gecko/gfx/layers/ipc/PLayers.ipdl

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=8 et :
 */
/* 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/. */

include LayersSurfaces;
using mozilla::ScreenRotation;
include protocol PCompositor;
include protocol PGrallocBuffer;
include protocol PLayer;
include protocol PRenderFrame;

include "gfxipc/ShadowLayerUtils.h";
include "mozilla/WidgetUtils.h";
include "mozilla/TimeStamp.h";

using gfxPoint3D;
using nscoord;
using nsRect;
using nsPoint;
using mozilla::TimeDuration;
using mozilla::TimeStamp;

/**
 * The layers protocol is spoken between thread contexts that manage
 * layer (sub)trees.  The protocol comprises atomically publishing
 * layer subtrees to a "shadow" thread context (which grafts the
 * subtree into its own tree), and atomically updating a published
 * subtree.  ("Atomic" in this sense is wrt painting.)
 */

namespace mozilla {
namespace layers {

struct TargetConfig {
  nsIntRect naturalBounds;
  ScreenRotation rotation;
};

// Create a shadow layer for |layer|
struct OpCreateThebesLayer     { PLayer layer; };
struct OpCreateContainerLayer  { PLayer layer; };
struct OpCreateImageLayer      { PLayer layer; };
struct OpCreateColorLayer      { PLayer layer; };
struct OpCreateCanvasLayer     { PLayer layer; };
struct OpCreateRefLayer        { PLayer layer; };

struct ThebesBuffer {
  SurfaceDescriptor buffer;
  nsIntRect rect;
  nsIntPoint rotation;
};
union OptionalThebesBuffer { ThebesBuffer; null_t; };

union CanvasSurface {
  SurfaceDescriptor;
  null_t;
};

struct CubicBezierFunction {
  float x1;
  float y1;
  float x2;
  float y2;
};

struct StepFunction {
  int steps;
  // 1 = nsTimingFunction::StepStart, 2 = nsTimingFunction::StepEnd
  int type;
};

union TimingFunction {
  CubicBezierFunction;
  StepFunction;
};

struct Color { gfxRGBA value; };
struct Opacity { float value; };
struct Perspective { float value; };
struct RotationX { float radians; };
struct RotationY { float radians; };
struct RotationZ { float radians; };
struct Rotation { float radians; };
struct Rotation3D {
  float x;
  float y;
  float z;
  float radians;
};
struct Scale {
  float x;
  float y;
  float z;
};
struct SkewX { float x; };
struct SkewY { float y; };
struct TransformMatrix { gfx3DMatrix value; };
struct Translation {
  float x;
  float y;
  float z;
};

union TransformFunction {
  Perspective;
  RotationX;
  RotationY;
  RotationZ;
  Rotation;
  Rotation3D;
  Scale;
  SkewX;
  SkewY;
  Translation;
  TransformMatrix;
};

union Animatable {
  Color;
  Opacity;
  TransformFunction[];
};

struct AnimationSegment {
  Animatable startState;
  Animatable endState;
  float startPortion;
  float endPortion;
  TimingFunction sampleFn;
};

// Transforms need extra information to correctly convert the list of transform
// functions to a gfx3DMatrix that can be applied directly to the layer.
struct TransformData {
  nsPoint origin;
  gfxPoint3D mozOrigin;
  gfxPoint3D perspectiveOrigin;
  nsRect bounds;
  nscoord perspective;
};

union AnimationData {
  null_t;
  TransformData;
};

struct Animation {
  TimeStamp startTime;
  TimeDuration duration;
  // For each frame, the interpolation point is computed based on the
  // startTime, the direction, the duration, and the current time.
  // The segments must uniquely cover the portion from 0.0 to 1.0
  AnimationSegment[] segments;
  // How many times to repeat the animation.  < 0 means "forever".
  float numIterations;
  // This uses the NS_STYLE_ANIMATION_DIRECTION_* constants.
  int32_t direction;
  AnimationData data;
};

