Invert DSF to map from delegated frame to layer space

cc/layers/delegated_renderer_layer_impl_unittest.cc

Index: cc/layers/delegated_renderer_layer_impl_unittest.cc
diff --git a/cc/layers/delegated_renderer_layer_impl_unittest.cc b/cc/layers/delegated_renderer_layer_impl_unittest.cc
index 3f30d15a3b79651463f9e31df14ad4a86b8e3002..fbaf8bbf24f5bb44292e10dd046f72fdbf1000b4 100644
--- a/cc/layers/delegated_renderer_layer_impl_unittest.cc
+++ b/cc/layers/delegated_renderer_layer_impl_unittest.cc
@@ -109,7 +109,7 @@ class DelegatedRendererLayerImplTestSimple
                                           gfx::Transform(1, 0, 0, 1, 9, 10));
     AddRenderPassQuad(pass3, pass2);
     delegated_renderer_layer->SetFrameDataForRenderPasses(
-        &delegated_render_passes);
+        1.f, &delegated_render_passes);
 
     // The RenderPasses should be taken by the layer.
     EXPECT_EQ(0u, delegated_render_passes.size());
@@ -245,11 +245,8 @@ TEST_F(DelegatedRendererLayerImplTestSimple,
   // The DelegatedRendererLayer is at position 3,3 compared to its target, and
   // has a translation transform of 1,1. So its root RenderPass' quads should
   // all be transformed by that combined amount.
-  // The DelegatedRendererLayer has a size of 10x10, but the root delegated
-  // RenderPass has a size of 8x8, so any quads should be scaled by 10/8.
   gfx::Transform transform;
   transform.Translate(4.0, 4.0);
-  transform.Scale(10.0 / 8.0, 10.0 / 8.0);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       transform, frame.render_passes[3]->quad_list[0]->quadTransform());
 
@@ -280,12 +277,8 @@ TEST_F(DelegatedRendererLayerImplTestSimple, RenderPassTransformIsModified) {
 
   // The DelegatedRendererLayer is at position 9,9 compared to the root, so all
   // render pass' transforms to the root should be shifted by this amount.
-  // The DelegatedRendererLayer has a size of 10x10, but the root delegated
-  // RenderPass has a size of 8x8, so any render passes should be scaled by
-  // 10/8.
   gfx::Transform transform;
   transform.Translate(9.0, 9.0);
-  transform.Scale(10.0 / 8.0, 10.0 / 8.0);
 
   // The first contributing surface has a translation of 5, 6.
   gfx::Transform five_six(1, 0, 0, 1, 5, 6);
@@ -468,12 +461,9 @@ TEST_F(DelegatedRendererLayerImplTestOwnSurface,
   ASSERT_EQ(6u, frame.render_passes.size());
 
   // Because the DelegatedRendererLayer owns a RenderSurfaceImpl, its root
-  // RenderPass' quads do not need to be translated at all. However, they are
-  // scaled from the frame's size (8x8) to the layer's bounds (10x10).
-  gfx::Transform transform;
-  transform.Scale(10.0 / 8.0, 10.0 / 8.0);
+  // RenderPass' quads do not need to be translated at all.
   EXPECT_TRANSFORMATION_MATRIX_EQ(
-      transform, frame.render_passes[3]->quad_list[0]->quadTransform());
+      gfx::Transform(), frame.render_passes[3]->quad_list[0]->quadTransform());
 
   // Quads from non-root RenderPasses should not be shifted either.
   ASSERT_EQ(2u, frame.render_passes[2]->quad_list.size());
@@ -492,6 +482,10 @@ TEST_F(DelegatedRendererLayerImplTestOwnSurface,
 class DelegatedRendererLayerImplTestTransform
     : public DelegatedRendererLayerImplTest {
  public:
+  DelegatedRendererLayerImplTestTransform()
+      : root_delegated_render_pass_is_clipped_(false),
+        delegated_device_scale_factor_(2.f) {}
+
   void SetUpTest() {
     host_impl_->SetDeviceScaleFactor(2.f);
 
@@ -511,8 +505,6 @@ class DelegatedRendererLayerImplTestTransform
     transform.Scale(2.0, 2.0);
     transform.Translate(8.0, 8.0);
     delegated_renderer_layer->SetTransform(transform);
-    delegated_renderer_layer->SetTransformOrigin(
-        gfx::Point3F(75 * 0.5f, 75 * 0.5f, 0.0f));
 
     ScopedPtrVector<RenderPass> delegated_render_passes;
 
@@ -629,7 +621,7 @@ class DelegatedRendererLayerImplTestTransform
     pass->AppendDrawQuad(color_quad.PassAs<DrawQuad>());
 
     delegated_renderer_layer->SetFrameDataForRenderPasses(
-        &delegated_render_passes);
+        delegated_device_scale_factor_, &delegated_render_passes);
 
