system/hwc3/GuestFrameComposer.h

/*
 * Copyright 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ANDROID_HWC_GUESTFRAMECOMPOSER_H
#define ANDROID_HWC_GUESTFRAMECOMPOSER_H

#include "AlternatingImageStorage.h"
#include "Common.h"
#include "Display.h"
#include "DrmClient.h"
#include "FrameComposer.h"
#include "Gralloc.h"
#include "Layer.h"

namespace aidl::android::hardware::graphics::composer3::impl {

class GuestFrameComposer : public FrameComposer {
   public:
    GuestFrameComposer() = default;

    GuestFrameComposer(const GuestFrameComposer&) = delete;
    GuestFrameComposer& operator=(const GuestFrameComposer&) = delete;

    GuestFrameComposer(GuestFrameComposer&&) = delete;
    GuestFrameComposer& operator=(GuestFrameComposer&&) = delete;

    HWC3::Error init() override;

    HWC3::Error registerOnHotplugCallback(const HotplugCallback& cb) override;

    HWC3::Error unregisterOnHotplugCallback() override;

    HWC3::Error onDisplayCreate(Display*) override;

    HWC3::Error onDisplayDestroy(Display*) override;

    HWC3::Error onDisplayClientTargetSet(Display*) override;

    // Determines if this composer can compose the given layers on the given
    // display and requests changes for layers that can't not be composed.
    HWC3::Error validateDisplay(Display* display, DisplayChanges* outChanges) override;

    // Performs the actual composition of layers and presents the composed result
    // to the display.
    HWC3::Error presentDisplay(
        Display* display, ::android::base::unique_fd* outDisplayFence,
        std::unordered_map<int64_t, ::android::base::unique_fd>* outLayerFences) override;

    HWC3::Error onActiveConfigChange(Display* /*display*/) override;

    const DrmClient* getDrmPresenter() const override { return &mDrmClient; }

   private:
    struct DisplayConfig {
        int width;
        int height;
        int dpiX;
        int dpiY;
        int refreshRateHz;
    };

    HWC3::Error getDisplayConfigsFromSystemProp(std::vector<DisplayConfig>* configs);

    // Returns true if the given layer's buffer has supported format.
    bool canComposeLayer(Layer* layer);

    // Composes the given layer into the given destination buffer.
    HWC3::Error composeLayerInto(AlternatingImageStorage& storage, Layer* layer,
                                 std::uint8_t* dstBuffer, std::uint32_t dstBufferWidth,
                                 std::uint32_t dstBufferHeight, std::uint32_t dstBufferStrideBytes,
                                 std::uint32_t dstBufferBytesPerPixel);

    struct DisplayInfo {
        // Additional per display buffer for the composition result.
        buffer_handle_t compositionResultBuffer = nullptr;

        std::shared_ptr<DrmBuffer> compositionResultDrmBuffer;

        // Scratch storage space for intermediate images during composition.
        AlternatingImageStorage compositionIntermediateStorage;
    };

    std::unordered_map<int64_t, DisplayInfo> mDisplayInfos;

    Gralloc mGralloc;

    DrmClient mDrmClient;

    // Cuttlefish on QEMU does not have a display. Disable presenting to avoid
    // spamming logcat with DRM commit failures.
    bool mPresentDisabled = false;

    HWC3::Error applyColorTransformToRGBA(const std::array<float, 16>& colorTransform,  //
                                          std::uint8_t* buffer,                         //
                                          std::uint32_t bufferWidth,                    //
                                          std::uint32_t bufferHeight,                   //
                                          std::uint32_t bufferStrideBytes);
};

}  // namespace aidl::android::hardware::graphics::composer3::impl

#endif