--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/opengl/gl2paintengineex/qglgradientcache.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,199 @@
+/****************************************************************************
+**
+** 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