Benchmark designed to exercise fractional image scale/translation

bench/BitmapFractionalBench.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 "Benchmark.h"
 #include "SkBlurMask.h"
 #include "SkCanvas.h"
 #include "SkPaint.h"
 #include "SkRandom.h"
 #include "SkShader.h"
 #include "SkString.h"
 
-class BitmapScaleBench: public Benchmark {
-    int         fLoopCount;
+class BitmapFractionalBench: public Benchmark {
     int         fInputSize;
     int         fOutputSize;
-    SkString    fName;
 
 public:
-    BitmapScaleBench( int is, int os)  {
+    BitmapFractionalBench( int is )  {
         fInputSize = is;
-        fOutputSize = os;
-
-        fLoopCount = 20;
+        fOutputSize = 2*is;
     }
 
 protected:
 
     SkBitmap fInputBitmap, fOutputBitmap;
     SkMatrix fMatrix;
 
     virtual const char* onGetName() {
-        return fName.c_str();
+        return "bitmap_fractional_bench";
     }
 
     int inputSize() const {
         return fInputSize;
     }
 
     int outputSize() const {
         return fOutputSize;
     }
 
-    float scale() const {
-        return float(outputSize())/inputSize();
-    }
-
     SkIPoint onGetSize() SK_OVERRIDE {
         return SkIPoint::Make( fOutputSize, fOutputSize );
     }
 
-    void setName(const char * name) {
-        fName.printf( "bitmap_scale_%s_%d_%d", name, fInputSize, fOutputSize );
-    }
-
     virtual void onPreDraw() {
         fInputBitmap.allocN32Pixels(fInputSize, fInputSize, true);
         fInputBitmap.eraseColor(SK_ColorWHITE);
 
         fOutputBitmap.allocN32Pixels(fOutputSize, fOutputSize, true);
-
-        fMatrix.setScale( scale(), scale() );
     }
 
     virtual void onDraw(const int loops, SkCanvas*) {
         SkPaint paint;
         this->setupPaint(&paint);
 
         preBenchSetup();
 
+        SkCanvas canvas( fOutputBitmap );
+        paint.setFilterLevel(SkPaint::kHigh_FilterLevel);
+        fInputBitmap.notifyPixelsChanged();
+
         for (int i = 0; i < loops; i++) {
-            doScaleImage();
+            // re-scale the image by a variety of close, fractional scales
+            for (int j = 0 ; j < 10 ; j++) {
+                fMatrix = SkMatrix::I();
+                fMatrix.setScale( 1 + j/3.f, 1 + j/3.f );
+                canvas.drawBitmapMatrix( fInputBitmap, fMatrix, &paint );
+            }
+            // Now try some fractional translates
+            for (int j = 0 ; j < 10 ; j++) {
+                fMatrix = SkMatrix::I();
+                fMatrix.setTranslate( j/3.f, j/3.f );
+                canvas.drawBitmapMatrix( fInputBitmap, fMatrix, &paint );
+            }
+            // Finally, some fractional translates with non-identity scale.
+            for (int j = 0 ; j < 10 ; j++) {
+                fMatrix = SkMatrix::I();
+                fMatrix.setTranslate( j/3.f, j/3.f );
+                fMatrix.preScale( 1.5, 1.5 );

[reed1, 2014/08/25 17:10:15]

may get some warnings of double->float here.

+                canvas.drawBitmapMatrix( fInputBitmap, fMatrix, &paint );
+            }
         }
     }
 
-    virtual void doScaleImage() = 0;
     virtual void preBenchSetup() {}
 private:
     typedef Benchmark INHERITED;
 };
 
-class BitmapFilterScaleBench: public BitmapScaleBench {
- public:
-    BitmapFilterScaleBench( int is, int os) : INHERITED(is, os) {
-        setName( "filter" );
-    }
-protected:
-    virtual void doScaleImage() SK_OVERRIDE {
-        SkCanvas canvas( fOutputBitmap );
-        SkPaint paint;
-
-        paint.setFilterLevel(SkPaint::kHigh_FilterLevel);
-        fInputBitmap.notifyPixelsChanged();
-        canvas.drawBitmapMatrix( fInputBitmap, fMatrix, &paint );
-    }
-private:
-    typedef BitmapScaleBench INHERITED;
-};
-
-DEF_BENCH(return new BitmapFilterScaleBench(10, 90);)
-DEF_BENCH(return new BitmapFilterScaleBench(30, 90);)
-DEF_BENCH(return new BitmapFilterScaleBench(80, 90);)
-DEF_BENCH(return new BitmapFilterScaleBench(90, 90);)
-DEF_BENCH(return new BitmapFilterScaleBench(90, 80);)
-DEF_BENCH(return new BitmapFilterScaleBench(90, 30);)
-DEF_BENCH(return new BitmapFilterScaleBench(90, 10);)
-DEF_BENCH(return new BitmapFilterScaleBench(256, 64);)
-DEF_BENCH(return new BitmapFilterScaleBench(64, 256);)
+DEF_BENCH(return new BitmapFractionalBench(256);)