Implement a generic matrix transform image filter.

This will be used in Blink to accommodate matrices that contain
rotation or shearing. This is a generalization of SkResizeImageFilter,
so I've replaced all uses of SkResizeImageFilter in Skia. (It might be
easier to review by diffing it with SkResizeImageFilter, too.)

R=reed@google.com

Review URL: https://codereview.chromium.org/211103006

git-svn-id: http://skia.googlecode.com/svn/trunk@13941 2bbb7eff-a529-9590-31e7-b0007b416f81

gm/imagefiltersclipped.cpp

@@ -16,7 +16,7 @@
 #include "SkOffsetImageFilter.h"
 #include "SkPerlinNoiseShader.h"
 #include "SkRectShaderImageFilter.h"
-#include "SkResizeImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkScalar.h"
 
 #define RESIZE_FACTOR_X SkIntToScalar(2)
@@ -91,6 +91,8 @@ protected:
         SkAutoTUnref<SkImageFilter> checkerboard(SkBitmapSource::Create(fCheckerboard));
         SkAutoTUnref<SkShader> noise(SkPerlinNoiseShader::CreateFractalNoise(
             SkDoubleToScalar(0.1), SkDoubleToScalar(0.05), 1, 0));
+        SkMatrix resizeMatrix;
+        resizeMatrix.setScale(RESIZE_FACTOR_X, RESIZE_FACTOR_Y);
 
         SkImageFilter* filters[] = {
             SkBlurImageFilter::Create(SkIntToScalar(12), SkIntToScalar(12)),
@@ -104,7 +106,7 @@ protected:
             SkDilateImageFilter::Create(2, 2, checkerboard.get()),
             SkErodeImageFilter::Create(2, 2, checkerboard.get()),
             SkOffsetImageFilter::Create(SkIntToScalar(-16), SkIntToScalar(32)),
-            SkResizeImageFilter::Create(RESIZE_FACTOR_X, RESIZE_FACTOR_Y, SkPaint::kNone_FilterLevel),
+            SkMatrixImageFilter::Create(resizeMatrix, SkPaint::kNone_FilterLevel),
             SkRectShaderImageFilter::Create(noise),
         };
 

gm/imagefiltersscaled.cpp

@@ -17,7 +17,7 @@
 #include "SkOffsetImageFilter.h"
 #include "SkPerlinNoiseShader.h"
 #include "SkRectShaderImageFilter.h"
-#include "SkResizeImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkScalar.h"
 
 #define RESIZE_FACTOR SkIntToScalar(4)
@@ -100,6 +100,8 @@ protected:
         SkScalar kd = SkIntToScalar(2);
         SkScalar surfaceScale = SkIntToScalar(1);
         SkColor white(0xFFFFFFFF);
+        SkMatrix resizeMatrix;
+        resizeMatrix.setScale(RESIZE_FACTOR, RESIZE_FACTOR);
 
         SkImageFilter* filters[] = {
             SkBlurImageFilter::Create(SkIntToScalar(4), SkIntToScalar(4)),
@@ -113,7 +115,7 @@ protected:
             SkDilateImageFilter::Create(1, 1, checkerboard.get()),
             SkErodeImageFilter::Create(1, 1, checkerboard.get()),
             SkOffsetImageFilter::Create(SkIntToScalar(32), 0),
-            SkResizeImageFilter::Create(RESIZE_FACTOR, RESIZE_FACTOR, SkPaint::kNone_FilterLevel),
+            SkMatrixImageFilter::Create(resizeMatrix, SkPaint::kNone_FilterLevel),
             SkRectShaderImageFilter::Create(noise),
             SkLightingImageFilter::CreatePointLitDiffuse(pointLocation, white, surfaceScale, kd),
             SkLightingImageFilter::CreateSpotLitDiffuse(spotLocation, spotTarget, spotExponent,

gm/imageresizetiled.cpp

@@ -6,7 +6,7 @@
  */
 
 #include "gm.h"
-#include "SkResizeImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkRandom.h"
 
