src/third_party/WebKit/Source/platform/graphics/CompositingReasons.h

   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 #ifndef CompositingReasons_h
   6 #define CompositingReasons_h
   7
   8 #include "wtf/MathExtras.h"
   9 #include <stdint.h>
  10
  11 namespace WebCore {
  12
  13 const uint64_t CompositingReasonNone                                   = 0;
  14 const uint64_t CompositingReasonAll                                    = ~static_cast<uint64_t>(0);
  15
  16 // Intrinsic reasons that can be known right away by the layer
  17 const uint64_t CompositingReason3DTransform                            = UINT64_C(1) << 0;
  18 const uint64_t CompositingReasonVideo                                  = UINT64_C(1) << 1;
  19 const uint64_t CompositingReasonCanvas                                 = UINT64_C(1) << 2;
  20 const uint64_t CompositingReasonPlugin                                 = UINT64_C(1) << 3;
  21 const uint64_t CompositingReasonIFrame                                 = UINT64_C(1) << 4;
  22 const uint64_t CompositingReasonBackfaceVisibilityHidden               = UINT64_C(1) << 5;
  23 const uint64_t CompositingReasonActiveAnimation                        = UINT64_C(1) << 6;
  24 const uint64_t CompositingReasonTransitionProperty                     = UINT64_C(1) << 7;
  25 const uint64_t CompositingReasonFilters                                = UINT64_C(1) << 8;
  26 const uint64_t CompositingReasonPositionFixed                          = UINT64_C(1) << 9;
  27 const uint64_t CompositingReasonPositionSticky                         = UINT64_C(1) << 10;
  28 const uint64_t CompositingReasonOverflowScrollingTouch                 = UINT64_C(1) << 11;
  29 const uint64_t CompositingReasonOverflowScrollingParent                = UINT64_C(1) << 12;
  30 const uint64_t CompositingReasonOutOfFlowClipping                      = UINT64_C(1) << 13;
  31 const uint64_t CompositingReasonVideoOverlay                           = UINT64_C(1) << 14;
  32 const uint64_t CompositingReasonWillChangeCompositingHint              = UINT64_C(1) << 15;
  33 // Bit 16 is available.
  34
  35 // Overlap reasons that require knowing what's behind you in paint-order before knowing the answer
  36 const uint64_t CompositingReasonAssumedOverlap                         = UINT64_C(1) << 17;
  37 const uint64_t CompositingReasonOverlap                                = UINT64_C(1) << 18;
  38 const uint64_t CompositingReasonNegativeZIndexChildren                 = UINT64_C(1) << 19;
  39 const uint64_t CompositingReasonNoSquashingTargetFound                 = UINT64_C(1) << 20;
  40
  41 // Subtree reasons that require knowing what the status of your subtree is before knowing the answer
  42 const uint64_t CompositingReasonTransformWithCompositedDescendants     = UINT64_C(1) << 21;
  43 const uint64_t CompositingReasonOpacityWithCompositedDescendants       = UINT64_C(1) << 22;
  44 const uint64_t CompositingReasonMaskWithCompositedDescendants          = UINT64_C(1) << 23;
  45 const uint64_t CompositingReasonReflectionWithCompositedDescendants    = UINT64_C(1) << 24;
  46 const uint64_t CompositingReasonFilterWithCompositedDescendants        = UINT64_C(1) << 25;
  47 const uint64_t CompositingReasonBlendingWithCompositedDescendants      = UINT64_C(1) << 26;
  48 const uint64_t CompositingReasonClipsCompositingDescendants            = UINT64_C(1) << 27;
  49 const uint64_t CompositingReasonPerspectiveWith3DDescendants           = UINT64_C(1) << 28;
  50 const uint64_t CompositingReasonPreserve3DWith3DDescendants            = UINT64_C(1) << 29;
  51 const uint64_t CompositingReasonReflectionOfCompositedParent           = UINT64_C(1) << 30;
  52 const uint64_t CompositingReasonIsolateCompositedDescendants           = UINT64_C(1) << 31;
  53
  54 // The root layer is a special case that may be forced to be a layer, but also it needs to be
  55 // a layer if anything else in the subtree is composited.
