Revert "Remove layer integral offset snapping (flutter#17712)" (flutt…

…er#17785)

This reverts commit 99f8d00.

I found some problems. Will revise and reland later, and put more details about the problems in the new PR.

TBR: @chinmaygarde @flar

flow/layers/image_filter_layer.cc

@@ -31,6 +31,9 @@ void ImageFilterLayer::Preroll(PrerollContext* context,
   if (!context->has_platform_view && context->raster_cache &&
       SkRect::Intersects(context->cull_rect, paint_bounds())) {
     SkMatrix ctm = matrix;
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+    ctm = RasterCache::GetIntegralTransCTM(ctm);
+#endif
     context->raster_cache->Prepare(context, this, ctm);
   }
 }
@@ -39,6 +42,12 @@ void ImageFilterLayer::Paint(PaintContext& context) const {
   TRACE_EVENT0("flutter", "ImageFilterLayer::Paint");
   FML_DCHECK(needs_painting());
 
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  SkAutoCanvasRestore save(context.leaf_nodes_canvas, true);
+  context.leaf_nodes_canvas->setMatrix(RasterCache::GetIntegralTransCTM(
+      context.leaf_nodes_canvas->getTotalMatrix()));
+#endif
+
   if (context.raster_cache) {
     const SkMatrix& ctm = context.leaf_nodes_canvas->getTotalMatrix();
     RasterCacheResult layer_cache =

flow/layers/image_filter_layer_unittests.cc

@@ -60,11 +60,14 @@ TEST_F(ImageFilterLayerTest, EmptyFilter) {
   layer->Paint(paint_context());
   EXPECT_EQ(mock_canvas().draw_calls(),
             std::vector({
+                MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+                MockCanvas::DrawCall{1, MockCanvas::SetMatrixData{SkMatrix()}},
                 MockCanvas::DrawCall{
-                    0, MockCanvas::SaveLayerData{child_bounds, filter_paint,
-                                                 nullptr, 1}},
+                    1, MockCanvas::SaveLayerData{child_bounds, filter_paint,
+                                                 nullptr, 2}},
                 MockCanvas::DrawCall{
-                    1, MockCanvas::DrawPathData{child_path, child_paint}},
+                    2, MockCanvas::DrawPathData{child_path, child_paint}},
+                MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                 MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}},
             }));
 }
@@ -93,11 +96,14 @@ TEST_F(ImageFilterLayerTest, SimpleFilter) {
   layer->Paint(paint_context());
   EXPECT_EQ(mock_canvas().draw_calls(),
             std::vector({
+                MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+                MockCanvas::DrawCall{1, MockCanvas::SetMatrixData{SkMatrix()}},
                 MockCanvas::DrawCall{
-                    0, MockCanvas::SaveLayerData{child_bounds, filter_paint,
-                                                 nullptr, 1}},
+                    1, MockCanvas::SaveLayerData{child_bounds, filter_paint,
+                                                 nullptr, 2}},
                 MockCanvas::DrawCall{
-                    1, MockCanvas::DrawPathData{child_path, child_paint}},
+                    2, MockCanvas::DrawPathData{child_path, child_paint}},
+                MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                 MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}},
             }));
 }
@@ -126,11 +132,14 @@ TEST_F(ImageFilterLayerTest, SimpleFilterBounds) {
   layer->Paint(paint_context());
   EXPECT_EQ(mock_canvas().draw_calls(),
             std::vector({
+                MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+                MockCanvas::DrawCall{1, MockCanvas::SetMatrixData{SkMatrix()}},
                 MockCanvas::DrawCall{
-                    0, MockCanvas::SaveLayerData{child_bounds, filter_paint,
-                                                 nullptr, 1}},
+                    1, MockCanvas::SaveLayerData{child_bounds, filter_paint,
+                                                 nullptr, 2}},
                 MockCanvas::DrawCall{
-                    1, MockCanvas::DrawPathData{child_path, child_paint}},
+                    2, MockCanvas::DrawPathData{child_path, child_paint}},
+                MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                 MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}},
             }));
 }
@@ -168,16 +177,19 @@ TEST_F(ImageFilterLayerTest, MultipleChildren) {
   SkPaint filter_paint;
   filter_paint.setImageFilter(layer_filter);
   layer->Paint(paint_context());
-  EXPECT_EQ(
-      mock_canvas().draw_calls(),
-      std::vector({MockCanvas::DrawCall{
-                       0, MockCanvas::SaveLayerData{children_bounds,
-                                                    filter_paint, nullptr, 1}},
-                   MockCanvas::DrawCall{
-                       1, MockCanvas::DrawPathData{child_path1, child_paint1}},
-                   MockCanvas::DrawCall{
-                       1, MockCanvas::DrawPathData{child_path2, child_paint2}},
-                   MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}}));
+  EXPECT_EQ(mock_canvas().draw_calls(),
+            std::vector(
+                {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+                 MockCanvas::DrawCall{1, MockCanvas::SetMatrixData{SkMatrix()}},
+                 MockCanvas::DrawCall{
+                     1, MockCanvas::SaveLayerData{children_bounds, filter_paint,
+                                                  nullptr, 2}},
+                 MockCanvas::DrawCall{
+                     2, MockCanvas::DrawPathData{child_path1, child_paint1}},
+                 MockCanvas::DrawCall{
+                     2, MockCanvas::DrawPathData{child_path2, child_paint2}},
+                 MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
+                 MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}}));
 }
 
