cc/output/overlay_candidate.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/output/overlay_candidate.h"
   6
   7 #include <algorithm>
   8 #include <limits>
   9 #include "base/logging.h"
  10 #include "cc/base/math_util.h"
  11 #include "ui/gfx/geometry/rect_conversions.h"
  12 #include "ui/gfx/geometry/vector3d_f.h"
  13
  14 namespace cc {
  15
  16 namespace {
  17 // Tolerance for considering axis vector elements to be zero.
  18 const SkMScalar kEpsilon = std::numeric_limits<float>::epsilon();
  19
  20 enum Axis { NONE, AXIS_POS_X, AXIS_NEG_X, AXIS_POS_Y, AXIS_NEG_Y };
  21
  22 Axis VectorToAxis(const gfx::Vector3dF& vec) {
  23   if (std::abs(vec.z()) > kEpsilon)
  24     return NONE;
  25   const bool x_zero = (std::abs(vec.x()) <= kEpsilon);
  26   const bool y_zero = (std::abs(vec.y()) <= kEpsilon);
  27   if (x_zero && !y_zero)
  28     return (vec.y() > 0) ? AXIS_POS_Y : AXIS_NEG_Y;
  29   else if (y_zero && !x_zero)
  30     return (vec.x() > 0) ? AXIS_POS_X : AXIS_NEG_X;
  31   else
  32     return NONE;
  33 }
  34
  35 }  // namespace
  36
  37 OverlayCandidate::OverlayCandidate()
  38     : transform(gfx::OVERLAY_TRANSFORM_NONE),
  39       format(RGBA_8888),
  40       uv_rect(0.f, 0.f, 1.f, 1.f),
  41       use_output_surface_for_resource(false),
  42       resource_id(0),
  43       plane_z_order(0),
  44       overlay_handled(false) {}
  45
  46 OverlayCandidate::~OverlayCandidate() {}
  47
  48 // static
  49 gfx::OverlayTransform OverlayCandidate::GetOverlayTransform(
  50     const gfx::Transform& quad_transform,
  51     bool y_flipped) {
  52   if (!quad_transform.Preserves2dAxisAlignment()) {
  53     return gfx::OVERLAY_TRANSFORM_INVALID;
  54   }
  55
  56   gfx::Vector3dF x_axis = MathUtil::GetXAxis(quad_transform);
  57   gfx::Vector3dF y_axis = MathUtil::GetYAxis(quad_transform);
  58   if (y_flipped) {
  59     y_axis.Scale(-1);
  60   }
  61
  62   Axis x_to = VectorToAxis(x_axis);
  63   Axis y_to = VectorToAxis(y_axis);
  64
  65   if (x_to == AXIS_POS_X && y_to == AXIS_POS_Y)
  66     return gfx::OVERLAY_TRANSFORM_NONE;
  67   else if (x_to == AXIS_NEG_X && y_to == AXIS_POS_Y)
  68     return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
  69   else if (x_to == AXIS_POS_X && y_to == AXIS_NEG_Y)
  70     return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
  71   else if (x_to == AXIS_NEG_Y && y_to == AXIS_POS_X)
  72     return gfx::OVERLAY_TRANSFORM_ROTATE_270;
  73   else if (x_to == AXIS_NEG_X && y_to == AXIS_NEG_Y)
  74     return gfx::OVERLAY_TRANSFORM_ROTATE_180;
  75   else if (x_to == AXIS_POS_Y && y_to == AXIS_NEG_X)
  76     return gfx::OVERLAY_TRANSFORM_ROTATE_90;
  77   else
  78     return gfx::OVERLAY_TRANSFORM_INVALID;
  79 }
  80
  81 // static
  82 gfx::OverlayTransform OverlayCandidate::ModifyTransform(
  83     gfx::OverlayTransform in,
  84     gfx::OverlayTransform delta) {
  85   // There are 8 different possible transforms. We can characterize these
  86   // by looking at where the origin moves and the direction the horizontal goes.
  87   // (TL=top-left, BR=bottom-right, H=horizontal, V=vertical).
  88   // NONE: TL, H
  89   // FLIP_VERTICAL: BL, H
  90   // FLIP_HORIZONTAL: TR, H
  91   // ROTATE_90: TR, V
  92   // ROTATE_180: BR, H
  93   // ROTATE_270: BL, V
  94   // Missing transforms: TL, V & BR, V
  95   // Basic combinations:
  96   // Flip X & Y -> Rotate 180 (TL,H -> TR,H -> BR,H or TL,H -> BL,H -> BR,H)
  97   // Flip X or Y + Rotate 180 -> other flip (eg, TL,H -> TR,H -> BL,H)
  98   // Rotate + Rotate simply adds values.
  99   // Rotate 90/270 + flip is invalid because we can only have verticals with
 100   // the origin in TR or BL.
 101   if (delta == gfx::OVERLAY_TRANSFORM_NONE)
 102     return in;
 103   switch (in) {
 104     case gfx::OVERLAY_TRANSFORM_NONE:
 105       return delta;
 106     case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 107       switch (delta) {
 108         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 109           return gfx::OVERLAY_TRANSFORM_NONE;
 110         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 111           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 112         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 113           return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
 114         default:
 115           return gfx::OVERLAY_TRANSFORM_INVALID;
 116       }
 117       break;
 118     case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 119       switch (delta) {
 120         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 121           return gfx::OVERLAY_TRANSFORM_NONE;
 122         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 123           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 124         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 125         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 126           return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
 127         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 128         default:
 129           return gfx::OVERLAY_TRANSFORM_INVALID;
 130       }
 131       break;
 132     case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 133       switch (delta) {
 134         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 135           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 136         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 137           return gfx::OVERLAY_TRANSFORM_ROTATE_270;
 138         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 139           return gfx::OVERLAY_TRANSFORM_NONE;
 140         default:
 141           return gfx::OVERLAY_TRANSFORM_INVALID;
 142       }
 143       break;
 144     case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 145       switch (delta) {
 146         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 147           return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
 148         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 149           return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
 150         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 151           return gfx::OVERLAY_TRANSFORM_ROTATE_270;
 152         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 153           return gfx::OVERLAY_TRANSFORM_NONE;
 154         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 155           return gfx::OVERLAY_TRANSFORM_ROTATE_90;
 156         default:
 157           return gfx::OVERLAY_TRANSFORM_INVALID;
 158       }
 159       break;
 160     case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 161       switch (delta) {
 162         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 163           return gfx::OVERLAY_TRANSFORM_NONE;
 164         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 165           return gfx::OVERLAY_TRANSFORM_ROTATE_90;
 166         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 167           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 168         default:
 169           return gfx::OVERLAY_TRANSFORM_INVALID;
 170       }
 171       break;
 172     default:
 173       return gfx::OVERLAY_TRANSFORM_INVALID;
 174   }
 175 }
 176
 177 // static
 178 gfx::RectF OverlayCandidate::GetOverlayRect(
 179     const gfx::Transform& quad_transform,
 180     const gfx::Rect& rect) {
 181   DCHECK(quad_transform.Preserves2dAxisAlignment());
 182
 183   gfx::RectF float_rect(rect);
 184   quad_transform.TransformRect(&float_rect);
 185   return float_rect;
 186 }
 187
 188 }  // namespace cc