InterpolationQuality GraphicsContext::imageInterpolationQuality() const
{
if (paintingDisabled())
return InterpolationDefault;
CGInterpolationQuality quality = CGContextGetInterpolationQuality(platformContext());
switch (quality) {
case kCGInterpolationDefault:
return InterpolationDefault;
case kCGInterpolationNone:
return InterpolationNone;
case kCGInterpolationLow:
return InterpolationLow;
#if HAVE(CG_INTERPOLATION_MEDIUM)
// kCGInterpolationMedium is known to be present in the CGInterpolationQuality enum.
case kCGInterpolationMedium:
#if USE(CG_INTERPOLATION_MEDIUM)
// Only map to InterpolationMedium if targeting a system that understands it.
return InterpolationMedium;
#else
return InterpolationDefault;
#endif // USE(CG_INTERPOLATION_MEDIUM)
#endif // HAVE(CG_INTERPOLATION_MEDIUM)
case kCGInterpolationHigh:
return InterpolationHigh;
}
return InterpolationDefault;
}
bool GiCanvasIos::drawCachedBitmap2(const GiCanvas* p, float x, float y, bool secondBmp)
{
bool ret = false;
if (p && p->getCanvasType() == getCanvasType()) {
GiCanvasIos* gs = (GiCanvasIos*)p;
int index = secondBmp ? 1 : 0;
CGImageRef image = gs->m_draw->_cacheserr[index] ? NULL : gs->m_draw->_caches[index];
CGContextRef context = m_draw->getContext();
if (context && image) {
CGRect rect = CGRectMake(x, y, m_draw->width(), m_draw->height());
CGAffineTransform af = CGAffineTransformMake(1, 0, 0, -1, 0, m_draw->height());
CGContextConcatCTM(context, af);
CGInterpolationQuality oldQuality = CGContextGetInterpolationQuality(context);
CGContextSetInterpolationQuality(context, kCGInterpolationNone);
CGContextDrawImage(context, rect, image);
CGContextSetInterpolationQuality(context, oldQuality);
CGContextConcatCTM(context, CGAffineTransformInvert(af));
ret = true;
}
}
return ret;
}
void GiCanvasIos::endPaint(bool draw)
{
if (m_draw->getContext())
{
if (draw && m_draw->_buffctx && m_draw->_context) {
CGContextRef context = m_draw->_context;
CGImageRef image = CGBitmapContextCreateImage(m_draw->_buffctx);
CGRect rect = CGRectMake(0, 0, m_draw->width(), m_draw->height()); // 逻辑宽高点数
if (image) {
CGAffineTransform af = CGAffineTransformMake(1, 0, 0, -1, 0, m_draw->height());
CGContextConcatCTM(context, af); // 图像是朝上的，上下文坐标系朝下，上下颠倒显示
CGInterpolationQuality old = CGContextGetInterpolationQuality(context);
CGContextSetInterpolationQuality(context, kCGInterpolationNone);
CGContextDrawImage(context, rect, image);
CGContextSetInterpolationQuality(context, old);
CGContextConcatCTM(context, CGAffineTransformInvert(af)); // 恢复成坐标系朝下
CGImageRelease(image);
}
}
if (m_draw->_buffctx) {
CGContextRelease(m_draw->_buffctx);
m_draw->_buffctx = NULL;
}
m_draw->_context = NULL;
if (owner())
owner()->_endPaint();
}
}
bool GiCanvasIos::drawCachedBitmap(float x, float y, bool secondBmp)
{
int index = secondBmp ? 1 : 0;
CGImageRef image = m_draw->_cacheserr[index] ? NULL : m_draw->_caches[index];
CGContextRef context = m_draw->getContext();
bool ret = false;
if (context && image) {
CGRect rect = CGRectMake(x, y, m_draw->width(), m_draw->height());
CGAffineTransform af = CGAffineTransformMake(1, 0, 0, -1, 0, m_draw->height());
CGContextConcatCTM(context, af); // 图像是朝上的，上下文坐标系朝下，上下颠倒显示
CGInterpolationQuality oldQuality = CGContextGetInterpolationQuality(context);
CGContextSetInterpolationQuality(context, kCGInterpolationNone);
CGContextDrawImage(context, rect, image);
CGContextSetInterpolationQuality(context, oldQuality);
CGContextConcatCTM(context, CGAffineTransformInvert(af)); // 恢复成坐标系朝下
ret = true;
}
return ret;
}
void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& destRect, const FloatRect& srcRect, ColorSpace styleColorSpace, CompositeOperator compositeOp)
{
startAnimation();
RetainPtr<CGImageRef> image = frameAtIndex(m_currentFrame);
if (!image) // If it's too early we won't have an image yet.
