Invert DSF to map from delegated frame to layer space

cc/layers/delegated_renderer_layer_impl_unittest.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/delegated_renderer_layer_impl.h"
 
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/layers/quad_sink.h"
 #include "cc/layers/solid_color_layer_impl.h"
 #include "cc/quads/render_pass_draw_quad.h"
@@ skipping 227 matching lines @@
   LayerTreeHostImpl::FrameData frame;
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // Each non-DelegatedRendererLayer added one RenderPass. The
   // DelegatedRendererLayer added two contributing passes.
   ASSERT_EQ(5u, frame.render_passes.size());
 
   // 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());
 
   // Quads from non-root RenderPasses should not be shifted though.
   ASSERT_EQ(2u, frame.render_passes[2]->quad_list.size());
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       gfx::Transform(), frame.render_passes[2]->quad_list[0]->quadTransform());
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       gfx::Transform(), frame.render_passes[2]->quad_list[1]->quadTransform());
   ASSERT_EQ(1u, frame.render_passes[1]->quad_list.size());
@@ skipping 10 matching lines @@
 
   // The delegated layer has a surface between it and the root.
   EXPECT_TRUE(delegated_renderer_layer_->render_target()->parent());
 
   // Each non-DelegatedRendererLayer added one RenderPass. The
   // DelegatedRendererLayer added two contributing passes.
   ASSERT_EQ(5u, frame.render_passes.size());
 
   // 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);
 
   // The second contributing surface has a translation of 7, 8.
   gfx::Transform seven_eight(1, 0, 0, 1, 7, 8);
 
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       transform * five_six, frame.render_passes[1]->transform_to_root_target);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
@@ skipping 162 matching lines @@
        QuadsFromRootRenderPassAreNotModifiedForTheTarget) {
   LayerTreeHostImpl::FrameData frame;
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // Each non-DelegatedRendererLayer added one RenderPass. The
   // DelegatedRendererLayer added two contributing passes and its owned surface
   // added one pass.
   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());
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       gfx::Transform(), frame.render_passes[2]->quad_list[0]->quadTransform());
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       gfx::Transform(), frame.render_passes[2]->quad_list[1]->quadTransform());
   ASSERT_EQ(1u, frame.render_passes[1]->quad_list.size());
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       gfx::Transform(), frame.render_passes[1]->quad_list[0]->quadTransform());
@@ skipping 17 matching lines @@
     root_layer->SetBounds(gfx::Size(100, 100));
 
     delegated_renderer_layer->SetPosition(gfx::Point(20, 20));
     delegated_renderer_layer->SetBounds(gfx::Size(75, 75));
     delegated_renderer_layer->SetContentBounds(gfx::Size(75, 75));
     delegated_renderer_layer->SetDrawsContent(true);
     gfx::Transform transform;
     transform.Scale(2.0, 2.0);
     transform.Translate(8.0, 8.0);
     delegated_renderer_layer->SetTransform(transform);
-    delegated_renderer_layer->SetTransformOrigin(

[jamesr, 2014/06/05 20:54:26]

deleting this (which doesn't seem all that relevant to the rest of the test)
makes the math easier to follow for me. legit?

[enne (OOO), 2014/06/05 23:02:14]

Yeah, I don't think it's relevant to DRLI and makes this easier to follow.  It
seems legit after I've stared at it a little.

-        gfx::Point3F(75 * 0.5f, 75 * 0.5f, 0.0f));
 
     ScopedPtrVector<RenderPass> delegated_render_passes;
 
     gfx::Size child_pass_content_bounds(7, 7);
     gfx::Rect child_pass_rect(20, 20, 7, 7);
     gfx::Transform child_pass_transform;
     child_pass_transform.Scale(0.8f, 0.8f);
     child_pass_transform.Translate(9.0, 9.0);
     gfx::Rect child_pass_clip_rect(21, 21, 3, 3);
     bool child_pass_clipped = false;
@@ skipping 182 matching lines @@
   // the drawable_content_rect of the delegated renderer layer.
   EXPECT_EQ(delegated_renderer_layer_->drawable_content_rect().ToString(),
             root_delegated_shared_quad_state->clip_rect.ToString());
 
   // Even though the quads in the root pass have no clip of their own, they
   // inherit the clip rect from the delegated renderer layer if it does not
   // own a surface.
   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(
       expected, root_delegated_shared_quad_state->content_to_target_transform);
 
   // The contributing render pass should not be transformed from its input.
   EXPECT_EQ(gfx::Rect(21, 21, 3, 3).ToString(),
             contrib_delegated_shared_quad_state->clip_rect.ToString());
   EXPECT_FALSE(contrib_delegated_shared_quad_state->is_clipped);
   expected.MakeIdentity();
@@ skipping 18 matching lines @@
   const SharedQuadState* contrib_delegated_shared_quad_state = NULL;
   VerifyRenderPasses(
       frame,
       2,
       &root_delegated_shared_quad_state,
       &contrib_delegated_shared_quad_state);
 
   // 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(
       expected, root_delegated_shared_quad_state->content_to_target_transform);
 
   // The contributing render pass should not be transformed from its input.
   EXPECT_EQ(gfx::Rect(21, 21, 3, 3).ToString(),
             contrib_delegated_shared_quad_state->clip_rect.ToString());
   EXPECT_FALSE(contrib_delegated_shared_quad_state->is_clipped);
   expected.MakeIdentity();
@@ skipping 19 matching lines @@
   const SharedQuadState* root_delegated_shared_quad_state = NULL;
   const SharedQuadState* contrib_delegated_shared_quad_state = NULL;
   VerifyRenderPasses(
       frame,
       3,
       &root_delegated_shared_quad_state,
       &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(),
+  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
   // unclipped quads remain unclipped.
   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);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       expected, root_delegated_shared_quad_state->content_to_target_transform);
 
   // The contributing render pass should not be transformed from its input.
   EXPECT_EQ(gfx::Rect(21, 21, 3, 3).ToString(),
             contrib_delegated_shared_quad_state->clip_rect.ToString());
   EXPECT_FALSE(contrib_delegated_shared_quad_state->is_clipped);
@@ skipping 19 matching lines @@
 
   const SharedQuadState* root_delegated_shared_quad_state = NULL;
   const SharedQuadState* contrib_delegated_shared_quad_state = NULL;
   VerifyRenderPasses(
       frame,
       3,
       &root_delegated_shared_quad_state,
       &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);
   EXPECT_TRANSFORMATION_MATRIX_EQ(
       expected, root_delegated_shared_quad_state->content_to_target_transform);
 
   // The contributing render pass should not be transformed from its input.
   EXPECT_EQ(gfx::Rect(21, 21, 3, 3).ToString(),
             contrib_delegated_shared_quad_state->clip_rect.ToString());
   EXPECT_FALSE(contrib_delegated_shared_quad_state->is_clipped);
@@ skipping 593 matching lines @@
       // The occlusion extends to 500 in the x-axis, pushing the left of the
       // visible part of the quad to 500 - 211 = 300 - 11 inside the quad.
       EXPECT_EQ(gfx::Rect(300 - 11, 0, 100 + 11, 500).ToString(),
                 impl.quad_list()[0]->visible_rect.ToString());
     }
   }
 }
 
 }  // namespace
 }  // namespace cc