Use GraphicContext::drawImageBuffer in FEBlend

Source/platform/graphics/filters/FEBlend.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 13 matching lines @@
 
 #include "config.h"
 #include "platform/graphics/filters/FEBlend.h"
 
 #include "SkBitmapSource.h"
 #include "SkXfermodeImageFilter.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/cpu/arm/filters/FEBlendNEON.h"
 #include "platform/graphics/filters/SkiaImageFilterBuilder.h"
 #include "platform/graphics/skia/NativeImageSkia.h"
+#include "platform/graphics/skia/SkiaUtils.h"
 #include "platform/text/TextStream.h"
 #include "wtf/Uint8ClampedArray.h"
 
 typedef unsigned char (*BlendType)(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB);
 
 namespace blink {
 
 FEBlend::FEBlend(Filter* filter, BlendModeType mode)
     : FilterEffect(filter)
     , m_mode(mode)
@@ skipping 11 matching lines @@
 }
 
 bool FEBlend::setBlendMode(BlendModeType mode)
 {
     if (m_mode == mode)
         return false;
     m_mode = mode;
     return true;
 }
 
-static inline unsigned char fastDivideBy255(uint16_t value)
+static WebBlendMode toWebBlendMode(BlendModeType mode)
 {
-    // This is an approximate algorithm for division by 255, but it gives accurate results for 16bit values.
-    uint16_t quotient = value >> 8;
-    uint16_t remainder = value - (quotient * 255) + 1;
-    return quotient + (remainder >> 8);
-}
-
-inline unsigned char feBlendNormal(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char)
-{
-    return fastDivideBy255((255 - alphaA) * colorB + colorA * 255);
-}
-
-inline unsigned char feBlendMultiply(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
-{
-    return fastDivideBy255((255 - alphaA) * colorB + (255 - alphaB + colorB) * colorA);
-}
-
-inline unsigned char feBlendScreen(unsigned char colorA, unsigned char colorB, unsigned char, unsigned char)
-{
-    return fastDivideBy255((colorB + colorA) * 255 - colorA * colorB);
-}
-
-inline unsigned char feBlendDarken(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
-{
-    return fastDivideBy255(std::min((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255));
-}
-
-inline unsigned char feBlendLighten(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB)
-{
-    return fastDivideBy255(std::max((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255));
-}
-
-inline unsigned char feBlendUnknown(unsigned char, unsigned char, unsigned char, unsigned char)
-{
-    return 0;
-}
-
-template<BlendType BlendFunction>
-static void platformApply(unsigned char* sourcePixelA, unsigned char* sourcePixelB,
-                          unsigned char* destinationPixel, unsigned pixelArrayLength)
-{
-    unsigned len = pixelArrayLength / 4;
-    for (unsigned pixelOffset = 0; pixelOffset < len; pixelOffset++) {
-        unsigned char alphaA = sourcePixelA[3];
-        unsigned char alphaB = sourcePixelB[3];
-        destinationPixel[0] = BlendFunction(sourcePixelA[0], sourcePixelB[0], alphaA, alphaB);
-        destinationPixel[1] = BlendFunction(sourcePixelA[1], sourcePixelB[1], alphaA, alphaB);
-        destinationPixel[2] = BlendFunction(sourcePixelA[2], sourcePixelB[2], alphaA, alphaB);
-        destinationPixel[3] = 255 - fastDivideBy255((255 - alphaA) * (255 - alphaB));
-        sourcePixelA += 4;
-        sourcePixelB += 4;
-        destinationPixel += 4;
+    switch (mode) {
+    case FEBLEND_MODE_NORMAL:
+        return WebBlendModeNormal;
+    case FEBLEND_MODE_MULTIPLY:
+        return WebBlendModeMultiply;
+    case FEBLEND_MODE_SCREEN:
+        return WebBlendModeScreen;
+    case FEBLEND_MODE_DARKEN:
+        return WebBlendModeDarken;
+    case FEBLEND_MODE_LIGHTEN:
+        return WebBlendModeLighten;
+    default:
+        return WebBlendModeNormal;

[f(malita), 2014/07/24 16:23:49]

ASSERT_NOT_REACHED()?

[fs, 2014/07/25 10:52:00]

Added.

     }
 }
 
-void FEBlend::platformApplyGeneric(unsigned char* sourcePixelA, unsigned char* sourcePixelB,
-                                   unsigned char* destinationPixel, unsigned pixelArrayLength)
-{
-    switch (m_mode) {
-    case FEBLEND_MODE_NORMAL:
-        platformApply<feBlendNormal>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    case FEBLEND_MODE_MULTIPLY:
-        platformApply<feBlendMultiply>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    case FEBLEND_MODE_SCREEN:
-        platformApply<feBlendScreen>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    case FEBLEND_MODE_DARKEN:
-        platformApply<feBlendDarken>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    case FEBLEND_MODE_LIGHTEN:
-        platformApply<feBlendLighten>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    case FEBLEND_MODE_UNKNOWN:
-        platformApply<feBlendUnknown>(sourcePixelA, sourcePixelB, destinationPixel, pixelArrayLength);
-        break;
-    }
-}
-
 void FEBlend::applySoftware()
 {
     FilterEffect* in = inputEffect(0);
     FilterEffect* in2 = inputEffect(1);
 
-    ASSERT(m_mode > FEBLEND_MODE_UNKNOWN);
-    ASSERT(m_mode <= FEBLEND_MODE_LIGHTEN);
+    ASSERT(m_mode > FEBLEND_MODE_UNKNOWN && m_mode <= FEBLEND_MODE_LIGHTEN);
 
+#if HAVE(ARM_NEON_INTRINSICS)
     Uint8ClampedArray* dstPixelArray = createPremultipliedImageResult();
     if (!dstPixelArray)
         return;
 