  56 const uint64_t CompositingReasonRoot                                   = UINT64_C(1) << 32;
  57
  58 // CompositedLayerMapping internal hierarchy reasons
  59 const uint64_t CompositingReasonLayerForAncestorClip                   = UINT64_C(1) << 33;
  60 const uint64_t CompositingReasonLayerForDescendantClip                 = UINT64_C(1) << 34;
  61 const uint64_t CompositingReasonLayerForPerspective                    = UINT64_C(1) << 35;
  62 const uint64_t CompositingReasonLayerForHorizontalScrollbar            = UINT64_C(1) << 36;
  63 const uint64_t CompositingReasonLayerForVerticalScrollbar              = UINT64_C(1) << 37;
  64 const uint64_t CompositingReasonLayerForScrollCorner                   = UINT64_C(1) << 38;
  65 const uint64_t CompositingReasonLayerForScrollingContents              = UINT64_C(1) << 39;
  66 const uint64_t CompositingReasonLayerForScrollingContainer             = UINT64_C(1) << 40;
  67 const uint64_t CompositingReasonLayerForSquashingContents              = UINT64_C(1) << 41;
  68 const uint64_t CompositingReasonLayerForSquashingContainer             = UINT64_C(1) << 42;
  69 const uint64_t CompositingReasonLayerForForeground                     = UINT64_C(1) << 43;
  70 const uint64_t CompositingReasonLayerForBackground                     = UINT64_C(1) << 44;
  71 const uint64_t CompositingReasonLayerForMask                           = UINT64_C(1) << 45;
  72 const uint64_t CompositingReasonLayerForClippingMask                   = UINT64_C(1) << 46;
  73
  74 // Various combinations of compositing reasons are defined here also, for more intutive and faster bitwise logic.
  75 const uint64_t CompositingReasonComboAllDirectReasons =
  76     CompositingReason3DTransform
  77     | CompositingReasonVideo
  78     | CompositingReasonCanvas
  79     | CompositingReasonPlugin
  80     | CompositingReasonIFrame
  81     | CompositingReasonBackfaceVisibilityHidden
  82     | CompositingReasonActiveAnimation
  83     | CompositingReasonTransitionProperty
  84     | CompositingReasonFilters
  85     | CompositingReasonPositionFixed
  86     | CompositingReasonPositionSticky
  87     | CompositingReasonOverflowScrollingTouch
  88     | CompositingReasonOverflowScrollingParent
  89     | CompositingReasonOutOfFlowClipping
  90     | CompositingReasonVideoOverlay
  91     | CompositingReasonWillChangeCompositingHint;
  92
  93 const uint64_t CompositingReasonComboAllStyleDeterminedReasons =
  94     CompositingReason3DTransform
  95     | CompositingReasonBackfaceVisibilityHidden
  96     | CompositingReasonActiveAnimation
  97     | CompositingReasonTransitionProperty
  98     | CompositingReasonFilters
  99     | CompositingReasonWillChangeCompositingHint;
 100
 101 const uint64_t CompositingReasonComboReasonsThatRequireOwnBacking =
 102     CompositingReasonComboAllDirectReasons
 103     | CompositingReasonOverlap
 104     | CompositingReasonAssumedOverlap
 105     | CompositingReasonNegativeZIndexChildren
 106     | CompositingReasonNoSquashingTargetFound
 107     | CompositingReasonTransformWithCompositedDescendants
 108     | CompositingReasonOpacityWithCompositedDescendants
 109     | CompositingReasonMaskWithCompositedDescendants
 110     | CompositingReasonFilterWithCompositedDescendants
 111     | CompositingReasonBlendingWithCompositedDescendants
 112     | CompositingReasonIsolateCompositedDescendants
 113     | CompositingReasonPreserve3DWith3DDescendants; // preserve-3d has to create backing store to ensure that 3d-transformed elements intersect.