 TEST_F(ImageFilterLayerTest, Nested) {
@@ -225,16 +237,22 @@ TEST_F(ImageFilterLayerTest, Nested) {
   layer1->Paint(paint_context());
   EXPECT_EQ(mock_canvas().draw_calls(),
             std::vector({
+                MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+                MockCanvas::DrawCall{1, MockCanvas::SetMatrixData{SkMatrix()}},
                 MockCanvas::DrawCall{
-                    0, MockCanvas::SaveLayerData{children_bounds, filter_paint1,
-                                                 nullptr, 1}},
+                    1, MockCanvas::SaveLayerData{children_bounds, filter_paint1,
+                                                 nullptr, 2}},
                 MockCanvas::DrawCall{
-                    1, MockCanvas::DrawPathData{child_path1, child_paint1}},
+                    2, MockCanvas::DrawPathData{child_path1, child_paint1}},
+                MockCanvas::DrawCall{2, MockCanvas::SaveData{3}},
+                MockCanvas::DrawCall{3, MockCanvas::SetMatrixData{SkMatrix()}},
                 MockCanvas::DrawCall{
-                    1, MockCanvas::SaveLayerData{child_path2.getBounds(),
-                                                 filter_paint2, nullptr, 2}},
+                    3, MockCanvas::SaveLayerData{child_path2.getBounds(),
+                                                 filter_paint2, nullptr, 4}},
                 MockCanvas::DrawCall{
-                    2, MockCanvas::DrawPathData{child_path2, child_paint2}},
+                    4, MockCanvas::DrawPathData{child_path2, child_paint2}},
+                MockCanvas::DrawCall{4, MockCanvas::RestoreData{3}},
+                MockCanvas::DrawCall{3, MockCanvas::RestoreData{2}},
                 MockCanvas::DrawCall{2, MockCanvas::RestoreData{1}},
                 MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}},
             }));

flow/layers/opacity_layer.cc

@@ -51,6 +51,9 @@ void OpacityLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
     if (!context->has_platform_view && context->raster_cache &&
         SkRect::Intersects(context->cull_rect, paint_bounds())) {
       SkMatrix ctm = child_matrix;
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+      ctm = RasterCache::GetIntegralTransCTM(ctm);
+#endif
       context->raster_cache->Prepare(context, container, ctm);
     }
   }
@@ -66,6 +69,11 @@ void OpacityLayer::Paint(PaintContext& context) const {
   SkAutoCanvasRestore save(context.internal_nodes_canvas, true);
   context.internal_nodes_canvas->translate(offset_.fX, offset_.fY);
 
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  context.internal_nodes_canvas->setMatrix(RasterCache::GetIntegralTransCTM(
+      context.leaf_nodes_canvas->getTotalMatrix()));
+#endif
+
   if (context.raster_cache) {
     ContainerLayer* container = GetChildContainer();
     const SkMatrix& ctm = context.leaf_nodes_canvas->getTotalMatrix();
@@ -79,7 +87,8 @@ void OpacityLayer::Paint(PaintContext& context) const {
   // Skia may clip the content with saveLayerBounds (although it's not a
   // guaranteed clip). So we have to provide a big enough saveLayerBounds. To do
   // so, we first remove the offset from paint bounds since it's already in the
-  // matrix. Then we round out the bounds.
+  // matrix. Then we round out the bounds because of our
+  // RasterCache::GetIntegralTransCTM optimization.
   //
   // Note that the following lines are only accessible when the raster cache is
   // not available (e.g., when we're using the software backend in golden

