skia2/include/gpu/GrSurface.h

/*
 * Copyright 2012 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrSurface_DEFINED
#define GrSurface_DEFINED

#include "GrTypes.h"
#include "GrBackendSurface.h"
#include "GrGpuResource.h"
#include "SkImageInfo.h"
#include "SkRect.h"

class GrRenderTarget;
class GrSurfacePriv;
class GrTexture;

class SK_API GrSurface : public GrGpuResource {
public:
    /**
     * Retrieves the width of the surface.
     */
    int width() const { return fWidth; }

    /**
     * Retrieves the height of the surface.
     */
    int height() const { return fHeight; }

    /**
     * Helper that gets the width and height of the surface as a bounding rectangle.
     */
    SkRect getBoundsRect() const { return SkRect::MakeIWH(this->width(), this->height()); }

    /**
     * Retrieves the pixel config specified when the surface was created.
     * For render targets this can be kUnknown_GrPixelConfig
     * if client asked us to render to a target that has a pixel
     * config that isn't equivalent with one of our configs.
     */
    GrPixelConfig config() const { return fConfig; }

    virtual GrBackendFormat backendFormat() const = 0;

    void setRelease(sk_sp<GrRefCntedCallback> releaseHelper) {
        this->onSetRelease(releaseHelper);
        fReleaseHelper = std::move(releaseHelper);
    }

    // These match the definitions in SkImage, from whence they came.
    // TODO: Remove Chrome's need to call this on a GrTexture
    typedef void* ReleaseCtx;
    typedef void (*ReleaseProc)(ReleaseCtx);
    void setRelease(ReleaseProc proc, ReleaseCtx ctx) {
        sk_sp<GrRefCntedCallback> helper(new GrRefCntedCallback(proc, ctx));
        this->setRelease(std::move(helper));
    }

    /**
     * @return the texture associated with the surface, may be null.
     */
    virtual GrTexture* asTexture() { return nullptr; }
    virtual const GrTexture* asTexture() const { return nullptr; }

    /**
     * @return the render target underlying this surface, may be null.
     */
    virtual GrRenderTarget* asRenderTarget() { return nullptr; }
    virtual const GrRenderTarget* asRenderTarget() const { return nullptr; }

    /** Access methods that are only to be used within Skia code. */
    inline GrSurfacePriv surfacePriv();
    inline const GrSurfacePriv surfacePriv() const;

    static size_t WorstCaseSize(const GrSurfaceDesc& desc, bool useNextPow2 = false);
    static size_t ComputeSize(GrPixelConfig config, int width, int height, int colorSamplesPerPixel,
                              GrMipMapped, bool useNextPow2 = false);

    /**
     * The pixel values of this surface cannot be modified (e.g. doesn't support write pixels or
     * MIP map level regen).
     */
    bool readOnly() const { return fSurfaceFlags & GrInternalSurfaceFlags::kReadOnly; }

protected:
    void setHasMixedSamples() {
        SkASSERT(this->asRenderTarget());
        fSurfaceFlags |= GrInternalSurfaceFlags::kMixedSampled;
    }
    bool hasMixedSamples() const { return fSurfaceFlags & GrInternalSurfaceFlags::kMixedSampled; }

    void setGLRTFBOIDIs0() {
        SkASSERT(this->asRenderTarget());
        fSurfaceFlags |= GrInternalSurfaceFlags::kGLRTFBOIDIs0;
    }
    bool glRTFBOIDis0() const {
        return fSurfaceFlags & GrInternalSurfaceFlags::kGLRTFBOIDIs0;
    }

    void setReadOnly() {
        SkASSERT(!this->asRenderTarget());
        fSurfaceFlags |= GrInternalSurfaceFlags::kReadOnly;
    }

    // Methods made available via GrSurfacePriv
    bool hasPendingRead() const;
    bool hasPendingWrite() const;
    bool hasPendingIO() const;

    // Provides access to methods that should be public within Skia code.
    friend class GrSurfacePriv;

    GrSurface(GrGpu* gpu, const GrSurfaceDesc& desc)
            : INHERITED(gpu)
            , fConfig(desc.fConfig)
            , fWidth(desc.fWidth)
            , fHeight(desc.fHeight)
            , fSurfaceFlags(GrInternalSurfaceFlags::kNone) {
    }

    ~GrSurface() override {
        // check that invokeReleaseProc has been called (if needed)
        SkASSERT(!fReleaseHelper);
    }

    void onRelease() override;
    void onAbandon() override;

private:
    const char* getResourceType() const override { return "Surface"; }

    // Unmanaged backends (e.g. Vulkan) may want to specially handle the release proc in order to
    // ensure it isn't called until GPU work related to the resource is completed.
    virtual void onSetRelease(sk_sp<GrRefCntedCallback>) {}

    void invokeReleaseProc() {
        // Depending on the ref count of fReleaseHelper this may or may not actually trigger the
        // ReleaseProc to be called.
        fReleaseHelper.reset();
    }

    GrPixelConfig              fConfig;
    int                        fWidth;
    int                        fHeight;
    GrInternalSurfaceFlags     fSurfaceFlags;
    sk_sp<GrRefCntedCallback>  fReleaseHelper;

    typedef GrGpuResource INHERITED;
};

#endif