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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrRenderTarget_DEFINED
#define GrRenderTarget_DEFINED
#include "GrSurface.h"
#include "SkRect.h"
class GrCaps;
class GrDrawTarget;
class GrStencilAttachment;
class GrRenderTargetPriv;
/**
* GrRenderTarget represents a 2D buffer of pixels that can be rendered to.
* A context's render target is set by setRenderTarget(). Render targets are
* created by a createTexture with the kRenderTarget_SurfaceFlag flag.
* Additionally, GrContext provides methods for creating GrRenderTargets
* that wrap externally created render targets.
*/
class GrRenderTarget : virtual public GrSurface {
public:
// GrSurface overrides
GrRenderTarget* asRenderTarget() override { return this; }
const GrRenderTarget* asRenderTarget() const override { return this; }
// GrRenderTarget
bool isStencilBufferMultisampled() const { return fDesc.fSampleCnt > 0; }
/**
* For our purposes, "Mixed Sampled" means the stencil buffer is multisampled but the color
* buffer is not.
*/
bool isMixedSampled() const { return fFlags & Flags::kMixedSampled; }
/**
* "Unified Sampled" means the stencil and color buffers are both multisampled.
*/
bool isUnifiedMultisampled() const { return fDesc.fSampleCnt > 0 && !this->isMixedSampled(); }
/**
* Returns the number of samples/pixel in the stencil buffer (Zero if non-MSAA).
*/
int numStencilSamples() const { return fDesc.fSampleCnt; }
/**
* Returns the number of samples/pixel in the color buffer (Zero if non-MSAA or mixed sampled).
*/
int numColorSamples() const { return this->isMixedSampled() ? 0 : fDesc.fSampleCnt; }
/**
* Call to indicate the multisample contents were modified such that the
* render target needs to be resolved before it can be used as texture. Gr
* tracks this for its own drawing and thus this only needs to be called
* when the render target has been modified outside of Gr. This has no
* effect on wrapped backend render targets.
*
* @param rect a rect bounding the area needing resolve. NULL indicates
* the whole RT needs resolving.
*/
void flagAsNeedingResolve(const SkIRect* rect = NULL);
/**
* Call to override the region that needs to be resolved.
*/
void overrideResolveRect(const SkIRect rect);
/**
* Call to indicate that GrRenderTarget was externally resolved. This may
* allow Gr to skip a redundant resolve step.
*/
void flagAsResolved() { fResolveRect.setLargestInverted(); }
/**
* @return true if the GrRenderTarget requires MSAA resolving
*/
bool needsResolve() const { return !fResolveRect.isEmpty(); }
/**
* Returns a rect bounding the region needing resolving.
*/
const SkIRect& getResolveRect() const { return fResolveRect; }
/**
* Provide a performance hint that the render target's contents are allowed
* to become undefined.
*/
void discard();
// a MSAA RT may require explicit resolving , it may auto-resolve (e.g. FBO
// 0 in GL), or be unresolvable because the client didn't give us the
// resolve destination.
enum ResolveType {
kCanResolve_ResolveType,
kAutoResolves_ResolveType,
kCantResolve_ResolveType,
};
virtual ResolveType getResolveType() const = 0;
/**
* Return the native ID or handle to the rendertarget, depending on the
* platform. e.g. on OpenGL, return the FBO ID.
*/
virtual GrBackendObject getRenderTargetHandle() const = 0;
// Checked when this object is asked to attach a stencil buffer.
virtual bool canAttemptStencilAttachment() const = 0;
// Provides access to functions that aren't part of the public API.
GrRenderTargetPriv renderTargetPriv();
const GrRenderTargetPriv renderTargetPriv() const;
void setLastDrawTarget(GrDrawTarget* dt);
GrDrawTarget* getLastDrawTarget() { return fLastDrawTarget; }
protected:
enum class Flags {
kNone = 0,
kMixedSampled = 1 << 0,
kWindowRectsSupport = 1 << 1
};
GR_DECL_BITFIELD_CLASS_OPS_FRIENDS(Flags);
GrRenderTarget(GrGpu*, const GrSurfaceDesc&, Flags = Flags::kNone,
GrStencilAttachment* = nullptr);
~GrRenderTarget() override;
// override of GrResource
void onAbandon() override;
void onRelease() override;
private:
// Allows the backends to perform any additional work that is required for attaching a
// GrStencilAttachment. When this is called, the GrStencilAttachment has already been put onto
// the GrRenderTarget. This function must return false if any failures occur when completing the
// stencil attachment.
virtual bool completeStencilAttachment() = 0;
friend class GrRenderTargetPriv;
GrStencilAttachment* fStencilAttachment;
uint8_t fMultisampleSpecsID;
Flags fFlags;
SkIRect fResolveRect;
// The last drawTarget that wrote to or is currently going to write to this renderTarget
// The drawTarget can be closed (e.g., no draw context is currently bound
// to this renderTarget).
// This back-pointer is required so that we can add a dependancy between
// the drawTarget used to create the current contents of this renderTarget
// and the drawTarget of a destination renderTarget to which this one is being drawn.
GrDrawTarget* fLastDrawTarget;
typedef GrSurface INHERITED;
};
GR_MAKE_BITFIELD_CLASS_OPS(GrRenderTarget::Flags);
#endif