| /**************************************************************************** |
| ** |
| ** Copyright (C) 2011 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. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** GNU Lesser General Public License Usage |
| ** 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. |
| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU General |
| ** Public License version 3.0 as published by the Free Software Foundation |
| ** and appearing in the file LICENSE.GPL included in the packaging of this |
| ** file. Please review the following information to ensure the GNU General |
| ** Public License version 3.0 requirements will be met: |
| ** http://www.gnu.org/copyleft/gpl.html. |
| ** |
| ** Other Usage |
| ** Alternatively, this file may be used in accordance with the terms and |
| ** conditions contained in a signed written agreement between you and Nokia. |
| ** |
| ** |
| ** |
| ** |
| ** |
| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| #include "qglgradientcache_p.h" |
| #include <private/qdrawhelper_p.h> |
| #include <private/qgl_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 |