diff options
Diffstat (limited to 'src/3rdparty/freetype/include/freetype/ftimage.h')
-rw-r--r-- | src/3rdparty/freetype/include/freetype/ftimage.h | 160 |
1 files changed, 100 insertions, 60 deletions
diff --git a/src/3rdparty/freetype/include/freetype/ftimage.h b/src/3rdparty/freetype/include/freetype/ftimage.h index face34fe49..7f2d721cdc 100644 --- a/src/3rdparty/freetype/include/freetype/ftimage.h +++ b/src/3rdparty/freetype/include/freetype/ftimage.h @@ -5,7 +5,7 @@ * FreeType glyph image formats and default raster interface * (specification). * - * Copyright (C) 1996-2019 by + * Copyright (C) 1996-2022 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * This file is part of the FreeType project, and may only be used, @@ -28,12 +28,6 @@ #define FTIMAGE_H_ - /* STANDALONE_ is from ftgrays.c */ -#ifndef STANDALONE_ -#include <ft2build.h> -#endif - - FT_BEGIN_HEADER @@ -202,6 +196,11 @@ FT_BEGIN_HEADER #define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2 #define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4 + /* */ + + /* For debugging, the @FT_Pixel_Mode enumeration must stay in sync */ + /* with the `pixel_modes` array in file `ftobjs.c`. */ + /************************************************************************** * @@ -401,6 +400,13 @@ FT_BEGIN_HEADER * if @FT_OUTLINE_IGNORE_DROPOUTS is set. See below for more * information. * + * FT_OUTLINE_OVERLAP :: + * [Since 2.10.3] This flag indicates that this outline contains + * overlapping contours and the anti-aliased renderer should perform + * oversampling to mitigate possible artifacts. This flag should _not_ + * be set for well designed glyphs without overlaps because it quadruples + * the rendering time. + * * 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. @@ -432,6 +438,7 @@ FT_BEGIN_HEADER #define FT_OUTLINE_IGNORE_DROPOUTS 0x8 #define FT_OUTLINE_SMART_DROPOUTS 0x10 #define FT_OUTLINE_INCLUDE_STUBS 0x20 +#define FT_OUTLINE_OVERLAP 0x40 #define FT_OUTLINE_HIGH_PRECISION 0x100 #define FT_OUTLINE_SINGLE_PASS 0x200 @@ -688,11 +695,13 @@ FT_BEGIN_HEADER * to get a simple enumeration without assigning special numbers. */ #ifndef FT_IMAGE_TAG -#define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) \ - value = ( ( (unsigned long)_x1 << 24 ) | \ - ( (unsigned long)_x2 << 16 ) | \ - ( (unsigned long)_x3 << 8 ) | \ - (unsigned long)_x4 ) + +#define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) \ + value = ( ( FT_STATIC_BYTE_CAST( unsigned long, _x1 ) << 24 ) | \ + ( FT_STATIC_BYTE_CAST( unsigned long, _x2 ) << 16 ) | \ + ( FT_STATIC_BYTE_CAST( unsigned long, _x3 ) << 8 ) | \ + FT_STATIC_BYTE_CAST( unsigned long, _x4 ) ) + #endif /* FT_IMAGE_TAG */ @@ -732,6 +741,10 @@ FT_BEGIN_HEADER * contours. Some Type~1 fonts, like those in the Hershey family, * contain glyphs in this format. These are described as @FT_Outline, * but FreeType isn't currently capable of rendering them correctly. + * + * FT_GLYPH_FORMAT_SVG :: + * [Since 2.12] The glyph is represented by an SVG document in the + * 'SVG~' table. */ typedef enum FT_Glyph_Format_ { @@ -740,7 +753,8 @@ FT_BEGIN_HEADER FT_IMAGE_TAG( FT_GLYPH_FORMAT_COMPOSITE, 'c', 'o', 'm', 'p' ), FT_IMAGE_TAG( FT_GLYPH_FORMAT_BITMAP, 'b', 'i', 't', 's' ), FT_IMAGE_TAG( FT_GLYPH_FORMAT_OUTLINE, 'o', 'u', 't', 'l' ), - FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't' ) + FT_IMAGE_TAG( FT_GLYPH_FORMAT_PLOTTER, 'p', 'l', 'o', 't' ), + FT_IMAGE_TAG( FT_GLYPH_FORMAT_SVG, 'S', 'V', 'G', ' ' ) } FT_Glyph_Format; @@ -765,17 +779,6 @@ FT_BEGIN_HEADER /*************************************************************************/ - /************************************************************************** - * - * A raster is a scan converter, in charge of rendering an outline into a - * bitmap. This section contains the public API for rasters. - * - * Note that in FreeType 2, all rasters are now encapsulated within - * specific modules called 'renderers'. See `ftrender.h` for more details - * on renderers. - * - */ - /************************************************************************** * @@ -789,16 +792,35 @@ FT_BEGIN_HEADER * How vectorial outlines are converted into bitmaps and pixmaps. * * @description: - * This section contains technical definitions. + * A raster or a rasterizer is a scan converter in charge of producing a + * pixel coverage bitmap that can be used as an alpha channel when + * compositing a glyph with a background. FreeType comes with two + * rasterizers: bilevel `raster1` and anti-aliased `smooth` are two + * separate modules. They are usually called from the high-level + * @FT_Load_Glyph or @FT_Render_Glyph functions and produce the entire + * coverage bitmap at once, while staying largely invisible to users. + * + * Instead of working with complete coverage bitmaps, it is also possible + * to intercept consecutive pixel runs on the same scanline with the same + * coverage, called _spans_, and process them individually. Only the + * `smooth` rasterizer permits this when calling @FT_Outline_Render with + * @FT_Raster_Params as