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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 "NativeImageSkia.h"
#include "SkiaUtils.h"
#include "skia/ext/image_operations.h"
NativeImageSkia::NativeImageSkia()
: SkBitmap(),
m_isDataComplete(false),
m_resizedImage(),
m_lastRequestSize(0, 0),
m_resizeRequests(0) {
}
int NativeImageSkia::decodedSize() const {
return getSize() + m_resizedImage.getSize();
}
bool NativeImageSkia::hasResizedBitmap(int w, int h) const {
if (m_lastRequestSize.width() == w && m_lastRequestSize.height() == h) {
m_resizeRequests++;
} else {
m_lastRequestSize = WebCore::IntSize(w, h);
m_resizeRequests = 0;
}
return m_resizedImage.width() == w && m_resizedImage.height() == h;
}
// FIXME(brettw) don't cache when image is in-progress.
SkBitmap NativeImageSkia::resizedBitmap(int w, int h) const {
if (m_resizedImage.width() != w || m_resizedImage.height() != h) {
m_resizedImage = skia::ImageOperations::Resize(*this,
skia::ImageOperations::RESIZE_LANCZOS3, gfx::Size(w, h));
}
return m_resizedImage;
}
// static
bool NativeImageSkia::shouldCacheResampling(int dest_width,
int dest_height,
int dest_subset_width,
int dest_subset_height) const {
// We can not cache incomplete frames. This might be a good optimization in
// the future, were we know how much of the frame has been decoded, so when
// we incrementally draw more of the image, we only have to resample the
// parts that are changed.
if (!m_isDataComplete)
return false;
// If the destination bitmap is small, we'll always allow caching, since
// there is not very much penalty for computing it and it may come in handy.
static const int kSmallBitmapSize = 4096;
if (dest_width * dest_height <= kSmallBitmapSize)
return true;
// If "too many" requests have been made for this bitmap, we assume that
// many more will be made as well, and we'll go ahead and cache it.
static const int kManyRequestThreshold = 4;
if (m_lastRequestSize.width() == dest_width &&
m_lastRequestSize.height() == dest_height) {
if (m_resizeRequests >= kManyRequestThreshold)
return true;
} else {
// When a different size is being requested, count this as a query
// (hasResizedBitmap) and reset the counter.
m_lastRequestSize = WebCore::IntSize(dest_width, dest_height);
m_resizeRequests = 0;
}
// Otherwise, use the heuristic that if more than 1/4 of the image is
// requested, it's worth caching.
int dest_size = dest_width * dest_height;
int dest_subset_size = dest_subset_width * dest_subset_height;
return dest_size / 4 < dest_subset_size;
}
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