gfx/src/nsPoint.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef NSPOINT_H
   8 #define NSPOINT_H
   9
  10 #include <cstdint>
  11 #include "nsCoord.h"
  12 #include "mozilla/gfx/BasePoint.h"
  13 #include "mozilla/gfx/Point.h"
  14
  15 // nsIntPoint represents a point in one of the types of pixels.
  16 // Uses of nsIntPoint should eventually be converted to CSSIntPoint,
  17 // LayoutDeviceIntPoint, etc. (see layout/base/Units.h).
  18 typedef mozilla::gfx::IntPoint nsIntPoint;
  19
  20 // nsPoint represents a point in app units.
  21
  22 struct nsPoint : public mozilla::gfx::BasePoint<nscoord, nsPoint> {
  23   typedef mozilla::gfx::BasePoint<nscoord, nsPoint> Super;
  24
  25   nsPoint() = default;
  26   nsPoint(const nsPoint& aPoint) = default;
  27   nsPoint(nscoord aX, nscoord aY) : Super(aX, aY) {}
  28
  29   inline nsIntPoint ScaleToNearestPixels(float aXScale, float aYScale,
  30                                          nscoord aAppUnitsPerPixel) const;
  31   inline nsIntPoint ToNearestPixels(nscoord aAppUnitsPerPixel) const;
  32
  33   /**
  34    * Return this point scaled to a different appunits per pixel (APP) ratio.
  35    * @param aFromAPP the APP to scale from
  36    * @param aToAPP the APP to scale to
  37    */
  38   [[nodiscard]] inline nsPoint ScaleToOtherAppUnits(int32_t aFromAPP,
  39                                                     int32_t aToAPP) const;
  40
  41   [[nodiscard]] inline nsPoint RemoveResolution(const float resolution) const;
  42   [[nodiscard]] inline nsPoint ApplyResolution(const float resolution) const;
  43 };
  44
  45 inline nsPoint ToAppUnits(const nsIntPoint& aPoint, nscoord aAppUnitsPerPixel);
  46
  47 inline nsIntPoint nsPoint::ScaleToNearestPixels(
  48     float aXScale, float aYScale, nscoord aAppUnitsPerPixel) const {
  49   return nsIntPoint(
  50       NSToIntRoundUp(NSAppUnitsToDoublePixels(x, aAppUnitsPerPixel) * aXScale),
  51       NSToIntRoundUp(NSAppUnitsToDoublePixels(y, aAppUnitsPerPixel) * aYScale));
  52 }
  53
  54 inline nsIntPoint nsPoint::ToNearestPixels(nscoord aAppUnitsPerPixel) const {
  55   return ScaleToNearestPixels(1.0f, 1.0f, aAppUnitsPerPixel);
  56 }
  57
  58 inline nsPoint nsPoint::ScaleToOtherAppUnits(int32_t aFromAPP,
  59                                              int32_t aToAPP) const {
  60   if (aFromAPP != aToAPP) {
  61     nsPoint point;
  62     point.x = NSToCoordRound(NSCoordScale(x, aFromAPP, aToAPP));
  63     point.y = NSToCoordRound(NSCoordScale(y, aFromAPP, aToAPP));
  64     return point;
  65   }
  66   return *this;
  67 }
  68
  69 inline nsPoint nsPoint::RemoveResolution(const float resolution) const {
  70   if (resolution != 1.0f) {
  71     nsPoint point;
  72     point.x = NSToCoordRound(NSCoordToFloat(x) / resolution);
  73     point.y = NSToCoordRound(NSCoordToFloat(y) / resolution);
  74     return point;
  75   }
  76   return *this;
  77 }
  78
  79 inline nsPoint nsPoint::ApplyResolution(const float resolution) const {
  80   if (resolution != 1.0f) {
  81     nsPoint point;
  82     point.x = NSToCoordRound(NSCoordToFloat(x) * resolution);
  83     point.y = NSToCoordRound(NSCoordToFloat(y) * resolution);
  84     return point;
  85   }
  86   return *this;
  87 }
  88
  89 // app units are integer multiples of pixels, so no rounding needed
  90 inline nsPoint ToAppUnits(const nsIntPoint& aPoint, nscoord aAppUnitsPerPixel) {
  91   return nsPoint(NSIntPixelsToAppUnits(aPoint.x, aAppUnitsPerPixel),
  92                  NSIntPixelsToAppUnits(aPoint.y, aAppUnitsPerPixel));
  93 }
  94
  95 #endif /* NSPOINT_H */