ref: 9d179e3d7038a9730527f65cebc9c52012d771f2
dir: /include/freetype/ftimage.h/
/***************************************************************************/
/* */
/* ftimage.h */
/* */
/* FreeType glyph image formats and default raster interface */
/* (specification). */
/* */
/* Copyright 1996-2016 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_
/* STANDALONE_ is from ftgrays.c */
#ifndef STANDALONE_
#include <ft2build.h>
#endif
FT_BEGIN_HEADER
/*************************************************************************/
/* */
/* <Section> */
/* basic_types */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <Type> */
/* FT_Pos */
/* */
/* <Description> */
/* The type FT_Pos is used to store vectorial coordinates. Depending */
/* on the context, these can represent distances in integer font */
/* units, or 16.16, or 26.6 fixed-point 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). */
/* */
/* <Note> */
/* The bounding box is specified with the coordinates of the lower */
/* left and the upper right corner. In PostScript, those values are */
/* often called (llx,lly) and (urx,ury), respectively. */
/* */
/* If `yMin' is negative, this value gives the glyph's descender. */
/* Otherwise, the glyph doesn't descend below the baseline. */
/* Similarly, if `ymax' is positive, this value gives the glyph's */
/* ascender. */
/* */
/* `xMin' gives the horizontal distance from the glyph's origin to */
/* the left edge of the glyph's bounding box. If `xMin' is negative, */
/* the glyph extends to the left of the origin. */
/* */
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. */
/* */
/* <Values> */
/* FT_PIXEL_MODE_NONE :: */
/* Value~0 is reserved. */
/* */
/* FT_PIXEL_MODE_MONO :: */
/* A monochrome bitmap, using 1~bit per pixel. Note that pixels */
/* are stored in most-significant order (MSB), which means that */
/* the left-most pixel in a byte has value 128. */
/* */
/* FT_PIXEL_MODE_GRAY :: */
/* An 8-bit bitmap, generally used to represent anti-aliased glyph */
/* images. Each pixel is stored in one byte. Note that the number */
/* of `gray' levels is stored in the `num_grays' field of the */
/* @FT_Bitmap structure (it generally is 256). */
/* */
/* FT_PIXEL_MODE_GRAY2 :: */
/* A 2-bit per pixel bitmap, used to represent embedded */
/* anti-aliased bitmaps in font files according to the OpenType */
/* specification. We haven't found a single font using this */
/* format, however. */
/* */
/* FT_PIXEL_MODE_GRAY4 :: */
/* A 4-bit per pixel bitmap, representing embedded anti-aliased */
/* bitmaps in font files according to the OpenType specification. */
/* We haven't found a single font using this format, however. */
/* */
/* FT_PIXEL_MODE_LCD :: */
/* An 8-bit bitmap, representing RGB or BGR decimated glyph images */
/* used for display on LCD displays; the bitmap is three times */
/* wider than the original glyph image. See also */
/* @FT_RENDER_MODE_LCD. */
/* */
/* FT_PIXEL_MODE_LCD_V :: */
/* An 8-bit bitmap, representing RGB or BGR decimated glyph images */
/* used for display on rotated LCD displays; the bitmap is three */
/* times taller than the original glyph image. See also */
/* @FT_RENDER_MODE_LCD_V. */
/* */
/* FT_PIXEL_MODE_BGRA :: */
/* An image with four 8-bit channels per pixel, representing a */
/* color image (such as emoticons) with alpha channel. For each */
/* pixel, the format is BGRA, which means, the blue channel comes */
/* first in memory. The color channels are pre-multiplied and in */
/* the sRGB colorspace. For example, full red at half-translucent */
/* opacity will be represented as `00,00,80,80', not `00,00,FF,80'. */
/* See also @FT_LOAD_COLOR. */
/* */
typedef enum FT_Pixel_Mode_
{
FT_PIXEL_MODE_NONE = 0,
FT_PIXEL_MODE_MONO,
FT_PIXEL_MODE_GRAY,
FT_PIXEL_MODE_GRAY2,
FT_PIXEL_MODE_GRAY4,
FT_PIXEL_MODE_LCD,
FT_PIXEL_MODE_LCD_V,
FT_PIXEL_MODE_BGRA,
FT_PIXEL_MODE_MAX /* do not remove */
} FT_Pixel_Mode;
/* these constants are deprecated; use the corresponding `FT_Pixel_Mode' */
/* values instead. */
