diff -r 000000000000 -r 6474c204b198 gfx/src/nsRect.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/src/nsRect.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,317 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+#ifndef NSRECT_H
+#define NSRECT_H
+
+#include <stdio.h>                      // for FILE
+#include <stdint.h>                     // for int32_t, int64_t
+#include <algorithm>                    // for min/max
+#include "nsDebug.h"                    // for NS_WARNING
+#include "gfxCore.h"                    // for NS_GFX
+#include "mozilla/Likely.h"             // for MOZ_UNLIKELY
+#include "mozilla/gfx/BaseRect.h"       // for BaseRect
+#include "nsCoord.h"                    // for nscoord, etc
+#include "nsISupportsImpl.h"            // for MOZ_COUNT_CTOR, etc
+#include "nsPoint.h"                    // for nsIntPoint, nsPoint
+#include "nsSize.h"                     // for nsIntSize, nsSize
+#include "nscore.h"                     // for NS_BUILD_REFCNT_LOGGING
+
+struct nsIntRect;
+struct nsMargin;
+struct nsIntMargin;
+
+struct NS_GFX nsRect :
+  public mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize, nsMargin> {
+  typedef mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize, nsMargin> Super;
+
+  static void VERIFY_COORD(nscoord aValue) { ::VERIFY_COORD(aValue); }
+
+  // Constructors
+  nsRect() : Super()
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(const nsRect& aRect) : Super(aRect)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(const nsPoint& aOrigin, const nsSize &aSize) : Super(aOrigin, aSize)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+  nsRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight) :
+      Super(aX, aY, aWidth, aHeight)
+  {
+    MOZ_COUNT_CTOR(nsRect);
+  }
+
+#ifdef NS_BUILD_REFCNT_LOGGING
+  ~nsRect() {
+    MOZ_COUNT_DTOR(nsRect);
+  }
+#endif
+
+  // We have saturating versions of all the Union methods. These avoid
+  // overflowing nscoord values in the 'width' and 'height' fields by
+  // clamping the width and height values to nscoord_MAX if necessary.
+
+  nsRect SaturatingUnion(const nsRect& aRect) const
+  {
+    if (IsEmpty()) {
+      return aRect;
+    } else if (aRect.IsEmpty()) {
+      return *static_cast<const nsRect*>(this);
+    } else {
+      return SaturatingUnionEdges(aRect);
+    }
+  }
+
+  nsRect SaturatingUnionEdges(const nsRect& aRect) const
+  {
+#ifdef NS_COORD_IS_FLOAT
+    return UnionEdges(aRect);
+#else
+    nsRect result;
+    result.x = std::min(aRect.x, x);
+    int64_t w = std::max(int64_t(aRect.x) + aRect.width, int64_t(x) + width) - result.x;
+    if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+      NS_WARNING("Overflowed nscoord_MAX in conversion to nscoord width");
+      // Clamp huge negative x to nscoord_MIN / 2 and try again.
+      result.x = std::max(result.x, nscoord_MIN / 2);
+      w = std::max(int64_t(aRect.x) + aRect.width, int64_t(x) + width) - result.x;
+      if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+        w = nscoord_MAX;
+      }
+    }
+    result.width = nscoord(w);
+
+    result.y = std::min(aRect.y, y);
+    int64_t h = std::max(int64_t(aRect.y) + aRect.height, int64_t(y) + height) - result.y;
+    if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+      NS_WARNING("Overflowed nscoord_MAX in conversion to nscoord height");
+      // Clamp huge negative y to nscoord_MIN / 2 and try again.
+      result.y = std::max(result.y, nscoord_MIN / 2);
+      h = std::max(int64_t(aRect.y) + aRect.height, int64_t(y) + height) - result.y;
+      if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+        h = nscoord_MAX;
+      }
+    }
+    result.height = nscoord(h);
+    return result;
+#endif
+  }
+
+#ifndef NS_COORD_IS_FLOAT
+  // Make all nsRect Union methods be saturating.
