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/*
* Copyright (c) 2008, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE COPYRIGHT
* OWNER 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 "AffineTransform.h"
#include "BitmapImage.h"
#include "BitmapImageSingleFrameSkia.h"
#include "ChromiumBridge.h"
#include "FloatConversion.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "Logging.h"
#include "NativeImageSkia.h"
#include "PlatformContextSkia.h"
#include "PlatformString.h"
#include "SkiaUtils.h"
#include "SkRect.h"
#include "SkShader.h"
#include "skia/ext/image_operations.h"
#include "skia/ext/platform_canvas.h"
#if USE(GLES2_RENDERING)
#include "GLES2Canvas.h"
#include "GLES2Context.h"
#include "SkPixelRef.h"
#endif
namespace WebCore {
// Used by computeResamplingMode to tell how bitmaps should be resampled.
enum ResamplingMode {
// Nearest neighbor resampling. Used when we detect that the page is
// trying to make a pattern by stretching a small bitmap very large.
RESAMPLE_NONE,
// Default skia resampling. Used for large growing of images where high
// quality resampling doesn't get us very much except a slowdown.
RESAMPLE_LINEAR,
// High quality resampling.
RESAMPLE_AWESOME,
};
static ResamplingMode computeResamplingMode(PlatformContextSkia* platformContext, const NativeImageSkia& bitmap, int srcWidth, int srcHeight, float destWidth, float destHeight)
{
if (platformContext->hasImageResamplingHint()) {
IntSize srcSize;
FloatSize dstSize;
platformContext->getImageResamplingHint(&srcSize, &dstSize);
srcWidth = srcSize.width();
srcHeight = srcSize.height();
destWidth = dstSize.width();
destHeight = dstSize.height();
}
int destIWidth = static_cast<int>(destWidth);
int destIHeight = static_cast<int>(destHeight);
// The percent change below which we will not resample. This usually means
// an off-by-one error on the web page, and just doing nearest neighbor
// sampling is usually good enough.
const float kFractionalChangeThreshold = 0.025f;
// Images smaller than this in either direction are considered "small" and
// are not resampled ever (see below).
const int kSmallImageSizeThreshold = 8;
// The amount an image can be stretched in a single direction before we
// say that it is being stretched so much that it must be a line or
// background that doesn't need resampling.
const float kLargeStretch = 3.0f;
// Figure out if we should resample this image. We try to prune out some
// common cases where resampling won't give us anything, since it is much
// slower than drawing stretched.
if (srcWidth == destIWidth && srcHeight == destIHeight) {
// We don't need to resample if the source and destination are the same.
return RESAMPLE_NONE;
}
if (srcWidth <= kSmallImageSizeThreshold
|| srcHeight <= kSmallImageSizeThreshold
|| destWidth <= kSmallImageSizeThreshold
|| destHeight <= kSmallImageSizeThreshold) {
// Never resample small images. These are often used for borders and
// rules (think 1x1 images used to make lines).
return RESAMPLE_NONE;
}
if (srcHeight * kLargeStretch <= destHeight || srcWidth * kLargeStretch <= destWidth) {
// Large image detected.
// Don't resample if it is being stretched a lot in only one direction.
// This is trying to catch cases where somebody has created a border
// (which might be large) and then is stretching it to fill some part
// of the page.
if (srcWidth == destWidth || srcHeight == destHeight)
return RESAMPLE_NONE;
// The image is growing a lot and in more than one direction. Resampling
// is slow and doesn't give us very much when growing a lot.
return RESAMPLE_LINEAR;
}
if ((fabs(destWidth - srcWidth) / srcWidth < kFractionalChangeThreshold)
&& (fabs(destHeight - srcHeight) / srcHeight < kFractionalChangeThreshold)) {
// It is disappointingly common on the web for image sizes to be off by
// one or two pixels. We don't bother resampling if the size difference
// is a small fraction of the original size.
return RESAMPLE_NONE;
}
// When the image is not yet done loading, use linear. We don't cache the
// partially resampled images, and as they come in incrementally, it causes
// us to have to resample the whole thing every time.
if (!bitmap.isDataComplete())
return RESAMPLE_LINEAR;
// Everything else gets resampled.
// If the platform context permits high quality interpolation, use it.
if (platformContext->interpolationQuality() == InterpolationHigh)
return RESAMPLE_AWESOME;
return RESAMPLE_LINEAR;
}
// Draws the given bitmap to the given canvas. The subset of the source bitmap
// identified by src_rect is drawn to the given destination rect. The bitmap
// will be resampled to resample_width * resample_height (this is the size of
// the whole image, not the subset). See shouldResampleBitmap for more.
//
// This does a lot of computation to resample only the portion of the bitmap
// that will only be drawn. This is critical for performance since when we are
// scrolling, for example, we are only drawing a small strip of the image.