#define ft_pixel_mode_none FT_PIXEL_MODE_NONE
#define ft_pixel_mode_mono FT_PIXEL_MODE_MONO
#define ft_pixel_mode_grays FT_PIXEL_MODE_GRAY
#define ft_pixel_mode_pal2 FT_PIXEL_MODE_GRAY2
#define ft_pixel_mode_pal4 FT_PIXEL_MODE_GRAY4
/*************************************************************************/
/* */
/* <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. */
/* */
/* Note that `padding' means the alignment of a */
/* bitmap to a byte border, and FreeType functions */
/* normally align to the smallest possible integer */
/* value. */
/* */
/* For the B/W rasterizer, `pitch' is always an even */
/* number. */
/* */
/* To change the pitch of a bitmap (say, to make it a */
/* multiple of 4), use @FT_Bitmap_Convert. */
/* Alternatively, you might use callback functions to */
/* directly render to the application's surface; see */
/* the file `example2.cpp' in the tutorial for a */
/* demonstration. */
/* */
/* 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_GRAY; it gives the number of gray */
/* levels used in the bitmap. */
/* */
/* pixel_mode :: The pixel mode, i.e., how pixel bits are stored. */
/* See @FT_Pixel_Mode for possible values. */
/* */
/* palette_mode :: This field is intended for paletted pixel modes; */
/* it indicates how the palette is stored. Not */
/* used currently. */
/* */
/* palette :: A typeless pointer to the bitmap palette; this */
/* field is intended for paletted pixel modes. Not */
/* used currently. */
/* */
typedef struct FT_Bitmap_
{
unsigned int rows;
unsigned int width;
int pitch;
unsigned char* buffer;
unsigned short num_grays;
unsigned char pixel_mode;
unsigned 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 Bézier control point, while it is `on' if */
/* set. */
/* */
/* Bit~1 is meaningful for `off' points only. If set, */
/* it indicates a third-order Bézier arc control point; */
/* and a second-order control point if unset. */
/* */
/* If bit~2 is set, bits 5-7 contain the drop-out mode */
/* (as defined in the OpenType specification; the value */
/* is the same as the argument to the SCANMODE */
/* instruction). */
/* */
/* Bits 3 and~4 are reserved for internal purposes. */
/* */
/* 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_XXX. */
/* */
/* <Note> */
/* The B/W rasterizer only checks bit~2 in the `tags' array for the */
/* first point of each contour. The drop-out mode as given with */
/* @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, and */
/* @FT_OUTLINE_INCLUDE_STUBS in `flags' is then overridden. */
/* */
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;
/* */
/* Following limits must be consistent with */
/* FT_Outline.{n_contours,n_points} */
#define FT_OUTLINE_CONTOURS_MAX SHRT_MAX
#define FT_OUTLINE_POINTS_MAX SHRT_MAX
/*************************************************************************/
/* */
/* <Enum> */
/* FT_OUTLINE_XXX */
/* */
/* <Description> */
/* A list of bit-field constants use for the flags in an outline's */
/* `flags' field. */
/* */
/* <Values> */
/* FT_OUTLINE_NONE :: */
/* Value~0 is reserved. */
/* */
/* FT_OUTLINE_OWNER :: */
/* If set, this flag indicates that the outline's field arrays */
/* (i.e., `points', `flags', and `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 rasterizer). */
/* */
/* 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. */
/* */
/* 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. See below for more information. */
/* */
/* FT_OUTLINE_SMART_DROPOUTS :: */
/* Select smart dropout control. If unset, use simple dropout */
/* control. Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See */
/* below for more information. */
/* */
/* FT_OUTLINE_INCLUDE_STUBS :: */
/* If set, turn pixels on for `stubs', otherwise exclude them. */
/* Ignored if @FT_OUTLINE_IGNORE_DROPOUTS is set. See below for */
/* more information. */
/* */
/* 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. */
/* */
/* <Note> */
/* The flags @FT_OUTLINE_IGNORE_DROPOUTS, @FT_OUTLINE_SMART_DROPOUTS, */
