Rewrite bleed GM bmp/img generators and change oversized texture case

gm/bleed.cpp

Index: gm/bleed.cpp
diff --git a/gm/bleed.cpp b/gm/bleed.cpp
index 37a38442fdd7c3b923f4ffbd65f13b70bb320af3..a72d490df0cba9eb1772f6cce48d2627c6fc5df6 100644
--- a/gm/bleed.cpp
+++ b/gm/bleed.cpp
@@ -19,197 +19,260 @@
 #include "SkGr.h"
 #endif
 
-static void draw_bitmap_rect(SkCanvas* canvas, const SkBitmap& bitmap, const SkImage*,
-                             const SkRect& src, const SkRect& dst,
-                             const SkPaint* paint, SkCanvas::SrcRectConstraint constraint) {
-    canvas->drawBitmapRect(bitmap, src, dst, paint, constraint);
-}
-
-static void draw_image_rect(SkCanvas* canvas, const SkBitmap&, const SkImage* image,
-                            const SkRect& src, const SkRect& dst,
-                            const SkPaint* paint, SkCanvas::SrcRectConstraint constraint) {
-    canvas->drawImageRect(image, src, dst, paint, constraint);
-}
-
-// Upload the tight-fitting sw-backed bitmap to a loose-fitting gpu-backed texture before drawing
-static void draw_texture_bitmap_rect(SkCanvas* canvas, const SkBitmap& bitmap, const SkImage*,
-                                     const SkRect& src, const SkRect& dst,
-                                     const SkPaint* paint,
-                                     SkCanvas::SrcRectConstraint constraint) {
-    GrContext* context = canvas->getGrContext();
-    if (!context) {
-        // For non-GPU canvases fallback to drawing the bitmap directly.
-        canvas->drawBitmapRect(bitmap, src, dst, paint, constraint);
-        return;
-    }
-#if SK_SUPPORT_GPU
-    GrSurfaceDesc desc;
-    desc.fConfig = kAlpha_8_SkColorType == bitmap.colorType() ? kAlpha_8_GrPixelConfig :
-                                                                kSkia8888_GrPixelConfig;
-    // Add some padding to the right and beneath the bitmap contents to exercise the case where
-    // the texture is larger than the bitmap. Outsets chosen to be small and different.
-    desc.fWidth = bitmap.width() + 16;
-    desc.fHeight = bitmap.height() + 23;
-    SkAutoTUnref<GrTexture> texture(context->textureProvider()->createTexture(desc, true));
-    if (!texture) {
-        return;
-    }
-    // Init the whole texture to 0 in the alpha case or solid green in the 32bit rgba case.
-    SkAutoLockPixels al(bitmap);
-    if (kAlpha_8_GrPixelConfig == texture->config()) {
-        SkAutoMalloc pixels(texture->width() * texture->height());
-        memset(pixels.get(), 0, texture->width() * texture->height());
-        texture->writePixels(0, 0, texture->width(), texture->height(), desc.fConfig, pixels.get(),
-                             0);
-    } else {
-        SkAutoMalloc pixels(texture->width() * texture->height() * sizeof(uint32_t));
-        SkOpts::memset32((uint32_t*)pixels.get(), 0xFF00FF00, texture->width()*texture->height());
-        texture->writePixels(0, 0, texture->width(), texture->height(), desc.fConfig, pixels.get(),
-                             0);
-    }
-
-    // Upload the bitmap contents to the upper left.
-    texture->writePixels(0, 0, bitmap.width(), bitmap.height(), desc.fConfig, bitmap.getPixels(),
-                         bitmap.rowBytes());
-
-    // Wrap the texture in a bitmap and draw it.
-    SkBitmap textureBmp;
-    GrWrapTextureInBitmap(texture, bitmap.width(), bitmap.height(), true, &textureBmp);
-    canvas->drawBitmapRect(textureBmp, src, dst, paint, constraint);
-#endif
-}
+/** Holds either a bitmap or image to be rendered and a rect that indicates what part of the bitmap
+    or image should be tested by the GM. The area outside of the rect is present to check
+    for bleed due to filtering/blurring. */
+struct TestPixels {
+    enum Type {
+        kBitmap,
+        kImage
+    };
+    Type                  fType;
+    SkBitmap              fBitmap;
+    SkAutoTUnref<SkImage> fImage;
+    SkIRect               fRect;  // The region of the bitmap/image that should be rendered.
+};
 