return;
if (mayFillWithSolidColor()) {
fillWithSolidColor(ctxt, destRect, solidColor(), styleColorSpace, compositeOp);
return;
}
float currHeight = CGImageGetHeight(image.get());
if (currHeight <= srcRect.y())
return;
CGContextRef context = ctxt->platformContext();
ctxt->save();
bool shouldUseSubimage = false;
// If the source rect is a subportion of the image, then we compute an inflated destination rect that will hold the entire image
// and then set a clip to the portion that we want to display.
FloatRect adjustedDestRect = destRect;
FloatSize selfSize = currentFrameSize();
if (srcRect.size() != selfSize) {
CGInterpolationQuality interpolationQuality = CGContextGetInterpolationQuality(context);
// When the image is scaled using high-quality interpolation, we create a temporary CGImage
// containing only the portion we want to display. We need to do this because high-quality
// interpolation smoothes sharp edges, causing pixels from outside the source rect to bleed
// into the destination rect. See <rdar://problem/6112909>.
shouldUseSubimage = (interpolationQuality == kCGInterpolationHigh || interpolationQuality == kCGInterpolationDefault) && (srcRect.size() != destRect.size() || !ctxt->getCTM().isIdentityOrTranslationOrFlipped());
float xScale = srcRect.width() / destRect.width();
float yScale = srcRect.height() / destRect.height();
if (shouldUseSubimage) {
FloatRect subimageRect = srcRect;
float leftPadding = srcRect.x() - floorf(srcRect.x());
float topPadding = srcRect.y() - floorf(srcRect.y());
subimageRect.move(-leftPadding, -topPadding);
adjustedDestRect.move(-leftPadding / xScale, -topPadding / yScale);
subimageRect.setWidth(ceilf(subimageRect.width() + leftPadding));
adjustedDestRect.setWidth(subimageRect.width() / xScale);
subimageRect.setHeight(ceilf(subimageRect.height() + topPadding));
adjustedDestRect.setHeight(subimageRect.height() / yScale);
image.adoptCF(CGImageCreateWithImageInRect(image.get(), subimageRect));
if (currHeight < srcRect.bottom()) {
ASSERT(CGImageGetHeight(image.get()) == currHeight - CGRectIntegral(srcRect).origin.y);
adjustedDestRect.setHeight(CGImageGetHeight(image.get()) / yScale);
}
} else {
adjustedDestRect.setLocation(FloatPoint(destRect.x() - srcRect.x() / xScale, destRect.y() - srcRect.y() / yScale));
adjustedDestRect.setSize(FloatSize(selfSize.width() / xScale, selfSize.height() / yScale));
}
CGContextClipToRect(context, destRect);
}
// If the image is only partially loaded, then shrink the destination rect that we're drawing into accordingly.
if (!shouldUseSubimage && currHeight < selfSize.height())
adjustedDestRect.setHeight(adjustedDestRect.height() * currHeight / selfSize.height());
ctxt->setCompositeOperation(compositeOp);
// Flip the coords.
CGContextScaleCTM(context, 1, -1);
adjustedDestRect.setY(-adjustedDestRect.bottom());
// Adjust the color space.
image = imageWithColorSpace(image.get(), styleColorSpace);
// Draw the image.
CGContextDrawImage(context, adjustedDestRect, image.get());
ctxt->restore();
if (imageObserver())
imageObserver()->didDraw(this);
}
