src/gpu/GrRenderTarget.h

/*
 * 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 "include/core/SkRect.h"
#include "include/gpu/GrSurface.h"

class GrCaps;
class GrRenderTargetPriv;
class GrStencilAttachment;
class GrBackendRenderTarget;

/**
 * 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:
    // Make manual MSAA resolve publicly accessible from GrRenderTarget.
    using GrSurface::setRequiresManualMSAAResolve;
    using GrSurface::requiresManualMSAAResolve;

    virtual bool alwaysClearStencil() const { return false; }

    // GrSurface overrides
    GrRenderTarget* asRenderTarget() override { return this; }
    const GrRenderTarget* asRenderTarget() const  override { return this; }

    /**
     * Returns the number of samples/pixel in the color buffer (One if non-MSAA).
     */
    int numSamples() const { return fSampleCnt; }

    virtual GrBackendRenderTarget getBackendRenderTarget() 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;

protected:
    GrRenderTarget(GrGpu*, const SkISize&, GrPixelConfig, int sampleCount, GrProtected,
                   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;

    int fSampleCnt;
    int fSamplePatternKey;
    sk_sp<GrStencilAttachment> fStencilAttachment;

    typedef GrSurface INHERITED;
};

#endif