[WIP] Add Context to SkDrawLooper.

tests/LayerDrawLooperTest.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 "SkBitmap.h"
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkDraw.h"
 #include "SkLayerDrawLooper.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 #include "SkRect.h"
 #include "SkRefCnt.h"
 #include "SkScalar.h"
+#include "SkSmallAllocator.h"
 #include "SkXfermode.h"
 #include "Test.h"
 
 static SkBitmap make_bm(int w, int h) {
     SkBitmap bm;
     bm.allocN32Pixels(w, h);
     return bm;
 }
 
 class FakeDevice : public SkBitmapDevice {
@@ skipping 22 matching lines @@
     // Add the back layer, with some layer info set.
     layerInfo.fOffset.set(10.0f, 20.0f);
     layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
     SkPaint* layerPaint = looperBuilder.addLayer(layerInfo);
     layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
 
     FakeDevice device;
     SkCanvas canvas(&device);
     SkPaint paint;
     SkAutoTUnref<SkLayerDrawLooper> looper(looperBuilder.detachLooper());
-    looper->init(&canvas);
+    SkSmallAllocator<1, 32> allocator;
+    void* buffer = allocator.reserveT<SkDrawLooper::Context>(looper->contextSize());
+    SkDrawLooper::Context* context = looper->createContext(&canvas, buffer);
 
     // The back layer should come first.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 10.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 20.0f == device.fLastMatrix.getTranslateY());
     paint.reset();
 
     // Then the front layer.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateY());
 
     // Only two layers were added, so that should be the end.
-    REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, !context->next(&canvas, &paint));
 }
 
 static void test_backToFront(skiatest::Reporter* reporter) {
     SkLayerDrawLooper::Builder looperBuilder;
     SkLayerDrawLooper::LayerInfo layerInfo;
 
     // Add the back layer, with the defaults.
     (void)looperBuilder.addLayerOnTop(layerInfo);
 
     // Add the front layer, with some layer info set.
     layerInfo.fOffset.set(10.0f, 20.0f);
     layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
     SkPaint* layerPaint = looperBuilder.addLayerOnTop(layerInfo);
     layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
 
     FakeDevice device;
     SkCanvas canvas(&device);
     SkPaint paint;
     SkAutoTUnref<SkLayerDrawLooper> looper(looperBuilder.detachLooper());
-    looper->init(&canvas);
+    SkSmallAllocator<1, 32> allocator;
+    void* buffer = allocator.reserveT<SkDrawLooper::Context>(looper->contextSize());
+    SkDrawLooper::Context* context = looper->createContext(&canvas, buffer);
 
     // The back layer should come first.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateY());
     paint.reset();
 
     // Then the front layer.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 10.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 20.0f == device.fLastMatrix.getTranslateY());
 
     // Only two layers were added, so that should be the end.
-    REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, !context->next(&canvas, &paint));
 }
 
 static void test_mixed(skiatest::Reporter* reporter) {
     SkLayerDrawLooper::Builder looperBuilder;
     SkLayerDrawLooper::LayerInfo layerInfo;
 
     // Add the back layer, with the defaults.
     (void)looperBuilder.addLayer(layerInfo);
 
     // Add the front layer, with some layer info set.
     layerInfo.fOffset.set(10.0f, 20.0f);
     layerInfo.fPaintBits |= SkLayerDrawLooper::kXfermode_Bit;
     SkPaint* layerPaint = looperBuilder.addLayerOnTop(layerInfo);
     layerPaint->setXfermodeMode(SkXfermode::kSrc_Mode);
 
     FakeDevice device;
     SkCanvas canvas(&device);
     SkPaint paint;
     SkAutoTUnref<SkLayerDrawLooper> looper(looperBuilder.detachLooper());
-    looper->init(&canvas);
+    SkSmallAllocator<1, 32> allocator;
+    void* buffer = allocator.reserveT<SkDrawLooper::Context>(looper->contextSize());
+    SkDrawLooper::Context* context = looper->createContext(&canvas, buffer);
 
     // The back layer should come first.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 0.0f == device.fLastMatrix.getTranslateY());
     paint.reset();
 
     // Then the front layer.
-    REPORTER_ASSERT(reporter, looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, context->next(&canvas, &paint));
     REPORTER_ASSERT(reporter, SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrc_Mode));
     canvas.drawRect(SkRect::MakeWH(50.0f, 50.0f), paint);
     REPORTER_ASSERT(reporter, 10.0f == device.fLastMatrix.getTranslateX());
     REPORTER_ASSERT(reporter, 20.0f == device.fLastMatrix.getTranslateY());
 
     // Only two layers were added, so that should be the end.
-    REPORTER_ASSERT(reporter, !looper->next(&canvas, &paint));
+    REPORTER_ASSERT(reporter, !context->next(&canvas, &paint));
 }
 
 DEF_TEST(LayerDrawLooper, reporter) {
     test_frontToBack(reporter);
     test_backToFront(reporter);
     test_mixed(reporter);
 }