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/***************************************************************************/
/*
*/
/* ftoutln.h
*/
/*
*/
/* Support for the FT_Outline type used to store glyph shapes of
*/
/* most scalable font formats (specification).
*/
/*
*/
/* Copyright 1996-2017 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).
*/
/*
*/
/* Similarly, the function returns success for an empty outline also
*/
/* (doing nothing, this is, not calling any emitter); if necessary,
*/
/* you should filter this out, too.
*/
/*
*/
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.
*/
/*
*/
/* <Note>
*/
/* An empty outline, or an outline with a single point only is also
*/
/* valid.
*/
/*
*/
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: */