Migrate more functions from MathUtil to gfx::Transform

cc/gl_renderer.cc

 // Copyright 2010 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/gl_renderer.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 501 matching lines @@
 }
 
 void GLRenderer::drawRenderPassQuad(DrawingFrame& frame, const RenderPassDrawQuad* quad)
 {
     CachedResource* contentsTexture = m_renderPassTextures.get(quad->render_pass_id);
     if (!contentsTexture || !contentsTexture->id())
         return;
 
     gfx::Transform quadRectMatrix;
     quadRectTransform(&quadRectMatrix, quad->quadTransform(), quad->rect);
-    gfx::Transform contentsDeviceTransform = MathUtil::to2dTransform(frame.windowMatrix * frame.projectionMatrix * quadRectMatrix);
+    gfx::Transform contentsDeviceTransform = frame.windowMatrix * frame.projectionMatrix * quadRectMatrix;
+    contentsDeviceTransform.FlattenTo2d();
 
     // Can only draw surface if device matrix is invertible.
     gfx::Transform contentsDeviceTransformInverse(gfx::Transform::kSkipInitialization);
     if (!contentsDeviceTransform.GetInverse(&contentsDeviceTransformInverse))
         return;
 
     scoped_ptr<ScopedResource> backgroundTexture = drawBackgroundFilters(
         frame, quad, contentsDeviceTransform, contentsDeviceTransformInverse);
 
     // FIXME: Cache this value so that we don't have to do it for both the surface and its replica.
@@ skipping 125 matching lines @@
         GLC(context(), context()->activeTexture(GL_TEXTURE0));
     }
 
     if (shaderEdgeLocation != -1) {
         float edge[24];
         deviceLayerEdges.toFloatArray(edge);
         deviceLayerBounds.toFloatArray(&edge[12]);
         GLC(context(), context()->uniform3fv(shaderEdgeLocation, 8, edge));
     }
 
-    // Map device space quad to surface space. contentsDeviceTransform has no 3d component since it was generated with to2dTransform() so we don't need to project.
+    // Map device space quad to surface space. contentsDeviceTransform has no 3d component since it was flattened, so we don't need to project.
     gfx::QuadF surfaceQuad = MathUtil::mapQuad(contentsDeviceTransformInverse, deviceLayerEdges.ToQuadF(), clipped);
     DCHECK(!clipped);
 
     setShaderOpacity(quad->opacity(), shaderAlphaLocation);
     setShaderQuadF(surfaceQuad, shaderQuadLocation);
     drawQuadGeometry(frame, quad->quadTransform(), quad->rect, shaderMatrixLocation);
 
     // Flush the compositor context before the filter bitmap goes out of
     // scope, so the draw gets processed before the filter texture gets deleted.
     if (filterBitmap.getTexture())
@@ skipping 84 matching lines @@
 
     // Map to normalized texture coordinates.
     const gfx::Size& textureSize = quad->texture_size;
     float fragmentTexTranslateX = clampTexRect.x() / textureSize.width();
     float fragmentTexTranslateY = clampTexRect.y() / textureSize.height();
     float fragmentTexScaleX = clampTexRect.width() / textureSize.width();
     float fragmentTexScaleY = clampTexRect.height() / textureSize.height();
 
 
     gfx::QuadF localQuad;
-    gfx::Transform deviceTransform = MathUtil::to2dTransform(frame.windowMatrix * frame.projectionMatrix * quad->quadTransform());
+    gfx::Transform deviceTransform = frame.windowMatrix * frame.projectionMatrix * quad->quadTransform();
+    deviceTransform.FlattenTo2d();
     if (!deviceTransform.IsInvertible())
         return;
 
     bool clipped = false;
     gfx::QuadF deviceLayerQuad = MathUtil::mapQuad(deviceTransform, gfx::QuadF(quad->visibleContentRect()), clipped);
     DCHECK(!clipped);
 
     TileProgramUniforms uniforms;
     // For now, we simply skip anti-aliasing with the quad is clipped. This only happens
     // on perspective transformed layers that go partially behind the camera.
@@ skipping 70 matching lines @@
 
         float sign = gfx::QuadF(tileRect).IsCounterClockwise() ? -1 : 1;
         bottomEdge.scale(sign);
         leftEdge.scale(sign);
         topEdge.scale(sign);
         rightEdge.scale(sign);
 
         // Create device space quad.
         LayerQuad deviceQuad(leftEdge, topEdge, rightEdge, bottomEdge);
 
-        // Map device space quad to local space. deviceTransform has no 3d component since it was generated with to2dTransform() so we don't need to project.
+        // Map device space quad to local space. deviceTransform has no 3d component since it was flattened, so we don't need to project.
         // We should have already checked that the transform was uninvertible above.
         gfx::Transform inverseDeviceTransform(gfx::Transform::kSkipInitialization);
         bool didInvert = deviceTransform.GetInverse(&inverseDeviceTransform);
         DCHECK(didInvert);
         localQuad = MathUtil::mapQuad(inverseDeviceTransform, deviceQuad.ToQuadF(), clipped);
 
         // We should not DCHECK(!clipped) here, because anti-aliasing inflation may cause deviceQuad to become
         // clipped. To our knowledge this scenario does not need to be handled differently than the unclipped case.
     } else {
         // Move fragment shader transform to vertex shader. We can do this while
@@ skipping 920 matching lines @@
 
     releaseRenderPassTextures();
 }
 
 bool GLRenderer::isContextLost()
 {
     return (m_context->getGraphicsResetStatusARB() != GL_NO_ERROR);
 }
 
 }  // namespace cc