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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtOpenGL module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include <private/qdrawhelper_p.h>
#include <private/qgl_p.h>
#include "qglgradientcache_p.h"
QT_BEGIN_NAMESPACE
static void QGL2GradientCache_free(void *ptr)
{
delete reinterpret_cast<QGL2GradientCache *>(ptr);
}
Q_GLOBAL_STATIC_WITH_ARGS(QGLContextResource, qt_gradient_caches, (QGL2GradientCache_free))
QGL2GradientCache *QGL2GradientCache::cacheForContext(const QGLContext *context)
{
QGL2GradientCache *p = reinterpret_cast<QGL2GradientCache *>(qt_gradient_caches()->value(context));
if (!p) {
QGLShareContextScope scope(context);
p = new QGL2GradientCache;
qt_gradient_caches()->insert(context, p);
}
return p;
}
void QGL2GradientCache::cleanCache() {
QGLGradientColorTableHash::const_iterator it = cache.constBegin();
for (; it != cache.constEnd(); ++it) {
const CacheInfo &cache_info = it.value();
glDeleteTextures(1, &cache_info.texId);
}
cache.clear();
}
GLuint QGL2GradientCache::getBuffer(const QGradient &gradient, qreal opacity)
{
quint64 hash_val = 0;
QGradientStops stops = gradient.stops();
for (int i = 0; i < stops.size() && i <= 2; i++)
hash_val += stops[i].second.rgba();
QGLGradientColorTableHash::const_iterator it = cache.constFind(hash_val);
if (it == cache.constEnd())
return addCacheElement(hash_val, gradient, opacity);
else {
do {
const CacheInfo &cache_info = it.value();
if (cache_info.stops == stops && cache_info.opacity == opacity && cache_info.interpolationMode == gradient.interpolationMode()) {
return cache_info.texId;
}
++it;
} while (it != cache.constEnd() && it.key() == hash_val);
// an exact match for these stops and opacity was not found, create new cache
return addCacheElement(hash_val, gradient, opacity);
}
}
GLuint QGL2GradientCache::addCacheElement(quint64 hash_val, const QGradient &gradient, qreal opacity)
{
if (cache.size() == maxCacheSize()) {
int elem_to_remove = qrand() % maxCacheSize();
quint64 key = cache.keys()[elem_to_remove];
// need to call glDeleteTextures on each removed cache entry:
QGLGradientColorTableHash::const_iterator it = cache.constFind(key);
do {
glDeleteTextures(1, &it.value().texId);
} while (++it != cache.constEnd() && it.key() == key);
cache.remove(key); // may remove more than 1, but OK
}
CacheInfo cache_entry(gradient.stops(), opacity, gradient.interpolationMode());
uint buffer[1024];
generateGradientColorTable(gradient, buffer, paletteSize(), opacity);
glGenTextures(1, &cache_entry.texId);
glBindTexture(GL_TEXTURE_2D, cache_entry.texId);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, paletteSize(), 1,
0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
return cache.insert(hash_val, cache_entry).value().texId;
}
// GL's expects pixels in RGBA (when using GL_RGBA), bin-endian (ABGR on x86).
// Qt always stores in ARGB reguardless of the byte-order the mancine uses.
static inline uint qtToGlColor(uint c)
{
uint o;
#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
o = (c & 0xff00ff00) // alpha & green already in the right place
| ((c >> 16) & 0x000000ff) // red
| ((c << 16) & 0x00ff0000); // blue
#else //Q_BIG_ENDIAN
o = (c << 8)
| ((c >> 24) & 0x000000ff);
#endif // Q_BYTE_ORDER
return o;
}
//TODO: Let GL generate the texture using an FBO
void QGL2GradientCache::generateGradientColorTable(const QGradient& gradient, uint *colorTable, int size, qreal opacity) const
{
int pos = 0;
QGradientStops s = gradient.stops();
QVector<uint> colors(s.size());
for (int i = 0; i < s.size(); ++i)
colors[i] = s[i].second.rgba(); // Qt LIES! It returns ARGB (on little-endian AND on big-endian)
bool colorInterpolation = (gradient.interpolationMode() == QGradient::ColorInterpolation);
uint alpha = qRound(opacity * 256);
uint current_color = ARGB_COMBINE_ALPHA(colors[0], alpha);
qreal incr = 1.0 / qreal(size);
qreal fpos = 1.5 * incr;
colorTable[pos++] = qtToGlColor(PREMUL(current_color));
while (fpos <= s.first().first) {
colorTable[pos] = colorTable[pos - 1];
pos++;
fpos += incr;
}
if (colorInterpolation)
current_color = PREMUL(current_color);
for (int i = 0; i < s.size() - 1; ++i) {
qreal delta = 1/(s[i+1].first - s[i].first);
uint next_color = ARGB_COMBINE_ALPHA(colors[i+1], alpha);
if (colorInterpolation)
next_color = PREMUL(next_color);
while (fpos < s[i+1].first && pos < size) {
int dist = int(256 * ((fpos - s[i].first) * delta));
int idist = 256 - dist;
if (colorInterpolation)
colorTable[pos] = qtToGlColor(INTERPOLATE_PIXEL_256(current_color, idist, next_color, dist));
else
colorTable[pos] = qtToGlColor(PREMUL(INTERPOLATE_PIXEL_256(current_color, idist, next_color, dist)));
++pos;
fpos += incr;
}
current_color = next_color;
}
Q_ASSERT(s.size() > 0);
uint last_color = qtToGlColor(PREMUL(ARGB_COMBINE_ALPHA(colors[s.size() - 1], alpha)));
for (;pos < size; ++pos)
colorTable[pos] = last_color;
// Make sure the last color stop is represented at the end of the table
colorTable[size-1] = last_color;
}
QT_END_NAMESPACE
|
