external/webkit r30707

1 files changed, 247 insertions, 0 deletions

diff --git a/WebCore/html/CanvasGradient.cpp b/WebCore/html/CanvasGradient.cpp
new file mode 100644
index 0000000..bed5f01
--- /dev/null
+++ b/WebCore/html/CanvasGradient.cpp
@@ -0,0 +1,247 @@
+/*
+ * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
+ * Copyright (C) 2007 Alp Toker <alp@atoker.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "CanvasGradient.h"
+
+#include "CSSParser.h"
+
+#if PLATFORM(CG)
+#include <ApplicationServices/ApplicationServices.h>
+#elif PLATFORM(QT)
+#include <QGradient>
+#elif PLATFORM(CAIRO)
+#include <cairo.h>
+#endif
+
+namespace WebCore {
+
+CanvasGradient::CanvasGradient(const FloatPoint& p0, const FloatPoint& p1)
+    : RefCounted<CanvasGradient>(0)
+    , m_radial(false), m_p0(p0), m_p1(p1), m_stopsSorted(false), m_lastStop(0)
+#if PLATFORM(CG) || PLATFORM(QT) || PLATFORM(CAIRO)
+    , m_shading(0)
+#endif
+{
+}
+
+CanvasGradient::CanvasGradient(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1)
+    : RefCounted<CanvasGradient>(0)
+    , m_radial(true), m_p0(p0), m_p1(p1), m_r0(r0), m_r1(r1), m_stopsSorted(false), m_lastStop(0)
+#if PLATFORM(CG) || PLATFORM(QT) || PLATFORM(CAIRO)
+    , m_shading(0)
+#endif
+{
+}
+
+CanvasGradient::~CanvasGradient()
+{
+#if PLATFORM(CG)
+    CGShadingRelease(m_shading);
+#elif PLATFORM(QT)
+    delete m_shading;
+#elif PLATFORM(CAIRO)
+    cairo_pattern_destroy(m_shading);
+#endif
+}
+
+void CanvasGradient::addColorStop(float value, const String& color)
+{
+    RGBA32 rgba = 0; // default is transparant black
+    CSSParser::parseColor(rgba, color);
+    m_stops.append(ColorStop(value,
+        ((rgba >> 16) & 0xFF) / 255.0f,
+        ((rgba >> 8) & 0xFF) / 255.0f,
+        (rgba & 0xFF) / 255.0f,
+        ((rgba >> 24) & 0xFF) / 255.0f));
+
+    m_stopsSorted = false;
+
+#if PLATFORM(CG)
+    CGShadingRelease(m_shading);
+    m_shading = 0;
+#elif PLATFORM(QT)
+    delete m_shading;
+    m_shading = 0;
+#elif PLATFORM(CAIRO)
+    cairo_pattern_destroy(m_shading);
+    m_shading = 0;
+#endif
+}
+
+#if PLATFORM(CG)
+
+static void gradientCallback(void* info, const CGFloat* in, CGFloat* out)
+{
+    float r, g, b, a;
+    static_cast<CanvasGradient*>(info)->getColor(*in, &r, &g, &b, &a);
+    out[0] = r;
+    out[1] = g;
+    out[2] = b;
+    out[3] = a;
+}
+
+CGShadingRef CanvasGradient::platformShading()
+{
+    if (m_shading)
+        return m_shading;
+
+    const CGFloat intervalRanges[2] = { 0, 1 };
+    const CGFloat colorComponentRanges[4 * 2] = { 0, 1, 0, 1, 0, 1, 0, 1 };
+    const CGFunctionCallbacks gradientCallbacks = { 0, gradientCallback, 0 };
+    CGFunctionRef colorFunction = CGFunctionCreate(this, 1, intervalRanges, 4, colorComponentRanges, &gradientCallbacks);
+
+    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
+
+    if (m_radial)
+        m_shading = CGShadingCreateRadial(colorSpace, m_p0, m_r0, m_p1, m_r1, colorFunction, true, true);
+    else
+        m_shading = CGShadingCreateAxial(colorSpace, m_p0, m_p1, colorFunction, true, true);
+
+    CGColorSpaceRelease(colorSpace);
+    CGFunctionRelease(colorFunction);
+
+    return m_shading;
+}
+
+#elif PLATFORM(QT)
+
+QGradient* CanvasGradient::platformShading()
+{
+    if (m_shading)
+        return m_shading;
+
+    if (m_radial)