 #define WIDTH 640
@@ -36,8 +36,10 @@ protected:
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         SkPaint paint;
+        SkMatrix matrix;
+        matrix.setScale(RESIZE_FACTOR, RESIZE_FACTOR);
         SkAutoTUnref<SkImageFilter> imageFilter(
-            SkResizeImageFilter::Create(RESIZE_FACTOR, RESIZE_FACTOR, SkPaint::kNone_FilterLevel));
+            SkMatrixImageFilter::Create(matrix, SkPaint::kNone_FilterLevel));
         paint.setImageFilter(imageFilter.get());
         const SkScalar tile_size = SkIntToScalar(100);
         SkRect bounds;

gm/matriximagefilter.cpp

@@ -0,0 +1,97 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkColor.h"
+#include "SkMatrixImageFilter.h"
+
+namespace skiagm {
+
+class MatrixImageFilterGM : public GM {
+public:
+    MatrixImageFilterGM() {
+        this->setBGColor(0x00000000);
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("matriximagefilter");
+    }
+
+    void draw(SkCanvas* canvas, const SkRect& rect, const SkBitmap& bitmap,
+              const SkMatrix& matrix, SkPaint::FilterLevel filterLevel) {
+        SkAutoTUnref<SkImageFilter> imageFilter(
+            SkMatrixImageFilter::Create(matrix, filterLevel));
+        SkPaint paint;
+        paint.setImageFilter(imageFilter.get());
+        canvas->saveLayer(&rect, &paint);
+        canvas->drawBitmap(bitmap, 0, 0);
+        canvas->restore();
+    }
+
+    virtual SkISize onISize() {
+        return make_isize(420, 100);
+    }
+
+    void make_checkerboard(SkBitmap* bitmap) {
+        bitmap->allocN32Pixels(64, 64);
+        SkCanvas canvas(*bitmap);
+        SkPaint darkPaint;
+        darkPaint.setColor(0xFF404040);
+        SkPaint lightPaint;
+        lightPaint.setColor(0xFFA0A0A0);
+        for (int y = 0; y < 64; y += 32) {
+            for (int x = 0; x < 64; x += 32) {
+                canvas.save();
+                canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
+                canvas.drawRect(SkRect::MakeXYWH(0, 0, 16, 16), darkPaint);
+                canvas.drawRect(SkRect::MakeXYWH(16, 0, 16, 16), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(0, 16, 16, 16), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(16, 16, 16, 16), darkPaint);
+                canvas.restore();
+            }
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->clear(0x00000000);
+        SkPaint paint;
+        SkMatrix matrix;
+        SkScalar margin = SkIntToScalar(10);
+        matrix.setSkew(SkDoubleToScalar(0.5), SkDoubleToScalar(0.2));
+        SkRect srcBounds;
+        SkBitmap checkerboard;
+        make_checkerboard(&checkerboard);
+        checkerboard.getBounds(&srcBounds);
+        // Outer paint does no filtering; leave it all for the filter
+        paint.setFilterLevel(SkPaint::kNone_FilterLevel);
+
+        SkRect srcRect = SkRect::MakeWH(96, 96);
+
+        canvas->translate(margin, margin);
+        draw(canvas, srcRect, checkerboard, matrix, SkPaint::kNone_FilterLevel);
+
+        canvas->translate(srcRect.width() + margin, 0);
+        draw(canvas, srcRect, checkerboard, matrix, SkPaint::kLow_FilterLevel);
+
+        canvas->translate(srcRect.width() + margin, 0);
+        draw(canvas, srcRect, checkerboard, matrix, SkPaint::kMedium_FilterLevel);
+
+        canvas->translate(srcRect.width() + margin, 0);
+        draw(canvas, srcRect, checkerboard, matrix, SkPaint::kHigh_FilterLevel);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new MatrixImageFilterGM; }
+static GMRegistry reg(MyFactory);
+
+}

gm/resizeimagefilter.cpp

@@ -9,7 +9,7 @@
 #include "SkBitmapDevice.h"
 #include "SkBitmapSource.h"
 #include "SkColor.h"
-#include "SkResizeImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkRefCnt.h"
 
 namespace skiagm {
@@ -38,11 +38,11 @@ protected:
         canvas->translate(rect.x(), rect.y());
         canvas->scale(deviceScaleX, deviceScaleY);
         canvas->translate(-rect.x(), -rect.y());
+        SkMatrix matrix;
+        matrix.setScale(SkScalarInvert(deviceScaleX),
+                        SkScalarInvert(deviceScaleY));
         SkAutoTUnref<SkImageFilter> imageFilter(
-            SkResizeImageFilter::Create(SkScalarInvert(deviceScaleX),
+            SkMatrixImageFilter::Create(matrix, filterLevel, input));
-                                        SkScalarInvert(deviceScaleY),
-                                        filterLevel,
-                                        input));
         SkPaint filteredPaint;
         filteredPaint.setImageFilter(imageFilter.get());
         canvas->saveLayer(&rect, &filteredPaint);