 114
 115 const uint64_t CompositingReasonComboSquashableReasons =
 116     CompositingReasonOverlap
 117     | CompositingReasonAssumedOverlap
 118     | CompositingReasonOverflowScrollingParent;
 119
 120 typedef uint64_t CompositingReasons;
 121
 122 // Any reasons other than overlap or assumed overlap will require the layer to be separately compositing.
 123 inline bool requiresCompositing(CompositingReasons reasons)
 124 {
 125     return reasons & ~CompositingReasonComboSquashableReasons;
 126 }
 127
 128 // If the layer has overlap or assumed overlap, but no other reasons, then it should be squashed.
 129 inline bool requiresSquashing(CompositingReasons reasons)
 130 {
 131     return !requiresCompositing(reasons) && (reasons & CompositingReasonComboSquashableReasons);
 132 }
 133
 134 struct CompositingReasonStringMap {
 135     CompositingReasons reason;
 136     const char* shortName;
 137     const char* description;
 138 };
 139
 140 // FIXME: This static data shouldn't be in a header. When it's in the header
 141 // it's copied into every compilation unit that includes the header.
 142 static const CompositingReasonStringMap compositingReasonStringMap[] = {
 143     { CompositingReasonNone,
 144         "Unknown",
 145         "No reason given" },
 146     { CompositingReason3DTransform,
 147         "transform3D",
 148         "Has a 3d transform" },
 149     { CompositingReasonVideo,
 150         "video",
 151         "Is an accelerated video" },
 152     { CompositingReasonCanvas,
 153         "canvas",
 154         "Is an accelerated canvas" },
 155     { CompositingReasonPlugin,
 156         "plugin",
 157         "Is an accelerated plugin" },
 158     { CompositingReasonIFrame,
 159         "iFrame",
 160         "Is an accelerated iFrame" },
 161     { CompositingReasonBackfaceVisibilityHidden,
 162         "backfaceVisibilityHidden",
 163         "Has backface-visibility: hidden" },
 164     { CompositingReasonActiveAnimation,
 165         "activeAnimation",
 166         "Has an active accelerated animation or transition" },
 167     { CompositingReasonTransitionProperty,
 168         "transitionProperty",
 169         "Has an acceleratable transition property (active or inactive)" },
 170     { CompositingReasonFilters,
 171         "filters",
 172         "Has an accelerated filter" },
 173     { CompositingReasonPositionFixed,
 174         "positionFixed",
 175         "Is fixed position" },
 176     { CompositingReasonPositionSticky,
 177         "positionSticky",
 178         "Is sticky position" },
 179     { CompositingReasonOverflowScrollingTouch,
 180         "overflowScrollingTouch",
 181         "Is a scrollable overflow element" },
 182     { CompositingReasonOverflowScrollingParent,
 183         "overflowScrollingParent",
 184         "Scroll parent is not an ancestor" },
 185     { CompositingReasonOutOfFlowClipping,
 186         "outOfFlowClipping",
 187         "Has clipping ancestor" },
 188     { CompositingReasonVideoOverlay,
 189         "videoOverlay",
 190         "Is overlay controls for video" },
 191     { CompositingReasonWillChangeCompositingHint,
 192         "willChange",
 193         "Has a will-change compositing hint" },
 194     { 0, 0, 0 }, // Available.
