Apply the CTM to filter parameters for 4 pixel-moving filters.

src/effects/SkDisplacementMapEffect.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDisplacementMapEffect.h"
 #include "SkFlattenableBuffers.h"
 #include "SkUnPreMultiply.h"
@@ skipping 29 matching lines @@
     return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedB32(l));
 }
 
 template<> uint32_t getValue<SkDisplacementMapEffect::kA_ChannelSelectorType>(
     SkColor l, const SkUnPreMultiply::Scale*) {
     return SkGetPackedA32(l);
 }
 
 template<SkDisplacementMapEffect::ChannelSelectorType typeX,
          SkDisplacementMapEffect::ChannelSelectorType typeY>
-void computeDisplacement(SkScalar scale, SkBitmap* dst, SkBitmap* displ, SkBitmap* src, const SkIRect& bounds)
+void computeDisplacement(const SkVector& scale, SkBitmap* dst,
+                         SkBitmap* displ, const SkIPoint& displOffset,
+                         SkBitmap* src, const SkIPoint& srcOffset,
+                         const SkIRect& bounds)
 {
     static const SkScalar Inv8bit = SkScalarDiv(SK_Scalar1, 255.0f);
     const int srcW = src->width();
     const int srcH = src->height();
-    const SkScalar scaleForColor = SkScalarMul(scale, Inv8bit);
-    const SkScalar scaleAdj = SK_ScalarHalf - SkScalarMul(scale, SK_ScalarHalf);
+    const SkVector scaleForColor = SkVector::Make(SkScalarMul(scale.fX, Inv8bit),
+                                                  SkScalarMul(scale.fY, Inv8bit));
+    const SkVector scaleAdj = SkVector::Make(SK_ScalarHalf - SkScalarMul(scale.fX, SK_ScalarHalf),
+                                             SK_ScalarHalf - SkScalarMul(scale.fY, SK_ScalarHalf));
     const SkUnPreMultiply::Scale* table = SkUnPreMultiply::GetScaleTable();
     SkPMColor* dstPtr = dst->getAddr32(0, 0);
     for (int y = bounds.top(); y < bounds.bottom(); ++y) {
-        const SkPMColor* displPtr = displ->getAddr32(bounds.left(), y);
+        const SkPMColor* displPtr = displ->getAddr32(bounds.left() - displOffset.fX,
+                                                     y - displOffset.fY);
         for (int x = bounds.left(); x < bounds.right(); ++x, ++displPtr) {
-            const SkScalar displX = SkScalarMul(scaleForColor,
-                SkIntToScalar(getValue<typeX>(*displPtr, table))) + scaleAdj;
-            const SkScalar displY = SkScalarMul(scaleForColor,
-                SkIntToScalar(getValue<typeY>(*displPtr, table))) + scaleAdj;
+            const SkScalar displX = SkScalarMul(scaleForColor.fX,
+                SkIntToScalar(getValue<typeX>(*displPtr, table))) + scaleAdj.fX;
+            const SkScalar displY = SkScalarMul(scaleForColor.fY,
+                SkIntToScalar(getValue<typeY>(*displPtr, table))) + scaleAdj.fY;
             // Truncate the displacement values
-            const int srcX = x + SkScalarTruncToInt(displX);
-            const int srcY = y + SkScalarTruncToInt(displY);
+            const int srcX = x + SkScalarTruncToInt(displX) - srcOffset.fX;
+            const int srcY = y + SkScalarTruncToInt(displY) - srcOffset.fY;
             *dstPtr++ = ((srcX < 0) || (srcX >= srcW) || (srcY < 0) || (srcY >= srcH)) ?
                       0 : *(src->getAddr32(srcX, srcY));
         }
     }
 }
 
