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

5 files changed, 114 insertions, 11 deletions

diff --git a/gm/imagefiltersclipped.cpp b/gm/imagefiltersclipped.cpp
index 84e63b8f0d..4187ba02aa 100644
--- a/gm/imagefiltersclipped.cpp
+++ b/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),
         };
 
diff --git a/gm/imagefiltersscaled.cpp b/gm/imagefiltersscaled.cpp
index 5dca30b822..0e7af56e09 100644
--- a/gm/imagefiltersscaled.cpp
+++ b/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,
diff --git a/gm/imageresizetiled.cpp b/gm/imageresizetiled.cpp
index eba87c5f1f..0e6bd6d6bc 100644
--- a/gm/imageresizetiled.cpp
+++ b/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;
diff --git a/gm/matriximagefilter.cpp b/gm/matriximagefilter.cpp
new file mode 100644
index 0000000000..ac8b94f148
--- /dev/null
+++ b/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);
+
+}
diff --git a/gm/resizeimagefilter.cpp b/gm/resizeimagefilter.cpp
index 02bbaff689..3f4f1fae65 100644
--- a/gm/resizeimagefilter.cpp
+++ b/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),
-                                        SkScalarInvert(deviceScaleY),
-                                        filterLevel,
-                                        input));
+            SkMatrixImageFilter::Create(matrix, filterLevel, input));
         SkPaint filteredPaint;
         filteredPaint.setImageFilter(imageFilter.get());
         canvas->saveLayer(&rect, &filteredPaint);