-// Create a black&white checked texture with 2 1-pixel rings
-// around the outside edge. The inner ring is red and the outer ring is blue.
-static void make_ringed_color_bitmap(SkBitmap* result, int width, int height) {
+/** Creates a bitmap with two one-pixel rings around a checkerboard. The checkerboard is 2x2
+    logically where each check has as many pixels as is necessary to fill the interior. The rect
+    to draw is set to the checkerboard portion. */
+template<typename PIXEL_TYPE>
+bool make_ringed_bitmap(GrContext*, TestPixels* result, int width, int height,
+                        SkColorType ct, SkAlphaType at,
+                        PIXEL_TYPE outerRingColor, PIXEL_TYPE innerRingColor,
+                        PIXEL_TYPE checkColor1, PIXEL_TYPE checkColor2) {
     SkASSERT(0 == width % 2 && 0 == height % 2);

[robertphillips, 2015/11/09 17:11:39]

I think the don't stomp memory limit is 2x2 but that wouldn't be a very
interesting texture.

SkASSERT(width > 6 && height > 6);

?

[bsalomon, 2015/11/09 17:44:11]

Done.

 
-    static const SkPMColor kRed = SkPreMultiplyColor(SK_ColorRED);
-    static const SkPMColor kBlue = SkPreMultiplyColor(SK_ColorBLUE);
-    static const SkPMColor kBlack = SkPreMultiplyColor(SK_ColorBLACK);
-    static const SkPMColor kWhite = SkPreMultiplyColor(SK_ColorWHITE);
-
-    result->allocN32Pixels(width, height, true);
+    result->fType = TestPixels::kBitmap;
+    SkImageInfo info = SkImageInfo::Make(width, height, ct, at);
+    size_t rowBytes = SkAlign4(info.minRowBytes());
+    result->fBitmap.allocPixels(info, rowBytes);
 
-    SkPMColor* scanline = result->getAddr32(0, 0);
+    PIXEL_TYPE* scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, 0);
     for (int x = 0; x < width; ++x) {
-        scanline[x] = kBlue;
+        scanline[x] = outerRingColor;
     }
-    scanline = result->getAddr32(0, 1);
-    scanline[0] = kBlue;
+    scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, 1);
+    scanline[0] = outerRingColor;
     for (int x = 1; x < width - 1; ++x) {
-        scanline[x] = kRed;
+        scanline[x] = innerRingColor;
     }
-    scanline[width-1] = kBlue;
-
-    for (int y = 2; y < height/2; ++y) {
-        scanline = result->getAddr32(0, y);
-        scanline[0] = kBlue;
-        scanline[1] = kRed;
-        for (int x = 2; x < width/2; ++x) {
-            scanline[x] = kBlack;
+    scanline[width - 1] = outerRingColor;
+
+    for (int y = 2; y < height / 2; ++y) {
+        scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, y);
+        scanline[0] = outerRingColor;
+        scanline[1] = innerRingColor;
+        for (int x = 2; x < width / 2; ++x) {
+            scanline[x] = checkColor1;
         }
-        for (int x = width/2; x < width-2; ++x) {
-            scanline[x] = kWhite;
+        for (int x = width / 2; x < width - 2; ++x) {
+            scanline[x] = checkColor2;
         }
-        scanline[width-2] = kRed;
-        scanline[width-1] = kBlue;
+        scanline[width - 2] = innerRingColor;
+        scanline[width - 1] = outerRingColor;
     }
 