     // The RenderPasses should be taken by the layer.
     EXPECT_EQ(0u, delegated_render_passes.size());
@@ -687,6 +679,7 @@ class DelegatedRendererLayerImplTestTransform
   LayerImpl* root_layer_;
   DelegatedRendererLayerImpl* delegated_renderer_layer_;
   bool root_delegated_render_pass_is_clipped_;
+  float delegated_device_scale_factor_;
 };
 
 TEST_F(DelegatedRendererLayerImplTestTransform, QuadsUnclipped_NoSurface) {
@@ -715,16 +708,15 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsUnclipped_NoSurface) {
   EXPECT_TRUE(root_delegated_shared_quad_state->is_clipped);
 
   gfx::Transform expected;
-  // Device scale factor is 2.
+  // Device scale factor.
   expected.Scale(2.0, 2.0);
   // This is the transform from the layer's space to its target.
-  // The position (20) - the width / scale (75 / 2) = 20 - 37.5 = -17.5
-  expected.Translate(-17.5, -17.5);
+  expected.Translate(20, 20);
   expected.Scale(2.0, 2.0);
   expected.Translate(8.0, 8.0);
-  // The frame has size 100x100 but the layer's bounds are 75x75.
-  expected.Scale(75.0 / 100.0, 75.0 / 100.0);
   // This is the transform within the source frame.
+  // Inverse device scale factor to go from physical space to layer space.
+  expected.Scale(0.5, 0.5);
   expected.Scale(1.5, 1.5);
   expected.Translate(7.0, 7.0);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
@@ -763,31 +755,27 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsClipped_NoSurface) {
   // Since the quads have a clip_rect it should be modified by delegated
   // renderer layer's draw_transform.
   // The position of the resulting clip_rect is:
-  // (clip rect position (10) * scale to layer (75/100) + translate (8)) *
-  //     layer scale (2) + layer position (20) = 51
-  // But the layer is centered, so: 51 - (75 / 2) = 51 - 75 / 2 = 13.5
-  // The device scale is 2, so everything gets doubled, giving 27.
+  // (clip rect position (10) * inverse dsf (1/2) + translate (8)) *
+  //     layer scale (2) + layer position (20) = 46
+  // The device scale is 2, so everything gets doubled, giving 92.
   //
-  // The size is 35x35 scaled to fit inside the layer's bounds at 75x75 from
-  // a frame at 100x100: 35 * 2 (device scale) * 75 / 100 = 52.5. The device
-  // scale doubles this to 105.
-  EXPECT_EQ(gfx::Rect(27, 27, 105, 105).ToString(),
+  // The size is 35x35 scaled by the device scale.
+  EXPECT_EQ(gfx::Rect(92, 92, 70, 70).ToString(),
             root_delegated_shared_quad_state->clip_rect.ToString());
 
   // The quads had a clip and it should be preserved.
   EXPECT_TRUE(root_delegated_shared_quad_state->is_clipped);
 
   gfx::Transform expected;
-  // Device scale factor is 2.
+  // Device scale factor.
   expected.Scale(2.0, 2.0);
   // This is the transform from the layer's space to its target.
-  // The position (20) - the width / scale (75 / 2) = 20 - 37.5 = -17.5
-  expected.Translate(-17.5, -17.5);
+  expected.Translate(20, 20);
   expected.Scale(2.0, 2.0);
   expected.Translate(8.0, 8.0);
-  // The frame has size 100x100 but the layer's bounds are 75x75.
-  expected.Scale(75.0 / 100.0, 75.0 / 100.0);
   // This is the transform within the source frame.
+  // Inverse device scale factor to go from physical space to layer space.
+  expected.Scale(0.5, 0.5);
   expected.Scale(1.5, 1.5);
   expected.Translate(7.0, 7.0);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
@@ -827,11 +815,7 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsUnclipped_Surface) {
 
   // When the layer owns a surface, then its position and translation are not
   // a part of its draw transform.
-  // The position of the resulting clip_rect is:
-  // (clip rect position (10) * scale to layer (75/100)) * device scale (2) = 15
-  // The size is 35x35 scaled to fit inside the layer's bounds at 75x75 from
-  // a frame at 100x100: 35 * 2 (device scale) * 75 / 100 = 52.5.
-  EXPECT_EQ(gfx::Rect(15, 15, 53, 53).ToString(),
+  EXPECT_EQ(gfx::Rect(10, 10, 35, 35).ToString(),
             root_delegated_shared_quad_state->clip_rect.ToString());
 
   // Since the layer owns a surface it doesn't need to clip its quads, so
@@ -839,10 +823,6 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsUnclipped_Surface) {
   EXPECT_FALSE(root_delegated_shared_quad_state->is_clipped);
 
   gfx::Transform expected;
-  // Device scale factor is 2.
-  expected.Scale(2.0, 2.0);
-  // The frame has size 100x100 but the layer's bounds are 75x75.
-  expected.Scale(75.0 / 100.0, 75.0 / 100.0);
   // This is the transform within the source frame.
   expected.Scale(1.5, 1.5);
   expected.Translate(7.0, 7.0);
@@ -882,22 +862,14 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsClipped_Surface) {
       &contrib_delegated_shared_quad_state);
 
