Type conversion fixes, ui/gfx/ edition.

ui/gfx/geometry/rect.h

 // Copyright (c) 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.
 
 // Defines a simple integer rectangle class.  The containment semantics
 // are array-like; that is, the coordinate (x, y) is considered to be
 // contained by the rectangle, but the coordinate (x + width, y) is not.
 // The class will happily let you create malformed rectangles (that is,
 // rectangles with negative width and/or height), but there will be assertions
 // in the operations (such as Contains()) to complain in this case.
 
 #ifndef UI_GFX_GEOMETRY_RECT_H_
 #define UI_GFX_GEOMETRY_RECT_H_
 
 #include <cmath>
 #include <iosfwd>
 #include <string>
 
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect_f.h"
+#include "ui/gfx/geometry/safe_integer_conversions.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/geometry/vector2d.h"
 
 #if defined(OS_WIN)
 typedef struct tagRECT RECT;
 #elif defined(OS_IOS)
 #include <CoreGraphics/CoreGraphics.h>
 #elif defined(OS_MACOSX)
 #include <ApplicationServices/ApplicationServices.h>
 #endif
@@ skipping 21 matching lines @@
 
 #if defined(OS_WIN)
   // Construct an equivalent Win32 RECT object.
   RECT ToRECT() const;
 #elif defined(OS_MACOSX)
   // Construct an equivalent CoreGraphics object.
   CGRect ToCGRect() const;
 #endif
 
   operator RectF() const {
-    return RectF(origin().x(), origin().y(), size().width(), size().height());
+    return RectF(static_cast<float>(x()), static_cast<float>(y()),
+                 static_cast<float>(width()), static_cast<float>(height()));
   }
 
   int x() const { return origin_.x(); }
   void set_x(int x) { origin_.set_x(x); }
 
   int y() const { return origin_.y(); }
   void set_y(int y) { origin_.set_y(y); }
 
   int width() const { return size_.width(); }
   void set_width(int width) { size_.set_width(width); }
@@ skipping 140 matching lines @@
 //
 // This could also be thought of as "the smallest rect that contains both
 // points", except that we consider points on the right/bottom edges of the
 // rect to be outside the rect.  So technically one or both points will not be
 // contained within the rect, because they will appear on one of these edges.
 GFX_EXPORT Rect BoundingRect(const Point& p1, const Point& p2);
 
 inline Rect ScaleToEnclosingRect(const Rect& rect,
                                  float x_scale,
                                  float y_scale) {
-  int x = std::floor(rect.x() * x_scale);
-  int y = std::floor(rect.y() * y_scale);
-  int r = rect.width() == 0 ? x : std::ceil(rect.right() * x_scale);
-  int b = rect.height() == 0 ? y : std::ceil(rect.bottom() * y_scale);
+  int x = ToFlooredInt(rect.x() * x_scale);

[danakj, 2014/10/23 15:35:44]

i had written these purposefully as static_casts instead of ToFloored/CeiledInt
because those functions do clamping stuff to make sure the result fits in an
int, whereas this method is going from int inputs to int outputs, so I wanted to
rely on the caller making sure things fit instead.

[Peter Kasting, 2014/10/23 17:29:45]

Is that a performance concern?  I originally added casts in here but it made the
code harder to read due to introducing line-wrapping; using these helpers is
very clear.  If you're worried only about clarity, we could simply add a comment
in these functions noting that the clamping portion of the helpers is
unnecessary.  If this is a performance problem, then we can probably cast and
note that it's impossible for the code to need clamping due to the source values
being integral.

[danakj, 2014/10/23 17:43:23]

I think we should cast unless we can show there is no negative performance
change by using the helpers. The testing methodology I used in
https://code.google.com/p/chromium/issues/detail?id=407444 would be appropriate
here too if you want to do that.

+  int y = ToFlooredInt(rect.y() * y_scale);
+  int r = rect.width() == 0 ? x : ToCeiledInt(rect.right() * x_scale);
+  int b = rect.height() == 0 ? y : ToCeiledInt(rect.bottom() * y_scale);
   return Rect(x, y, r - x, b - y);
 }
 
 inline Rect ScaleToEnclosingRect(const Rect& rect, float scale) {
   return ScaleToEnclosingRect(rect, scale, scale);
 }
 
 inline Rect ScaleToEnclosedRect(const Rect& rect,
                                 float x_scale,
                                 float y_scale) {
-  int x = std::ceil(rect.x() * x_scale);
-  int y = std::ceil(rect.y() * y_scale);
-  int r = rect.width() == 0 ? x : std::floor(rect.right() * x_scale);
-  int b = rect.height() == 0 ? y : std::floor(rect.bottom() * y_scale);
+  int x = ToCeiledInt(rect.x() * x_scale);
+  int y = ToCeiledInt(rect.y() * y_scale);
+  int r = rect.width() == 0 ? x : ToFlooredInt(rect.right() * x_scale);
+  int b = rect.height() == 0 ? y : ToFlooredInt(rect.bottom() * y_scale);
   return Rect(x, y, r - x, b - y);
 }
 
 inline Rect ScaleToEnclosedRect(const Rect& rect, float scale) {
   return ScaleToEnclosedRect(rect, scale, scale);
 }
 
 // This is declared here for use in gtest-based unit tests but is defined in
 // the gfx_test_support target. Depend on that to use this in your unit test.
 // This should not be used in production code - call ToString() instead.
 void PrintTo(const Rect& rect, ::std::ostream* os);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GEOMETRY_RECT_H_