cc: Stop converting Rect to QuadF to map to an enclosed rect.

cc/base/math_util.h

 // 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.
 
 #ifndef CC_BASE_MATH_UTIL_H_
 #define CC_BASE_MATH_UTIL_H_
 
 #include <algorithm>
 #include <cmath>
 #include <vector>
@@ skipping 90 matching lines @@
   // Background: Existing transform code does not do the right thing in
   // MapRect / MapQuad / ProjectQuad when there is a perspective projection that
   // causes one of the transformed vertices to go to w < 0. In those cases, it
   // is necessary to perform clipping in homogeneous coordinates, after applying
   // the transform, before dividing-by-w to convert to cartesian coordinates.
   //
   // These functions return the axis-aligned rect that encloses the correctly
   // clipped, transformed polygon.
   static gfx::Rect MapEnclosingClippedRect(const gfx::Transform& transform,
                                            const gfx::Rect& rect);
+  static gfx::Rect MapEnclosedClippedRect(const gfx::Transform& transform,
+                                          const gfx::Rect& rect);
   static gfx::RectF MapClippedRect(const gfx::Transform& transform,
                                    const gfx::RectF& rect);
   static gfx::Rect ProjectEnclosingClippedRect(const gfx::Transform& transform,
                                                const gfx::Rect& rect);
+  static gfx::Rect ProjectEnclosedClippedRect(const gfx::Transform& transform,
+                                              const gfx::Rect& rect);
   static gfx::RectF ProjectClippedRect(const gfx::Transform& transform,
                                        const gfx::RectF& rect);
 
+  // These functions are only valid to call for inputs where it is known they
+  // will not require clipping in homogeneous coordinates.
+  static gfx::Rect MapEnclosedNonClippedRect(const gfx::Transform& transform,

[enne (OOO), 2014/08/21 17:54:05]

Is it worth having unit tests for these functions? Or verifying that they do the
same as the clipped versions when their inputs are not clipped?

[danakj, 2014/08/21 17:58:08]

Ya I will write tests but I am not happy with the API as is. I think your point
about bounding box is great.

+                                             const gfx::Rect& rect);
+  static gfx::Rect ProjectEnclosedNonClippedRect(
+      const gfx::Transform& transform,
+      const gfx::Rect& rect);
+
   // Returns an array of vertices that represent the clipped polygon. After
   // returning, indexes from 0 to num_vertices_in_clipped_quad are valid in the
   // clipped_quad array. Note that num_vertices_in_clipped_quad may be zero,
   // which means the entire quad was clipped, and none of the vertices in the
   // array are valid.
   static void MapClippedQuad(const gfx::Transform& transform,
                              const gfx::QuadF& src_quad,
                              gfx::PointF clipped_quad[8],
                              int* num_vertices_in_clipped_quad);
   static bool MapClippedQuad3d(const gfx::Transform& transform,
@@ skipping 89 matching lines @@
 
   // Returns a base::Value representation of the floating point value.
   // If the value is inf, returns max double/float representation.
   static double AsDoubleSafely(double value);
   static float AsFloatSafely(float value);
 };
 
 }  // namespace cc
 
 #endif  // CC_BASE_MATH_UTIL_H_