1 files changed, 490 insertions, 0 deletions
diff --git a/gfx/src/nsRect.h b/gfx/src/nsRect.h
new file mode 100644
index 0000000000..ccf48f0d9e
--- /dev/null
+++ b/gfx/src/nsRect.h
@@ -0,0 +1,490 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 <stdint.h>          // for int32_t, int64_t
+#include <algorithm>         // for min/max
+#include "mozilla/Likely.h"  // for MOZ_UNLIKELY
+#include "mozilla/gfx/BaseRect.h"
+#include "mozilla/gfx/Rect.h"
+#include "nsCoord.h"      // for nscoord, etc
+#include "nsISupports.h"  // for MOZ_COUNT_CTOR, etc
+#include "nsPoint.h"      // for nsIntPoint, nsPoint
+#include "nsSize.h"       // for IntSize, nsSize
+#if !defined(ANDROID) && (defined(__SSE2__) || defined(_M_X64) || \
+                          (defined(_M_IX86_FP) && _M_IX86_FP >= 2))
+#  if defined(_MSC_VER) && !defined(__clang__)
+#    include "smmintrin.h"
+#  else
+#    include "emmintrin.h"
+#  endif
+#endif
+
+struct nsMargin;
+
+typedef mozilla::gfx::IntRect nsIntRect;
+
+struct nsRect : public mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize,
+                                              nsMargin> {
+  typedef mozilla::gfx::BaseRect<nscoord, nsRect, nsPoint, nsSize, nsMargin>
+      Super;
+
+  // Constructors
+  nsRect() { 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);
+  }
+  nsRect& operator=(const nsRect&) = default;
+
+  MOZ_COUNTED_DTOR(nsRect)
+
+  // 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.
+
+  // Returns the smallest rectangle that contains both the area of both
+  // this and aRect. Thus, empty input rectangles are ignored.
+  // Note: if both rectangles are empty, returns aRect.
+  [[nodiscard]] nsRect SaturatingUnion(const nsRect& aRect) const {
+    if (IsEmpty()) {
+      return aRect;
+    } else if (aRect.IsEmpty()) {
+      return *static_cast<const nsRect*>(this);
+    } else {
+      return SaturatingUnionEdges(aRect);
+    }
+  }
+
+  [[nodiscard]] nsRect SaturatingUnionEdges(const nsRect& aRect) const {
+    nscoord resultX = std::min(aRect.X(), x);
+    int64_t w =
+        std::max(int64_t(aRect.X()) + aRect.Width(), int64_t(x) + width) -
+        resultX;
+    if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+      // Clamp huge negative x to nscoord_MIN / 2 and try again.
+      resultX = std::max(resultX, nscoord_MIN / 2);
+      w = std::max(int64_t(aRect.X()) + aRect.Width(), int64_t(x) + width) -
+          resultX;
+      if (MOZ_UNLIKELY(w > nscoord_MAX)) {
+        w = nscoord_MAX;
+      }
+    }
+
+    nscoord resultY = std::min(aRect.y, y);
+    int64_t h =
+        std::max(int64_t(aRect.Y()) + aRect.Height(), int64_t(y) + height) -
+        resultY;
+    if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+      // Clamp huge negative y to nscoord_MIN / 2 and try again.
+      resultY = std::max(resultY, nscoord_MIN / 2);
+      h = std::max(int64_t(aRect.Y()) + aRect.Height(), int64_t(y) + height) -
+          resultY;
+      if (MOZ_UNLIKELY(h > nscoord_MAX)) {
+        h = nscoord_MAX;
+      }
+    }
+    return nsRect(resultX, resultY, nscoord(w), nscoord(h));
+  }
+
+  // Make all nsRect Union methods be saturating.