 template<SkDisplacementMapEffect::ChannelSelectorType typeX>
 void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
-                         SkScalar scale, SkBitmap* dst, SkBitmap* displ, SkBitmap* src, const SkIRect& bounds)
+                         const SkVector& scale, SkBitmap* dst,
+                         SkBitmap* displ, const SkIPoint& displOffset,
+                         SkBitmap* src, const SkIPoint& srcOffset,
+                         const SkIRect& bounds)
 {
     switch (yChannelSelector) {
       case SkDisplacementMapEffect::kR_ChannelSelectorType:
         computeDisplacement<typeX, SkDisplacementMapEffect::kR_ChannelSelectorType>(
-            scale, dst, displ, src, bounds);
+            scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kG_ChannelSelectorType:
         computeDisplacement<typeX, SkDisplacementMapEffect::kG_ChannelSelectorType>(
-            scale, dst, displ, src, bounds);
+            scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kB_ChannelSelectorType:
         computeDisplacement<typeX, SkDisplacementMapEffect::kB_ChannelSelectorType>(
-            scale, dst, displ, src, bounds);
+            scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kA_ChannelSelectorType:
         computeDisplacement<typeX, SkDisplacementMapEffect::kA_ChannelSelectorType>(
-            scale, dst, displ, src, bounds);
+            scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
       default:
         SkDEBUGFAIL("Unknown Y channel selector");
     }
 }
 
 void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                          SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
-                         SkScalar scale, SkBitmap* dst, SkBitmap* displ, SkBitmap* src, const SkIRect& bounds)
+                         const SkVector& scale, SkBitmap* dst,
+                         SkBitmap* displ, const SkIPoint& displOffset,
+                         SkBitmap* src, const SkIPoint& srcOffset,
+                         const SkIRect& bounds)
 {
     switch (xChannelSelector) {
       case SkDisplacementMapEffect::kR_ChannelSelectorType:
         computeDisplacement<SkDisplacementMapEffect::kR_ChannelSelectorType>(
-            yChannelSelector, scale, dst, displ, src, bounds);
+            yChannelSelector, scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kG_ChannelSelectorType:
         computeDisplacement<SkDisplacementMapEffect::kG_ChannelSelectorType>(
-            yChannelSelector, scale, dst, displ, src, bounds);
+            yChannelSelector, scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kB_ChannelSelectorType:
         computeDisplacement<SkDisplacementMapEffect::kB_ChannelSelectorType>(
-            yChannelSelector, scale, dst, displ, src, bounds);
+            yChannelSelector, scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kA_ChannelSelectorType:
         computeDisplacement<SkDisplacementMapEffect::kA_ChannelSelectorType>(
-            yChannelSelector, scale, dst, displ, src, bounds);
+            yChannelSelector, scale, dst, displ, displOffset, src, srcOffset, bounds);
         break;
       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
       default:
         SkDEBUGFAIL("Unknown X channel selector");
     }
 }
 
 bool channel_selector_type_is_valid(SkDisplacementMapEffect::ChannelSelectorType cst) {
     switch (cst) {
     case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
@@ skipping 47 matching lines @@
 }
 
 bool SkDisplacementMapEffect::onFilterImage(Proxy* proxy,
                                             const SkBitmap& src,
                                             const SkMatrix& ctm,
                                             SkBitmap* dst,
                                             SkIPoint* offset) {
     SkBitmap displ = src, color = src;
     SkImageFilter* colorInput = getColorInput();
     SkImageFilter* displacementInput = getDisplacementInput();
-    if ((colorInput && !colorInput->filterImage(proxy, src, ctm, &color, offset)) ||
-        (displacementInput && !displacementInput->filterImage(proxy, src, ctm, &displ, offset))) {
+    SkIPoint colorOffset = SkIPoint::Make(0, 0), displOffset = SkIPoint::Make(0, 0);
+    if ((colorInput && !colorInput->filterImage(proxy, src, ctm, &color, &colorOffset)) ||
+        (displacementInput && !displacementInput->filterImage(proxy, src, ctm, &displ, &displOffset))) {
         return false;
     }
     if ((displ.config() != SkBitmap::kARGB_8888_Config) ||
         (color.config() != SkBitmap::kARGB_8888_Config)) {
         return false;
     }
 
     SkAutoLockPixels alp_displacement(displ), alp_color(color);
     if (!displ.getPixels() || !color.getPixels()) {
         return false;
     }
     SkIRect bounds;
     color.getBounds(&bounds);
+    bounds.offset(colorOffset);

[sugoi, 2014/01/17 21:56:27]

We offset the source here and then we subtract a constant offset (srcOffset) to
every pixel within the loop ? It seems inefficient, unless I'm missing
something.