   // When the layer owns a surface, then its position and translation are not
-  // a part of its draw transform.
-  // The position of the resulting clip_rect is:
-  // (clip rect position (10) * scale to layer (75/100)) * device scale (2) = 15
-  // The size is 35x35 scaled to fit inside the layer's bounds at 75x75 from
-  // a frame at 100x100: 35 * 2 (device scale) * 75 / 100 = 52.5.
-  EXPECT_EQ(gfx::Rect(15, 15, 53, 53).ToString(),
+  // a part of its draw transform. The clip_rect should be preserved.
+  EXPECT_EQ(gfx::Rect(10, 10, 35, 35).ToString(),
             root_delegated_shared_quad_state->clip_rect.ToString());
 
   // The quads had a clip and it should be preserved.
   EXPECT_TRUE(root_delegated_shared_quad_state->is_clipped);
 
   gfx::Transform expected;
-  // Device scale factor is 2.
-  expected.Scale(2.0, 2.0);
-  // The frame has size 100x100 but the layer's bounds are 75x75.
-  expected.Scale(75.0 / 100.0, 75.0 / 100.0);
   // This is the transform within the source frame.
   expected.Scale(1.5, 1.5);
   expected.Translate(7.0, 7.0);
@@ -919,6 +891,45 @@ TEST_F(DelegatedRendererLayerImplTestTransform, QuadsClipped_Surface) {
   host_impl_->DidDrawAllLayers(frame);
 }
 
+TEST_F(DelegatedRendererLayerImplTestTransform, MismatchedDeviceScaleFactor) {
+  root_delegated_render_pass_is_clipped_ = true;
+  delegated_device_scale_factor_ = 1.3f;
+
+  SetUpTest();
+
+  LayerTreeHostImpl::FrameData frame;
+  EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
+
+  const SharedQuadState* root_delegated_shared_quad_state = NULL;
+  const SharedQuadState* contrib_delegated_shared_quad_state = NULL;
+  VerifyRenderPasses(frame,
+                     2,
+                     &root_delegated_shared_quad_state,
+                     &contrib_delegated_shared_quad_state);
+
+  // The parent tree's device scale factor is 2.0, but the child has submitted a
+  // frame with a device scale factor of 1.3.  Absent any better option, the
+  // only thing we can do is scale from 1.3 -> 2.0.
+
+  gfx::Transform expected;
+  // Device scale factor (from parent).
+  expected.Scale(2.0, 2.0);
+  // This is the transform from the layer's space to its target.
+  expected.Translate(20, 20);
+  expected.Scale(2.0, 2.0);
+  expected.Translate(8.0, 8.0);
+  // This is the transform within the source frame.
+  // Inverse device scale factor (from child).
+  expected.Scale(1.0f / 1.3f, 1.0f / 1.3f);
+  expected.Scale(1.5, 1.5);
+  expected.Translate(7.0, 7.0);
+  EXPECT_TRANSFORMATION_MATRIX_EQ(
+      expected, root_delegated_shared_quad_state->content_to_target_transform);
+
+  host_impl_->DrawLayers(&frame, gfx::FrameTime::Now());
+  host_impl_->DidDrawAllLayers(frame);
+}
+
 class DelegatedRendererLayerImplTestClip
     : public DelegatedRendererLayerImplTest {
  public:
@@ -1051,7 +1062,7 @@ class DelegatedRendererLayerImplTestClip
     pass->AppendDrawQuad(color_quad.PassAs<DrawQuad>());
 
     delegated_renderer_layer->SetFrameDataForRenderPasses(
-        &delegated_render_passes);
+        1.f, &delegated_render_passes);
 
     // The RenderPasses should be taken by the layer.
     EXPECT_EQ(0u, delegated_render_passes.size());
@@ -1355,7 +1366,7 @@ TEST_F(DelegatedRendererLayerImplTest, InvalidRenderPassDrawQuad) {
   AddRenderPassQuad(pass1, missing_pass.get());
 
   delegated_renderer_layer->SetFrameDataForRenderPasses(
-      &delegated_render_passes);
+      1.f, &delegated_render_passes);
 
   // The RenderPasses should be taken by the layer.
   EXPECT_EQ(0u, delegated_render_passes.size());
@@ -1408,7 +1419,7 @@ TEST_F(DelegatedRendererLayerImplTest, Occlusion) {
                                         gfx::Transform());
   AddRenderPassQuad(pass1, pass2, 0, FilterOperations(), transform);
   delegated_renderer_layer_impl->SetFrameDataForRenderPasses(
-      &delegated_render_passes);
+      1.f, &delegated_render_passes);
 
   impl.CalcDrawProps(viewport_size);