+  [[nodiscard]] nsRect UnionEdges(const nsRect& aRect) const {
+    return SaturatingUnionEdges(aRect);
+  }
+  [[nodiscard]] nsRect Union(const nsRect& aRect) const {
+    return SaturatingUnion(aRect);
+  }
+  [[nodiscard]] nsRect UnsafeUnion(const nsRect& aRect) const {
+    return Super::Union(aRect);
+  }
+  void UnionRect(const nsRect& aRect1, const nsRect& aRect2) {
+    *this = aRect1.Union(aRect2);
+  }
+
+#if defined(_MSC_VER) && !defined(__clang__) && \
+    (defined(_M_X64) || defined(_M_IX86))
+  // Only MSVC supports inlining intrinsics for archs you're not compiling for.
+  [[nodiscard]] nsRect Intersect(const nsRect& aRect) const {
+    nsRect result;
+    if (mozilla::gfx::Factory::HasSSE4()) {
+      __m128i rect1 = _mm_loadu_si128((__m128i*)&aRect);  // x1, y1, w1, h1
+      __m128i rect2 = _mm_loadu_si128((__m128i*)this);    // x2, y2, w2, h2
+
+      __m128i resultRect = _mm_max_epi32(rect1, rect2);  // xr, yr, zz, zz
+
+      // result.width = std::min<int32_t>(x - result.x + width,
+      //                                  aRect.x - result.x + aRect.width);
+      // result.height = std::min<int32_t>(y - result.y + height,
+      //                                   aRect.y - result.y + aRect.height);
+      __m128i widthheight = _mm_min_epi32(
+          _mm_add_epi32(_mm_sub_epi32(rect1, resultRect),
+                        _mm_srli_si128(rect1, 8)),
+          _mm_add_epi32(_mm_sub_epi32(rect2, resultRect),
+                        _mm_srli_si128(rect2, 8)));  // w, h, zz, zz
+      widthheight = _mm_slli_si128(widthheight, 8);  // 00, 00, wr, hr
+
+      resultRect =
+          _mm_blend_epi16(resultRect, widthheight, 0xF0);  // xr, yr, wr, hr
+
+      if ((_mm_movemask_ps(_mm_castsi128_ps(
+               _mm_cmplt_epi32(resultRect, _mm_setzero_si128()))) &
+           0xC) != 0) {
+        // It's potentially more efficient to store all 0s. But the non SSE4
+        // code leaves x/y intact so let's do the same here.
+        resultRect = _mm_and_si128(resultRect,
+                                   _mm_set_epi32(0, 0, 0xFFFFFFFF, 0xFFFFFFFF));
+      }
+
+      _mm_storeu_si128((__m128i*)&result, resultRect);
+
+      return result;
+    }
+
+    result.x = std::max<int32_t>(x, aRect.x);
+    result.y = std::max<int32_t>(y, aRect.y);
+    result.width = std::min<int32_t>(x - result.x + width,
+                                     aRect.x - result.x + aRect.width);
+    result.height = std::min<int32_t>(y - result.y + height,
+                                      aRect.y - result.y + aRect.height);
+    if (result.width < 0 || result.height < 0) {
+      result.SizeTo(0, 0);
+    }
+    return result;
+  }
+
+  bool IntersectRect(const nsRect& aRect1, const nsRect& aRect2) {
+    if (mozilla::gfx::Factory::HasSSE4()) {
+      __m128i rect1 = _mm_loadu_si128((__m128i*)&aRect1);  // x1, y1, w1, h1
+      __m128i rect2 = _mm_loadu_si128((__m128i*)&aRect2);  // x2, y2, w2, h2
+
+      __m128i resultRect = _mm_max_epi32(rect1, rect2);  // xr, yr, zz, zz
+      // result.width = std::min<int32_t>(x - result.x + width,
+      //                                  aRect.x - result.x + aRect.width);
+      // result.height = std::min<int32_t>(y - result.y + height,
+      //                                   aRect.y - result.y + aRect.height);
+      __m128i widthheight = _mm_min_epi32(
+          _mm_add_epi32(_mm_sub_epi32(rect1, resultRect),
+                        _mm_srli_si128(rect1, 8)),
+          _mm_add_epi32(_mm_sub_epi32(rect2, resultRect),
+                        _mm_srli_si128(rect2, 8)));  // w, h, zz, zz
+      widthheight = _mm_slli_si128(widthheight, 8);  // 00, 00, wr, hr
+
+      resultRect =
+          _mm_blend_epi16(resultRect, widthheight, 0xF0);  // xr, yr, wr, hr
+
+      if ((_mm_movemask_ps(_mm_castsi128_ps(
+               _mm_cmpgt_epi32(resultRect, _mm_setzero_si128()))) &
+           0xC) != 0xC) {
+        // It's potentially more efficient to store all 0s. But the non SSE4
+        // code leaves x/y intact so let's do the same here.