+        m_shading = new QRadialGradient(m_p0.x(), m_p0.y(), m_r0, m_p1.x(), m_p1.y());
+    else m_shading = new QLinearGradient(m_p0.x(), m_p0.y(), m_p1.x(), m_p1.y());
+
+    QColor stopColor;
+    Vector<ColorStop>::iterator stopIterator = m_stops.begin();;
+    while (stopIterator != m_stops.end()) {
+        stopColor.setRgbF(stopIterator->red, stopIterator->green, stopIterator->blue, stopIterator->alpha);
+        m_shading->setColorAt(stopIterator->stop, stopColor);
+        ++stopIterator;
+    }
+
+    return m_shading;
+}
+
+#elif PLATFORM(CAIRO)
+
+cairo_pattern_t* CanvasGradient::platformShading()
+{
+    if (m_shading)
+        return m_shading;
+
+    if (m_radial)
+        m_shading = cairo_pattern_create_radial(m_p0.x(), m_p0.y(), m_r0, m_p1.x(), m_p1.y(), m_r1);
+    else
+        m_shading = cairo_pattern_create_linear(m_p0.x(), m_p0.y(), m_p1.x(), m_p1.y());
+
+    Vector<ColorStop>::iterator stopIterator = m_stops.begin();
+    while (stopIterator != m_stops.end()) {
+        cairo_pattern_add_color_stop_rgba(m_shading, stopIterator->stop, stopIterator->red, stopIterator->green, stopIterator->blue, stopIterator->alpha);
+        ++stopIterator;
+    }
+
+    return m_shading;
+}
+
+#endif
+
+static inline bool compareStops(const CanvasGradient::ColorStop &a, const CanvasGradient::ColorStop &b)
+{
+    return a.stop < b.stop;
+}
+
+void CanvasGradient::getColor(float value, float* r, float* g, float* b, float* a)
+{
+    ASSERT(value >= 0);
+    ASSERT(value <= 1);
+
+    if (m_stops.isEmpty()) {
+        *r = 0;
+        *g = 0;
+        *b = 0;
+        *a = 0;
+        return;
+    }
+    if (!m_stopsSorted) {
+        if (m_stops.size())
+            std::stable_sort(m_stops.begin(), m_stops.end(), compareStops);
+        m_stopsSorted = true;
+    }
+    if (value <= 0 || value <= m_stops.first().stop) {
+        *r = m_stops.first().red;
+        *g = m_stops.first().green;
+        *b = m_stops.first().blue;
+        *a = m_stops.first().alpha;
+        return;
+    }
+    if (value >= 1 || value >= m_stops.last().stop) {
+        *r = m_stops.last().red;
+        *g = m_stops.last().green;
+        *b = m_stops.last().blue;
+        *a = m_stops.last().alpha;
+        return;
+    }
+
+    // Find stop before and stop after and interpolate.
+    int stop = findStop(value);
+    const ColorStop& lastStop = m_stops[stop];    
+    const ColorStop& nextStop = m_stops[stop + 1];
+    float stopFraction = (value - lastStop.stop) / (nextStop.stop - lastStop.stop);
+    *r = lastStop.red + (nextStop.red - lastStop.red) * stopFraction;
+    *g = lastStop.green + (nextStop.green - lastStop.green) * stopFraction;
+    *b = lastStop.blue + (nextStop.blue - lastStop.blue) * stopFraction;
+    *a = lastStop.alpha + (nextStop.alpha - lastStop.alpha) * stopFraction;
+}
+
+int CanvasGradient::findStop(float value) const
+{
+    ASSERT(value >= 0);
+    ASSERT(value <= 1);
+    ASSERT(m_stopsSorted);
+
+    int numStops = m_stops.size();
+    ASSERT(numStops >= 2);
+    ASSERT(m_lastStop < numStops - 1);
+
+    int i = m_lastStop;
+    if (value < m_stops[i].stop)
+        i = 1;
+    else
+        i = m_lastStop + 1;
+
+    for (; i < numStops - 1; ++i)
+        if (value < m_stops[i].stop)
+            break;
+
+    m_lastStop = i - 1;
+    return m_lastStop;
+}
+
+} //namespace