     IntRect effectADrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
     RefPtr<Uint8ClampedArray> srcPixelArrayA = in->asPremultipliedImage(effectADrawingRect);
 
     IntRect effectBDrawingRect = requestedRegionOfInputImageData(in2->absolutePaintRect());
     RefPtr<Uint8ClampedArray> srcPixelArrayB = in2->asPremultipliedImage(effectBDrawingRect);
 
     unsigned pixelArrayLength = srcPixelArrayA->length();
     ASSERT(pixelArrayLength == srcPixelArrayB->length());
 
-#if HAVE(ARM_NEON_INTRINSICS)
     if (pixelArrayLength >= 8) {
         platformApplyNEON(srcPixelArrayA->data(), srcPixelArrayB->data(), dstPixelArray->data(), pixelArrayLength);
-    }
-    else { // If there is just one pixel we expand it to two.
+    } else {
+        // If there is just one pixel we expand it to two.
         ASSERT(pixelArrayLength > 0);
         uint32_t sourceA[2] = {0, 0};
         uint32_t sourceBAndDest[2] = {0, 0};
 
         sourceA[0] = reinterpret_cast<uint32_t*>(srcPixelArrayA->data())[0];
         sourceBAndDest[0] = reinterpret_cast<uint32_t*>(srcPixelArrayB->data())[0];
         platformApplyNEON(reinterpret_cast<uint8_t*>(sourceA), reinterpret_cast<uint8_t*>(sourceBAndDest), reinterpret_cast<uint8_t*>(sourceBAndDest), 8);
         reinterpret_cast<uint32_t*>(dstPixelArray->data())[0] = sourceBAndDest[0];
     }
 #else
-    platformApplyGeneric(srcPixelArrayA->data(), srcPixelArrayB->data(), dstPixelArray->data(), pixelArrayLength);
+    ImageBuffer* resultImage = createImageBufferResult();
+    if (!resultImage)
+        return;
+    GraphicsContext* filterContext = resultImage->context();
+
+    ImageBuffer* imageBuffer = in->asImageBuffer();
+    ImageBuffer* imageBuffer2 = in2->asImageBuffer();
+    ASSERT(imageBuffer);
+    ASSERT(imageBuffer2);
+
+    WebBlendMode blendMode = toWebBlendMode(m_mode);
+    filterContext->drawImageBuffer(imageBuffer2, drawingRegionOfInputImage(in2->absolutePaintRect()));
+    filterContext->drawImageBuffer(imageBuffer, drawingRegionOfInputImage(in->absolutePaintRect()), 0, CompositeSourceOver, blendMode);

[f(malita), 2014/07/24 16:23:49]

Did you run some perf measurements by any chance? I'm somewhat concerned by two
blits vs. one pass before.

[fs, 2014/07/25 10:52:00]

I wrote a simple TC that filled the viewport w/ reasonably sized rectangle with
a blend-filter applied, and then cycled the fill of them in rAF-loop, and logged
the time between each rAF-callback. Ran it passing --disable-deferred-filters
(and --disable-gpu). This new code is actually slightly faster on my machine
(likely because of the SSE2-codepaths in Skia), so feel slightly less bad about
this now... The approximate timings I saw were:

w/ patch: ~85ms (jittery)
unpatched: ~100ms (jittery)

and for comparison:
deferred-filters: 50ms (fairly stable)

I guess the MIPS-people will be unhappy though =)

 #endif
 }
 
-static SkXfermode::Mode toSkiaMode(BlendModeType mode)
-{
-    switch (mode) {
-    case FEBLEND_MODE_NORMAL:
-        return SkXfermode::kSrcOver_Mode;
-    case FEBLEND_MODE_MULTIPLY:
-        return SkXfermode::kMultiply_Mode;
-    case FEBLEND_MODE_SCREEN:
-        return SkXfermode::kScreen_Mode;
-    case FEBLEND_MODE_DARKEN:
-        return SkXfermode::kDarken_Mode;
-    case FEBLEND_MODE_LIGHTEN:
-        return SkXfermode::kLighten_Mode;
-    default:
-        return SkXfermode::kSrcOver_Mode;
-    }
-}
-
 PassRefPtr<SkImageFilter> FEBlend::createImageFilter(SkiaImageFilterBuilder* builder)
 {
     RefPtr<SkImageFilter> foreground(builder->build(inputEffect(0), operatingColorSpace()));
     RefPtr<SkImageFilter> background(builder->build(inputEffect(1), operatingColorSpace()));
-    SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(toSkiaMode(m_mode)));
+    RefPtr<SkXfermode> mode(WebCoreCompositeToSkiaComposite(CompositeSourceOver, toWebBlendMode(m_mode)));
     SkImageFilter::CropRect cropRect = getCropRect(builder->cropOffset());
-    return adoptRef(SkXfermodeImageFilter::Create(mode, background.get(), foreground.get(), &cropRect));
+    return adoptRef(SkXfermodeImageFilter::Create(mode.get(), background.get(), foreground.get(), &cropRect));
 }
 
 static TextStream& operator<<(TextStream& ts, const BlendModeType& type)
 {
     switch (type) {
     case FEBLEND_MODE_UNKNOWN:
         ts << "UNKNOWN";
         break;
     case FEBLEND_MODE_NORMAL:
         ts << "NORMAL";
@@ skipping 19 matching lines @@
     writeIndent(ts, indent);
     ts << "[feBlend";
     FilterEffect::externalRepresentation(ts);
     ts << " mode=\"" << m_mode << "\"]\n";
     inputEffect(0)->externalRepresentation(ts, indent + 1);
     inputEffect(1)->externalRepresentation(ts, indent + 1);
     return ts;
 }
 
 } // namespace blink