+        resultRect = _mm_and_si128(resultRect,
+                                   _mm_set_epi32(0, 0, 0xFFFFFFFF, 0xFFFFFFFF));
+        _mm_storeu_si128((__m128i*)this, resultRect);
+        return false;
+      }
+
+      _mm_storeu_si128((__m128i*)this, resultRect);
+
+      return true;
+    }
+
+    int32_t newX = std::max<int32_t>(aRect1.x, aRect2.x);
+    int32_t newY = std::max<int32_t>(aRect1.y, aRect2.y);
+    width = std::min<int32_t>(aRect1.x - newX + aRect1.width,
+                              aRect2.x - newX + aRect2.width);
+    height = std::min<int32_t>(aRect1.y - newY + aRect1.height,
+                               aRect2.y - newY + aRect2.height);
+    x = newX;
+    y = newY;
+    if (width <= 0 || height <= 0) {
+      SizeTo(0, 0);
+      return false;
+    }
+    return true;
+  }
+#endif
+
+  // Return whether this rect's right or bottom edge overflow int32.
+  bool Overflows() const;
+
+  /**
+   * Return this rect scaled to a different appunits per pixel (APP) ratio.
+   * 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.
+   * @param aFromAPP the APP to scale from
+   * @param aToAPP the APP to scale to
+   * @note this can turn an empty rectangle into a non-empty rectangle
+   */
+  [[nodiscard]] inline nsRect ScaleToOtherAppUnitsRoundOut(
+      int32_t aFromAPP, int32_t aToAPP) const;
+  [[nodiscard]] inline nsRect ScaleToOtherAppUnitsRoundIn(int32_t aFromAPP,
+                                                          int32_t aToAPP) const;
+
+  [[nodiscard]] inline mozilla::gfx::IntRect ScaleToNearestPixels(
+      float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+
+  [[nodiscard]] inline mozilla::gfx::IntRect ToNearestPixels(
+      nscoord aAppUnitsPerPixel) const;
+
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  [[nodiscard]] inline mozilla::gfx::IntRect ScaleToOutsidePixels(
+      float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+
+  // Note: this can turn an empty rectangle into a non-empty rectangle
+  [[nodiscard]] inline mozilla::gfx::IntRect ToOutsidePixels(
+      nscoord aAppUnitsPerPixel) const;
+
+  [[nodiscard]] inline mozilla::gfx::IntRect ScaleToInsidePixels(
+      float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const;
+
+  [[nodiscard]] inline mozilla::gfx::IntRect 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); }
+
+  [[nodiscard]] inline nsRect RemoveResolution(const float aResolution) const;
+
+  [[nodiscard]] mozilla::Maybe<nsRect> EdgeInclusiveIntersection(
+      const nsRect& aOther) const {
+    nscoord left = std::max(x, aOther.x);
+    nscoord top = std::max(y, aOther.y);
+    nscoord right = std::min(XMost(), aOther.XMost());
+    nscoord bottom = std::min(YMost(), aOther.YMost());
+    if (left > right || top > bottom) {
+      return mozilla::Nothing();
+    }
+    return mozilla::Some(nsRect(left, top, right - left, bottom - top));
+  }
+};
+
+/*