-    for (int y = height/2; y < height-2; ++y) {
-        scanline = result->getAddr32(0, y);
-        scanline[0] = kBlue;
-        scanline[1] = kRed;
-        for (int x = 2; x < width/2; ++x) {
-            scanline[x] = kWhite;
+    for (int y = height / 2; y < height - 2; ++y) {
+        scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, y);
+        scanline[0] = outerRingColor;
+        scanline[1] = innerRingColor;
+        for (int x = 2; x < width / 2; ++x) {
+            scanline[x] = checkColor2;
         }
-        for (int x = width/2; x < width-2; ++x) {
-            scanline[x] = kBlack;
+        for (int x = width / 2; x < width - 2; ++x) {
+            scanline[x] = checkColor1;
         }
-        scanline[width-2] = kRed;
-        scanline[width-1] = kBlue;
+        scanline[width - 2] = innerRingColor;
+        scanline[width - 1] = outerRingColor;
     }
 
-    scanline = result->getAddr32(0, height-2);
-    scanline[0] = kBlue;
+    scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, height - 2);
+    scanline[0] = outerRingColor;
     for (int x = 1; x < width - 1; ++x) {
-        scanline[x] = kRed;
+        scanline[x] = innerRingColor;
     }
-    scanline[width-1] = kBlue;
+    scanline[width - 1] = outerRingColor;
 
-    scanline = result->getAddr32(0, height-1);
+    scanline = (PIXEL_TYPE*)result->fBitmap.getAddr(0, height - 1);
     for (int x = 0; x < width; ++x) {
-        scanline[x] = kBlue;
+        scanline[x] = outerRingColor;
     }
-    result->setImmutable();
+    result->fBitmap.setImmutable();
+    result->fRect.set(2, 2, width - 2, height - 2);
+    return true;
+}
+
+/** Create a black and white checked texture with 2 1-pixel rings around the outside edge.
+    The inner ring is red and the outer ring is blue. */
+static bool make_ringed_color_bitmap(GrContext* ctx, TestPixels* result, int width, int height) {
+    static const SkPMColor kBlue  = SkPreMultiplyColor(SK_ColorBLUE);
+    static const SkPMColor kRed   = SkPreMultiplyColor(SK_ColorRED);
+    static const SkPMColor kBlack = SkPreMultiplyColor(SK_ColorBLACK);
+    static const SkPMColor kWhite = SkPreMultiplyColor(SK_ColorWHITE);
+    return make_ringed_bitmap<SkPMColor>(ctx, result, width, height, kBGRA_8888_SkColorType,
+                                         kPremul_SkAlphaType, kBlue, kRed, kBlack, kWhite);
 }
 
 /** Makes a alpha bitmap with 1 wide rect/ring of 0s, an inset of 1s, and the interior is a 2x2
     checker board of 3/4 and 1/2. The inner checkers are large enough to fill the interior with
     the 2x2 checker grid. */
-static void make_ringed_alpha_bitmap(SkBitmap* result, int width, int height) {
-    SkASSERT(0 == width % 2 && 0 == height % 2);
+static bool make_ringed_alpha_bitmap(GrContext* ctx, TestPixels* result, int width, int height) {
+    static const uint8_t kZero = 0x00;
+    static const uint8_t kHalf = 0x80;
+    static const uint8_t k3Q   = 0xC0;
+    static const uint8_t kOne  = 0xFF;
+    return make_ringed_bitmap<uint8_t>(ctx, result, width, height, kAlpha_8_SkColorType,
+                                       kPremul_SkAlphaType, kZero, kOne, k3Q, kHalf);
+}
 