gyp/effects.gypi

@@ -58,6 +58,7 @@
     '<(skia_src_path)/effects/SkTableMaskFilter.cpp',
     '<(skia_src_path)/effects/SkTestImageFilters.cpp',
     '<(skia_src_path)/effects/SkTileImageFilter.cpp',
+    '<(skia_src_path)/effects/SkMatrixImageFilter.cpp',
     '<(skia_src_path)/effects/SkTransparentShader.cpp',
     '<(skia_src_path)/effects/SkXfermodeImageFilter.cpp',
 

gyp/gmslides.gypi

@@ -107,6 +107,7 @@
     '../gm/lcdtext.cpp',
     '../gm/linepaths.cpp',
     '../gm/matrixconvolution.cpp',
+    '../gm/matriximagefilter.cpp',
     '../gm/megalooper.cpp',
     '../gm/mixedxfermodes.cpp',
     '../gm/modecolorfilters.cpp',

include/effects/SkMatrixImageFilter.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkMatrixImageFilter_DEFINED
+#define SkMatrixImageFilter_DEFINED
+
+#include "SkImageFilter.h"
+#include "SkScalar.h"
+#include "SkSize.h"
+#include "SkPoint.h"
+#include "SkPaint.h"
+
+/*! \class SkMatrixImageFilter
+    Matrix transformation image filter.  This filter draws its source
+    input transformed by the given matrix.
+ */
+
+class SK_API SkMatrixImageFilter : public SkImageFilter {
+public:
+    /** Construct a 2D transformation image filter.
+     *  @param transform    The matrix to apply when drawing the src bitmap
+     *  @param filterLevel  The quality of filtering to apply when scaling.
+     *  @param input        The input image filter.  If NULL, the src bitmap
+     *                      passed to filterImage() is used instead.
+     */
+
+    static SkMatrixImageFilter* Create(const SkMatrix& transform,
+                                       SkPaint::FilterLevel,
+                                       SkImageFilter* input = NULL);
+    virtual ~SkMatrixImageFilter();
+
+    virtual void computeFastBounds(const SkRect&, SkRect*) const SK_OVERRIDE;
+
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkMatrixImageFilter)
+
+protected:
+    SkMatrixImageFilter(const SkMatrix& transform,
+                        SkPaint::FilterLevel,
+                        SkImageFilter* input = NULL);
+    SkMatrixImageFilter(SkReadBuffer& buffer);
+    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
+
+    virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
+                               SkBitmap* result, SkIPoint* loc) const SK_OVERRIDE;
+    virtual bool onFilterBounds(const SkIRect& src, const SkMatrix&,
+                                SkIRect* dst) const SK_OVERRIDE;
+
+private:
+    SkMatrix              fTransform;
+    SkPaint::FilterLevel  fFilterLevel;
+    typedef SkImageFilter INHERITED;
+};
+
+#endif