+ * App Unit/Pixel conversions
+ */
+
+inline nsRect nsRect::ScaleToOtherAppUnitsRoundOut(int32_t aFromAPP,
+                                                   int32_t aToAPP) const {
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  rect.SetBox(NSToCoordFloor(NSCoordScale(x, aFromAPP, aToAPP)),
+              NSToCoordFloor(NSCoordScale(y, aFromAPP, aToAPP)),
+              NSToCoordCeil(NSCoordScale(XMost(), aFromAPP, aToAPP)),
+              NSToCoordCeil(NSCoordScale(YMost(), aFromAPP, aToAPP)));
+  return rect;
+}
+
+inline nsRect nsRect::ScaleToOtherAppUnitsRoundIn(int32_t aFromAPP,
+                                                  int32_t aToAPP) const {
+  if (aFromAPP == aToAPP) {
+    return *this;
+  }
+
+  nsRect rect;
+  rect.SetBox(NSToCoordCeil(NSCoordScale(x, aFromAPP, aToAPP)),
+              NSToCoordCeil(NSCoordScale(y, aFromAPP, aToAPP)),
+              NSToCoordFloor(NSCoordScale(XMost(), aFromAPP, aToAPP)),
+              NSToCoordFloor(NSCoordScale(YMost(), aFromAPP, aToAPP)));
+  return rect;
+}
+
+#if !defined(ANDROID) && (defined(__SSE2__) || defined(_M_X64) || \
+                          (defined(_M_IX86_FP) && _M_IX86_FP >= 2))
+// Life would be so much better if we had SSE4 here.
+static MOZ_ALWAYS_INLINE __m128i floor_ps2epi32(__m128 x) {
+  __m128 one = _mm_set_ps(1.0f, 1.0f, 1.0f, 1.0f);
+
+  __m128 t = _mm_cvtepi32_ps(_mm_cvttps_epi32(x));
+  __m128 r = _mm_sub_ps(t, _mm_and_ps(_mm_cmplt_ps(x, t), one));
+
+  return _mm_cvttps_epi32(r);
+}
+
+static MOZ_ALWAYS_INLINE __m128i ceil_ps2epi32(__m128 x) {
+  __m128 t = _mm_sub_ps(_mm_setzero_ps(), x);
+  __m128i r = _mm_sub_epi32(_mm_setzero_si128(), floor_ps2epi32(t));
+
+  return r;
+}
+#endif
+
+// scale the rect but round to preserve centers
+inline mozilla::gfx::IntRect nsRect::ScaleToNearestPixels(
+    float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const {
+  mozilla::gfx::IntRect rect;
+  // Android x86 builds have bindgen issues.
+#if !defined(ANDROID) && (defined(__SSE2__) || defined(_M_X64) || \
+                          (defined(_M_IX86_FP) && _M_IX86_FP >= 2))
+  __m128 appUnitsPacked = _mm_set_ps(aAppUnitsPerPixel, aAppUnitsPerPixel,
+                                     aAppUnitsPerPixel, aAppUnitsPerPixel);
+  __m128 scalesPacked = _mm_set_ps(aYScale, aXScale, aYScale, aXScale);
+  __m128 biasesPacked = _mm_set_ps(0.5f, 0.5f, 0.5f, 0.5f);
+
+  __m128i rectPacked = _mm_loadu_si128((__m128i*)this);
+  __m128i topLeft = _mm_slli_si128(rectPacked, 8);
+
+  rectPacked = _mm_add_epi32(rectPacked, topLeft);  // X, Y, XMost(), YMost()
+
+  __m128 rectFloat = _mm_cvtepi32_ps(rectPacked);
+
+  // Scale, i.e. ([ x y xmost ymost ] / aAppUnitsPerPixel) * [ aXScale aYScale
+  // aXScale aYScale ]
+  rectFloat = _mm_mul_ps(_mm_div_ps(rectFloat, appUnitsPacked), scalesPacked);
+
+  // Floor
+  // Executed with bias and roundmode down, since round-nearest rounds 0.5
+  // downward half the time.