// Resampling the whole image every time is very slow, so this speeds up things
// dramatically.
static void drawResampledBitmap(SkCanvas& canvas, SkPaint& paint, const NativeImageSkia& bitmap, const SkIRect& srcIRect, const SkRect& destRect)
{
// First get the subset we need. This is efficient and does not copy pixels.
SkBitmap subset;
bitmap.extractSubset(&subset, srcIRect);
SkRect srcRect;
srcRect.set(srcIRect);
// Whether we're doing a subset or using the full source image.
bool srcIsFull = srcIRect.fLeft == 0 && srcIRect.fTop == 0
&& srcIRect.width() == bitmap.width()
&& srcIRect.height() == bitmap.height();
// We will always draw in integer sizes, so round the destination rect.
SkIRect destRectRounded;
destRect.round(&destRectRounded);
SkIRect resizedImageRect = // Represents the size of the resized image.
{ 0, 0, destRectRounded.width(), destRectRounded.height() };
if (srcIsFull && bitmap.hasResizedBitmap(destRectRounded.width(), destRectRounded.height())) {
// Yay, this bitmap frame already has a resized version.
SkBitmap resampled = bitmap.resizedBitmap(destRectRounded.width(), destRectRounded.height());
canvas.drawBitmapRect(resampled, 0, destRect, &paint);
return;
}
// Compute the visible portion of our rect.
SkRect destBitmapSubsetSk;
ClipRectToCanvas(canvas, destRect, &destBitmapSubsetSk);
destBitmapSubsetSk.offset(-destRect.fLeft, -destRect.fTop);
// The matrix inverting, etc. could have introduced rounding error which
// causes the bounds to be outside of the resized bitmap. We round outward
// so we always lean toward it being larger rather than smaller than we
// need, and then clamp to the bitmap bounds so we don't get any invalid
// data.
SkIRect destBitmapSubsetSkI;
destBitmapSubsetSk.roundOut(&destBitmapSubsetSkI);
if (!destBitmapSubsetSkI.intersect(resizedImageRect))
return; // Resized image does not intersect.
if (srcIsFull && bitmap.shouldCacheResampling(
resizedImageRect.width(),
resizedImageRect.height(),
destBitmapSubsetSkI.width(),
destBitmapSubsetSkI.height())) {
// We're supposed to resize the entire image and cache it, even though
// we don't need all of it.
SkBitmap resampled = bitmap.resizedBitmap(destRectRounded.width(),
destRectRounded.height());
canvas.drawBitmapRect(resampled, 0, destRect, &paint);
} else {
// We should only resize the exposed part of the bitmap to do the
// minimal possible work.
// Resample the needed part of the image.
SkBitmap resampled = skia::ImageOperations::Resize(subset,
skia::ImageOperations::RESIZE_LANCZOS3,
destRectRounded.width(), destRectRounded.height(),
destBitmapSubsetSkI);
// Compute where the new bitmap should be drawn. Since our new bitmap
// may be smaller than the original, we have to shift it over by the
// same amount that we cut off the top and left.
destBitmapSubsetSkI.offset(destRect.fLeft, destRect.fTop);
SkRect offsetDestRect;
offsetDestRect.set(destBitmapSubsetSkI);
canvas.drawBitmapRect(resampled, 0, offsetDestRect, &paint);
}
}
static void paintSkBitmap(PlatformContextSkia* platformContext, const NativeImageSkia& bitmap, const SkIRect& srcRect, const SkRect& destRect, const SkXfermode::Mode& compOp)
{
SkPaint paint;
paint.setXfermodeMode(compOp);
paint.setFilterBitmap(true);
int alpha = roundf(platformContext->getAlpha() * 256);
if (alpha > 255)
alpha = 255;
else if (alpha < 0)
alpha = 0;
paint.setAlpha(alpha);
skia::PlatformCanvas* canvas = platformContext->canvas();
ResamplingMode resampling = platformContext->isPrinting() ? RESAMPLE_NONE :
computeResamplingMode(platformContext, bitmap, srcRect.width(), srcRect.height(),
SkScalarToFloat(destRect.width()),
SkScalarToFloat(destRect.height()));
if (resampling == RESAMPLE_AWESOME) {
drawResampledBitmap(*canvas, paint, bitmap, srcRect, destRect);
} else {
// No resampling necessary, we can just draw the bitmap. We want to
// filter it if we decided to do linear interpolation above, or if there
// is something interesting going on with the matrix (like a rotation).
// Note: for serialization, we will want to subset the bitmap first so
// we don't send extra pixels.
canvas->drawBitmapRect(bitmap, &srcRect, destRect, &paint);
}
}
// Transforms the given dimensions with the given matrix. Used to see how big
// images will be once transformed.
static void TransformDimensions(const SkMatrix& matrix, float srcWidth, float srcHeight, float* destWidth, float* destHeight) {
// Transform 3 points to see how long each side of the bitmap will be.
