skyline/app/src/main/cpp/skyline/gpu/texture/texture.cpp

// SPDX-License-Identifier: MPL-2.0
// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)

#include <gpu.h>
#include <common/trace.h>
#include <kernel/types/KProcess.h>
#include "texture.h"

namespace skyline::gpu {
    GuestTexture::GuestTexture(const DeviceState &state, u8 *pointer, texture::Dimensions dimensions, texture::Format format, texture::TileMode tiling, texture::TileConfig layout) : state(state), pointer(pointer), dimensions(dimensions), format(format), tileMode(tiling), tileConfig(layout) {}

    std::shared_ptr<Texture> GuestTexture::InitializeTexture(vk::Image backing, std::optional<vk::ImageTiling> tiling, vk::ImageLayout pLayout, std::optional<texture::Format> pFormat, std::optional<texture::Dimensions> pDimensions, texture::Swizzle swizzle) {
        if (!host.expired())
            throw exception("Trying to create multiple Texture objects from a single GuestTexture");
        auto sharedHost{std::make_shared<Texture>(*state.gpu, backing, pLayout, shared_from_this(), pDimensions ? *pDimensions : dimensions, pFormat ? *pFormat : format, tiling ? *tiling : (tileMode == texture::TileMode::Block) ? vk::ImageTiling::eOptimal : vk::ImageTiling::eLinear, swizzle)};
        host = sharedHost;
        return sharedHost;
    }

    std::shared_ptr<Texture> GuestTexture::InitializeTexture(vk::raii::Image &&backing, std::optional<vk::ImageTiling> tiling, vk::ImageLayout pLayout, std::optional<texture::Format> pFormat, std::optional<texture::Dimensions> pDimensions, texture::Swizzle swizzle) {
        if (!host.expired())
            throw exception("Trying to create multiple Texture objects from a single GuestTexture");
        auto sharedHost{std::make_shared<Texture>(*state.gpu, std::move(backing), pLayout, shared_from_this(), pDimensions ? *pDimensions : dimensions, pFormat ? *pFormat : format, tiling ? *tiling : (tileMode == texture::TileMode::Block) ? vk::ImageTiling::eOptimal : vk::ImageTiling::eLinear, swizzle)};
        host = sharedHost;
        return sharedHost;
    }

    Texture::Texture(GPU &gpu, BackingType &&backing, vk::ImageLayout layout, std::shared_ptr<GuestTexture> guest, texture::Dimensions dimensions, texture::Format format, vk::ImageTiling tiling, vk::ComponentMapping mapping) : gpu(gpu), backing(std::move(backing)), layout(layout), guest(std::move(guest)), dimensions(dimensions), format(format), tiling(tiling), mapping(mapping) {
        if (GetBacking())
            SynchronizeHost();
    }

    bool Texture::WaitOnBacking() {
        if (GetBacking()) [[likely]] {
            return false;
        } else {
            std::unique_lock lock(mutex, std::adopt_lock);
            backingCondition.wait(lock, [&]() -> bool { return GetBacking(); });
            lock.release();
            return true;
        }
    }

    void Texture::WaitOnFence() {
        if (cycle) {
            cycle->Wait();
            cycle.reset();
        }
    }

    void Texture::SwapBacking(BackingType &&pBacking, vk::ImageLayout pLayout) {
        WaitOnFence();

        backing = std::move(pBacking);
        layout = pLayout;
        if (GetBacking())
            backingCondition.notify_all();
    }

    void Texture::TransitionLayout(vk::ImageLayout pLayout) {
        WaitOnBacking();
        WaitOnFence();

        if (layout != pLayout) {
            cycle = gpu.scheduler.Submit([&](vk::raii::CommandBuffer &commandBuffer) {
                commandBuffer.pipelineBarrier(layout != vk::ImageLayout::eUndefined ? vk::PipelineStageFlagBits::eTopOfPipe : vk::PipelineStageFlagBits::eBottomOfPipe, vk::PipelineStageFlagBits::eBottomOfPipe, {}, {}, {}, vk::ImageMemoryBarrier{
                    .image = GetBacking(),
                    .srcAccessMask = vk::AccessFlagBits::eMemoryWrite,
                    .dstAccessMask = vk::AccessFlagBits::eMemoryRead,
                    .oldLayout = layout,
                    .newLayout = pLayout,
                    .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .subresourceRange = {
                        .aspectMask = vk::ImageAspectFlagBits::eColor,
                        .levelCount = 1,
                        .layerCount = 1,
                    },
                });
            });
            layout = pLayout;
        }
    }