flow/layers/opacity_layer_unittests.cc

@@ -58,6 +58,10 @@ TEST_F(OpacityLayerTest, FullyOpaque) {
   const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
   const SkMatrix layer_transform =
       SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
+      SkMatrix::Concat(initial_transform, layer_transform));
+#endif
   const SkPaint child_paint = SkPaint(SkColors::kGreen);
   const SkRect expected_layer_bounds =
       layer_transform.mapRect(child_path.getBounds());
@@ -82,6 +86,10 @@ TEST_F(OpacityLayerTest, FullyOpaque) {
   auto expected_draw_calls = std::vector(
       {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
        MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           1, MockCanvas::SetMatrixData{integral_layer_transform}},
+#endif
        MockCanvas::DrawCall{
            1, MockCanvas::SaveLayerData{opacity_bounds, opacity_paint, nullptr,
                                         2}},
@@ -99,6 +107,10 @@ TEST_F(OpacityLayerTest, FullyTransparent) {
   const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
   const SkMatrix layer_transform =
       SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
+      SkMatrix::Concat(initial_transform, layer_transform));
+#endif
   const SkPaint child_paint = SkPaint(SkColors::kGreen);
   const SkRect expected_layer_bounds =
       layer_transform.mapRect(child_path.getBounds());
@@ -121,6 +133,10 @@ TEST_F(OpacityLayerTest, FullyTransparent) {
   auto expected_draw_calls = std::vector(
       {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
        MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           1, MockCanvas::SetMatrixData{integral_layer_transform}},
+#endif
        MockCanvas::DrawCall{1, MockCanvas::SaveData{2}},
        MockCanvas::DrawCall{
            2, MockCanvas::ClipRectData{kEmptyRect, SkClipOp::kIntersect,
@@ -139,6 +155,10 @@ TEST_F(OpacityLayerTest, HalfTransparent) {
   const SkMatrix initial_transform = SkMatrix::MakeTrans(0.5f, 0.5f);
   const SkMatrix layer_transform =
       SkMatrix::MakeTrans(layer_offset.fX, layer_offset.fY);
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  const SkMatrix integral_layer_transform = RasterCache::GetIntegralTransCTM(
+      SkMatrix::Concat(initial_transform, layer_transform));
+#endif
   const SkPaint child_paint = SkPaint(SkColors::kGreen);
   const SkRect expected_layer_bounds =
       layer_transform.mapRect(child_path.getBounds());
@@ -165,6 +185,10 @@ TEST_F(OpacityLayerTest, HalfTransparent) {
   auto expected_draw_calls = std::vector(
       {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
        MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer_transform}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           1, MockCanvas::SetMatrixData{integral_layer_transform}},
+#endif
        MockCanvas::DrawCall{
            1, MockCanvas::SaveLayerData{opacity_bounds, opacity_paint, nullptr,
                                         2}},
@@ -187,6 +211,13 @@ TEST_F(OpacityLayerTest, Nested) {
       SkMatrix::MakeTrans(layer1_offset.fX, layer1_offset.fY);
   const SkMatrix layer2_transform =
       SkMatrix::MakeTrans(layer2_offset.fX, layer2_offset.fY);
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  const SkMatrix integral_layer1_transform = RasterCache::GetIntegralTransCTM(
+      SkMatrix::Concat(initial_transform, layer1_transform));
+  const SkMatrix integral_layer2_transform = RasterCache::GetIntegralTransCTM(
+      SkMatrix::Concat(SkMatrix::Concat(initial_transform, layer1_transform),
+                       layer2_transform));
+#endif
   const SkPaint child1_paint = SkPaint(SkColors::kRed);
   const SkPaint child2_paint = SkPaint(SkColors::kBlue);
   const SkPaint child3_paint = SkPaint(SkColors::kGreen);
@@ -247,13 +278,21 @@ TEST_F(OpacityLayerTest, Nested) {
   auto expected_draw_calls = std::vector(
       {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
        MockCanvas::DrawCall{1, MockCanvas::ConcatMatrixData{layer1_transform}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           1, MockCanvas::SetMatrixData{integral_layer1_transform}},
+#endif
        MockCanvas::DrawCall{
            1, MockCanvas::SaveLayerData{opacity1_bounds, opacity1_paint,
                                         nullptr, 2}},
        MockCanvas::DrawCall{
            2, MockCanvas::DrawPathData{child1_path, child1_paint}},
        MockCanvas::DrawCall{2, MockCanvas::SaveData{3}},
        MockCanvas::DrawCall{3, MockCanvas::ConcatMatrixData{layer2_transform}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           3, MockCanvas::SetMatrixData{integral_layer2_transform}},
+#endif
        MockCanvas::DrawCall{
            3, MockCanvas::SaveLayerData{opacity2_bounds, opacity2_paint,
                                         nullptr, 4}},