src/effects/SkMatrixImageFilter.cpp

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2014 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkMatrixImageFilter.h"
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkDevice.h"
+#include "SkColorPriv.h"
+#include "SkReadBuffer.h"
+#include "SkWriteBuffer.h"
+#include "SkMatrix.h"
+#include "SkRect.h"
+
+SkMatrixImageFilter::SkMatrixImageFilter(const SkMatrix& transform,
+                                         SkPaint::FilterLevel filterLevel,
+                                         SkImageFilter* input)
+  : INHERITED(input),
+    fTransform(transform),
+    fFilterLevel(filterLevel) {
+}
+
+SkMatrixImageFilter* SkMatrixImageFilter::Create(const SkMatrix& transform,
+                                                 SkPaint::FilterLevel filterLevel,
+                                                 SkImageFilter* input) {
+    return SkNEW_ARGS(SkMatrixImageFilter, (transform, filterLevel, input));
+}
+
+SkMatrixImageFilter::SkMatrixImageFilter(SkReadBuffer& buffer)
+  : INHERITED(1, buffer) {
+    buffer.readMatrix(&fTransform);
+    fFilterLevel = static_cast<SkPaint::FilterLevel>(buffer.readInt());
+}
+
+void SkMatrixImageFilter::flatten(SkWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
+    buffer.writeMatrix(fTransform);
+    buffer.writeInt(fFilterLevel);
+}
+
+SkMatrixImageFilter::~SkMatrixImageFilter() {
+}
+
+bool SkMatrixImageFilter::onFilterImage(Proxy* proxy,
+                                        const SkBitmap& source,
+                                        const Context& ctx,
+                                        SkBitmap* result,
+                                        SkIPoint* offset) const {
+    SkBitmap src = source;
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
+    if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset)) {
+        return false;
+    }
+
+    SkRect dstRect;
+    SkIRect srcBounds, dstBounds;
+    src.getBounds(&srcBounds);
+    srcBounds.offset(srcOffset);
+    SkRect srcRect = SkRect::Make(srcBounds);
+    SkMatrix matrix;
+    if (!ctx.ctm().invert(&matrix)) {
+        return false;
+    }
+    matrix.postConcat(fTransform);
+    matrix.postConcat(ctx.ctm());
+    matrix.mapRect(&dstRect, srcRect);
+    dstRect.roundOut(&dstBounds);
+
+    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(dstBounds.width(), dstBounds.height()));
+    if (NULL == device.get()) {
+        return false;
+    }
+
+    SkCanvas canvas(device.get());
+    canvas.translate(-SkIntToScalar(dstBounds.x()), -SkIntToScalar(dstBounds.y()));
+    canvas.concat(matrix);
+    SkPaint paint;
+
+    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+    paint.setFilterLevel(fFilterLevel);
+    canvas.drawBitmap(src, srcRect.x(), srcRect.y(), &paint);
+
+    *result = device.get()->accessBitmap(false);
+    offset->fX = dstBounds.fLeft;
+    offset->fY = dstBounds.fTop;
+    return true;
+}
+
+void SkMatrixImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
+    SkRect bounds = src;
+    if (getInput(0)) {
+        getInput(0)->computeFastBounds(src, &bounds);
+    }
+    SkMatrix matrix;
+    matrix.setTranslate(-bounds.x(), -bounds.y());
+    matrix.postConcat(fTransform);
+    matrix.postTranslate(bounds.x(), bounds.y());
+    matrix.mapRect(dst, bounds);
+}
+
+bool SkMatrixImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
+                                         SkIRect* dst) const {
+    SkMatrix transformInverse;
+    if (!fTransform.invert(&transformInverse)) {
+        return false;
+    }
+    SkMatrix matrix;
+    if (!ctm.invert(&matrix)) {
+        return false;
+    }
+    matrix.postConcat(transformInverse);
+    matrix.postConcat(ctm);
+    SkRect floatBounds;
+    matrix.mapRect(&floatBounds, SkRect::Make(src));
+    SkIRect bounds;
+    floatBounds.roundOut(&bounds);
+    if (getInput(0) && !getInput(0)->filterBounds(bounds, ctm, &bounds)) {
+        return false;
+    }
+
+    *dst = bounds;
+    return true;
+}

src/ports/SkGlobalInitialization_chromium.cpp

@@ -58,6 +58,7 @@
 #include "SkTableColorFilter.h"
 #include "SkTestImageFilters.h"
 #include "SkTileImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 
 static void InitializeFlattenables(int*) {
@@ -96,6 +97,7 @@ static void InitializeFlattenables(int*) {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkStippleMaskFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSumPathEffect)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkTileImageFilter)
+    SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMatrixImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkXfermodeImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMagnifierImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMatrixConvolutionImageFilter)

src/ports/SkGlobalInitialization_default.cpp

@@ -58,6 +58,7 @@
 #include "SkTableColorFilter.h"
 #include "SkTestImageFilters.h"
 #include "SkTileImageFilter.h"
+#include "SkMatrixImageFilter.h"
 #include "SkXfermodeImageFilter.h"
 
 static void InitializeFlattenables(int*) {
@@ -96,6 +97,7 @@ static void InitializeFlattenables(int*) {
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkStippleMaskFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSumPathEffect)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkTileImageFilter)
+    SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMatrixImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkXfermodeImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMagnifierImageFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkMatrixConvolutionImageFilter)