/***************************************************************************/ | |
/* */ | |
/* ftoutln.h */ | |
/* */ | |
/* Support for the FT_Outline type used to store glyph shapes of */ | |
/* most scalable font formats (specification). */ | |
/* */ | |
/* Copyright 1996-2015 by */ | |
/* David Turner, Robert Wilhelm, and Werner Lemberg. */ | |
/* */ | |
/* This file is part of the FreeType project, and may only be used, */ | |
/* modified, and distributed under the terms of the FreeType project */ | |
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ | |
/* this file you indicate that you have read the license and */ | |
/* understand and accept it fully. */ | |
/* */ | |
/***************************************************************************/ | |
#ifndef __FTOUTLN_H__ | |
#define __FTOUTLN_H__ | |
#include <ft2build.h> | |
#include FT_FREETYPE_H | |
#ifdef FREETYPE_H | |
#error "freetype.h of FreeType 1 has been loaded!" | |
#error "Please fix the directory search order for header files" | |
#error "so that freetype.h of FreeType 2 is found first." | |
#endif | |
FT_BEGIN_HEADER | |
/*************************************************************************/ | |
/* */ | |
/* <Section> */ | |
/* outline_processing */ | |
/* */ | |
/* <Title> */ | |
/* Outline Processing */ | |
/* */ | |
/* <Abstract> */ | |
/* Functions to create, transform, and render vectorial glyph images. */ | |
/* */ | |
/* <Description> */ | |
/* This section contains routines used to create and destroy scalable */ | |
/* glyph images known as `outlines'. These can also be measured, */ | |
/* transformed, and converted into bitmaps and pixmaps. */ | |
/* */ | |
/* <Order> */ | |
/* FT_Outline */ | |
/* FT_Outline_New */ | |
/* FT_Outline_Done */ | |
/* FT_Outline_Copy */ | |
/* FT_Outline_Translate */ | |
/* FT_Outline_Transform */ | |
/* FT_Outline_Embolden */ | |
/* FT_Outline_EmboldenXY */ | |
/* FT_Outline_Reverse */ | |
/* FT_Outline_Check */ | |
/* */ | |
/* FT_Outline_Get_CBox */ | |
/* FT_Outline_Get_BBox */ | |
/* */ | |
/* FT_Outline_Get_Bitmap */ | |
/* FT_Outline_Render */ | |
/* FT_Outline_Decompose */ | |
/* FT_Outline_Funcs */ | |
/* FT_Outline_MoveToFunc */ | |
/* FT_Outline_LineToFunc */ | |
/* FT_Outline_ConicToFunc */ | |
/* FT_Outline_CubicToFunc */ | |
/* */ | |
/* FT_Orientation */ | |
/* FT_Outline_Get_Orientation */ | |
/* */ | |
/* FT_OUTLINE_XXX */ | |
/* */ | |
/*************************************************************************/ | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Decompose */ | |
/* */ | |
/* <Description> */ | |
/* Walk over an outline's structure to decompose it into individual */ | |
/* segments and Bézier arcs. This function also emits `move to' */ | |
/* operations to indicate the start of new contours in the outline. */ | |
/* */ | |
/* <Input> */ | |
/* outline :: A pointer to the source target. */ | |
/* */ | |
/* func_interface :: A table of `emitters', i.e., function pointers */ | |
/* called during decomposition to indicate path */ | |
/* operations. */ | |
/* */ | |
/* <InOut> */ | |
/* user :: A typeless pointer that is passed to each */ | |
/* emitter during the decomposition. It can be */ | |
/* used to store the state during the */ | |
/* decomposition. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* A contour that contains a single point only is represented by a */ | |
/* `move to' operation followed by `line to' to the same point. In */ | |
/* most cases, it is best to filter this out before using the */ | |
/* outline for stroking purposes (otherwise it would result in a */ | |
/* visible dot when round caps are used). */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Decompose( FT_Outline* outline, | |
const FT_Outline_Funcs* func_interface, | |
void* user ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_New */ | |
/* */ | |
/* <Description> */ | |
/* Create a new outline of a given size. */ | |
/* */ | |
/* <Input> */ | |
/* library :: A handle to the library object from where the */ | |
/* outline is allocated. Note however that the new */ | |
/* outline will *not* necessarily be *freed*, when */ | |
/* destroying the library, by @FT_Done_FreeType. */ | |
/* */ | |
/* numPoints :: The maximum number of points within the outline. */ | |
/* Must be smaller than or equal to 0xFFFF (65535). */ | |
/* */ | |
/* numContours :: The maximum number of contours within the outline. */ | |
/* This value must be in the range 0 to `numPoints'. */ | |
/* */ | |
/* <Output> */ | |
/* anoutline :: A handle to the new outline. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* The reason why this function takes a `library' parameter is simply */ | |
/* to use the library's memory allocator. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_New( FT_Library library, | |
FT_UInt numPoints, | |
FT_Int numContours, | |
FT_Outline *anoutline ); | |
FT_EXPORT( FT_Error ) | |
FT_Outline_New_Internal( FT_Memory memory, | |
FT_UInt numPoints, | |
FT_Int numContours, | |
FT_Outline *anoutline ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Done */ | |
/* */ | |
/* <Description> */ | |
/* Destroy an outline created with @FT_Outline_New. */ | |
/* */ | |
/* <Input> */ | |
/* library :: A handle of the library object used to allocate the */ | |
/* outline. */ | |
/* */ | |
/* outline :: A pointer to the outline object to be discarded. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* If the outline's `owner' field is not set, only the outline */ | |
/* descriptor will be released. */ | |
/* */ | |
/* The reason why this function takes an `library' parameter is */ | |
/* simply to use ft_mem_free(). */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Done( FT_Library library, | |
FT_Outline* outline ); | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Done_Internal( FT_Memory memory, | |
FT_Outline* outline ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Check */ | |
/* */ | |
/* <Description> */ | |
/* Check the contents of an outline descriptor. */ | |
/* */ | |
/* <Input> */ | |
/* outline :: A handle to a source outline. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Check( FT_Outline* outline ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Get_CBox */ | |
/* */ | |
/* <Description> */ | |
/* Return an outline's `control box'. The control box encloses all */ | |
/* the outline's points, including Bézier control points. Though it */ | |
/* coincides with the exact bounding box for most glyphs, it can be */ | |
/* slightly larger in some situations (like when rotating an outline */ | |
/* that contains Bézier outside arcs). */ | |
/* */ | |
/* Computing the control box is very fast, while getting the bounding */ | |
/* box can take much more time as it needs to walk over all segments */ | |
/* and arcs in the outline. To get the latter, you can use the */ | |
/* `ftbbox' component, which is dedicated to this single task. */ | |
/* */ | |
/* <Input> */ | |
/* outline :: A pointer to the source outline descriptor. */ | |
/* */ | |
/* <Output> */ | |
/* acbox :: The outline's control box. */ | |
/* */ | |
/* <Note> */ | |
/* See @FT_Glyph_Get_CBox for a discussion of tricky fonts. */ | |
/* */ | |
FT_EXPORT( void ) | |
FT_Outline_Get_CBox( const FT_Outline* outline, | |
FT_BBox *acbox ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Translate */ | |
/* */ | |
/* <Description> */ | |
/* Apply a simple translation to the points of an outline. */ | |
/* */ | |
/* <InOut> */ | |
/* outline :: A pointer to the target outline descriptor. */ | |
/* */ | |
/* <Input> */ | |
/* xOffset :: The horizontal offset. */ | |
/* */ | |
/* yOffset :: The vertical offset. */ | |
/* */ | |
FT_EXPORT( void ) | |
FT_Outline_Translate( const FT_Outline* outline, | |
FT_Pos xOffset, | |
FT_Pos yOffset ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Copy */ | |
/* */ | |
/* <Description> */ | |
/* Copy an outline into another one. Both objects must have the */ | |
/* same sizes (number of points & number of contours) when this */ | |
/* function is called. */ | |
/* */ | |
/* <Input> */ | |
/* source :: A handle to the source outline. */ | |
/* */ | |
/* <Output> */ | |
/* target :: A handle to the target outline. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Copy( const FT_Outline* source, | |
FT_Outline *target ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Transform */ | |
/* */ | |
/* <Description> */ | |
/* Apply a simple 2x2 matrix to all of an outline's points. Useful */ | |
/* for applying rotations, slanting, flipping, etc. */ | |
/* */ | |
/* <InOut> */ | |
/* outline :: A pointer to the target outline descriptor. */ | |
/* */ | |
/* <Input> */ | |
/* matrix :: A pointer to the transformation matrix. */ | |
/* */ | |
/* <Note> */ | |
/* You can use @FT_Outline_Translate if you need to translate the */ | |
/* outline's points. */ | |
/* */ | |
FT_EXPORT( void ) | |
FT_Outline_Transform( const FT_Outline* outline, | |
const FT_Matrix* matrix ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Embolden */ | |
/* */ | |
/* <Description> */ | |
/* Embolden an outline. The new outline will be at most 4~times */ | |
/* `strength' pixels wider and higher. You may think of the left and */ | |
/* bottom borders as unchanged. */ | |
/* */ | |
/* Negative `strength' values to reduce the outline thickness are */ | |
/* possible also. */ | |
/* */ | |
/* <InOut> */ | |
/* outline :: A handle to the target outline. */ | |
/* */ | |
/* <Input> */ | |
/* strength :: How strong the glyph is emboldened. Expressed in */ | |
/* 26.6 pixel format. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* The used algorithm to increase or decrease the thickness of the */ | |
/* glyph doesn't change the number of points; this means that certain */ | |
/* situations like acute angles or intersections are sometimes */ | |
/* handled incorrectly. */ | |
/* */ | |
/* If you need `better' metrics values you should call */ | |
/* @FT_Outline_Get_CBox or @FT_Outline_Get_BBox. */ | |
/* */ | |
/* Example call: */ | |
/* */ | |
/* { */ | |
/* FT_Load_Glyph( face, index, FT_LOAD_DEFAULT ); */ | |
/* if ( face->glyph->format == FT_GLYPH_FORMAT_OUTLINE ) */ | |
/* FT_Outline_Embolden( &face->glyph->outline, strength ); */ | |
/* } */ | |
/* */ | |
/* To get meaningful results, font scaling values must be set with */ | |
/* functions like @FT_Set_Char_Size before calling FT_Render_Glyph. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Embolden( FT_Outline* outline, | |
FT_Pos strength ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_EmboldenXY */ | |
/* */ | |
/* <Description> */ | |
/* Embolden an outline. The new outline will be `xstrength' pixels */ | |
/* wider and `ystrength' pixels higher. Otherwise, it is similar to */ | |
/* @FT_Outline_Embolden, which uses the same strength in both */ | |
/* directions. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_EmboldenXY( FT_Outline* outline, | |
FT_Pos xstrength, | |
FT_Pos ystrength ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Reverse */ | |
/* */ | |
/* <Description> */ | |
/* Reverse the drawing direction of an outline. This is used to */ | |
/* ensure consistent fill conventions for mirrored glyphs. */ | |
/* */ | |
/* <InOut> */ | |
/* outline :: A pointer to the target outline descriptor. */ | |
/* */ | |
/* <Note> */ | |
/* This function toggles the bit flag @FT_OUTLINE_REVERSE_FILL in */ | |
/* the outline's `flags' field. */ | |
/* */ | |
/* It shouldn't be used by a normal client application, unless it */ | |
/* knows what it is doing. */ | |
/* */ | |
FT_EXPORT( void ) | |
FT_Outline_Reverse( FT_Outline* outline ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Get_Bitmap */ | |
/* */ | |
/* <Description> */ | |
/* Render an outline within a bitmap. The outline's image is simply */ | |
/* OR-ed to the target bitmap. */ | |
/* */ | |
/* <Input> */ | |
/* library :: A handle to a FreeType library object. */ | |
/* */ | |
/* outline :: A pointer to the source outline descriptor. */ | |
/* */ | |
/* <InOut> */ | |
/* abitmap :: A pointer to the target bitmap descriptor. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* This function does NOT CREATE the bitmap, it only renders an */ | |
/* outline image within the one you pass to it! Consequently, the */ | |
/* various fields in `abitmap' should be set accordingly. */ | |
/* */ | |
/* It will use the raster corresponding to the default glyph format. */ | |
/* */ | |
/* The value of the `num_grays' field in `abitmap' is ignored. If */ | |
/* you select the gray-level rasterizer, and you want less than 256 */ | |
/* gray levels, you have to use @FT_Outline_Render directly. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Get_Bitmap( FT_Library library, | |
FT_Outline* outline, | |
const FT_Bitmap *abitmap ); | |
/*************************************************************************/ | |
/* */ | |
/* <Function> */ | |
/* FT_Outline_Render */ | |
/* */ | |
/* <Description> */ | |
/* Render an outline within a bitmap using the current scan-convert. */ | |
/* This function uses an @FT_Raster_Params structure as an argument, */ | |
/* allowing advanced features like direct composition, translucency, */ | |
/* etc. */ | |
/* */ | |
/* <Input> */ | |
/* library :: A handle to a FreeType library object. */ | |
/* */ | |
/* outline :: A pointer to the source outline descriptor. */ | |
/* */ | |
/* <InOut> */ | |
/* params :: A pointer to an @FT_Raster_Params structure used to */ | |
/* describe the rendering operation. */ | |
/* */ | |
/* <Return> */ | |
/* FreeType error code. 0~means success. */ | |
/* */ | |
/* <Note> */ | |
/* You should know what you are doing and how @FT_Raster_Params works */ | |
/* to use this function. */ | |
/* */ | |
/* The field `params.source' will be set to `outline' before the scan */ | |
/* converter is called, which means that the value you give to it is */ | |
/* actually ignored. */ | |
/* */ | |
/* The gray-level rasterizer always uses 256 gray levels. If you */ | |
/* want less gray levels, you have to provide your own span callback. */ | |
/* See the @FT_RASTER_FLAG_DIRECT value of the `flags' field in the */ | |
/* @FT_Raster_Params structure for more details. */ | |
/* */ | |
FT_EXPORT( FT_Error ) | |
FT_Outline_Render( FT_Library library, | |
FT_Outline* outline, | |
FT_Raster_Params* params ); | |
/************************************************************************** | |
* | |
* @enum: | |
* FT_Orientation | |
* | |
* @description: | |
* A list of values used to describe an outline's contour orientation. | |
* | |
* The TrueType and PostScript specifications use different conventions | |
* to determine whether outline contours should be filled or unfilled. | |
* | |
* @values: | |
* FT_ORIENTATION_TRUETYPE :: | |
* According to the TrueType specification, clockwise contours must | |
* be filled, and counter-clockwise ones must be unfilled. | |
* | |
* FT_ORIENTATION_POSTSCRIPT :: | |
* According to the PostScript specification, counter-clockwise contours | |
* must be filled, and clockwise ones must be unfilled. | |
* | |
* FT_ORIENTATION_FILL_RIGHT :: | |
* This is identical to @FT_ORIENTATION_TRUETYPE, but is used to | |
* remember that in TrueType, everything that is to the right of | |
* the drawing direction of a contour must be filled. | |
* | |
* FT_ORIENTATION_FILL_LEFT :: | |
* This is identical to @FT_ORIENTATION_POSTSCRIPT, but is used to | |
* remember that in PostScript, everything that is to the left of | |
* the drawing direction of a contour must be filled. | |
* | |
* FT_ORIENTATION_NONE :: | |
* The orientation cannot be determined. That is, different parts of | |
* the glyph have different orientation. | |
* | |
*/ | |
typedef enum FT_Orientation_ | |
{ | |
FT_ORIENTATION_TRUETYPE = 0, | |
FT_ORIENTATION_POSTSCRIPT = 1, | |
FT_ORIENTATION_FILL_RIGHT = FT_ORIENTATION_TRUETYPE, | |
FT_ORIENTATION_FILL_LEFT = FT_ORIENTATION_POSTSCRIPT, | |
FT_ORIENTATION_NONE | |
} FT_Orientation; | |
/************************************************************************** | |
* | |
* @function: | |
* FT_Outline_Get_Orientation | |
* | |
* @description: | |
* This function analyzes a glyph outline and tries to compute its | |
* fill orientation (see @FT_Orientation). This is done by integrating | |
* the total area covered by the outline. The positive integral | |
* corresponds to the clockwise orientation and @FT_ORIENTATION_POSTSCRIPT | |
* is returned. The negative integral corresponds to the counter-clockwise | |
* orientation and @FT_ORIENTATION_TRUETYPE is returned. | |
* | |
* Note that this will return @FT_ORIENTATION_TRUETYPE for empty | |
* outlines. | |
* | |
* @input: | |
* outline :: | |
* A handle to the source outline. | |
* | |
* @return: | |
* The orientation. | |
* | |
*/ | |
FT_EXPORT( FT_Orientation ) | |
FT_Outline_Get_Orientation( FT_Outline* outline ); | |
/* */ | |
FT_END_HEADER | |
#endif /* __FTOUTLN_H__ */ | |
/* END */ | |
/* Local Variables: */ | |
/* coding: utf-8 */ | |
/* End: */ |