// Change a layer's attributes
struct CommonLayerAttributes {
  nsIntRegion visibleRegion;
  TransformMatrix transform;
  float postXScale;
  float postYScale;
  PRUint32 contentFlags;
  Opacity opacity;
  bool useClipRect;
  nsIntRect clipRect;
  bool isFixedPosition;
  gfxPoint fixedPositionAnchor;
  nullable PLayer maskLayer;
  // Animated colors will only honored for ColorLayers.
  Animation[] animations;
 };

struct ThebesLayerAttributes {
  nsIntRegion validRegion;
};
struct ContainerLayerAttributes {
  FrameMetrics metrics;
  float preXScale;
  float preYScale;
};
struct ColorLayerAttributes     { Color color; };
struct CanvasLayerAttributes    { GraphicsFilterType filter; };
struct RefLayerAttributes       { int64_t id; };
struct ImageLayerAttributes     {
  GraphicsFilterType filter;
  bool forceSingleTile;
};

union SpecificLayerAttributes {
  null_t;
  ThebesLayerAttributes;
  ContainerLayerAttributes;
  ColorLayerAttributes;
  CanvasLayerAttributes;
  RefLayerAttributes;
  ImageLayerAttributes;
};

struct LayerAttributes {
  CommonLayerAttributes common;
  SpecificLayerAttributes specific;
};

struct OpSetLayerAttributes {
  PLayer layer;
  LayerAttributes attrs;
};


// Monkey with the tree structure
struct OpSetRoot      { PLayer root; };
struct OpInsertAfter  { PLayer container; PLayer childLayer; PLayer after; };
struct OpAppendChild  { PLayer container; PLayer childLayer; };
struct OpRemoveChild  { PLayer container; PLayer childLayer; };


// Paint (buffer update)
struct OpPaintThebesBuffer {
  PLayer layer;
  ThebesBuffer newFrontBuffer;
  nsIntRegion updatedRegion;
};

struct OpPaintTiledLayerBuffer {
  PLayer layer;
  // Bug 747811
  // FIXME: We need to support sharing tile across process.
  uintptr_t tiledLayerBuffer;
};

struct OpPaintCanvas  {
  PLayer layer;
  CanvasSurface newFrontBuffer;
  bool needYFlip;
};

struct OpPaintImage  {
  PLayer layer;
  SharedImage newFrontBuffer;
};


// A unit of a changeset; a set of these comprise a changeset
union Edit {
  OpCreateThebesLayer;
  OpCreateContainerLayer;
  OpCreateImageLayer;
  OpCreateColorLayer;
  OpCreateCanvasLayer;
  OpCreateRefLayer;

  OpSetLayerAttributes;

  OpSetRoot;
  OpInsertAfter;
  OpAppendChild;
  OpRemoveChild;

  OpPaintThebesBuffer;
  OpPaintTiledLayerBuffer;
  OpPaintCanvas;
  OpPaintImage;
};


// Replies to operations
struct OpBufferSwap   { PLayer layer; CanvasSurface newBackBuffer; };

struct OpImageSwap { PLayer layer; SharedImage newBackImage; };

struct OpThebesBufferSwap {
  PLayer layer;
  OptionalThebesBuffer newBackBuffer;
  nsIntRegion newValidRegion;
  // If the parent took the child's old back buffer and returned its
  // old front buffer, |readOnlyFrontBuffer| may (if non-null) contain
  // the child's old back buffer (parent's new front buffer).  This
  // buffer can be used to read back the newly updated region into the
  // child's new back buffer.  This buffer must be considered
  // read-only, but sadly that's not enforced.
  OptionalThebesBuffer readOnlyFrontBuffer;
  nsIntRegion frontUpdatedRegion;
};

// Unit of a "changeset reply".  This is a weird abstraction, probably
// only to be used for buffer swapping.
union EditReply {
  OpBufferSwap;
  OpThebesBufferSwap;
  OpImageSwap;
};


sync protocol PLayers {
  manager PRenderFrame or PCompositor;
  manages PGrallocBuffer;
  manages PLayer;

parent:
  /**
   * Only the parent side has privileges to allocate the buffer.
   * Allocation may fail (pmem is a scarce resource), and if so null_t
   * is returned.
   */
  sync PGrallocBuffer(gfxIntSize size, gfxContentType content)
    returns (MaybeMagicGrallocBufferHandle handle);
  async PLayer();

  // The isFirstPaint flag can be used to indicate that this is the first update
  // for a particular document.
  sync Update(Edit[] cset, TargetConfig targetConfig, bool isFirstPaint)
    returns (EditReply[] reply);

  // Composite the layer tree to the given surface, and return the surface.
  sync DrawToSurface(SurfaceDescriptor surfaceIn)
    returns (SurfaceDescriptor surfaceOut);

  // We don't need to send a sync transaction if
  // no transaction operate require a swap.
  async UpdateNoSwap(Edit[] cset, TargetConfig targetConfig, bool isFirstPaint);

  async __delete__();
};

} // namespace layers
} // namespace mozilla