+  rectFloat = _mm_add_ps(rectFloat, biasesPacked);
+  rectPacked = floor_ps2epi32(rectFloat);
+
+  topLeft = _mm_slli_si128(rectPacked, 8);
+  rectPacked = _mm_sub_epi32(rectPacked, topLeft);  // X, Y, Width, Height
+
+  // Avoid negative width/height due to overflow.
+  __m128i mask = _mm_or_si128(_mm_cmpgt_epi32(rectPacked, _mm_setzero_si128()),
+                              _mm_set_epi32(0, 0, 0xFFFFFFFF, 0xFFFFFFFF));
+  // Mask will now contain [ 0xFFFFFFFF 0xFFFFFFFF (width <= 0 ? 0 : 0xFFFFFFFF)
+  // (height <= 0 ? 0 : 0xFFFFFFFF) ]
+  rectPacked = _mm_and_si128(rectPacked, mask);
+
+  _mm_storeu_si128((__m128i*)&rect, rectPacked);
+#else
+  rect.SetNonEmptyBox(
+      NSToIntRoundUp(NSAppUnitsToFloatPixels(x, aAppUnitsPerPixel) * aXScale),
+      NSToIntRoundUp(NSAppUnitsToFloatPixels(y, aAppUnitsPerPixel) * aYScale),
+      NSToIntRoundUp(NSAppUnitsToFloatPixels(XMost(), aAppUnitsPerPixel) *
+                     aXScale),
+      NSToIntRoundUp(NSAppUnitsToFloatPixels(YMost(), aAppUnitsPerPixel) *
+                     aYScale));
+#endif
+  return rect;
+}
+
+// scale the rect but round to smallest containing rect
+inline mozilla::gfx::IntRect nsRect::ScaleToOutsidePixels(
+    float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const {
+  mozilla::gfx::IntRect rect;
+  // Android x86 builds have bindgen issues.
+#if !defined(ANDROID) && (defined(__SSE2__) || defined(_M_X64) || \
+                          (defined(_M_IX86_FP) && _M_IX86_FP >= 2))
+  __m128 appUnitsPacked = _mm_set_ps(aAppUnitsPerPixel, aAppUnitsPerPixel,
+                                     aAppUnitsPerPixel, aAppUnitsPerPixel);
+  __m128 scalesPacked = _mm_set_ps(aYScale, aXScale, aYScale, aXScale);
+
+  __m128i rectPacked = _mm_loadu_si128((__m128i*)this);  // x, y, w, h
+  __m128i topLeft = _mm_slli_si128(rectPacked, 8);       // 0, 0, x, y
+
+  rectPacked = _mm_add_epi32(rectPacked, topLeft);  // X, Y, XMost(), YMost()
+
+  __m128 rectFloat = _mm_cvtepi32_ps(rectPacked);
+
+  // Scale i.e. ([ x y xmost ymost ] / aAppUnitsPerPixel) *
+  //             [ aXScale aYScale aXScale aYScale ]
+  rectFloat = _mm_mul_ps(_mm_div_ps(rectFloat, appUnitsPacked), scalesPacked);
+  rectPacked = ceil_ps2epi32(rectFloat);    // xx, xx, XMost(), YMost()
+  __m128i tmp = floor_ps2epi32(rectFloat);  // x, y, xx, xx
+
+  // _mm_move_sd is 1 cycle method of getting the blending we want.
+  rectPacked = _mm_castpd_si128(
+      _mm_move_sd(_mm_castsi128_pd(rectPacked),
+                  _mm_castsi128_pd(tmp)));  // x, y, XMost(), YMost()
+
+  topLeft = _mm_slli_si128(rectPacked, 8);          // 0, 0, r.x, r.y
+  rectPacked = _mm_sub_epi32(rectPacked, topLeft);  // r.x, r.y, r.w, r.h
+
+  // Avoid negative width/height due to overflow.
