD_V, or if the values of some | |
| * parameters are incorrect. | |
| * | |
| * when 'in_mode' is @FT_PIXEL_MODE_LCD, this function assumes that the | |
| * width of the input bitmap is three times 'org_width'. otherwise, | |
| * they're identical. | |
| * | |
| * when 'in_mode' is @FT_PIXEL_MODE_LCD_V, this function assumes that | |
| * the height of the input bitmap is three times 'org_height'. otherwise | |
| * they're identical. | |
| * | |
| * the absolute value on 'in_bytes' should always match the number of | |
| * _bytes_ in a row of input pixels. It can be negative however to | |
| * indicate "inverted" bitmap. See the description of the 'pitch' | |
| * field in @FT_Bitmap | |
| */ | |
| FT_EXPORT( FT_Error ) | |
| FT_RgbFilter_ApplyInPlace( FT_RgbFilter filter_or_null, | |
| FT_Bool inverted, | |
| FT_Pixel_Mode in_mode, | |
| FT_Byte* in_bytes, | |
| FT_Long in_pitch, | |
| FT_Int org_width, | |
| FT_Int org_height ); | |
| /** | |
| * @type: FT_RgbFilter | |
| * | |
| * @description: | |
| * create a new RGB filter object | |
| * | |
| * @input: | |
| * library :: handle to FreeType library instance | |
| * values_9 :: an array of 9 16.16 fixed float values | |
| * | |
| * @output: | |
| * pfilter :: handle to new filter object. NULL in case of error | |
| * | |
| * @return: | |
| * error code. 0 means success | |
| * | |
| * @note: | |
| * see the description of 'values_9' in @FT_RgbFilter_Reset. | |
| */ | |
| FT_EXPORT_DEF( FT_Error ) | |
| FT_RgbFilter_New( FT_Library library, | |
| FT_Fixed* values_9, | |
| FT_RgbFilter *pfilter ); | |
| /** | |
| * @type: FT_RgbFilter_Done | |
| * | |
| * @description: | |
| * destroy a given RGB filter object | |
| * | |
| * @input: | |
| * filter :: handle to target filter object | |
| */ | |
| FT_EXPORT( void ) | |
| FT_RgbFilter_Done( FT_RgbFilter filter ); | |
| /** | |
| * @type: FT_RgbFilter_Reset | |
| * | |
| * @description: | |
| * reset a given color filter object | |
| * | |
| * @input: | |
| * filter :: handle to target RGB filter | |
| * values_9 :: an array of 9 fixed-float multipliers used by the RGB | |
| * filter algorithm. | |
| * | |
| * @note: | |
| * the 9 values are used according to the following scheme, at least | |
| * for the 'normal' RGB decimation mode: | |
| * | |
| * { | |
| * red = pix[0]*values[0] + pix[1]*values[1] + pix[2]*values[2]; | |
| * green = pix[0]*values[3] + pix[1]*values[4] + pix[2]*values[5]; | |
| * blue = pix[0]*values[6] + pix[1]*values[7] + pix[2]*values[8]; | |
| * | |
| * red /= 65536; | |
| * green /= 65536; | |
| * blue /= 65536; | |
| * } | |
| * | |
| */ | |
| FT_EXPORT( void ) | |
| FT_RgbFilter_Reset( FT_RgbFilter filter, | |
| FT_Fixed* values_9 ); | |
| /* */ | |
| FT_END_HEADER | |
| #endif /* __FT_RGB_H__ */ |