-    static const SkPMColor kZero = 0x00;
-    static const SkPMColor kHalf = 0x80;
-    static const SkPMColor k3Q   = 0xC0;
-    static const SkPMColor kOne  = 0xFF;
-    SkImageInfo info = SkImageInfo::MakeA8(width, height);
-    // The 4 byte alignment seems to be necessary to allow this bmp to be converted
-    // to an image.
-    result->allocPixels(info, SkAlign4(width));
+/** Helper to reuse above functions to produce images rather than bmps */
+static void bmp_to_image(TestPixels* result) {
+    SkASSERT(TestPixels::kBitmap == result->fType);
+    result->fImage.reset(SkImage::NewFromBitmap(result->fBitmap));
+    SkASSERT(result->fImage);
+    result->fType = TestPixels::kImage;
+    result->fBitmap.reset();
+}
+
+/** Color image case. */
+bool make_ringed_color_image(GrContext* ctx, TestPixels* result, int width, int height) {
+    if (make_ringed_color_bitmap(ctx, result, width, height)) {
+        bmp_to_image(result);
+        return true;
+    }
+    return false;
+}
+
+/** Alpha image case. */
+bool make_ringed_alpha_image(GrContext* ctx, TestPixels* result, int width, int height) {
+    if (make_ringed_alpha_bitmap(ctx, result, width, height)) {
+        bmp_to_image(result);
+        return true;
+    }
+    return false;
+}
+
+/** Similar to make_ringed_bitmap with these modifications:
+        - The backing store is a texture.
+        - The texture is larger than the bitmap dimensions (it is surrounded by non-content 
+          padding on the right/bottom of the contents.)
+        - The right/bottom sides of the rings are omitted so that the rect to draw is adjacent to
+          the texture padding.
+ */
+template <typename PIXEL_TYPE>
+bool make_oversized_texture_bitmap(GrContext* ctx, TestPixels* result, int width, int height,
+                                   GrPixelConfig config, PIXEL_TYPE outerRingColor,
+                                   PIXEL_TYPE innerRingColor, PIXEL_TYPE checkColor1,
+                                   PIXEL_TYPE checkColor2, PIXEL_TYPE padColor) {
+    SkASSERT(0 == width % 2 && 0 == height % 2);

[robertphillips, 2015/11/09 17:11:39]

Same extra assert here ?

[bsalomon, 2015/11/09 17:44:11]

Done.

+#if SK_SUPPORT_GPU
+    if (!ctx) {
+        return false;
+    }
+    /** Put arbitrary pad to the right and below the bitmap content. */
+    static const int kXPad = 10;
+    static const int kYPad = 17;
+    size_t rowBytes = (width + kXPad) * sizeof(PIXEL_TYPE);
+    SkAutoTMalloc<PIXEL_TYPE> pixels(rowBytes*(height + kYPad));
 
-    uint8_t* scanline = result->getAddr8(0, 0);
+    PIXEL_TYPE* scanline = pixels.get();
     for (int x = 0; x < width; ++x) {
-        scanline[x] = kOne;
+        scanline[x] = outerRingColor;
     }
-    scanline = result->getAddr8(0, 1);
-    scanline[0] = kOne;
-    for (int x = 1; x < width - 1; ++x) {
-        scanline[x] = kOne;
+    for (int x = width; x < width + kXPad; ++x) {
+        scanline[x] = padColor;
     }
-    scanline[width - 1] = kZero;
 
-    for (int y = 2; y < height / 2; ++y) {
-        scanline = result->getAddr8(0, y);
-        scanline[0] = kZero;
-        scanline[1] = kOne;
-        for (int x = 2; x < width / 2; ++x) {
-            scanline[x] = k3Q;
+    scanline = (PIXEL_TYPE*)((char*)scanline + rowBytes);
+    scanline[0] = outerRingColor;
+    for (int x = 1; x < width; ++x) {
+        scanline[x] = innerRingColor;
+    }
+    for (int x = width; x < width + kXPad; ++x) {
+        scanline[x] = padColor;
+    }
+
+    for (int y = 2; y < height / 2 + 1; ++y) {
+        scanline = (PIXEL_TYPE*)((char*)scanline + rowBytes);
+        scanline[0] = outerRingColor;
+        scanline[1] = innerRingColor;
+        for (int x = 2; x < width / 2 + 1; ++x) {
+            scanline[x] = checkColor1;
         }
-        for (int x = width / 2; x < width - 2; ++x) {
-            scanline[x] = kHalf;
+        for (int x = width / 2 + 1; x < width; ++x) {
+            scanline[x] = checkColor2;
+        }
+        for (int x = width; x < width + kXPad; ++x) {
+            scanline[x] = padColor;
         }
-        scanline[width - 2] = kOne;
-        scanline[width - 1] = kZero;
     }
 
