You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
108 lines
3.6 KiB
108 lines
3.6 KiB
/* 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., 51 Franklin Street, Fifth Floor,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include "config.h"
|
|
#include "art_rgba_affine.h"
|
|
|
|
#include <math.h>
|
|
#include <libart_lgpl/art_misc.h>
|
|
#include <libart_lgpl/art_point.h>
|
|
#include <libart_lgpl/art_affine.h>
|
|
#include <art_rgb_affine_private.h>
|
|
|
|
/* This module handles compositing of affine-transformed rgb images
|
|
over rgb pixel buffers. */
|
|
|
|
/**
|
|
* art_rgb_affine: Affine transform source RGB image 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.
|
|
* @src: Source image RGB buffer.
|
|
* @src_width: Width of source image.
|
|
* @src_height: Height of source image.
|
|
* @src_rowstride: Rowstride of @src buffer.
|
|
* @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. Since the source image is opaque RGB,
|
|
* this argument only affects the edges. 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_rgba_affine (art_u8 *dst, int x0, int y0, int x1, int y1, int dst_rowstride,
|
|
const art_u8 *src,
|
|
int src_width, int src_height, int src_rowstride,
|
|
const double affine[6],
|
|
ArtFilterLevel level,
|
|
ArtAlphaGamma *alphagamma)
|
|
{
|
|
/* Note: this is a slow implementation, and is missing all filter
|
|
levels other than NEAREST. It is here for clarity of presentation
|
|
and to establish the interface. */
|
|
int x, y;
|
|
double inv[6];
|
|
art_u8 *dst_p, *dst_linestart;
|
|
const art_u8 *src_p;
|
|
ArtPoint pt, src_pt;
|
|
int src_x, src_y;
|
|
int run_x0, run_x1;
|
|
|
|
dst_linestart = dst;
|
|
art_affine_invert (inv, affine);
|
|
for (y = y0; y < y1; y++)
|
|
{
|
|
pt.y = y + 0.5;
|
|
run_x0 = x0;
|
|
run_x1 = x1;
|
|
art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height,
|
|
inv);
|
|
dst_p = dst_linestart + (run_x0 - x0) * 4;
|
|
for (x = run_x0; x < run_x1; x++)
|
|
{
|
|
pt.x = x + 0.5;
|
|
art_affine_point (&src_pt, &pt, inv);
|
|
src_x = floor (src_pt.x);
|
|
src_y = floor (src_pt.y);
|
|
src_p = src + (src_y * src_rowstride) + src_x * 4;
|
|
dst_p[0] = src_p[0];
|
|
dst_p[1] = src_p[1];
|
|
dst_p[2] = src_p[2];
|
|
dst_p[3] = src_p[3];
|
|
dst_p += 4;
|
|
}
|
|
dst_linestart += dst_rowstride;
|
|
}
|
|
}
|