diff options
Diffstat (limited to 'src/3rdparty/freetype/include/freetype/ftimage.h')
| -rw-r--r-- | src/3rdparty/freetype/include/freetype/ftimage.h | 1771 |
1 files changed, 902 insertions, 869 deletions
diff --git a/src/3rdparty/freetype/include/freetype/ftimage.h b/src/3rdparty/freetype/include/freetype/ftimage.h index 79ede1959d..face34fe49 100644 --- a/src/3rdparty/freetype/include/freetype/ftimage.h +++ b/src/3rdparty/freetype/include/freetype/ftimage.h @@ -1,27 +1,27 @@ -/***************************************************************************/ -/* */ -/* ftimage.h */ -/* */ -/* FreeType glyph image formats and default raster interface */ -/* (specification). */ -/* */ -/* Copyright 1996-2018 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. */ - /* */ - /*************************************************************************/ +/**************************************************************************** + * + * ftimage.h + * + * FreeType glyph image formats and default raster interface + * (specification). + * + * Copyright (C) 1996-2019 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_ @@ -37,40 +37,42 @@ 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. */ - /* */ + /************************************************************************** + * + * @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. */ - /* */ + /************************************************************************** + * + * @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; @@ -79,39 +81,41 @@ FT_BEGIN_HEADER } 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. */ - /* */ + /************************************************************************** + * + * @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; @@ -120,63 +124,60 @@ FT_BEGIN_HEADER } 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 :: */ - /* [Since 2.5] 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. */ - /* */ + /************************************************************************** + * + * @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 :: + * [Since 2.5] 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, @@ -193,7 +194,7 @@ FT_BEGIN_HEADER } FT_Pixel_Mode; - /* these constants are deprecated; use the corresponding `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 @@ -202,62 +203,61 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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; @@ -272,65 +272,68 @@ FT_BEGIN_HEADER } 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' if */ - /* 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. */ - /* */ - /* 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. */ - /* */ + /************************************************************************** + * + * @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' if 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. + * + * 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 */ @@ -352,78 +355,76 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @enum: + * FT_OUTLINE_XXX + * + * @description: + * A list of bit-field constants used 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 @@ -437,7 +438,7 @@ FT_BEGIN_HEADER /* these constants are deprecated; use the corresponding */ - /* `FT_OUTLINE_XXX' values instead */ + /* `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 @@ -448,20 +449,25 @@ FT_BEGIN_HEADER /* */ -#define FT_CURVE_TAG( flag ) ( flag & 3 ) +#define FT_CURVE_TAG( flag ) ( flag & 0x03 ) -#define FT_CURVE_TAG_ON 1 -#define FT_CURVE_TAG_CONIC 0 -#define FT_CURVE_TAG_CUBIC 2 + /* see the `tags` field in `FT_Outline` for a description of the values */ +#define FT_CURVE_TAG_ON 0x01 +#define FT_CURVE_TAG_CONIC 0x00 +#define FT_CURVE_TAG_CUBIC 0x02 -#define FT_CURVE_TAG_HAS_SCANMODE 4 +#define FT_CURVE_TAG_HAS_SCANMODE 0x04 -#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_X 0x08 /* reserved for TrueType hinter */ +#define FT_CURVE_TAG_TOUCH_Y 0x10 /* reserved for TrueType hinter */ #define FT_CURVE_TAG_TOUCH_BOTH ( FT_CURVE_TAG_TOUCH_X | \ FT_CURVE_TAG_TOUCH_Y ) + /* values 0x20, 0x40, and 0x80 are reserved */ + + /* these constants are deprecated; use the corresponding */ + /* `FT_CURVE_TAG_XXX` values instead */ #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 @@ -469,26 +475,28 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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 ); @@ -496,26 +504,28 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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 ); @@ -523,30 +533,33 @@ FT_BEGIN_HEADER #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 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. */ - /* */ + /************************************************************************** + * + * @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 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_ConicToFunc)( const FT_Vector* control, const FT_Vector* to, @@ -555,30 +568,34 @@ FT_BEGIN_HEADER #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 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. */ - /* */ + /************************************************************************** + * + * @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 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_CubicToFunc)( const FT_Vector* control1, const FT_Vector* control2, @@ -588,43 +605,49 @@ FT_BEGIN_HEADER #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 Beziers. */ - /* */ - /* <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' = (y << shift) - delta */ - /* } */ - /* */ - /* Set the values of `shift' and `delta' to~0 to get the original */ - /* point coordinates. */ - /* */ + /************************************************************************** + * + * @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. + * + * @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' = (y << 