-    for (int y = height / 2; y < height - 2; ++y) {
-        scanline = result->getAddr8(0, y);
-        scanline[0] = kZero;
-        scanline[1] = kOne;
-        for (int x = 2; x < width / 2; ++x) {
-            scanline[x] = kHalf;
+    for (int y = height / 2 + 1; y < height; ++y) {
+        scanline = (PIXEL_TYPE*)((char*)scanline + rowBytes);
+        scanline[0] = outerRingColor;
+        scanline[1] = innerRingColor;
+        for (int x = 2; x < width / 2 + 1; ++x) {
+            scanline[x] = checkColor2;
         }
-        for (int x = width / 2; x < width - 2; ++x) {
-            scanline[x] = k3Q;
+        for (int x = width / 2 + 1; x < width; ++x) {
+            scanline[x] = checkColor1;
+        }
+        for (int x = width; x < width + kXPad; ++x) {
+            scanline[x] = padColor;
         }
-        scanline[width - 2] = kOne;
-        scanline[width - 1] = kZero;
     }
 
-    scanline = result->getAddr8(0, height - 2);
-    scanline[0] = kZero;
-    for (int x = 1; x < width - 1; ++x) {
-        scanline[x] = kOne;
+    for (int y = height; y < height + kYPad; ++y) {
+        scanline = (PIXEL_TYPE*)((char*)scanline + rowBytes);
+        for (int x = 0; x < width + kXPad; ++x) {
+            scanline[x] = padColor;
+        }
     }
-    scanline[width - 1] = kZero;
 
-    scanline = result->getAddr8(0, height - 1);
-    for (int x = 0; x < width; ++x) {
-        scanline[x] = kZero;
+    GrSurfaceDesc desc;
+    desc.fConfig = config;
+    desc.fWidth = width + kXPad;
+    desc.fHeight = height + kYPad;
+    SkAutoTUnref<GrTexture> texture(ctx->textureProvider()->createTexture(desc, true, pixels.get(),
+                                                                          rowBytes));
+
+    if (!texture) {
+        return false;
     }
-    result->setImmutable();
+
+    GrWrapTextureInBitmap(texture, width, height, true, &result->fBitmap);
+    result->fType = TestPixels::kBitmap;
+    result->fBitmap.setImmutable();
+    result->fRect.set(2, 2, width, height);
+    return true;
+#else
+    return false;
+#endif
+}
+
+/** Make the color version of the oversized texture-backed bitmap */
+static bool make_ringed_oversized_color_texture_bitmap(GrContext* ctx, TestPixels* result,
+                                                       int width, int height) {
+    static const SkPMColor kBlue = SkPreMultiplyColor(SK_ColorBLUE);
+    static const SkPMColor kRed = SkPreMultiplyColor(SK_ColorRED);
+    static const SkPMColor kBlack = SkPreMultiplyColor(SK_ColorBLACK);
+    static const SkPMColor kWhite = SkPreMultiplyColor(SK_ColorWHITE);
+    static const SkPMColor kGreen = SkPreMultiplyColor(SK_ColorGREEN);
+    return make_oversized_texture_bitmap<SkPMColor>(
+        ctx, result, width, height, kSkia8888_GrPixelConfig, kBlue, kRed, kBlack, kWhite, kGreen);
+}
+
+/** Make the alpha version of the oversized texture-backed bitmap */
+static bool make_ringed_oversized_alpha_texture_bitmap(GrContext* ctx, TestPixels* result,
+                                                       int width, int height) {
+    static const uint8_t kZero = 0x00;
+    static const uint8_t kHalf = 0x80;
+    static const uint8_t k3Q   = 0xC0;
+    static const uint8_t kOne  = 0xFF;
+    static const uint8_t k1Q   = 0x40;
+    return make_oversized_texture_bitmap<uint8_t>(
+        ctx, result, width, height, kAlpha_8_GrPixelConfig, kZero, kOne, k3Q, kHalf, k1Q);
 }
 
