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       resource_id(0),
  42       plane_z_order(0),
  43       overlay_handled(false) {}
  44
  45 OverlayCandidate::~OverlayCandidate() {}
  46
  47 // static
  48 gfx::OverlayTransform OverlayCandidate::GetOverlayTransform(
  49     const gfx::Transform& quad_transform,
  50     bool y_flipped) {
  51   if (!quad_transform.Preserves2dAxisAlignment()) {
  52     return gfx::OVERLAY_TRANSFORM_INVALID;
  53   }
  54
  55   gfx::Vector3dF x_axis = MathUtil::GetXAxis(quad_transform);
  56   gfx::Vector3dF y_axis = MathUtil::GetYAxis(quad_transform);
  57   if (y_flipped) {
  58     y_axis.Scale(-1);
  59   }
  60
  61   Axis x_to = VectorToAxis(x_axis);
  62   Axis y_to = VectorToAxis(y_axis);
  63
  64   if (x_to == AXIS_POS_X && y_to == AXIS_POS_Y)
  65     return gfx::OVERLAY_TRANSFORM_NONE;
  66   else if (x_to == AXIS_NEG_X && y_to == AXIS_POS_Y)
  67     return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
  68   else if (x_to == AXIS_POS_X && y_to == AXIS_NEG_Y)
  69     return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
  70   else if (x_to == AXIS_NEG_Y && y_to == AXIS_POS_X)
  71     return gfx::OVERLAY_TRANSFORM_ROTATE_270;
  72   else if (x_to == AXIS_NEG_X && y_to == AXIS_NEG_Y)
  73     return gfx::OVERLAY_TRANSFORM_ROTATE_180;
  74   else if (x_to == AXIS_POS_Y && y_to == AXIS_NEG_X)
  75     return gfx::OVERLAY_TRANSFORM_ROTATE_90;
  76   else
  77     return gfx::OVERLAY_TRANSFORM_INVALID;
  78 }
  79
  80 // static
  81 gfx::OverlayTransform OverlayCandidate::ModifyTransform(
  82     gfx::OverlayTransform in,
  83     gfx::OverlayTransform delta) {
  84   // There are 8 different possible transforms. We can characterize these
  85   // by looking at where the origin moves and the direction the horizontal goes.
  86   // (TL=top-left, BR=bottom-right, H=horizontal, V=vertical).
  87   // NONE: TL, H
  88   // FLIP_VERTICAL: BL, H
  89   // FLIP_HORIZONTAL: TR, H
  90   // ROTATE_90: TR, V
  91   // ROTATE_180: BR, H
  92   // ROTATE_270: BL, V
  93   // Missing transforms: TL, V & BR, V
  94   // Basic combinations:
  95   // Flip X & Y -> Rotate 180 (TL,H -> TR,H -> BR,H or TL,H -> BL,H -> BR,H)
  96   // Flip X or Y + Rotate 180 -> other flip (eg, TL,H -> TR,H -> BL,H)
  97   // Rotate + Rotate simply adds values.
  98   // Rotate 90/270 + flip is invalid because we can only have verticals with
  99   // the origin in TR or BL.
 100   if (delta == gfx::OVERLAY_TRANSFORM_NONE)
 101     return in;
 102   switch (in) {
 103     case gfx::OVERLAY_TRANSFORM_NONE:
 104       return delta;
 105     case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 106       switch (delta) {
 107         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 108           return gfx::OVERLAY_TRANSFORM_NONE;
 109         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 110           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 111         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 112           return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
 113         default:
 114           return gfx::OVERLAY_TRANSFORM_INVALID;
 115       }
 116       break;
 117     case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 118       switch (delta) {
 119         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 120           return gfx::OVERLAY_TRANSFORM_NONE;
 121         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 122           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 123         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 124         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 125           return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
 126         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 127         default:
 128           return gfx::OVERLAY_TRANSFORM_INVALID;
 129       }
 130       break;
 131     case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 132       switch (delta) {
 133         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 134           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 135         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 136           return gfx::OVERLAY_TRANSFORM_ROTATE_270;
 137         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 138           return gfx::OVERLAY_TRANSFORM_NONE;
 139         default:
 140           return gfx::OVERLAY_TRANSFORM_INVALID;
 141       }
 142       break;
 143     case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 144       switch (delta) {
 145         case gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL:
 146           return gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL;
 147         case gfx::OVERLAY_TRANSFORM_FLIP_VERTICAL:
 148           return gfx::OVERLAY_TRANSFORM_FLIP_HORIZONTAL;
 149         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 150           return gfx::OVERLAY_TRANSFORM_ROTATE_270;
 151         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 152           return gfx::OVERLAY_TRANSFORM_NONE;
 153         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 154           return gfx::OVERLAY_TRANSFORM_ROTATE_90;
 155         default:
 156           return gfx::OVERLAY_TRANSFORM_INVALID;
 157       }
 158       break;
 159     case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 160       switch (delta) {
 161         case gfx::OVERLAY_TRANSFORM_ROTATE_90:
 162           return gfx::OVERLAY_TRANSFORM_NONE;
 163         case gfx::OVERLAY_TRANSFORM_ROTATE_180:
 164           return gfx::OVERLAY_TRANSFORM_ROTATE_90;
 165         case gfx::OVERLAY_TRANSFORM_ROTATE_270:
 166           return gfx::OVERLAY_TRANSFORM_ROTATE_180;
 167         default:
 168           return gfx::OVERLAY_TRANSFORM_INVALID;
 169       }
 170       break;
 171     default:
 172       return gfx::OVERLAY_TRANSFORM_INVALID;
 173   }
 174 }
 175
 176 // static
 177 gfx::RectF OverlayCandidate::GetOverlayRect(
 178     const gfx::Transform& quad_transform,
 179     const gfx::Rect& rect) {
 180   DCHECK(quad_transform.Preserves2dAxisAlignment());
 181
 182   gfx::RectF float_rect(rect);
 183   quad_transform.TransformRect(&float_rect);
 184   return float_rect;
 185 }
 186
 187 }  // namespace cc