Remove gpu shader optimatization for solid white or trans black colors

Running test on the added bench which draws a grid of all white paths, all blue paths, or alternating checkered white/blue paths.

With optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~160
N7       ~800        ~1100       ~1500
Moto-e   ~830        ~1100       ~2500

Without optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~80
N7       ~1100       ~1100       ~1100
Moto-e   ~1100       ~1100       ~1500

BUG=skia:
R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/375823005

1 files changed, 199 insertions, 0 deletions

diff --git a/bench/AlternatingColorPatternBench.cpp b/bench/AlternatingColorPatternBench.cpp
new file mode 100644
index 0000000000..2a2e771d52
--- /dev/null
+++ b/bench/AlternatingColorPatternBench.cpp
@@ -0,0 +1,199 @@
+/*
+ * 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 "Benchmark.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkPaint.h"
+#include "SkString.h"
+
+enum ColorPattern {
+    kWhite_ColorPattern,
+    kBlue_ColorPattern,
+    kOpaqueBitmap_ColorPattern,
+    kAlphaBitmap_ColorPattern,
+};
+
+static const struct ColorPatternData{
+    SkColor         fColor;
+    bool            fIsBitmap;
+    const char*     fName;
+} gColorPatterns[] = {
+    // Keep this in same order as ColorPattern enum
+    { SK_ColorWHITE, false,  "white"        }, // kWhite_ColorPattern
+    { SK_ColorBLUE,  false,  "blue"         }, // kBlue_ColorPattern
+    { SK_ColorWHITE, true,   "obaqueBitMap" }, // kOpaqueBitmap_ColorPattern
+    { 0x10000000,    true,   "alphaBitmap"  }, // kAlphaBitmap_ColorPattern
+};
+
+enum DrawType {
+    kRect_DrawType,
+    kPath_DrawType,
+};
+
+static void makebm(SkBitmap* bm, int w, int h) {
+    bm->allocN32Pixels(w, h);
+    bm->eraseColor(SK_ColorTRANSPARENT);
+
+    SkCanvas    canvas(*bm);
+    SkScalar    s = SkIntToScalar(SkMin32(w, h));
+    static const SkPoint     kPts0[] = { { 0, 0 }, { s, s } };
+    static const SkPoint     kPts1[] = { { s/2, 0 }, { s/2, s } };
+    static const SkScalar    kPos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
+    static const SkColor kColors0[] = {0x80F00080, 0xF0F08000, 0x800080F0 };
+    static const SkColor kColors1[] = {0xF08000F0, 0x8080F000, 0xF000F080 };
+
+
+    SkPaint     paint;
+
+    paint.setShader(SkGradientShader::CreateLinear(kPts0, kColors0, kPos,
+                    SK_ARRAY_COUNT(kColors0), SkShader::kClamp_TileMode))->unref();
+    canvas.drawPaint(paint);
+    paint.setShader(SkGradientShader::CreateLinear(kPts1, kColors1, kPos,
+                    SK_ARRAY_COUNT(kColors1), SkShader::kClamp_TileMode))->unref();
+    canvas.drawPaint(paint);
+}
+
+/**
+ * This bench draws a grid of either rects or filled paths, with two alternating color patterns.
+ * This color patterns are passed in as enums to the class. The options are:
+ *   1) solid white color
+ *   2) solid blue color
+ *   3) opaque bitmap
+ *   4) partial alpha bitmap
+ * The same color pattern can be set for both arguments to create a uniform pattern on all draws.
+ *
+ * The bench is used to test a few things. First it can test any optimizations made for a specific
+ * color pattern (for example drawing an opaque bitmap versus one with partial alpha). Also it can
+ * be used to test the cost of program switching and/or batching when alternating between different
+ * patterns when on the gpu.
+ */
+class AlternatingColorPatternBench : public Benchmark {
+public:
+    enum {
+        NX = 5,
+        NY = 5,
+        NUM_DRAWS = NX * NY,
+    };
+    SkPath  fPaths[NUM_DRAWS];
+    SkRect  fRects[NUM_DRAWS];
+    U8CPU fAlphas[NUM_DRAWS];
+    SkColor fColors[NUM_DRAWS];
+    SkShader* fShaders[NUM_DRAWS];
+
+    SkString        fName;
+    ColorPatternData    fPattern1;
+    ColorPatternData    fPattern2;
+    DrawType fDrawType;
+    SkBitmap fBmp;
+
+    SkShader* fBmShader;
+
+    AlternatingColorPatternBench(ColorPattern pattern1, ColorPattern pattern2, DrawType drawType) {