 static SkShader* make_shader() {
@@ -234,26 +297,24 @@ enum BleedTest {
 
 const struct {
     const char* fName;
-    void(*fBmpMaker)(SkBitmap* result, int width, int height);
-    SkShader*(*fShaderMaker)();
-    void(*fDraw)(SkCanvas*, const SkBitmap&, const SkImage*, const SkRect&, const SkRect&,
-                 const SkPaint*, SkCanvas::SrcRectConstraint);
+    bool (*fPixelMaker)(GrContext*, TestPixels* result, int width, int height);
+    SkShader* (*fShaderMaker)();
 } gBleedRec[] = {
-    { "bleed",                          make_ringed_color_bitmap, make_null_shader,  draw_bitmap_rect         },
-    { "bleed_texture_bmp",              make_ringed_color_bitmap, make_null_shader,  draw_texture_bitmap_rect },
-    { "bleed_image",                    make_ringed_color_bitmap, make_null_shader,  draw_image_rect          },
-    { "bleed_alpha_bmp",                make_ringed_alpha_bitmap, make_null_shader,  draw_bitmap_rect         },
-    { "bleed_alpha_texture_bmp",        make_ringed_alpha_bitmap, make_null_shader,  draw_texture_bitmap_rect },
-    { "bleed_alpha_image",              make_ringed_alpha_bitmap, make_null_shader,  draw_image_rect          },
-    { "bleed_alpha_bmp_shader",         make_ringed_alpha_bitmap, make_shader,       draw_bitmap_rect         },
-    { "bleed_alpha_texture_bmp_shader", make_ringed_alpha_bitmap, make_shader,       draw_texture_bitmap_rect },
-    { "bleed_alpha_image_shader",       make_ringed_alpha_bitmap, make_shader,       draw_image_rect          },
+    { "bleed",                          make_ringed_color_bitmap,                   make_null_shader },
+    { "bleed_texture_bmp",              make_ringed_oversized_color_texture_bitmap, make_null_shader },
+    { "bleed_image",                    make_ringed_color_image,                    make_null_shader },
+    { "bleed_alpha_bmp",                make_ringed_alpha_bitmap,                   make_null_shader },
+    { "bleed_alpha_texture_bmp",        make_ringed_oversized_alpha_texture_bitmap, make_null_shader },
+    { "bleed_alpha_image",              make_ringed_alpha_image,                    make_null_shader },
+    { "bleed_alpha_bmp_shader",         make_ringed_alpha_bitmap,                   make_shader      },
+    { "bleed_alpha_texture_bmp_shader", make_ringed_oversized_alpha_texture_bitmap, make_shader      },
+    { "bleed_alpha_image_shader",       make_ringed_alpha_image,                    make_shader      },
 };
 

[robertphillips, 2015/11/09 17:11:39]

// This GM exercises the behavior of the drawBitmapRect & drawImageRect calls.
Specifically their handling of:
   SrcRectConstraint (bleed vs. no-bleed)
   handling of the sub-region feature of SkBitmap
   handling of the sub-region feature (area-of-interest) of drawBitmap*
   handling of 8888 vs. A8
   (gpu-only) handling of tiled vs. non-tiled drawing)

In particular, we should never see the padding outside of an SkBitmap's
sub-region (green for 8888, 1/4 for alpha).
In some instances we can see the two outer rings outside of the area-of-interest
(i.e., the inner four checks) due to AA or filtering.

?
   

[bsalomon, 2015/11/09 17:44:11]

Done

 // This GM exercises the drawBitmapRect constraints
 class BleedGM : public skiagm::GM {
 public:
-    BleedGM(BleedTest bt) : fBT(bt) {}
+    BleedGM(BleedTest bt) : fBT(bt), fCreatedPixels(false) {}
 
 protected:
 
@@ -265,24 +326,21 @@ protected:
         return SkISize::Make(1200, 1080);
     }
 