/* and @FT_OUTLINE_INCLUDE_STUBS are ignored by the smooth */
/* rasterizer. */
/* */
/* There exists a second mechanism to pass the drop-out mode to the */
/* B/W rasterizer; see the `tags' field in @FT_Outline. */
/* */
/* Please refer to the description of the `SCANTYPE' instruction in */
/* the OpenType specification (in file `ttinst1.doc') how simple */
/* drop-outs, smart drop-outs, and stubs are defined. */
/* */
#define FT_OUTLINE_NONE 0x0
#define FT_OUTLINE_OWNER 0x1
#define FT_OUTLINE_EVEN_ODD_FILL 0x2
#define FT_OUTLINE_REVERSE_FILL 0x4
#define FT_OUTLINE_IGNORE_DROPOUTS 0x8
#define FT_OUTLINE_SMART_DROPOUTS 0x10
#define FT_OUTLINE_INCLUDE_STUBS 0x20
#define FT_OUTLINE_HIGH_PRECISION 0x100
#define FT_OUTLINE_SINGLE_PASS 0x200
/* these constants are deprecated; use the corresponding */
/* `FT_OUTLINE_XXX' values instead */
#define ft_outline_none FT_OUTLINE_NONE
#define ft_outline_owner FT_OUTLINE_OWNER
#define ft_outline_even_odd_fill FT_OUTLINE_EVEN_ODD_FILL
#define ft_outline_reverse_fill FT_OUTLINE_REVERSE_FILL
#define ft_outline_ignore_dropouts FT_OUTLINE_IGNORE_DROPOUTS
#define ft_outline_high_precision FT_OUTLINE_HIGH_PRECISION
#define ft_outline_single_pass FT_OUTLINE_SINGLE_PASS
/* */
#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_HAS_SCANMODE 4
#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 )
#define FT_Curve_Tag_On FT_CURVE_TAG_ON
#define FT_Curve_Tag_Conic FT_CURVE_TAG_CONIC
#define FT_Curve_Tag_Cubic FT_CURVE_TAG_CUBIC
#define FT_Curve_Tag_Touch_X FT_CURVE_TAG_TOUCH_X
#define FT_Curve_Tag_Touch_Y FT_CURVE_TAG_TOUCH_Y
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Outline_MoveToFunc */
/* */
/* <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_MoveToFunc)( const FT_Vector* to,
void* user );
#define FT_Outline_MoveTo_Func FT_Outline_MoveToFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Outline_LineToFunc */
/* */
/* <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_LineToFunc)( const FT_Vector* to,
void* user );
#define FT_Outline_LineTo_Func FT_Outline_LineToFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Outline_ConicToFunc */
/* */
/* <Description> */
/* A function pointer type used to describe the signature of a `conic */
/* to' function during outline walking or decomposition. */
/* */
/* A `conic to' is emitted to indicate a second-order Bézier 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_ConicToFunc)( const FT_Vector* control,
const FT_Vector* to,
void* user );
#define FT_Outline_ConicTo_Func FT_Outline_ConicToFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Outline_CubicToFunc */
/* */
/* <Description> */
/* A function pointer type used to describe the signature of a `cubic */
/* to' function during outline walking or decomposition. */
/* */
/* A `cubic to' is emitted to indicate a third-order Bézier arc. */
/* */
/* <Input> */
/* control1 :: A pointer to the first Bézier control point. */
/* */
/* control2 :: A pointer to the second Bézier 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_CubicToFunc)( const FT_Vector* control1,
const FT_Vector* control2,
const FT_Vector* to,
void* user );
#define FT_Outline_CubicTo_Func FT_Outline_CubicToFunc
/*************************************************************************/
/* */
/* <Struct> */
/* FT_Outline_Funcs */
/* */
/* <Description> */
/* A structure to hold various function pointers used during outline */
/* decomposition in order to emit segments, conic, and cubic Béziers. */
/* */
/* <Fields> */
/* move_to :: The `move to' emitter. */
/* */
/* line_to :: The segment emitter. */
/* */
/* conic_to :: The second-order Bézier arc emitter. */
/* */
/* cubic_to :: The third-order Bézier 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 values of `shift' and `delta' to~0 to get the original */
/* point coordinates. */
/* */
typedef struct FT_Outline_Funcs_
{
FT_Outline_MoveToFunc move_to;
FT_Outline_LineToFunc line_to;
FT_Outline_ConicToFunc conic_to;
FT_Outline_CubicToFunc cubic_to;
int shift;
FT_Pos delta;
} FT_Outline_Funcs;
/*************************************************************************/
/* */
/* <Section> */
/* basic_types */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <Macro> */
/* FT_IMAGE_TAG */
/* */
/* <Description> */
/* This macro converts four-letter tags to an unsigned long type. */
/* */
/* <Note> */
/* Since many 16-bit compilers don't like 32-bit enumerations, you */
/* should redefine this macro in case of problems to something like */
/* this: */
/* */
/* { */
/* #define FT_IMAGE_TAG( value, _x1, _x2, _x3, _x4 ) value */
/* } */
/* */
/* 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 )
#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. */
/* */
/* <Values> */
/* FT_GLYPH_FORMAT_NONE :: */
/* The value~0 is reserved. */
/* */
/* FT_GLYPH_FORMAT_COMPOSITE :: */
/* The glyph image is a composite of several other images. This */
/* format is _only_ used with @FT_LOAD_NO_RECURSE, and is used to */
/* report compound glyphs (like accented characters). */
/* */
/* FT_GLYPH_FORMAT_BITMAP :: */
/* The glyph image is a bitmap, and can be described as an */
/* @FT_Bitmap. You generally need to access the `bitmap' field of */
/* the @FT_GlyphSlotRec structure to read it. */
/* */
/* FT_GLYPH_FORMAT_OUTLINE :: */
/* The glyph image is a vectorial outline made of line segments */
/* and Bézier arcs; it can be described as an @FT_Outline; you */
/* generally want to access the `outline' field of the */
/* @FT_GlyphSlotRec structure to read it. */
/* */
/* FT_GLYPH_FORMAT_PLOTTER :: */
/* The glyph image is a vectorial path with no inside and outside */
/* 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. */
/* */
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;
/* these constants are deprecated; use the corresponding */
/* `FT_Glyph_Format' values instead. */
#define ft_glyph_format_none FT_GLYPH_FORMAT_NONE
#define ft_glyph_format_composite FT_GLYPH_FORMAT_COMPOSITE
#define ft_glyph_format_bitmap FT_GLYPH_FORMAT_BITMAP
#define ft_glyph_format_outline FT_GLYPH_FORMAT_OUTLINE
#define ft_glyph_format_plotter FT_GLYPH_FORMAT_PLOTTER
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** 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 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. */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <Section> */
/* raster */
/* */
/* <Title> */
/* Scanline Converter */
/* */
/* <Abstract> */
/* How vectorial outlines are converted into bitmaps and pixmaps. */
/* */
/* <Description> */
/* This section contains technical definitions. */
/* */
/* <Order> */
/* FT_Raster */
/* FT_Span */
/* FT_SpanFunc */
/* */
/* FT_Raster_Params */
/* FT_RASTER_FLAG_XXX */
/* */
/* FT_Raster_NewFunc */
/* FT_Raster_DoneFunc */
/* FT_Raster_ResetFunc */
/* FT_Raster_SetModeFunc */
/* FT_Raster_RenderFunc */
/* FT_Raster_Funcs */
/* */
/*************************************************************************/
/*************************************************************************/
/* */
/* <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. */
/* */
/* <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). */
/* */
/* <Note> */
/* 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. */
/* */
typedef struct FT_Span_
{
short x;
unsigned short len;
unsigned char coverage;
} FT_Span;
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_SpanFunc */
/* */
/* <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 is 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_SpanFunc)( int y,
int count,
const FT_Span* spans,
void* user );
#define FT_Raster_Span_Func FT_SpanFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_BitTest_Func */
/* */
/* <Description> */
/* Deprecated, unimplemented. */
/* */
typedef int
(*FT_Raster_BitTest_Func)( int y,
int x,
void* user );
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_BitSet_Func */
/* */
/* <Description> */
/* Deprecated, unimplemented. */
/* */
typedef void
(*FT_Raster_BitSet_Func)( int y,
int x,
void* user );