+  nsRect UnionEdges(const nsRect& aRect) const
+  {
+    return SaturatingUnionEdges(aRect);
+  }
+  void UnionRectEdges(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.UnionEdges(aRect2);
+  }
+  nsRect Union(const nsRect& aRect) const
+  {
+    return SaturatingUnion(aRect);
+  }
+  void UnionRect(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.Union(aRect2);
+  }
+#endif
+
+  void SaturatingUnionRect(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.SaturatingUnion(aRect2);
+  }
+  void SaturatingUnionRectEdges(const nsRect& aRect1, const nsRect& aRect2)
+  {
+    *this = aRect1.SaturatingUnionEdges(aRect2);
+  }
+
+  // Converts this rect from aFromAPP, an appunits per pixel ratio, to aToAPP.
+  // In the RoundOut version we make the rect the smallest rect containing the
+  // unrounded result. In the RoundIn version we make the rect the largest rect
+  // contained in the unrounded result.
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  inline nsRect ConvertAppUnitsRoundOut(int32_t aFromAPP, int32_t aToAPP) const;
+  inline nsRect ConvertAppUnitsRoundIn(int32_t aFromAPP, int32_t aToAPP) const;
+
+  inline nsIntRect ScaleToNearestPixels(float aXScale, float aYScale,
+                                        nscoord aAppUnitsPerPixel) const;
+  inline nsIntRect ToNearestPixels(nscoord aAppUnitsPerPixel) const;
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  inline nsIntRect ScaleToOutsidePixels(float aXScale, float aYScale,
+                                        nscoord aAppUnitsPerPixel) const;
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  inline nsIntRect ToOutsidePixels(nscoord aAppUnitsPerPixel) const;
+  inline nsIntRect ScaleToInsidePixels(float aXScale, float aYScale,
+                                       nscoord aAppUnitsPerPixel) const;
+  inline nsIntRect ToInsidePixels(nscoord aAppUnitsPerPixel) const;
+
+  // This is here only to keep IPDL-generated code happy. DO NOT USE.
+  bool operator==(const nsRect& aRect) const
+  {
+    return IsEqualEdges(aRect);
+  }
+};
+
+struct NS_GFX nsIntRect :
+  public mozilla::gfx::BaseRect<int32_t, nsIntRect, nsIntPoint, nsIntSize, nsIntMargin> {
+  typedef mozilla::gfx::BaseRect<int32_t, nsIntRect, nsIntPoint, nsIntSize, nsIntMargin> Super;
+
+  // Constructors
+  nsIntRect() : Super()
+  {
+  }
+  nsIntRect(const nsIntRect& aRect) : Super(aRect)
+  {
+  }
+  nsIntRect(const nsIntPoint& aOrigin, const nsIntSize &aSize) : Super(aOrigin, aSize)
+  {
+  }
+  nsIntRect(int32_t aX, int32_t aY, int32_t aWidth, int32_t aHeight) :
+      Super(aX, aY, aWidth, aHeight)
+  {
+  }
+
+  inline nsRect ToAppUnits(nscoord aAppUnitsPerPixel) const;
+
+  // Returns a special nsIntRect that's used in some places to signify
+  // "all available space".
+  static const nsIntRect& GetMaxSizedIntRect() {
+    static const nsIntRect r(0, 0, INT32_MAX, INT32_MAX);
+    return r;
+  }
+
+  // This is here only to keep IPDL-generated code happy. DO NOT USE.
