pjs/other-licenses/libart_lgpl/art_rgb_pixbuf_affine.c

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3.4 KiB
C
Исходник Обычный вид История

/* Libart_LGPL - library of basic graphic primitives
* Copyright (C) 1998 Raph Levien
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "art_rgb_pixbuf_affine.h"
#include <math.h>
#include "art_misc.h"
#include "art_point.h"
#include "art_affine.h"
#include "art_pixbuf.h"
#include "art_rgb_affine.h"
#include "art_rgb_affine.h"
#include "art_rgb_rgba_affine.h"
/* This module handles compositing of affine-transformed generic
pixbuf images over rgb pixel buffers. */
/* Composite the source image over the destination image, applying the
affine transform. */
/**
* art_rgb_pixbuf_affine: Affine transform source RGB pixbuf and composite.
* @dst: Destination image RGB buffer.
* @x0: Left coordinate of destination rectangle.
* @y0: Top coordinate of destination rectangle.
* @x1: Right coordinate of destination rectangle.
* @y1: Bottom coordinate of destination rectangle.
* @dst_rowstride: Rowstride of @dst buffer.
* @pixbuf: source image pixbuf.
* @affine: Affine transform.
* @level: Filter level.
* @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
*
* Affine transform the source image stored in @src, compositing over
* the area of destination image @dst specified by the rectangle
* (@x0, @y0) - (@x1, @y1). As usual in libart, the left and top edges
* of this rectangle are included, and the right and bottom edges are
* excluded.
*
* The @alphagamma parameter specifies that the alpha compositing be
* done in a gamma-corrected color space. In the current
* implementation, it is ignored.
*
* The @level parameter specifies the speed/quality tradeoff of the
* image interpolation. Currently, only ART_FILTER_NEAREST is
* implemented.
**/
void
art_rgb_pixbuf_affine (art_u8 *dst,
int x0, int y0, int x1, int y1, int dst_rowstride,
const ArtPixBuf *pixbuf,
const double affine[6],
ArtFilterLevel level,
ArtAlphaGamma *alphagamma)
{
if (pixbuf->format != ART_PIX_RGB)
{
art_warn ("art_rgb_pixbuf_affine: need RGB format image\n");
return;
}
if (pixbuf->bits_per_sample != 8)
{
art_warn ("art_rgb_pixbuf_affine: need 8-bit sample data\n");
return;
}
if (pixbuf->n_channels != 3 + (pixbuf->has_alpha != 0))
{
art_warn ("art_rgb_pixbuf_affine: need 8-bit sample data\n");
return;
}
if (pixbuf->has_alpha)
art_rgb_rgba_affine (dst, x0, y0, x1, y1, dst_rowstride,
pixbuf->pixels,
pixbuf->width, pixbuf->height, pixbuf->rowstride,
affine,
level,
alphagamma);
else
art_rgb_affine (dst, x0, y0, x1, y1, dst_rowstride,
pixbuf->pixels,
pixbuf->width, pixbuf->height, pixbuf->rowstride,
affine,
level,
alphagamma);
}