-    void onOnceBeforeDraw() override {
-        gBleedRec[fBT].fBmpMaker(&fBitmapSmall, kSmallTextureSize, kSmallTextureSize);
-        fImageSmall.reset(SkImage::NewFromBitmap(fBitmapSmall));
-
-        // To exercise the GPU's tiling path we need a texture
-        // too big for the GPU to handle in one go
-        gBleedRec[fBT].fBmpMaker(&fBitmapBig, 2*kMaxTileSize, 2*kMaxTileSize);
-        fImageBig.reset(SkImage::NewFromBitmap(fBitmapBig));
-
-        fShader.reset(gBleedRec[fBT].fShaderMaker());
+    void drawPixels(SkCanvas* canvas, const TestPixels& pixels, const SkRect& src,
+                    const SkRect& dst, const SkPaint* paint,
+                    SkCanvas::SrcRectConstraint constraint) {
+        if (TestPixels::kBitmap == pixels.fType) {
+            canvas->drawBitmapRect(pixels.fBitmap, src, dst, paint, constraint);
+        } else {
+            canvas->drawImageRect(pixels.fImage, src, dst, paint, constraint);
+        }
     }
 
-    // Draw only the center of the small bitmap
+    // Draw the area of interest of the small image
     void drawCase1(SkCanvas* canvas, int transX, int transY, bool aa,
                    SkCanvas::SrcRectConstraint constraint, SkFilterQuality filter) {
-        SkRect src = SkRect::MakeXYWH(2, 2,
-                                      SkIntToScalar(kSmallTextureSize-4),
-                                      SkIntToScalar(kSmallTextureSize-4));
+
+        SkRect src = SkRect::Make(fSmallTestPixels.fRect);
         SkRect dst = SkRect::MakeXYWH(SkIntToScalar(transX), SkIntToScalar(transY),
                                       SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
 
@@ -292,15 +350,13 @@ protected:
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(aa);
 
-        gBleedRec[fBT].fDraw(canvas, fBitmapSmall, fImageSmall, src, dst, &paint, constraint);
+        this->drawPixels(canvas, fSmallTestPixels, src, dst, &paint, constraint);
     }
 
-    // Draw almost all of the large bitmap
+    // Draw the area of interest of the large image
     void drawCase2(SkCanvas* canvas, int transX, int transY, bool aa,
                    SkCanvas::SrcRectConstraint constraint, SkFilterQuality filter) {
-        SkRect src = SkRect::MakeXYWH(2, 2,
-                                      SkIntToScalar(fBitmapBig.width()-4),
-                                      SkIntToScalar(fBitmapBig.height()-4));
+        SkRect src = SkRect::Make(fBigTestPixels.fRect);
         SkRect dst = SkRect::MakeXYWH(SkIntToScalar(transX), SkIntToScalar(transY),
                                       SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
 
@@ -310,15 +366,16 @@ protected:
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(aa);
 
-        gBleedRec[fBT].fDraw(canvas, fBitmapBig, fImageBig, src, dst, &paint, constraint);
+        this->drawPixels(canvas, fBigTestPixels, src, dst, &paint, constraint);
     }
 
-    // Draw ~1/4 of the large bitmap
+    // Draw upper-left 1/4 of the area of interest of the large image
     void drawCase3(SkCanvas* canvas, int transX, int transY, bool aa,
                    SkCanvas::SrcRectConstraint constraint, SkFilterQuality filter) {
-        SkRect src = SkRect::MakeXYWH(2, 2,
-                                      SkIntToScalar(fBitmapBig.width()/2-2),
-                                      SkIntToScalar(fBitmapBig.height()/2-2));
+        SkRect src = SkRect::MakeXYWH(SkIntToScalar(fBigTestPixels.fRect.fLeft),
+                                      SkIntToScalar(fBigTestPixels.fRect.fTop),
+                                      fBigTestPixels.fRect.width()/2.f,
+                                      fBigTestPixels.fRect.height()/2.f);
         SkRect dst = SkRect::MakeXYWH(SkIntToScalar(transX), SkIntToScalar(transY),
                                       SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
 
@@ -328,15 +385,13 @@ protected:
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(aa);
 
-        gBleedRec[fBT].fDraw(canvas, fBitmapBig, fImageBig, src, dst, &paint, constraint);
+        this->drawPixels(canvas, fBigTestPixels, src, dst, &paint, constraint);
     }
 