[Stephen White, 2014/01/18 01:23:19]

We have to offset it to intersect it below. But we can untranslate it
afterwards.

Fixed.

     if (!this->applyCropRect(&bounds, ctm)) {
         return false;
     }
     SkIRect displBounds;
     displ.getBounds(&displBounds);
+    displBounds.offset(displOffset);
     if (!this->applyCropRect(&displBounds, ctm)) {
         return false;
     }
     if (!bounds.intersect(displBounds)) {
         return false;
     }
 
     dst->setConfig(color.config(), bounds.width(), bounds.height());
     dst->allocPixels();
     if (!dst->getPixels()) {
         return false;
     }
 
-    computeDisplacement(fXChannelSelector, fYChannelSelector, fScale, dst, &displ, &color, bounds);
+    SkVector scale = SkVector::Make(fScale, fScale);
+    ctm.mapVectors(&scale, 1);
+
+    computeDisplacement(fXChannelSelector, fYChannelSelector, scale, dst,
+                        &displ, displOffset, &color, colorOffset, bounds);
 
     offset->fX = bounds.left();
     offset->fY = bounds.top();
     return true;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
 class GrGLDisplacementMapEffect : public GrGLEffect {
@@ skipping 21 matching lines @@
 
     typedef GrGLEffect INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class GrDisplacementMapEffect : public GrEffect {
 public:
     static GrEffectRef* Create(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                                SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
-                               SkScalar scale, GrTexture* displacement, GrTexture* color) {
+                               SkVector scale,
+                               GrTexture* displacement, const SkMatrix& displacementMatrix,
+                               GrTexture* color, const SkMatrix& colorMatrix) {
         AutoEffectUnref effect(SkNEW_ARGS(GrDisplacementMapEffect, (xChannelSelector,
                                                                     yChannelSelector,
                                                                     scale,
                                                                     displacement,
-                                                                    color)));
+                                                                    displacementMatrix,
+                                                                    color,
+                                                                    colorMatrix)));
         return CreateEffectRef(effect);
     }
 
     virtual ~GrDisplacementMapEffect();
 
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
     SkDisplacementMapEffect::ChannelSelectorType xChannelSelector() const
         { return fXChannelSelector; }
     SkDisplacementMapEffect::ChannelSelectorType yChannelSelector() const
         { return fYChannelSelector; }
-    SkScalar scale() const { return fScale; }
+    const SkVector& scale() const { return fScale; }
 
     typedef GrGLDisplacementMapEffect GLEffect;
     static const char* Name() { return "DisplacementMap"; }
 
     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
 
 private:
     virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
 
     GrDisplacementMapEffect(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                             SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
-                            SkScalar scale, GrTexture* displacement, GrTexture* color);
+                            const SkVector& scale,
+                            GrTexture* displacement, const SkMatrix& displacementMatrix,
+                            GrTexture* color, const SkMatrix& colorMatrix);
 
     GR_DECLARE_EFFECT_TEST;
 
