Add Vector2d classes that represent offsets, instead of using Point.

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 "config.h"
 
 #include "cc/gl_renderer.h"
 
 #include "FloatQuad.h"
 #include "NotImplemented.h"
@@ skipping 674 matching lines @@
     // Clamp texture coordinates to avoid sampling outside the layer
     // by deflating the tile region half a texel or half a texel
     // minus epsilon for one pixel layers. The resulting clamp region
     // is mapped to the unit square by the vertex shader and mapped
     // back to normalized texture coordinates by the fragment shader
     // after being clamped to 0-1 range.
     const float epsilon = 1 / 1024.0f;
     float clampX = min(0.5, clampRect.width() / 2.0 - epsilon);
     float clampY = min(0.5, clampRect.height() / 2.0 - epsilon);
     clampRect.Inset(clampX, clampY, clampX, clampY);
-    gfx::PointF clampOffset = clampRect.origin() - tileRect.origin();
 
-    gfx::PointF textureOffset = quad->textureOffset() + clampOffset +
-                                (tileRect.origin() - quad->quadRect().origin());
+    gfx::PointF textureOffset = quad->textureOffset() + clampRect.OffsetFromOrigin() - quad->quadRect().OffsetFromOrigin();
 
     // Map clamping rectangle to unit square.
     float vertexTexTranslateX = -clampRect.x() / clampRect.width();
     float vertexTexTranslateY = -clampRect.y() / clampRect.height();
     float vertexTexScaleX = tileRect.width() / clampRect.width();
     float vertexTexScaleY = tileRect.height() / clampRect.height();
 
     // Map to normalized texture coordinates.
     const gfx::Size& textureSize = quad->textureSize();
     float fragmentTexTranslateX = textureOffset.x() / textureSize.width();
@@ skipping 883 matching lines @@
 
     releaseRenderPassTextures();
 }
 
 bool GLRenderer::isContextLost()
 {
     return (m_context->getGraphicsResetStatusARB() != GL_NO_ERROR);
 }
 
 } // namespace cc