described below. + * + * Working with either complete bitmaps or spans it is important to think + * of them as colorless coverage objects suitable as alpha channels to + * blend arbitrary colors with a background. For best results, it is + * recommended to use gamma correction, too. + * + * This section also describes the public API needed to set up alternative + * @FT_Renderer modules. * * @order: - * FT_Raster * FT_Span * FT_SpanFunc - * * FT_Raster_Params * FT_RASTER_FLAG_XXX * + * FT_Raster * FT_Raster_NewFunc * FT_Raster_DoneFunc * FT_Raster_ResetFunc @@ -811,24 +833,12 @@ FT_BEGIN_HEADER /************************************************************************** * - * @type: - * FT_Raster - * - * @description: - * An opaque 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 pixels when rendering - * an anti-aliased bitmap. + * A structure to model a single span of consecutive pixels when + * rendering an anti-aliased bitmap. * * @fields: * x :: @@ -845,8 +855,8 @@ FT_BEGIN_HEADER * This structure is used by the span drawing callback type named * @FT_SpanFunc that takes the y~coordinate of the span as a parameter. * - * The coverage value is always between 0 and 255. If you want less gray - * values, the callback function has to reduce them. + * The anti-aliased rasterizer produces coverage values from 0 to 255, + * this is, from completely transparent to completely opaque. */ typedef struct FT_Span_ { @@ -864,8 +874,8 @@ FT_BEGIN_HEADER * * @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. + * to let client applications draw themselves the pixel spans on each + * scan line. * * @input: * y :: @@ -881,11 +891,12 @@ FT_BEGIN_HEADER * 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 callback allows client applications to directly render the 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. + * background bitmap using alpha compositing. It can also be used for + * oversampling and averaging. */ typedef void (*FT_SpanFunc)( int y, @@ -955,11 +966,17 @@ FT_BEGIN_HEADER * will be clipped to a box specified in the `clip_box` field of the * @FT_Raster_Params structure. Otherwise, the `clip_box` is * effectively set to the bounding box and all spans are generated. + * + * FT_RASTER_FLAG_SDF :: + * This flag is set to indicate that a signed distance field glyph + * image should be generated. This is only used while rendering with + * the @FT_RENDER_MODE_SDF render mode. */ #define FT_RASTER_FLAG_DEFAULT 0x0 #define FT_RASTER_FLAG_AA 0x1 #define FT_RASTER_FLAG_DIRECT 0x2 #define FT_RASTER_FLAG_CLIP 0x4 +#define FT_RASTER_FLAG_SDF 0x8 /* these constants are deprecated; use the corresponding */ /* `FT_RASTER_FLAG_XXX` values instead */ @@ -1004,20 +1021,26 @@ FT_BEGIN_HEADER * User-supplied data that is passed to each drawing callback. * * clip_box :: - * An optional clipping box. It is only used in direct rendering mode. - * Note that coordinates here should be expressed in _integer_ pixels - * (and not in 26.6 fixed-point units). + * An optional span clipping box expressed in _integer_ pixels + * (not in 26.6 fixed-point units). * * @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 is - * generated. - * - * If the @FT_RASTER_FLAG_DIRECT bit flag is set in `flags`, the raster - * will call the `gray_spans` callback to draw gray pixel spans. This - * allows direct composition over a pre-existing bitmap through - * user-provided callbacks to perform the span drawing and composition. - * Not supported by the monochrome rasterizer. + * The @FT_RASTER_FLAG_AA bit flag must be set in the `flags` to + * generate an anti-aliased glyph bitmap, otherwise a monochrome bitmap + * is generated. The `target` should have appropriate pixel mode and its + * dimensions define the clipping region. + * + * If both @FT_RASTER_FLAG_AA and @FT_RASTER_FLAG_DIRECT bit flags + * are set in `flags`, the raster calls an @FT_SpanFunc callback + * `gray_spans` with `user` data as an argument ignoring `target`. This + * allows direct composition over a pre-existing user surface to perform + * the span drawing and composition. To optionally clip the spans, set + * the @FT_RASTER_FLAG_CLIP flag and `clip_box`. The monochrome raster + * does not support the direct mode. + * + * The gray-level rasterizer always uses 256 gray levels. If you want + * fewer gray levels, you have to use @FT_RASTER_FLAG_DIRECT and reduce + * the levels in the callback function. */ typedef struct FT_Raster_Params_ { @@ -1036,6 +1059,23 @@ FT_BEGIN_HEADER /************************************************************************** * + * @type: + * FT_Raster + * + * @description: + * An opaque handle (pointer) to a raster object. Each object can be + * used independently to convert an outline into a bitmap or pixmap. + * + * @note: + * In FreeType 2, all rasters are now encapsulated within specific + * @FT_Renderer modules and only used in their context. + * + */ + typedef struct FT_RasterRec_* FT_Raster; + + + /************************************************************************** + * * @functype: * FT_Raster_NewFunc * |