flow/layers/picture_layer.cc

@@ -26,6 +26,9 @@ void PictureLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
 
     SkMatrix ctm = matrix;
     ctm.postTranslate(offset_.x(), offset_.y());
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+    ctm = RasterCache::GetIntegralTransCTM(ctm);
+#endif
     cache->Prepare(context->gr_context, sk_picture, ctm,
                    context->dst_color_space, is_complex_, will_change_);
   }
@@ -41,6 +44,10 @@ void PictureLayer::Paint(PaintContext& context) const {
 
   SkAutoCanvasRestore save(context.leaf_nodes_canvas, true);
   context.leaf_nodes_canvas->translate(offset_.x(), offset_.y());
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+  context.leaf_nodes_canvas->setMatrix(RasterCache::GetIntegralTransCTM(
+      context.leaf_nodes_canvas->getTotalMatrix()));
+#endif
 
   if (context.raster_cache) {
     const SkMatrix& ctm = context.leaf_nodes_canvas->getTotalMatrix();

flow/layers/picture_layer_unittests.cc

@@ -11,6 +11,10 @@
 #include "flutter/testing/mock_canvas.h"
 #include "third_party/skia/include/core/SkPicture.h"
 
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+#include "flutter/flow/raster_cache.h"
+#endif
+
 namespace flutter {
 namespace testing {
 
@@ -81,11 +85,16 @@ TEST_F(PictureLayerTest, SimplePicture) {
   EXPECT_FALSE(layer->needs_system_composite());
 
   layer->Paint(paint_context());
-  auto expected_draw_calls =
-      std::vector({MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
-                   MockCanvas::DrawCall{
-                       1, MockCanvas::ConcatMatrixData{layer_offset_matrix}},
-                   MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
+  auto expected_draw_calls = std::vector(
+      {MockCanvas::DrawCall{0, MockCanvas::SaveData{1}},
+       MockCanvas::DrawCall{1,
+                            MockCanvas::ConcatMatrixData{layer_offset_matrix}},
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+       MockCanvas::DrawCall{
+           1, MockCanvas::SetMatrixData{RasterCache::GetIntegralTransCTM(
+                  layer_offset_matrix)}},
+#endif
+       MockCanvas::DrawCall{1, MockCanvas::RestoreData{0}}});
   EXPECT_EQ(mock_canvas().draw_calls(), expected_draw_calls);
 }
 

flow/raster_cache.h

@@ -62,6 +62,13 @@ class RasterCache {
     return bounds;
   }
 
+  static SkMatrix GetIntegralTransCTM(const SkMatrix& ctm) {
+    SkMatrix result = ctm;
+    result[SkMatrix::kMTransX] = SkScalarRoundToScalar(ctm.getTranslateX());
+    result[SkMatrix::kMTransY] = SkScalarRoundToScalar(ctm.getTranslateY());
+    return result;
+  }
+
   // Return true if the cache is generated.
   //
   // We may return false and not generate the cache if

flow/raster_cache_key.h

@@ -15,8 +15,11 @@ template <typename ID>
 class RasterCacheKey {
  public:
   RasterCacheKey(ID id, const SkMatrix& ctm) : id_(id), matrix_(ctm) {
-    matrix_[SkMatrix::kMTransX] = 0;
-    matrix_[SkMatrix::kMTransY] = 0;
+    matrix_[SkMatrix::kMTransX] = SkScalarFraction(ctm.getTranslateX());
+    matrix_[SkMatrix::kMTransY] = SkScalarFraction(ctm.getTranslateY());
+#ifndef SUPPORT_FRACTIONAL_TRANSLATION
+    FML_DCHECK(matrix_.getTranslateX() == 0 && matrix_.getTranslateY() == 0);
+#endif
   }
 
   ID id() const { return id_; }