SkPoint src_points[3]; // (0, 0), (width, 0), (0, height).
src_points[0].set(0, 0);
src_points[1].set(SkFloatToScalar(srcWidth), 0);
src_points[2].set(0, SkFloatToScalar(srcHeight));
// Now measure the length of the two transformed vectors relative to the
// transformed origin to see how big the bitmap will be. Note: for skews,
// this isn't the best thing, but we don't have skews.
SkPoint dest_points[3];
matrix.mapPoints(dest_points, src_points, 3);
*destWidth = SkScalarToFloat((dest_points[1] - dest_points[0]).length());
*destHeight = SkScalarToFloat((dest_points[2] - dest_points[0]).length());
}
// A helper method for translating negative width and height values.
static FloatRect normalizeRect(const FloatRect& rect)
{
FloatRect norm = rect;
if (norm.width() < 0) {
norm.setX(norm.x() + norm.width());
norm.setWidth(-norm.width());
}
if (norm.height() < 0) {
norm.setY(norm.y() + norm.height());
norm.setHeight(-norm.height());
}
return norm;
}
bool FrameData::clear(bool clearMetadata)
{
if (clearMetadata)
m_haveMetadata = false;
if (m_frame) {
// ImageSource::createFrameAtIndex() allocated |m_frame| and passed
// ownership to BitmapImage; we must delete it here.
delete m_frame;
m_frame = 0;
return true;
}
return false;
}
PassRefPtr<Image> Image::loadPlatformResource(const char *name)
{
return ChromiumBridge::loadPlatformImageResource(name);
}
void Image::drawPattern(GraphicsContext* context,
const FloatRect& floatSrcRect,
const AffineTransform& patternTransform,
const FloatPoint& phase,
ColorSpace styleColorSpace,
CompositeOperator compositeOp,
const FloatRect& destRect)
{
FloatRect normSrcRect = normalizeRect(floatSrcRect);
if (destRect.isEmpty() || normSrcRect.isEmpty())
return; // nothing to draw
NativeImageSkia* bitmap = nativeImageForCurrentFrame();
if (!bitmap)
return;
// This is a very inexpensive operation. It will generate a new bitmap but
// it will internally reference the old bitmap's pixels, adjusting the row
// stride so the extra pixels appear as padding to the subsetted bitmap.
SkBitmap srcSubset;
SkIRect srcRect = enclosingIntRect(normSrcRect);
bitmap->extractSubset(&srcSubset, srcRect);
SkBitmap resampled;
SkShader* shader;
// Figure out what size the bitmap will be in the destination. The
// destination rect is the bounds of the pattern, we need to use the
// matrix to see how bit it will be.
float destBitmapWidth, destBitmapHeight;
TransformDimensions(patternTransform, srcRect.width(), srcRect.height(),
&destBitmapWidth, &destBitmapHeight);
// Compute the resampling mode.
ResamplingMode resampling;
if (context->platformContext()->isPrinting())
resampling = RESAMPLE_LINEAR;
else {
resampling = computeResamplingMode(context->platformContext(), *bitmap,
srcRect.width(), srcRect.height(),
destBitmapWidth, destBitmapHeight);
}
// Load the transform WebKit requested.
SkMatrix matrix(patternTransform);
if (resampling == RESAMPLE_AWESOME) {
// Do nice resampling.
SkBitmap resampled;
int width = static_cast<int>(destBitmapWidth);
int height = static_cast<int>(destBitmapHeight);
if (!srcRect.fLeft && !srcRect.fTop
&& srcRect.fRight == bitmap->width() && srcRect.fBottom == bitmap->height()
&& (bitmap->hasResizedBitmap(width, height)
|| bitmap->shouldCacheResampling(width, height, width, height))) {
// resizedBitmap() caches resized image.
resampled = bitmap->resizedBitmap(width, height);
} else {
resampled = skia::ImageOperations::Resize(srcSubset,
skia::ImageOperations::RESIZE_LANCZOS3, width, height);
}
shader = SkShader::CreateBitmapShader(resampled, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
// Since we just resized the bitmap, we need to undo the scale set in
// the image transform.
matrix.setScaleX(SkIntToScalar(1));
matrix.setScaleY(SkIntToScalar(1));
} else {
// No need to do nice resampling.
shader = SkShader::CreateBitmapShader(srcSubset, SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
}
// We also need to translate it such that the origin of the pattern is the
// origin of the destination rect, which is what WebKit expects. Skia uses
// the coordinate system origin as the base for the patter. If WebKit wants
// a shifted image, it will shift it from there using the patternTransform.
