/*
* 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)
: m_radial(false), m_p0(p0), m_p1(p1), m_stopsSorted(false), m_lastStop(0)
#if PLATFORM(CG)
, m_shading(0)
#elif PLATFORM(QT)
, m_shading(0)
#elif PLATFORM(CAIRO)
, m_shading(0)
#endif
{
}
CanvasGradient::CanvasGradient(const FloatPoint& p0, float r0, const FloatPoint& p1, float r1)
: m_radial(true), m_p0(p0), m_p1(p1), m_r0(r0), m_r1(r1), m_stopsSorted(false), m_lastStop(0)
#if PLATFORM(CG)
, m_shading(0)
#elif PLATFORM(QT)
, m_shading(0)
#elif 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 = CSSParser::parseColor(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