Handle large rects better.

ui/gfx/geometry/rect_conversions.cc

 // 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.
 
 #include "ui/gfx/geometry/rect_conversions.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
 #include "ui/gfx/geometry/safe_integer_conversions.h"
 
 namespace gfx {
 
 Rect ToEnclosingRect(const RectF& rect) {
   int min_x = ToFlooredInt(rect.x());
   int min_y = ToFlooredInt(rect.y());
-  float max_x = rect.right();
-  float max_y = rect.bottom();
-  int width =
-      rect.width() == 0
-          ? 0
-          : std::max(
-                ToCeiledInt(static_cast<double>(ToCeiledInt(max_x)) - min_x),
-                0);
-  int height =
-      rect.height() == 0
-          ? 0
-          : std::max(
-                ToCeiledInt(static_cast<double>(ToCeiledInt(max_y)) - min_y),
-                0);
+  int max_x = ToCeiledInt(rect.right());
+  int max_y = ToCeiledInt(rect.bottom());
+  int width = base::SaturatedSubtraction(max_x, min_x);
+  int height = base::SaturatedSubtraction(max_y, min_y);

[Peter Mayo, 2017/03/14 18:35:59]

move into set from range in header

+
+  // clamping may move one side, choose to move the bigger by recomputing it.
+  // The computation of right is implicit, so this happens vacuosly.
+  //  If Right is small, move left to width away.
+  //  If Left is big(negative), move them both to keep the center.
+  if (width >= std::numeric_limits<int>::max() / 2) {
+    if (base::SaturatedAbsolute(max_x) < width / 2)
+      min_x = max_x - width;
+    else if (base::SaturatedAbsolute(min_x) > width / 2)
+      min_x = min_x + width / 4;
+  }
+
+  // Same computation, other axis.
+  if (height >= std::numeric_limits<int>::max() / 2) {
+    if (base::SaturatedAbsolute(max_y) < height / 2)
+      min_y = max_y - height;
+    else if (base::SaturatedAbsolute(min_y) > height / 2)
+      min_y = min_y + height / 4;
+  }
+
   return Rect(min_x, min_y, width, height);
 }
 
 Rect ToEnclosedRect(const RectF& rect) {
   int min_x = ToCeiledInt(rect.x());
   int min_y = ToCeiledInt(rect.y());
-  float max_x = rect.right();
-  float max_y = rect.bottom();
-  int width = std::max(
-      ToFlooredInt(static_cast<float>(ToFlooredInt(max_x)) - min_x), 0);
-  int height = std::max(
-      ToFlooredInt(static_cast<float>(ToFlooredInt(max_y)) - min_y), 0);
+  int max_x = ToFlooredInt(rect.right());
+  int max_y = ToFlooredInt(rect.bottom());
+  int width = base::SaturatedSubtraction(max_x, min_x);
+  int height = base::SaturatedSubtraction(max_y, min_y);
+
+  // clamping may move one side, choose to move the bigger by recomputing it.
+  // The computation of right is implicit, so this happens vacuosly.
+  //  If Right is small, move left to width away.
+  //  If Left is big(negative), move them both to keep the center.
+  if (width >= std::numeric_limits<int>::max() / 2) {
+    if (base::SaturatedAbsolute(max_x) < width / 2)
+      min_x = max_x - width;
+    else if (base::SaturatedAbsolute(min_x) > width / 2)
+      min_x = min_x + width / 4;
+  }
+
+  // Same computation, other axis.
+  if (height >= std::numeric_limits<int>::max() / 2) {
+    if (base::SaturatedAbsolute(max_y) < height / 2)
+      min_y = max_y - height;
+    else if (base::SaturatedAbsolute(min_y) > height / 2)
+      min_y = min_y + height / 4;
+  }
+
   return Rect(min_x, min_y, width, height);
 }
 
 Rect ToNearestRect(const RectF& rect) {
   float float_min_x = rect.x();
   float float_min_y = rect.y();
   float float_max_x = rect.right();
   float float_max_y = rect.bottom();
 
   int min_x = ToRoundedInt(float_min_x);
   int min_y = ToRoundedInt(float_min_y);
   int max_x = ToRoundedInt(float_max_x);
   int max_y = ToRoundedInt(float_max_y);
 
   // If these DCHECKs fail, you're using the wrong method, consider using
   // ToEnclosingRect or ToEnclosedRect instead.
   DCHECK(std::abs(min_x - float_min_x) < 0.01f);
   DCHECK(std::abs(min_y - float_min_y) < 0.01f);
   DCHECK(std::abs(max_x - float_max_x) < 0.01f);
   DCHECK(std::abs(max_y - float_max_y) < 0.01f);
 
   return Rect(min_x, min_y, max_x - min_x, max_y - min_y);

[Peter Mayo, 2017/03/17 00:30:48]

Oops - missed this in the previous CL.

 }
 
 bool IsNearestRectWithinDistance(const gfx::RectF& rect, float distance) {
   float float_min_x = rect.x();
   float float_min_y = rect.y();
   float float_max_x = rect.right();
   float float_max_y = rect.bottom();
 
   int min_x = ToRoundedInt(float_min_x);
   int min_y = ToRoundedInt(float_min_y);
   int max_x = ToRoundedInt(float_max_x);
   int max_y = ToRoundedInt(float_max_y);
 
   return
       (std::abs(min_x - float_min_x) < distance) &&
       (std::abs(min_y - float_min_y) < distance) &&
       (std::abs(max_x - float_max_x) < distance) &&
       (std::abs(max_y - float_max_y) < distance);
 }
 
 Rect ToFlooredRectDeprecated(const RectF& rect) {
   return Rect(ToFlooredInt(rect.x()),
               ToFlooredInt(rect.y()),
               ToFlooredInt(rect.width()),
               ToFlooredInt(rect.height()));
 }
 
 }  // namespace gfx