    void Texture::SynchronizeHost() {
        TRACE_EVENT("gpu", "Texture::SynchronizeHost");
        auto pointer{guest->pointer};
        auto size{format.GetSize(dimensions)};

        auto stagingBuffer{[&]() {
            if (tiling == vk::ImageTiling::eOptimal) {
                return gpu.memory.AllocateStagingBuffer(size);
            } else {
                throw exception("Guest -> Host synchronization of images tiled as '{}' isn't implemented", vk::to_string(tiling));
            }
        }()};

        if (guest->tileMode == texture::TileMode::Block) {
            // Reference on Block-linear tiling: https://gist.github.com/PixelyIon/d9c35050af0ef5690566ca9f0965bc32
            constexpr u8 sectorWidth{16}; // The width of a sector in bytes
            constexpr u8 sectorHeight{2}; // The height of a sector in lines
            constexpr u8 gobWidth{64}; // The width of a GOB in bytes
            constexpr u8 gobHeight{8}; // The height of a GOB in lines

            auto blockHeight{guest->tileConfig.blockHeight}; // The height of the blocks in GOBs
            auto robHeight{gobHeight * blockHeight}; // The height of a single ROB (Row of Blocks) in lines
            auto surfaceHeight{dimensions.height / guest->format.blockHeight}; // The height of the surface in lines
            auto surfaceHeightRobs{util::AlignUp(surfaceHeight, robHeight) / robHeight}; // The height of the surface in ROBs (Row Of Blocks)
            auto robWidthBytes{util::AlignUp((guest->tileConfig.surfaceWidth / guest->format.blockWidth) * guest->format.bpb, gobWidth)}; // The width of a ROB in bytes
            auto robWidthBlocks{robWidthBytes / gobWidth}; // The width of a ROB in blocks (and GOBs because block width == 1 on the Tegra X1)
            auto robBytes{robWidthBytes * robHeight}; // The size of a ROB in bytes
            auto gobYOffset{robWidthBytes * gobHeight}; // The offset of the next Y-axis GOB from the current one in linear space

            auto inputSector{pointer}; // The address of the input sector
            auto outputRob{stagingBuffer->data()}; // The address of the output block

            for (u32 rob{}, y{}, paddingY{}; rob < surfaceHeightRobs; rob++) { // Every Surface contains `surfaceHeightRobs` ROBs
                auto outputBlock{outputRob}; // We iterate through a block independently of the ROB
                for (u32 block{}; block < robWidthBlocks; block++) { // Every ROB contains `surfaceWidthBlocks` Blocks
                    auto outputGob{outputBlock}; // We iterate through a GOB independently of the block
                    for (u32 gobY{}; gobY < blockHeight; gobY++) { // Every Block contains `blockHeight` Y-axis GOBs
                        for (u32 index{}; index < sectorWidth * sectorHeight; index++) { // Every Y-axis GOB contains `sectorWidth * sectorHeight` sectors
                            u32 xT{((index << 3) & 0b10000) | ((index << 1) & 0b100000)}; // Morton-Swizzle on the X-axis
                            u32 yT{((index >> 1) & 0b110) | (index & 0b1)}; // Morton-Swizzle on the Y-axis
                            std::memcpy(outputGob + (yT * robWidthBytes) + xT, inputSector, sectorWidth);
                            inputSector += sectorWidth; // `sectorWidth` bytes are of sequential image data
                        }
                        outputGob += gobYOffset; // Increment the output GOB to the next Y-axis GOB
                    }
                    inputSector += paddingY; // Increment the input sector to the next sector
                    outputBlock += gobWidth; // Increment the output block to the next block (As Block Width = 1 GOB Width)
                }
                outputRob += robBytes; // Increment the output block to the next ROB