     GrCoordTransform            fDisplacementTransform;
     GrTextureAccess             fDisplacementAccess;
     GrCoordTransform            fColorTransform;
     GrTextureAccess             fColorAccess;
     SkDisplacementMapEffect::ChannelSelectorType fXChannelSelector;
     SkDisplacementMapEffect::ChannelSelectorType fYChannelSelector;
-    SkScalar fScale;
+    SkVector fScale;
 
     typedef GrEffect INHERITED;
 };
 
 bool SkDisplacementMapEffect::filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
                                              SkBitmap* result, SkIPoint* offset) {
     SkBitmap colorBM;
     SkIPoint colorOffset = SkIPoint::Make(0, 0);
     if (!SkImageFilterUtils::GetInputResultGPU(getColorInput(), proxy, src, ctm, &colorBM,
                                                &colorOffset)) {
@@ skipping 13 matching lines @@
     desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
     desc.fWidth = src.width();
     desc.fHeight = src.height();
     desc.fConfig = kSkia8888_GrPixelConfig;
 
     GrAutoScratchTexture ast(context, desc);
     SkAutoTUnref<GrTexture> dst(ast.detach());
 
     GrContext::AutoRenderTarget art(context, dst->asRenderTarget());
 
-    GrPaint paint;
-    paint.addColorEffect(
-        GrDisplacementMapEffect::Create(fXChannelSelector,
-                                        fYChannelSelector,
-                                        fScale,
-                                        displacement,
-                                        color))->unref();
+    SkVector scale = SkVector::Make(fScale, fScale);
+    ctm.mapVectors(&scale, 1);
     SkIRect bounds;
     src.getBounds(&bounds);
+    bounds.offset(colorOffset);
     if (!this->applyCropRect(&bounds, ctm)) {
         return false;
     }
     SkIRect displBounds;
     displacementBM.getBounds(&displBounds);
+    displBounds.offset(displacementOffset);
     if (!this->applyCropRect(&displBounds, ctm)) {
         return false;
     }
     if (!bounds.intersect(displBounds)) {
         return false;
     }
-    SkRect srcRect = SkRect::Make(bounds);
-    SkRect dstRect = SkRect::MakeWH(srcRect.width(), srcRect.height());
-    context->drawRectToRect(paint, dstRect, srcRect);
+
+    GrPaint paint;
+    SkMatrix colorMatrix = GrEffect::MakeDivByTextureWHMatrix(color);
+    colorMatrix.preTranslate(-SkIntToScalar(colorOffset.fX),
+                             -SkIntToScalar(colorOffset.fY));
+    SkMatrix displacementMatrix = GrEffect::MakeDivByTextureWHMatrix(displacement);
+    displacementMatrix.preTranslate(-SkIntToScalar(displacementOffset.fX),
+                                    -SkIntToScalar(displacementOffset.fY));
+    paint.addColorEffect(
+        GrDisplacementMapEffect::Create(fXChannelSelector,
+                                        fYChannelSelector,
+                                        scale,
+                                        displacement,
+                                        displacementMatrix,
+                                        color,
+                                        colorMatrix))->unref();
+    SkMatrix matrix;
+    matrix.setTranslate(-SkIntToScalar(bounds.left()), -SkIntToScalar(bounds.top()));

[sugoi, 2014/01/17 21:56:27]

Same comment about offsetting the bounds and translating back.

[Stephen White, 2014/01/18 01:23:19]

Fixed (although I don't think it'll make it any faster in the GPU case.)

