1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/* 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_affine.h"
#include <math.h>
#include "art_misc.h"
#include "art_point.h"
#include "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_rgb_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) * 3;
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 * 3;
dst_p[0] = src_p[0];
dst_p[1] = src_p[1];
dst_p[2] = src_p[2];
dst_p += 3;
}
dst_linestart += dst_rowstride;
}
}
|
