+++ /dev/null
-/***************************************************************************/
-/* */
-/* ftimage.h */
-/* */
-/* FreeType glyph image formats and default raster interface */
-/* (specification). */
-/* */
-/* Copyright 1996-2001 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. */
-/* */
-/***************************************************************************/
-
- /*************************************************************************/
- /* */
- /* Note: A `raster' is simply a scan-line converter, used to render */
- /* FT_Outlines into FT_Bitmaps. */
- /* */
- /*************************************************************************/
-
-
-#ifndef __FTIMAGE_H__
-#define __FTIMAGE_H__
-
-
-#include <ft2build.h>
-
-
-FT_BEGIN_HEADER
-
-
- /*************************************************************************/
- /* */
- /* <Section> */
- /* basic_types */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <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;
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FT_BBox */
- /* */
- /* <Description> */
- /* A structure used to hold an outline's bounding box, i.e., the */
- /* coordinates of its extrema in the horizontal and vertical */
- /* directions. */
- /* */
- /* <Fields> */
- /* xMin :: The horizontal minimum (left-most). */
- /* */
- /* yMin :: The vertical minimum (bottom-most). */
- /* */
- /* xMax :: The horizontal maximum (right-most). */
- /* */
- /* yMax :: The vertical maximum (top-most). */
- /* */
- typedef struct FT_BBox_
- {
- FT_Pos xMin, yMin;
- FT_Pos xMax, yMax;
-
- } FT_BBox;
-
-
- /*************************************************************************/
- /* */
- /* <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> */
- /* For now, the only pixel mode supported by FreeType are mono and */
- /* grays. However, drivers might be added in the future to support */
- /* more `colorful' options. */
- /* */
- /* 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 specification. */
- /* */
- /* 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;
- unsigned char* buffer;
- short num_grays;
- char pixel_mode;
- char palette_mode;
- void* palette;
-
- } FT_Bitmap;
-
-
- /*************************************************************************/
- /* */
- /* <Section> */
- /* outline_processing */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FT_Outline */
- /* */
- /* <Description> */
- /* This structure is used to describe an outline to the scan-line */
- /* converter. */
- /* */
- /* <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 set. */
- /* */
- /* 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 :: If 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. If set to */
- /* 1, the outline will be filled using */
- /* the even-odd fill rule (only works */
- /* with the smooth raster). */
- /* */
- /* 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 if */
- /* 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. */
- /* If 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. */
- /* */
- /* shift :: The shift that is applied to coordinates before they */
- /* are sent to the emitter. */
- /* */
- /* delta :: The delta that is applied to coordinates before they */
- /* are sent to the emitter, but after the shift. */
- /* */
- /* <Note> */
- /* The point coordinates sent to the emitters are the transformed */
- /* version of the original coordinates (this is important for high */
- /* accuracy during scan-conversion). The transformation is simple: */
- /* */
- /* x' = (x << shift) - delta */
- /* y' = (x << shift) - delta */
- /* */
- /* Set the value of `shift' and `delta' to 0 to get the original */
- /* point coordinates. */
- /* */
- 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;
-
-
- /*************************************************************************/
- /* */
- /* <Section> */
- /* basic_types */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <Macro> */
- /* FT_IMAGE_TAG */
- /* */
- /* <Description> */
- /* This macro converts four letter tags into an unsigned long. */
- /* */
-#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 )
-#endif /* FT_IMAGE_TAG */
-
-
- /*************************************************************************/
- /* */
- /* <Enum> */
- /* FT_Glyph_Format */
- /* */
- /* <Description> */
- /* An enumeration type used to describe the 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 unimplemented). */
- /* */
- /* 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_IMAGE_TAG( ft_glyph_format_none, 0, 0, 0, 0 ),
-
- 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_Glyph_Format;
-
-
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
- /***** *****/
- /***** R A S T E R D E F I N I T I O N S *****/
- /***** *****/
- /*************************************************************************/
- /*************************************************************************/