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; @@ -638,33 +661,32 @@ FT_BEGIN_HEADER } 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. */ - /* */ + /************************************************************************** + * + * @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 ) | \ @@ -674,44 +696,43 @@ FT_BEGIN_HEADER #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 Bezier 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. */ - /* */ + /************************************************************************** + * + * @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 + * Bezier 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 ), @@ -725,7 +746,7 @@ FT_BEGIN_HEADER /* these constants are deprecated; use the corresponding */ - /* `FT_Glyph_Format' values instead. */ + /* `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 @@ -744,87 +765,89 @@ 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. */ - /* */ - /*************************************************************************/ - - - /*************************************************************************/ - /* */ - /* <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. */ - /* */ + /************************************************************************** + * + * 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. */ - /* */ + /************************************************************************** + * + * @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; @@ -834,32 +857,36 @@ FT_BEGIN_HEADER } 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. */ - /* */ + /************************************************************************** + * + * @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 upward 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. + */ typedef void (*FT_SpanFunc)( int y, int count, @@ -869,131 +896,129 @@ FT_BEGIN_HEADER #define FT_Raster_Span_Func FT_SpanFunc - /*************************************************************************/ - /* */ - /* <FuncType> */ - /* FT_Raster_BitTest_Func */ - /* */ - /* <Description> */ - /* Deprecated, unimplemented. */ - /* */ + /************************************************************************** + * + * @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. */ - /* */ + /************************************************************************** + * + * @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. */ - /* */ + /************************************************************************** + * + * @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 and the output will be clipped to its size. + * + * 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. Otherwise, the `clip_box` is + * effectively set to the bounding box and all spans are generated. + */ #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 */ + /* `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. */ - /* */ + /************************************************************************** + * + * @struct: + * FT_Raster_Params + * + * @description: + * A structure to hold the parameters used by a raster's render function, + * passed as an argument to @FT_Outline_Render. + * + * @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; @@ -1009,30 +1034,32 @@ FT_BEGIN_HEADER } 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. */ - /* */ + /************************************************************************** + * + * @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 ); @@ -1040,49 +1067,52 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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 rasterizers. This was not */ - /* thread safe, however, and now FreeType never allocates this pool. */ - /* */ - /* This function is called after a new raster object is created. */ - /* */ - /* <Input> */ - /* raster :: A handle to the new raster object. */ - /* */ - /* pool_base :: Previously, the address in memory of the render pool. */ - /* Set this to NULL. */ - /* */ - /* pool_size :: Previously, the size in bytes of the render pool. */ - /* Set this to 0. */ - /* */ - /* <Note> */ - /* Rasterizers should rely on dynamic or stack allocation if they */ - /* want to (a handle to the memory allocator is passed to the */ - /* rasterizer constructor). */ - /* */ + /************************************************************************** + * + * @functype: + * FT_Raster_ResetFunc + * + * @description: + * FreeType used to provide an area of memory called the 'render pool' + * available to all registered rasterizers. This was not thread safe, + * however, and now FreeType never allocates this pool. + * + * This function is called after a new raster object is created. + * + * @input: + * raster :: + * A handle to the new raster object. + * + * pool_base :: + * Previously, the address in memory of the render pool. Set this to + * `NULL`. + * + * pool_size :: + * Previously, the size in bytes of the render pool. Set this to 0. + * + * @note: + * Rasterizers should rely on dynamic or stack allocation if they want to + * (a handle to the memory allocator is passed to the rasterizer + * constructor). + */ typedef void (*FT_Raster_ResetFunc)( FT_Raster raster, unsigned char* pool_base, @@ -1091,24 +1121,26 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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, @@ -1117,40 +1149,36 @@ FT_BEGIN_HEADER #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). */ - /* */ + /************************************************************************** + * + * @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. + */ typedef int (*FT_Raster_RenderFunc)( FT_Raster raster, const FT_Raster_Params* params ); @@ -1158,25 +1186,30 @@ FT_BEGIN_HEADER #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. */ - /* */ + /************************************************************************** + * + * @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; |