float adjustedX = phase.x() + normSrcRect.x() *
narrowPrecisionToFloat(patternTransform.a());
float adjustedY = phase.y() + normSrcRect.y() *
narrowPrecisionToFloat(patternTransform.d());
matrix.postTranslate(SkFloatToScalar(adjustedX),
SkFloatToScalar(adjustedY));
shader->setLocalMatrix(matrix);
SkPaint paint;
paint.setShader(shader)->unref();
paint.setXfermodeMode(WebCoreCompositeToSkiaComposite(compositeOp));
paint.setFilterBitmap(resampling == RESAMPLE_LINEAR);
context->platformContext()->paintSkPaint(destRect, paint);
}
#if USE(GLES2_RENDERING)
static void drawBitmapGLES2(GraphicsContext* ctxt, NativeImageSkia* bitmap, const FloatRect& srcRect, const FloatRect& dstRect, ColorSpace styleColorSpace, CompositeOperator compositeOp)
{
ctxt->platformContext()->prepareForHardwareDraw();
GLES2Canvas* gpuCanvas = ctxt->platformContext()->gpuCanvas();
GLES2Texture* texture = gpuCanvas->getTexture(bitmap);
if (!texture) {
ASSERT(bitmap->config() == SkBitmap::kARGB_8888_Config);
ASSERT(bitmap->rowBytes() == bitmap->width() * 4);
texture = gpuCanvas->createTexture(bitmap, GLES2Texture::BGRA8, bitmap->width(), bitmap->height());
ASSERT(bitmap->pixelRef());
texture->load(bitmap->pixelRef()->pixels());
}
gpuCanvas->drawTexturedRect(texture, srcRect, dstRect, styleColorSpace, compositeOp);
}
#endif
// ================================================
// BitmapImage Class
// ================================================
// FIXME: These should go to BitmapImageSkia.cpp
void BitmapImage::initPlatformData()
{
// This is not used. On Mac, the "platform" data is a cache of some OS
// specific versions of the image that are created is some cases. These
// aren't normally used, it is equivalent to getHBITMAP on Windows, and
// the platform data is the cache.
}
void BitmapImage::invalidatePlatformData()
{
// See initPlatformData above.
}
void BitmapImage::checkForSolidColor()
{
m_checkedForSolidColor = true;
}
void BitmapImage::draw(GraphicsContext* ctxt, const FloatRect& dstRect,
const FloatRect& srcRect, ColorSpace colorSpace, CompositeOperator compositeOp)
{
if (!m_source.initialized())
return;
// Spin the animation to the correct frame before we try to draw it, so we
// don't draw an old frame and then immediately need to draw a newer one,
// causing flicker and wasting CPU.
startAnimation();
NativeImageSkia* bm = nativeImageForCurrentFrame();
if (!bm)
return; // It's too early and we don't have an image yet.
FloatRect normDstRect = normalizeRect(dstRect);
FloatRect normSrcRect = normalizeRect(srcRect);
if (normSrcRect.isEmpty() || normDstRect.isEmpty())
return; // Nothing to draw.
#if USE(GLES2_RENDERING)
if (ctxt->platformContext()->useGPU()) {
drawBitmapGLES2(ctxt, bm, normSrcRect, normDstRect, colorSpace, compositeOp);
return;
}
#endif
ctxt->platformContext()->prepareForSoftwareDraw();
paintSkBitmap(ctxt->platformContext(),
*bm,
enclosingIntRect(normSrcRect),
normDstRect,
WebCoreCompositeToSkiaComposite(compositeOp));
}
// FIXME: These should go into BitmapImageSingleFrameSkia.cpp
void BitmapImageSingleFrameSkia::draw(GraphicsContext* ctxt,
const FloatRect& dstRect,
const FloatRect& srcRect,
ColorSpace styleColorSpace,
CompositeOperator compositeOp)
{
FloatRect normDstRect = normalizeRect(dstRect);
FloatRect normSrcRect = normalizeRect(srcRect);
if (normSrcRect.isEmpty() || normDstRect.isEmpty())
return; // Nothing to draw.
#if USE(GLES2_RENDERING)
if (ctxt->platformContext()->useGPU()) {
drawBitmapGLES2(ctxt, &m_nativeImage, srcRect, dstRect, styleColorSpace, compositeOp);
return;
}
#endif
ctxt->platformContext()->prepareForSoftwareDraw();
paintSkBitmap(ctxt->platformContext(),
m_nativeImage,
enclosingIntRect(normSrcRect),
normDstRect,
WebCoreCompositeToSkiaComposite(compositeOp));
}
PassRefPtr<BitmapImageSingleFrameSkia> BitmapImageSingleFrameSkia::create(const SkBitmap& bitmap)
{
RefPtr<BitmapImageSingleFrameSkia> image(adoptRef(new BitmapImageSingleFrameSkia()));
bitmap.copyTo(&image->m_nativeImage, bitmap.config());
return image.release();
}
} // namespace WebCore
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