                y += robHeight; // Increment the Y position to the next ROB
                blockHeight = static_cast<u8>(std::min(static_cast<u32>(blockHeight), (surfaceHeight - y) / gobHeight)); // Calculate the amount of Y GOBs which aren't padding
                paddingY = (guest->tileConfig.blockHeight - blockHeight) * (sectorWidth * sectorWidth * sectorHeight); // Calculate the amount of padding between contiguous sectors
            }
        } else if (guest->tileMode == texture::TileMode::Pitch) {
            auto sizeLine{guest->format.GetSize(dimensions.width, 1)}; // The size of a single line of pixel data
            auto sizeStride{guest->format.GetSize(guest->tileConfig.pitch, 1)}; // The size of a single stride of pixel data

            auto inputLine{pointer}; // The address of the input line
            auto outputLine{stagingBuffer->data()}; // The address of the output line

            for (u32 line{}; line < dimensions.height; line++) {
                std::memcpy(outputLine, inputLine, sizeLine);
                inputLine += sizeStride;
                outputLine += sizeLine;
            }
        } else if (guest->tileMode == texture::TileMode::Linear) {
            std::memcpy(stagingBuffer->data(), pointer, size);
        }

        if (WaitOnBacking() && size != format.GetSize(dimensions))
            throw exception("Backing properties changing during sync is not supported");
        WaitOnFence();

        cycle = gpu.scheduler.Submit([&](vk::raii::CommandBuffer &commandBuffer) {
            auto image{GetBacking()};
            if (layout != vk::ImageLayout::eTransferDstOptimal) {
                commandBuffer.pipelineBarrier(layout != vk::ImageLayout::eUndefined ? vk::PipelineStageFlagBits::eTopOfPipe : vk::PipelineStageFlagBits::eBottomOfPipe, vk::PipelineStageFlagBits::eTransfer, {}, {}, {}, vk::ImageMemoryBarrier{
                    .image = image,
                    .srcAccessMask = vk::AccessFlagBits::eMemoryRead | vk::AccessFlagBits::eMemoryWrite,
                    .dstAccessMask = vk::AccessFlagBits::eTransferWrite,
                    .oldLayout = layout,
                    .newLayout = vk::ImageLayout::eTransferDstOptimal,
                    .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .subresourceRange = {
                        .aspectMask = vk::ImageAspectFlagBits::eColor,
                        .levelCount = 1,
                        .layerCount = 1,
                    },
                });

                if (layout == vk::ImageLayout::eUndefined)
                    layout = vk::ImageLayout::eTransferDstOptimal;
            }

            commandBuffer.copyBufferToImage(stagingBuffer->vkBuffer, image, vk::ImageLayout::eTransferDstOptimal, vk::BufferImageCopy{
                .imageExtent = dimensions,
                .imageSubresource = {
                    .aspectMask = vk::ImageAspectFlagBits::eColor,
                    .layerCount = 1,
                },
            });

            if (layout != vk::ImageLayout::eTransferDstOptimal)
                commandBuffer.pipelineBarrier(vk::PipelineStageFlagBits::eTransfer, vk::PipelineStageFlagBits::eTransfer, {}, {}, {}, vk::ImageMemoryBarrier{
                    .image = image,
                    .srcAccessMask = vk::AccessFlagBits::eTransferWrite,
                    .dstAccessMask = vk::AccessFlagBits::eMemoryRead,
                    .oldLayout = vk::ImageLayout::eTransferDstOptimal,
                    .newLayout = layout,
                    .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
                    .subresourceRange = {
                        .aspectMask = vk::ImageAspectFlagBits::eColor,
                        .levelCount = 1,
                        .layerCount = 1,
                    },
                });
        });

        cycle->AttachObject(stagingBuffer);
    }

    void Texture::SynchronizeGuest() {
        WaitOnBacking();
        WaitOnFence();

        TRACE_EVENT("gpu", "Texture::SynchronizeGuest");
        // TODO: Write Host -> Guest Synchronization
    }
}