+    context->concatMatrix(matrix);
+    context->drawRect(paint, SkRect::Make(bounds));
     offset->fX = bounds.left();
     offset->fY = bounds.top();
     return SkImageFilterUtils::WrapTexture(dst, bounds.width(), bounds.height(), result);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GrDisplacementMapEffect::GrDisplacementMapEffect(
                              SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
                              SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
-                             SkScalar scale,
+                             const SkVector& scale,
                              GrTexture* displacement,
-                             GrTexture* color)
-    : fDisplacementTransform(kLocal_GrCoordSet, displacement)
+                             const SkMatrix& displacementMatrix,
+                             GrTexture* color,
+                             const SkMatrix& colorMatrix)
+    : fDisplacementTransform(kLocal_GrCoordSet, displacementMatrix, displacement)
     , fDisplacementAccess(displacement)
-    , fColorTransform(kLocal_GrCoordSet, color)
+    , fColorTransform(kLocal_GrCoordSet, colorMatrix, color)
     , fColorAccess(color)
     , fXChannelSelector(xChannelSelector)
     , fYChannelSelector(yChannelSelector)
     , fScale(scale) {
     this->addCoordTransform(&fDisplacementTransform);
     this->addTextureAccess(&fDisplacementAccess);
     this->addCoordTransform(&fColorTransform);
     this->addTextureAccess(&fColorAccess);
     this->setWillNotUseInputColor();
 }
@@ skipping 36 matching lines @@
                                            GrEffectUnitTest::kAlphaTextureIdx;
     int texIdxColor = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
                                            GrEffectUnitTest::kAlphaTextureIdx;
     static const int kMaxComponent = 4;
     SkDisplacementMapEffect::ChannelSelectorType xChannelSelector =
         static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
         random->nextRangeU(1, kMaxComponent));
     SkDisplacementMapEffect::ChannelSelectorType yChannelSelector =
         static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
         random->nextRangeU(1, kMaxComponent));
-    SkScalar scale = random->nextRangeScalar(0, 100.0f);
+    SkVector scale = SkVector::Make(random->nextRangeScalar(0, 100.0f),
+                                    random->nextRangeScalar(0, 100.0f));
 
     return GrDisplacementMapEffect::Create(xChannelSelector, yChannelSelector, scale,
-                                           textures[texIdxDispl], textures[texIdxColor]);
+                                           textures[texIdxDispl], SkMatrix::I(),
+                                           textures[texIdxColor], SkMatrix::I());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GrGLDisplacementMapEffect::GrGLDisplacementMapEffect(const GrBackendEffectFactory& factory,
                                                      const GrDrawEffect& drawEffect)
     : INHERITED(factory)
     , fXChannelSelector(drawEffect.castEffect<GrDisplacementMapEffect>().xChannelSelector())
     , fYChannelSelector(drawEffect.castEffect<GrDisplacementMapEffect>().yChannelSelector()) {
 }
@@ skipping 76 matching lines @@
     builder->fsCodeAppendf("%s = %s ? vec4(0.0) : ", outputColor, outOfBounds);
     builder->fsAppendTextureLookup(samplers[1], cCoords, coords[1].type());
     builder->fsCodeAppend(";\n");
 }
 
 void GrGLDisplacementMapEffect::setData(const GrGLUniformManager& uman,
                                         const GrDrawEffect& drawEffect) {
     const GrDisplacementMapEffect& displacementMap =
         drawEffect.castEffect<GrDisplacementMapEffect>();
     GrTexture* colorTex = displacementMap.texture(1);
-    SkScalar scaleX = SkScalarDiv(displacementMap.scale(), SkIntToScalar(colorTex->width()));
-    SkScalar scaleY = SkScalarDiv(displacementMap.scale(), SkIntToScalar(colorTex->height()));
+    SkScalar scaleX = SkScalarDiv(displacementMap.scale().fX, SkIntToScalar(colorTex->width()));
+    SkScalar scaleY = SkScalarDiv(displacementMap.scale().fY, SkIntToScalar(colorTex->height()));
     uman.set2f(fScaleUni, SkScalarToFloat(scaleX),
                colorTex->origin() == kTopLeft_GrSurfaceOrigin ?
                SkScalarToFloat(scaleY) : SkScalarToFloat(-scaleY));
 }
 
 GrGLEffect::EffectKey GrGLDisplacementMapEffect::GenKey(const GrDrawEffect& drawEffect,
                                                         const GrGLCaps&) {
     const GrDisplacementMapEffect& displacementMap =
         drawEffect.castEffect<GrDisplacementMapEffect>();
 
     EffectKey xKey = displacementMap.xChannelSelector();
     EffectKey yKey = displacementMap.yChannelSelector() << SkDisplacementMapEffect::kKeyBits;
 
     return xKey | yKey;
 }
 #endif