3f2d45aff6
Implement a bicubic resampling image filter, with raster and GPU backends. In order to get this to work on the GPU side, I had to modify the width and height of the drawn texture in drawSprite() and drawDevice() to use the filtered texture's dimensions, instead of the source texture. (This wasn't a problem before since all other image filters produce results the same dimensions as their input texture.) For now, this implementation only does axis-aligned scaling (same as the Lanczos-3 implementation in Chrome). It's also done for correctness and clarity, not speed, so there are lots of opportunities for speedups. Committed: https://code.google.com/p/skia/source/detail?r=7275 Review URL: https://codereview.appspot.com/7033049 git-svn-id: http://skia.googlecode.com/svn/trunk@7287 2bbb7eff-a529-9590-31e7-b0007b416f81
85 lines
2.4 KiB
C++
85 lines
2.4 KiB
C++
/*
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* Copyright 2013 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "gm.h"
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#include "SkColor.h"
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#include "SkBicubicImageFilter.h"
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namespace skiagm {
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class BicubicGM : public GM {
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public:
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BicubicGM() : fInitialized(false) {
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this->setBGColor(0x00000000);
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}
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protected:
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virtual SkString onShortName() {
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return SkString("bicubicfilter");
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}
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void make_checkerboard(int width, int height) {
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SkASSERT(width % 2 == 0);
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SkASSERT(height % 2 == 0);
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fCheckerboard.setConfig(SkBitmap::kARGB_8888_Config, width, height);
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fCheckerboard.allocPixels();
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SkAutoLockPixels lock(fCheckerboard);
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for (int y = 0; y < height; y += 2) {
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SkPMColor* s = fCheckerboard.getAddr32(0, y);
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for (int x = 0; x < width; x += 2) {
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*s++ = 0xFFFFFFFF;
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*s++ = 0xFF000000;
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}
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s = fCheckerboard.getAddr32(0, y + 1);
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for (int x = 0; x < width; x += 2) {
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*s++ = 0xFF000000;
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*s++ = 0xFFFFFFFF;
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}
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}
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}
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virtual SkISize onISize() {
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return make_isize(400, 300);
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}
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virtual void onDraw(SkCanvas* canvas) {
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if (!fInitialized) {
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make_checkerboard(4, 4);
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fInitialized = true;
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}
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SkScalar sk32 = SkIntToScalar(32);
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canvas->clear(0x00000000);
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SkPaint bilinearPaint, bicubicPaint;
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SkSize scale = SkSize::Make(sk32, sk32);
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canvas->save();
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canvas->scale(sk32, sk32);
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bilinearPaint.setFilterBitmap(true);
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canvas->drawBitmap(fCheckerboard, 0, 0, &bilinearPaint);
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canvas->restore();
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SkAutoTUnref<SkImageFilter> bicubic(SkBicubicImageFilter::CreateMitchell(scale));
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bicubicPaint.setImageFilter(bicubic);
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SkRect srcBounds;
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fCheckerboard.getBounds(&srcBounds);
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canvas->translate(SkIntToScalar(140), 0);
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canvas->saveLayer(&srcBounds, &bicubicPaint);
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canvas->drawBitmap(fCheckerboard, 0, 0);
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canvas->restore();
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}
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private:
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typedef GM INHERITED;
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SkBitmap fCheckerboard;
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bool fInitialized;
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};
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//////////////////////////////////////////////////////////////////////////////
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static GM* MyFactory(void*) { return new BicubicGM; }
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static GMRegistry reg(MyFactory);
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}
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