+        fPattern1 = gColorPatterns[pattern1];
+        fPattern2 = gColorPatterns[pattern2];
+        fName.printf("colorPattern_%s_%s_%s",
+                     fPattern1.fName, fPattern2.fName,
+                     kRect_DrawType == drawType ? "rect" : "path");
+        fDrawType = drawType;
+    }
+
+    virtual ~AlternatingColorPatternBench() {
+        fBmShader->unref();
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return fName.c_str();
+    }
+
+    virtual void onPreDraw() {
+        int w = 40;
+        int h = 40;
+        makebm(&fBmp, w, h);
+        fBmShader = SkShader::CreateBitmapShader(fBmp,
+                                                 SkShader::kRepeat_TileMode,
+                                                 SkShader::kRepeat_TileMode);
+        int offset = 2;
+        int count = 0;
+        for (int j = 0; j < NY; ++j) {
+            for (int i = 0; i < NX; ++i) {
+                int x = (w + offset) * i;
+                int y = (h * offset) * j;
+                if (kRect_DrawType == fDrawType) {
+                    fRects[count].set(SkIntToScalar(x), SkIntToScalar(y),
+                                      SkIntToScalar(x + w), SkIntToScalar(y + h));
+                } else {
+                    fPaths[count].moveTo(SkIntToScalar(x), SkIntToScalar(y));
+                    fPaths[count].rLineTo(SkIntToScalar(w), 0);
+                    fPaths[count].rLineTo(0, SkIntToScalar(h));
+                    fPaths[count].rLineTo(SkIntToScalar(-w + 1), 0);
+                }
+                if (0 == count % 2) {
+                    fColors[count]  = fPattern1.fColor;
+                    fShaders[count] = fPattern1.fIsBitmap ? fBmShader : NULL;
+                } else {
+                    fColors[count]  = fPattern2.fColor;
+                    fShaders[count] = fPattern2.fIsBitmap ? fBmShader : NULL;
+                }
+                ++count;
+            }
+        }
+    }
+
+    virtual void onDraw(const int loops, SkCanvas* canvas) SK_OVERRIDE {
+        SkPaint paint;
+        paint.setAntiAlias(false);
+        paint.setFilterLevel(SkPaint::kLow_FilterLevel);
+
+        for (int i = 0; i < loops; ++i) {
+            for (int j = 0; j < NUM_DRAWS; ++j) {
+                paint.setColor(fColors[j]);
+                paint.setShader(fShaders[j]);
+                if (kRect_DrawType == fDrawType) {
+                    canvas->drawRect(fRects[j], paint);
+                } else {
+                    canvas->drawPath(fPaths[j], paint);
+                }
+            }
+        }
+    }
+
+private:
+    typedef Benchmark INHERITED;
+};
+
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kWhite_ColorPattern, kWhite_ColorPattern,
+                              kPath_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kBlue_ColorPattern, kBlue_ColorPattern,
+                              kPath_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kWhite_ColorPattern, kBlue_ColorPattern,
+                              kPath_DrawType)); )
+
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kOpaqueBitmap_ColorPattern, kOpaqueBitmap_ColorPattern,
+                              kPath_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kAlphaBitmap_ColorPattern, kAlphaBitmap_ColorPattern,
+                              kPath_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kOpaqueBitmap_ColorPattern, kAlphaBitmap_ColorPattern,
+                              kPath_DrawType)); )
+
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kOpaqueBitmap_ColorPattern, kOpaqueBitmap_ColorPattern,
+                              kRect_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kAlphaBitmap_ColorPattern, kAlphaBitmap_ColorPattern,
+                              kRect_DrawType)); )
+DEF_BENCH( return SkNEW_ARGS(AlternatingColorPatternBench,
+                             (kOpaqueBitmap_ColorPattern, kAlphaBitmap_ColorPattern,
+                              kRect_DrawType)); )
+