freetype2/src/base/ftoutln.c

287 lines
14 KiB
C

/***************************************************************************/
/* */
/* ftoutln.c */
/* */
/* FreeType outline management (body). */
/* */
/* Copyright 1996-1999 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. */
/* */
/***************************************************************************/
/*************************************************************************/
/* */
/* All functions are declared in freetype.h. */
/* */
/*************************************************************************/
#include <freetype.h>
#include <ftconfig.h>
#include <ftobjs.h>
#include <ftimage.h>
#include <ftoutln.h>
/*************************************************************************/
/* */
/* <Function> */
/* FT_Copy_Outline */
/* */
/* <Description> */
/* Copies 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. */
/* target :: A handle to the target outline. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
BASE_FUNC
FT_Error FT_Copy_Outline( FT_Outline* source,
FT_Outline* target )
{
if ( !source || !target ||
source->n_points != target->n_points ||
source->n_contours != target->n_contours )
return FT_Err_Invalid_Argument;
MEM_Copy( target->points, source->points,
source->n_points * 2 * sizeof ( FT_Pos ) );
MEM_Copy( target->flags, source->flags,
source->n_points * sizeof ( FT_Byte ) );
MEM_Copy( target->contours, source->contours,
source->n_contours * sizeof ( FT_Short ) );
target->high_precision = source->high_precision;
target->second_pass = target->second_pass;
target->dropout_mode = source->dropout_mode;
return FT_Err_Ok;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Get_Outline_Bitmap */
/* */
/* <Description> */
/* Renders 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. */
/* map :: A pointer to the target bitmap descriptor. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* YES. Rendering is synchronized, so that concurrent calls to the */
/* scan-line converter will be serialized. */
/* */
/* <Note> */
/* This function does NOT CREATE the bitmap, it only renders an */
/* outline image within the one you pass to it! */
/* */
/* It will use the raster correponding to the default glyph format. */
/* */
BASE_FUNC
FT_Error FT_Get_Outline_Bitmap( FT_Library library,
FT_Outline* outline,
FT_Bitmap* map )
{
FT_Error error;
FT_Glyph_Format* format;
error = FT_Err_Invalid_Glyph_Format;
format = FT_Get_Glyph_Format( library, ft_glyph_format_outline );
if (!format) goto Exit;
error = FT_Err_Invalid_Glyph_Format;
if (!format->raster) goto Exit;
error = format->raster_interface->render( format->raster, outline, map );
Exit:
return error;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Transform_Outline */
/* */
/* <Description> */
/* Applies a simple 2x2 matrix to all of an outline's points. Useful */
/* for applying rotations, slanting, flipping, etc. */
/* */
/* <Input> */
/* outline :: A pointer to the target outline descriptor. */
/* matrix :: A pointer to the transformation matrix. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
/* <Note> */
/* You can use FT_Translate_Outline() if you need to translate the */
/* outline's points. */
/* */
BASE_FUNC
void FT_Transform_Outline( FT_Outline* outline,
FT_Matrix* matrix )
{
FT_UShort n;
FT_Vector* vec;
vec = outline->points;
for ( n = 0; n < outline->n_points; n++ )
{
FT_Pos x, y;
x = FT_MulFix( vec->x, matrix->xx ) +
FT_MulFix( vec->y, matrix->xy );
y = FT_MulFix( vec->x, matrix->yx ) +
FT_MulFix( vec->y, matrix->yy );
vec->x = x;
vec->y = y;
vec++;
}
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Transform_Vector */
/* */
/* <Description> */
/* Transforms a single vector through a 2x2 matrix. */
/* */
/* <InOut> */
/* x :: The horizontal vector coordinate. */
/* y :: The vertical vector coordinate. */
/* */
/* <Input> */
/* matrix :: A pointer to the source 2x2 matrix. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
void FT_Transform_Vector( FT_Pos* x,
FT_Pos* y,
FT_Matrix* matrix )
{
FT_Pos xz, yz;
xz = FT_MulFix( *x, matrix->xx ) +
FT_MulFix( *y, matrix->xy );
yz = FT_MulFix( *x, matrix->yx ) +
FT_MulFix( *y, matrix->yy );
*x = xz;
*y = yz;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Multiply */
/* */
/* <Description> */
/* Performs the matrix operation `b = a*b'. */
/* */
/* <Input> */
/* a :: A pointer to matrix `a'. */
/* */
/* <InOut> */
/* b :: A pointer to matrix `b'. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
void FT_Matrix_Multiply( FT_Matrix* a,
FT_Matrix* b )
{
FT_Fixed xx, xy, yx, yy;
xx = FT_MulFix( a->xx, b->xx ) + FT_MulFix( a->xy, b->yx );
xy = FT_MulFix( a->xx, b->xy ) + FT_MulFix( a->xy, b->yy );
yx = FT_MulFix( a->yx, b->xx ) + FT_MulFix( a->yy, b->yx );
yy = FT_MulFix( a->yx, b->xy ) + FT_MulFix( a->yy, b->yy );
b->xx = xx; b->xy = xy;
b->yx = yx; b->yy = yy;
}
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Invert */
/* */
/* <Description> */
/* Inverts a 2x2 matrix. Returns an error if it can't be inverted. */
/* */
/* <InOut> */
/* matrix :: A pointer to the target matrix. Remains untouched in */
/* case of error. */
/* */
/* <Return> */
/* FreeType error code. 0 means success. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
BASE_FUNC
FT_Error FT_Matrix_Invert( FT_Matrix* matrix )
{
FT_Pos delta, xx, yy;
/* compute discriminant */
delta = FT_MulFix( matrix->xx, matrix->yy ) -
FT_MulFix( matrix->xy, matrix->yx );
if ( !delta )
return FT_Err_Invalid_Argument; /* matrix can't be inverted */
matrix->xy = - FT_DivFix( matrix->xy, delta );
matrix->yx = - FT_DivFix( matrix->yx, delta );
xx = matrix->xx;
yy = matrix->yy;
matrix->xx = FT_DivFix( yy, delta );
matrix->yy = FT_DivFix( xx, delta );
return FT_Err_Ok;
}
/* END */