 195     { CompositingReasonAssumedOverlap,
 196         "assumedOverlap",
 197         "Might overlap other composited content" },
 198     { CompositingReasonOverlap,
 199         "overlap",
 200         "Overlaps other composited content" },
 201     { CompositingReasonNegativeZIndexChildren,
 202         "negativeZIndexChildren",
 203         "Parent with composited negative z-index content" },
 204     {  CompositingReasonNoSquashingTargetFound,
 205         "noSquashingTargetFound",
 206         "Cannot be squashed due to no compatible squashing owner found" },
 207     { CompositingReasonTransformWithCompositedDescendants,
 208         "transformWithCompositedDescendants",
 209         "Has a transform that needs to be known by compositor because of composited descendants" },
 210     { CompositingReasonOpacityWithCompositedDescendants,
 211         "opacityWithCompositedDescendants",
 212         "Has opacity that needs to be applied by compositor because of composited descendants" },
 213     { CompositingReasonMaskWithCompositedDescendants,
 214         "maskWithCompositedDescendants",
 215         "Has a mask that needs to be known by compositor because of composited descendants" },
 216     { CompositingReasonReflectionWithCompositedDescendants,
 217         "reflectionWithCompositedDescendants",
 218         "Has a reflection that needs to be known by compositor because of composited descendants" },
 219     { CompositingReasonFilterWithCompositedDescendants,
 220         "filterWithCompositedDescendants",
 221         "Has a filter effect that needs to be known by compositor because of composited descendants" },
 222     { CompositingReasonBlendingWithCompositedDescendants,
 223         "blendingWithCompositedDescendants",
 224         "Has a blenidng effect that needs to be known by compositor because of composited descendants" },
 225     { CompositingReasonClipsCompositingDescendants,
 226         "clipsCompositingDescendants",
 227         "Has a clip that needs to be known by compositor because of composited descendants" },
 228     { CompositingReasonPerspectiveWith3DDescendants,
 229         "perspectiveWith3DDescendants",
 230         "Has a perspective transform that needs to be known by compositor because of 3d descendants" },
 231     { CompositingReasonPreserve3DWith3DDescendants,
 232         "preserve3DWith3DDescendants",
 233         "Has a preserves-3d property that needs to be known by compositor because of 3d descendants" },
 234     { CompositingReasonReflectionOfCompositedParent,
 235         "reflectionOfCompositedParent",
 236         "Is a reflection of a composited layer" },
 237     { CompositingReasonIsolateCompositedDescendants,
 238         "isolateCompositedDescendants",
 239         "Should isolate descendants to apply a blend effect" },
 240     { CompositingReasonRoot,
 241         "root",
 242         "Is the root layer" },
 243     { CompositingReasonLayerForAncestorClip,
 244         "layerForAncestorClip",
 245         "Secondary layer, applies a clip due to a sibling in the compositing tree" },
 246     { CompositingReasonLayerForDescendantClip,
 247         "layerForDescendantClip",
 248         "Secondary layer, to clip descendants of the owning layer" },
 249     { CompositingReasonLayerForPerspective,
 250         "layerForPerspective",
 251         "Secondary layer, to house the perspective transform for all descendants" },
 252     { CompositingReasonLayerForHorizontalScrollbar,
 253         "layerForHorizontalScrollbar",
 254         "Secondary layer, the horizontal scrollbar layer" },
 255     { CompositingReasonLayerForVerticalScrollbar,
 256         "layerForVerticalScrollbar",
 257         "Secondary layer, the vertical scrollbar layer" },
 258     { CompositingReasonLayerForScrollCorner,
 259         "layerForScrollCorner",
 260         "Secondary layer, the scroll corner layer" },
 261     { CompositingReasonLayerForScrollingContents,
 262         "layerForScrollingContents",
 263         "Secondary layer, to house contents that can be scrolled" },
 264     { CompositingReasonLayerForScrollingContainer,
 265         "layerForScrollingContainer",
 266         "Secondary layer, used to position the scolling contents while scrolling" },
 267     { CompositingReasonLayerForSquashingContents,
 268         "layerForSquashingContents",
 269         "Secondary layer, home for a group of squashable content" },
 270     { CompositingReasonLayerForSquashingContainer,
 271         "layerForSquashingContainer",
 272         "Secondary layer, no-op layer to place the squashing layer correctly in the composited layer tree" },
 273     { CompositingReasonLayerForForeground,
 274         "layerForForeground",
 275         "Secondary layer, to contain any normal flow and positive z-index contents on top of a negative z-index layer" },
 276     { CompositingReasonLayerForBackground,
 277         "layerForBackground",
 278         "Secondary layer, to contain acceleratable background content" },
 279     { CompositingReasonLayerForMask,
 280         "layerForMask",
 281         "Secondary layer, to contain the mask contents" },
 282     { CompositingReasonLayerForClippingMask,
 283         "layerForClippingMask",
 284         "Secondary layer, for clipping mask" }
 285 };
 286
 287 } // namespace WebCore
 288
 289 #endif // CompositingReasons_h