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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/* 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_a_affine.h"
#include <math.h>
#include "art_affine.h"
#include "art_point.h"
#include "art_rgb_affine_private.h"
/* This module handles compositing of affine-transformed alpha only images
over rgb pixel buffers. */
/* Composite the source image over the destination image, applying the
affine transform. */
/**
* art_rgb_a_affine: Affine transform source Alpha 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 alpha buffer.
* @src_width: Width of source image.
* @src_height: Height of source image.
* @src_rowstride: Rowstride of @src buffer.
* @rgb: RGB foreground color, in 0xRRGGBB.
* @affine: Affine transform.
* @level: Filter level.
* @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
*
* Affine transform the solid color rgb with alpha specified by 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_a_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,
art_u32 rgb,
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 alpha;
art_u8 bg_r, bg_g, bg_b;
art_u8 fg_r, fg_g, fg_b;
int tmp;
int run_x0, run_x1;
art_u8 r, g, b;
r = (rgb>>16)&0xff;
g = (rgb>>8)&0xff;
b = (rgb)&0xff;
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;
if (src_x >= 0 && src_x < src_width &&
src_y >= 0 && src_y < src_height)
{
alpha = *src_p;
if (alpha)
{
if (alpha == 255)
{
dst_p[0] = r;
dst_p[1] = g;
dst_p[2] = b;
}
else
{
bg_r = dst_p[0];
bg_g = dst_p[1];
bg_b = dst_p[2];
tmp = (r - bg_r) * alpha;
fg_r = bg_r + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = (g - bg_g) * alpha;
fg_g = bg_g + ((tmp + (tmp >> 8) + 0x80) >> 8);
tmp = (b - bg_b) * alpha;
fg_b = bg_b + ((tmp + (tmp >> 8) + 0x80) >> 8);
dst_p[0] = fg_r;
dst_p[1] = fg_g;
dst_p[2] = fg_b;
}
}
} else { dst_p[0] = 255; dst_p[1] = 0; dst_p[2] = 0; }
dst_p += 3;
}
dst_linestart += dst_rowstride;
}
}
|