+  __m128i mask = _mm_or_si128(_mm_cmpgt_epi32(rectPacked, _mm_setzero_si128()),
+                              _mm_set_epi32(0, 0, 0xFFFFFFFF, 0xFFFFFFFF));
+  // clang-format off
+  // Mask will now contain [ 0xFFFFFFFF 0xFFFFFFFF (width <= 0 ? 0 : 0xFFFFFFFF) (height <= 0 ? 0 : 0xFFFFFFFF) ]
+  // clang-format on
+  rectPacked = _mm_and_si128(rectPacked, mask);
+
+  _mm_storeu_si128((__m128i*)&rect, rectPacked);
+#else
+  rect.SetNonEmptyBox(
+      NSToIntFloor(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) *
+                   aXScale),
+      NSToIntFloor(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) *
+                   aYScale),
+      NSToIntCeil(NSAppUnitsToFloatPixels(XMost(), float(aAppUnitsPerPixel)) *
+                  aXScale),
+      NSToIntCeil(NSAppUnitsToFloatPixels(YMost(), float(aAppUnitsPerPixel)) *
+                  aYScale));
+#endif
+  return rect;
+}
+
+// scale the rect but round to largest contained rect
+inline mozilla::gfx::IntRect nsRect::ScaleToInsidePixels(
+    float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const {
+  mozilla::gfx::IntRect rect;
+  rect.SetNonEmptyBox(
+      NSToIntCeil(NSAppUnitsToFloatPixels(x, float(aAppUnitsPerPixel)) *
+                  aXScale),
+      NSToIntCeil(NSAppUnitsToFloatPixels(y, float(aAppUnitsPerPixel)) *
+                  aYScale),
+      NSToIntFloor(NSAppUnitsToFloatPixels(XMost(), float(aAppUnitsPerPixel)) *
+                   aXScale),
+      NSToIntFloor(NSAppUnitsToFloatPixels(YMost(), float(aAppUnitsPerPixel)) *
+                   aYScale));
+  return rect;
+}
+
+inline mozilla::gfx::IntRect nsRect::ToNearestPixels(
+    nscoord aAppUnitsPerPixel) const {
+  return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline mozilla::gfx::IntRect nsRect::ToOutsidePixels(
+    nscoord aAppUnitsPerPixel) const {
+  return ScaleToOutsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline mozilla::gfx::IntRect nsRect::ToInsidePixels(
+    nscoord aAppUnitsPerPixel) const {
+  return ScaleToInsidePixels(1.0f, 1.0f, aAppUnitsPerPixel);
+}
+
+inline nsRect nsRect::RemoveResolution(const float aResolution) const {
+  MOZ_ASSERT(aResolution > 0.0f);
+  nsRect rect;
+  rect.MoveTo(NSToCoordRound(NSCoordToFloat(x) / aResolution),
+              NSToCoordRound(NSCoordToFloat(y) / aResolution));
+  // A 1x1 rect indicates we are just hit testing a point, so pass down a 1x1
+  // rect as well instead of possibly rounding the width or height to zero.
+  if (width == 1 && height == 1) {
+    rect.SizeTo(1, 1);
+  } else {
+    rect.SizeTo(NSToCoordCeil(NSCoordToFloat(width) / aResolution),
+                NSToCoordCeil(NSCoordToFloat(height) / aResolution));
+  }
+
+  return rect;
+}
+
+const mozilla::gfx::IntRect& GetMaxSizedIntRect();
+
+// app units are integer multiples of pixels, so no rounding needed
+template <class units>
+nsRect ToAppUnits(const mozilla::gfx::IntRectTyped<units>& aRect,
+                  nscoord aAppUnitsPerPixel) {
+  return nsRect(NSIntPixelsToAppUnits(aRect.X(), aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.Y(), aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.Width(), aAppUnitsPerPixel),
+                NSIntPixelsToAppUnits(aRect.Height(), aAppUnitsPerPixel));
+}
+
+#endif /* NSRECT_H */