-    // Draw the center of the small bitmap with a normal blur
+    // Draw the area of interest of the small image with a normal blur
     void drawCase4(SkCanvas* canvas, int transX, int transY, bool aa,
                    SkCanvas::SrcRectConstraint constraint, SkFilterQuality filter) {
-        SkRect src = SkRect::MakeXYWH(2, 2,
-                                      SkIntToScalar(kSmallTextureSize-4),
-                                      SkIntToScalar(kSmallTextureSize-4));
+        SkRect src = SkRect::Make(fSmallTestPixels.fRect);
         SkRect dst = SkRect::MakeXYWH(SkIntToScalar(transX), SkIntToScalar(transY),
                                       SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
 
@@ -349,15 +404,13 @@ protected:
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(aa);
 
-        gBleedRec[fBT].fDraw(canvas, fBitmapSmall, fImageSmall, src, dst, &paint, constraint);
+        this->drawPixels(canvas, fSmallTestPixels, src, dst, &paint, constraint);
     }
 
-    // Draw the center of the small bitmap with a outer blur
+    // Draw the area of interest of the small image with a outer blur
     void drawCase5(SkCanvas* canvas, int transX, int transY, bool aa,
                    SkCanvas::SrcRectConstraint constraint, SkFilterQuality filter) {
-        SkRect src = SkRect::MakeXYWH(2, 2,
-                                      SkIntToScalar(kSmallTextureSize - 4),
-                                      SkIntToScalar(kSmallTextureSize - 4));
+        SkRect src = SkRect::Make(fSmallTestPixels.fRect);
         SkRect dst = SkRect::MakeXYWH(SkIntToScalar(transX), SkIntToScalar(transY),
                                       SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
 
@@ -370,10 +423,40 @@ protected:
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(aa);
 
-        gBleedRec[fBT].fDraw(canvas, fBitmapSmall, fImageSmall, src, dst, &paint, constraint);
+        this->drawPixels(canvas, fSmallTestPixels, src, dst, &paint, constraint);
     }
 
     void onDraw(SkCanvas* canvas) override {
+        // We don't create pixels in an onOnceBeforeDraw() override because we want access to
+        // GrContext.
+        GrContext* context = canvas->getGrContext();
+#if SK_SUPPORT_GPU
+        // Workaround for SampleApp.
+        if (GrTexture* tex = fBigTestPixels.fBitmap.getTexture()) {
+            if (tex->wasDestroyed()) {
+                fCreatedPixels = false;
+            }
+        }
+#endif
+        bool madePixels = fCreatedPixels;
+
+        if (!madePixels) {
+            madePixels =  gBleedRec[fBT].fPixelMaker(context, &fSmallTestPixels, kSmallTextureSize,
+                                                     kSmallTextureSize);
+            madePixels &= gBleedRec[fBT].fPixelMaker(context, &fBigTestPixels, 2 * kMaxTileSize,
+                                                     2 * kMaxTileSize);
+            fCreatedPixels = madePixels;
+        }
+
+        // Assume that if we coulnd't make the bitmap/image it's because it's a GPU test on a
+        // non-GPU backend.
+        if (!madePixels) {
+            skiagm::GM::DrawGpuOnlyMessage(canvas);
+            return;
+        }
+
+        fShader.reset(gBleedRec[fBT].fShaderMaker());
+
         canvas->clear(SK_ColorGRAY);
         SkTDArray<SkMatrix> matrices;
         // Draw with identity
@@ -486,14 +569,13 @@ private:
     static const int kSmallTextureSize = 6;
     static const int kMaxTileSize = 32;
 
-    SkBitmap fBitmapSmall;
-    SkBitmap fBitmapBig;
-    SkAutoTUnref<SkImage> fImageSmall;
-    SkAutoTUnref<SkImage> fImageBig;
+    bool                    fCreatedPixels;
+    TestPixels              fBigTestPixels;
+    TestPixels              fSmallTestPixels;
 
-    SkAutoTUnref<SkShader> fShader;
+    SkAutoTUnref<SkShader>  fShader;
 
-    const BleedTest fBT;
+    const BleedTest         fBT;
 
     typedef GM INHERITED;
 };