Source/WebCore/platform/graphics/nicosia/texmap/NicosiaBackingStoreTextureMapperImpl.h

/*
 * Copyright (C) 2018 Metrological Group B.V.
 * Copyright (C) 2018 Igalia S.L.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials provided
 *    with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if USE(TEXTURE_MAPPER)

#include "CoordinatedBackingStore.h"
#include "NicosiaPlatformLayer.h"
#include "SurfaceUpdateInfo.h"
#include "TiledBackingStore.h"
#include "TiledBackingStoreClient.h"
#include <memory>
#include <wtf/Lock.h>

namespace Nicosia {

class BackingStoreTextureMapperImpl final : public BackingStore::Impl, public WebCore::TiledBackingStoreClient {
    WTF_MAKE_FAST_ALLOCATED;
public:
    static Factory createFactory();

    BackingStoreTextureMapperImpl();
    virtual ~BackingStoreTextureMapperImpl();
    bool isTextureMapperImpl() const override { return true; }

    // A move-only tile update container.
    struct TileUpdate {
        TileUpdate() = default;
        TileUpdate(const TileUpdate&) = delete;
        TileUpdate& operator=(const TileUpdate&) = delete;
        TileUpdate(TileUpdate&&) = default;
        TileUpdate& operator=(TileUpdate&&) = default;

        struct CreationData {
            uint32_t tileID;
            float scale;
        };
        Vector<CreationData> tilesToCreate;

        struct UpdateData {
            uint32_t tileID;
            WebCore::IntRect tileRect;
            WebCore::SurfaceUpdateInfo updateInfo;
        };
        Vector<UpdateData> tilesToUpdate;

        struct RemovalData {
            uint32_t tileID;
        };
        Vector<RemovalData> tilesToRemove;
    };

    // An immutable layer-side state object. flushUpdate() prepares
    // the current update for consumption by the composition-side.
    struct LayerState {
        LayerState() = default;
        LayerState(const LayerState&) = delete;
        LayerState& operator=(const LayerState&) = delete;
        LayerState(LayerState&&) = delete;
        LayerState& operator=(LayerState&&) = delete;

        std::unique_ptr<WebCore::TiledBackingStore> mainBackingStore;

        TileUpdate update;
        bool isFlushing { false };
        bool isPurging { false };
        bool hasPendingTileCreation { false };
    };
    LayerState& layerState() { return m_layerState; }

    void flushUpdate();

    // An immutable composition-side state object. takeUpdate() returns the accumulated
    // tile update information that's to be fed to the CoordinatedBackingStore object.
    struct CompositionState {
        CompositionState() = default;
        CompositionState(const CompositionState&) = delete;
        CompositionState& operator=(const CompositionState&) = delete;
        CompositionState(CompositionState&&) = delete;
        CompositionState& operator=(CompositionState&&) = delete;

        RefPtr<WebCore::CoordinatedBackingStore> backingStore;
    };
    CompositionState& compositionState() { return m_compositionState; }

    TileUpdate takeUpdate();

    // TiledBackingStoreClient
    // FIXME: Move these to private once updateTile() is not called from CoordinatedGrahpicsLayer.
    void tiledBackingStoreHasPendingTileCreation() override;
    void createTile(uint32_t, float) override;
    void updateTile(uint32_t, const WebCore::SurfaceUpdateInfo&, const WebCore::IntRect&) override;
    void removeTile(uint32_t) override;

private:
    LayerState m_layerState;
    CompositionState m_compositionState;

    struct {
        Lock lock;
        TileUpdate pending;
    } m_update;
};

} // namespace Nicosia

SPECIALIZE_TYPE_TRAITS_NICOSIA_BACKINGSTORE_IMPL(BackingStoreTextureMapperImpl, isTextureMapperImpl());

#endif // USE(TEXTURE_MAPPER)