+  bool operator==(const nsIntRect& aRect) const
+  {
+    return IsEqualEdges(aRect);
+  }
+};
+
+/*
+ * App Unit/Pixel conversions
+ */
+
+inline nsRect
+nsRect::ConvertAppUnitsRoundOut(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  nscoord right = NSToCoordCeil(NSCoordScale(XMost(), aFromAPP, aToAPP));
+  nscoord bottom = NSToCoordCeil(NSCoordScale(YMost(), aFromAPP, aToAPP));
+  rect.x = NSToCoordFloor(NSCoordScale(x, aFromAPP, aToAPP));
+  rect.y = NSToCoordFloor(NSCoordScale(y, aFromAPP, aToAPP));
+  rect.width = (right - rect.x);
+  rect.height = (bottom - rect.y);
+
+  return rect;
+}
+
+inline nsRect
+nsRect::ConvertAppUnitsRoundIn(int32_t aFromAPP, int32_t aToAPP) const
+{
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  nscoord right = NSToCoordFloor(NSCoordScale(XMost(), aFromAPP, aToAPP));
+  nscoord bottom = NSToCoordFloor(NSCoordScale(YMost(), aFromAPP, aToAPP));
+  rect.x = NSToCoordCeil(NSCoordScale(x, aFromAPP, aToAPP));
+  rect.y = NSToCoordCeil(NSCoordScale(y, aFromAPP, aToAPP));
+  rect.width = (right - rect.x);
+  rect.height = (bottom - rect.y);
+
+  return rect;
+}
+
+// scale the rect but round to preserve centers
+inline nsIntRect
+nsRect::ScaleToNearestPixels(float aXScale, float aYScale,
+                             nscoord aAppUnitsPerPixel) const
+{
+  nsIntRect rect;
+  rect.x = NSToIntRoundUp(NSAppUnitsToDoublePixels(x, aAppUnitsPerPixel) * aXScale);
+  rect.y = NSToIntRoundUp(NSAppUnitsToDoublePixels(y, aAppUnitsPerPixel) * aYScale);
+  rect.width  = NSToIntRoundUp(NSAppUnitsToDoublePixels(XMost(),
+                               aAppUnitsPerPixel) * aXScale) - rect.x;
+  rect.height = NSToIntRoundUp(NSAppUnitsToDoublePixels(YMost(),
+                               aAppUnitsPerPixel) * aYScale) - rect.y;
+  return rect;
+}
+
+// scale the rect but round to smallest containing rect
+inline nsIntRect
+nsRect::ScaleToOutsidePixels(float aXScale, float aYScale,
+                             nscoord aAppUnitsPerPixel) const
+{
+  nsIntRect rect;
+  rect.x = NSToIntFloor(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) * aXScale);
+  rect.y = NSToIntFloor(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) * aYScale);
+  rect.width  = NSToIntCeil(NSAppUnitsToFloatPixels(XMost(),
+                            float(aAppUnitsPerPixel)) * aXScale) - rect.x;
+  rect.height = NSToIntCeil(NSAppUnitsToFloatPixels(YMost(),
+                            float(aAppUnitsPerPixel)) * aYScale) - rect.y;
+  return rect;
+}
+
+// scale the rect but round to largest contained rect
+inline nsIntRect
+nsRect::ScaleToInsidePixels(float aXScale, float aYScale,
+                            nscoord aAppUnitsPerPixel) const
+{
+  nsIntRect rect;
+  rect.x = NSToIntCeil(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) * aXScale);
+  rect.y = NSToIntCeil(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) * aYScale);
+  rect.width  = NSToIntFloor(NSAppUnitsToFloatPixels(XMost(),
+                             float(aAppUnitsPerPixel)) * aXScale) - rect.x;
+  rect.height = NSToIntFloor(NSAppUnitsToFloatPixels(YMost(),
+                             float(aAppUnitsPerPixel)) * aYScale) - rect.y;
+  return rect;
+}
+
+inline nsIntRect
+nsRect::ToNearestPixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsIntRect
+nsRect::ToOutsidePixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToOutsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsIntRect
+nsRect::ToInsidePixels(nscoord aAppUnitsPerPixel) const
+{
+  return ScaleToInsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+// app units are integer multiples of pixels, so no rounding needed
+inline nsRect
+nsIntRect::ToAppUnits(nscoord aAppUnitsPerPixel) const
+{
+  return nsRect(NSIntPixelsToAppUnits(x, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(y, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(width, aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(height, aAppUnitsPerPixel));
+}
+
+#ifdef DEBUG
+// Diagnostics
+extern NS_GFX FILE* operator<<(FILE* out, const nsRect& rect);
+#endif // DEBUG
+
+#endif /* NSRECT_H */