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* A raster is a scan converter, in charge of rendering an outline into */
- /* a 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 `freetype/ftrender.h' for */
- /* more details on renderers. */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <Section> */
- /* Raster */
- /* */
- /* <Title> */
- /* Scanline converter */
- /* */
- /* <Abstract> */
- /* How vectorial outlines are converted into bitmaps and pixmaps. */
- /* */
- /* <Description> */
- /* This section contains technical definitions. */
- /* */
- /*************************************************************************/
-
-
- /*************************************************************************/
- /* */
- /* <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 monochrome 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 parameter. */
- /* */
- /* 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 whether 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 */
- /* to set an individual target pixel. This is crucial to implement */
- /* drop-out control according to the TrueType specification. */
- /* */
- /* <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 to list the bit flags as used in the `flags' field */
- /* of a FT_Raster_Params structure. */
- /* */
- /* <Fields> */
- /* ft_raster_flag_default :: This value is 0. */
- /* */
- /* ft_raster_flag_aa :: This flag is set to indicate that an */
- /* anti-aliased glyph image should be */
- /* generated. Otherwise, it will be */
- /* monochrome (1-bit) */
- /* */
- /* ft_raster_flag_direct :: This flag is set to indicate direct */
- /* rendering. In this mode, client */
- /* applications must provide their own span */
- /* callback. This lets them directly */
- /* draw or compose over an existing bitmap. */
- /* If this bit is not set, the target */
- /* pixmap's buffer _must_ be zeroed before */
- /* rendering. */
- /* */
- /* Note that for now, direct rendering is */
- /* only possible with anti-aliased glyphs. */
- /* */
- /* ft_raster_flag_clip :: This flag is only used in direct */
- /* rendering mode. If set, the output will */
- /* be clipped to a box specified in the */
- /* "clip_box" field of the FT_Raster_Params */
- /* structure. */
- /* */
- /* Note that by default, the glyph bitmap */
- /* is clipped to the target pixmap, except */
- /* in direct rendering mode where all spans */
- /* are generated if no clipping box is set. */
- /* */
- typedef enum
- {
- ft_raster_flag_default = 0,
- ft_raster_flag_aa = 1,
- ft_raster_flag_direct = 2,
- ft_raster_flag_clip = 4
-
- } FT_Raster_Flag;
-
-
- /*************************************************************************/
- /* */
- /* <Struct> */
- /* FT_Raster_Params */
- /* */
- /* <Description> */
- /* A structure to hold the arguments used by a raster's render */
- /* function. */
- /* */
- /* <Fields> */
- /* target :: The target bitmap. */
- /* */
- /* source :: A pointer to the source glyph image (e.g. an */
- /* FT_Outline). */
- /* */
- /* flags :: The rendering flags. */
- /* */
- /* gray_spans :: The gray span drawing callback. */
- /* */
- /* black_spans :: The black span drawing callback. */
- /* */
- /* bit_test :: The bit test callback. */
- /* */
- /* bit_set :: The bit set callback. */
- /* */
- /* user :: 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> */
- /* 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. */
- /* */
- /* 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, in the case of an aa glyph bitmap, it will call */
- /* `black_spans', and `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 as defined in 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_BBox clip_box;
-
- } FT_Raster_Params;
-
-
- /*************************************************************************/
- /* */
- /* <FuncType> */
- /* FT_Raster_New_Func */
- /* */
- /* <Description> */
- /* A function used to create a new raster object. */
- /* */
- /* <Input> */
- /* memory :: A handle to the memory allocator. */
- /* */
- /* <Output> */
- /* raster :: A handle to the 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 :: A handle to the 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 :: A handle to the new raster object. */
- /* */
- /* pool_base :: The address in memory of the render pool. */
- /* */
- /* pool_size :: The size in bytes of the 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,
- unsigned char* pool_base,
- unsigned 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 :: A handle to the 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 :: A handle to the raster object. */
- /* */
- /* params :: A 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 if 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 :: A function to render 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;
-
-
- /* */
-
-
-FT_END_HEADER
-
-#endif /* __FTIMAGE_H__ */
-
-
-/* END */
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