/*************************************************************************/
/* */
/* <Enum> */
/* FT_RASTER_FLAG_XXX */
/* */
/* <Description> */
/* A list of bit flag constants as used in the `flags' field of a */
/* @FT_Raster_Params structure. */
/* */
/* <Values> */
/* 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. */
/* */
/* 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. */
/* */
#define FT_RASTER_FLAG_DEFAULT 0x0
#define FT_RASTER_FLAG_AA 0x1
#define FT_RASTER_FLAG_DIRECT 0x2
#define FT_RASTER_FLAG_CLIP 0x4
/* these constants are deprecated; use the corresponding */
/* `FT_RASTER_FLAG_XXX' values instead */
#define ft_raster_flag_default FT_RASTER_FLAG_DEFAULT
#define ft_raster_flag_aa FT_RASTER_FLAG_AA
#define ft_raster_flag_direct FT_RASTER_FLAG_DIRECT
#define ft_raster_flag_clip FT_RASTER_FLAG_CLIP
/*************************************************************************/
/* */
/* <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 :: Unused. */
/* */
/* bit_test :: Unused. */
/* */
/* bit_set :: Unused. */
/* */
/* 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 that coordinates here */
/* should be expressed in _integer_ pixels (and 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. */
/* */
typedef struct FT_Raster_Params_
{
const FT_Bitmap* target;
const void* source;
int flags;
FT_SpanFunc gray_spans;
FT_SpanFunc black_spans; /* unused */
FT_Raster_BitTest_Func bit_test; /* unused */
FT_Raster_BitSet_Func bit_set; /* unused */
void* user;
FT_BBox clip_box;
} FT_Raster_Params;
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_NewFunc */
/* */
/* <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 an @FT_Memory object, 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_NewFunc)( void* memory,
FT_Raster* raster );
#define FT_Raster_New_Func FT_Raster_NewFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_DoneFunc */
/* */
/* <Description> */
/* A function used to destroy a given raster object. */
/* */
/* <Input> */
/* raster :: A handle to the raster object. */
/* */
typedef void
(*FT_Raster_DoneFunc)( FT_Raster raster );
#define FT_Raster_Done_Func FT_Raster_DoneFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_ResetFunc */
/* */
/* <Description> */
/* FreeType used to provide an area of memory called the `render */
/* pool' available to all registered rasters. This was not thread */
/* safe however and now FreeType never allocates this pool. NULL */
/* is always passed in as pool_base. */
/* */
/* 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 should ignore the render pool and rely on dynamic or stack */
/* allocation if they want to (a handle to the memory allocator is */
/* passed to the raster constructor). */
/* */
typedef void
(*FT_Raster_ResetFunc)( FT_Raster raster,
unsigned char* pool_base,
unsigned long pool_size );
#define FT_Raster_Reset_Func FT_Raster_ResetFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_SetModeFunc */
/* */
/* <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_SetModeFunc)( FT_Raster raster,
unsigned long mode,
void* args );
#define FT_Raster_Set_Mode_Func FT_Raster_SetModeFunc
/*************************************************************************/
/* */
/* <FuncType> */
/* FT_Raster_RenderFunc */
/* */
/* <Description> */
/* Invoke 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 an @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 that support direct */
/* composition). */
/* */
typedef int
(*FT_Raster_RenderFunc)( FT_Raster raster,
const FT_Raster_Params* params );
#define FT_Raster_Render_Func FT_Raster_RenderFunc
/*************************************************************************/
/* */
/* <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_NewFunc raster_new;
FT_Raster_ResetFunc raster_reset;
FT_Raster_SetModeFunc raster_set_mode;
FT_Raster_RenderFunc raster_render;
FT_Raster_DoneFunc raster_done;
} FT_Raster_Funcs;
/* */
FT_END_HEADER
#endif /* FTIMAGE_H_ */
/* END */
/* Local Variables: */
/* coding: utf-8 */
/* End: */