include/gpu/GrTexture.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 GrTexture_DEFINED
#define GrTexture_DEFINED

#include "GrBackendSurface.h"
#include "GrSamplerState.h"
#include "GrSurface.h"
#include "SkImage.h"
#include "SkPoint.h"
#include "SkRefCnt.h"
#include "../private/GrTypesPriv.h"

class GrTexturePriv;

class SK_API GrTexture : virtual public GrSurface {
public:
    GrTexture* asTexture() override { return this; }
    const GrTexture* asTexture() const override { return this; }

    virtual GrBackendTexture getBackendTexture() const = 0;

    /**
     * This function indicates that the texture parameters (wrap mode, filtering, ...) have been
     * changed externally to Skia.
     */
    virtual void textureParamsModified() = 0;

    /**
     * This function steals the backend texture from a uniquely owned GrTexture with no pending
     * IO, passing it out to the caller. The GrTexture is deleted in the process.
     *
     * Note that if the GrTexture is not uniquely owned (no other refs), or has pending IO, this
     * function will fail.
     */
    static bool StealBackendTexture(sk_sp<GrTexture>,
                                    GrBackendTexture*,
                                    SkImage::BackendTextureReleaseProc*);

#ifdef SK_DEBUG
    void validate() const {
        this->INHERITED::validate();
    }
#endif

    /**
     * Installs a proc on this texture. It will be called when the texture becomes "idle". Idle is
     * defined to mean that the texture has no refs or pending IOs and that GPU I/O operations on
     * the texture are completed if the backend API disallows deletion of a texture before such
     * operations occur (e.g. Vulkan). After the idle proc is called it is removed. The idle proc
     * will always be called before the texture is destroyed, even in unusual shutdown scenarios
     * (e.g. GrContext::abandonContext()).
     */
    virtual void addIdleProc(sk_sp<GrRefCntedCallback> callback) {
        callback->addChild(std::move(fIdleCallback));
        fIdleCallback = std::move(callback);
    }

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

protected:
    GrTexture(GrGpu*, const GrSurfaceDesc&, GrTextureType, GrMipMapsStatus);

    virtual bool onStealBackendTexture(GrBackendTexture*, SkImage::BackendTextureReleaseProc*) = 0;

    sk_sp<GrRefCntedCallback> fIdleCallback;

    void willRemoveLastRefOrPendingIO() override {
        // We're about to be idle in the resource cache. Do our part to trigger the idle callback.
        fIdleCallback.reset();
    }

private:

    void computeScratchKey(GrScratchKey*) const override;
    size_t onGpuMemorySize() const override;
    void markMipMapsDirty();
    void markMipMapsClean();

    GrTextureType                 fTextureType;
    GrMipMapsStatus               fMipMapsStatus;
    int                           fMaxMipMapLevel;
    friend class GrTexturePriv;

    typedef GrSurface INHERITED;
};

#endif