// Copyright 2017 The NXT Authors
//
// 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 BACKEND_COMMANDS_H_
#define BACKEND_COMMANDS_H_

#include "backend/RenderPassDescriptor.h"
#include "backend/Texture.h"

#include "nxt/nxtcpp.h"

namespace backend {

    // Definition of the commands that are present in the CommandIterator given by the
    // CommandBufferBuilder. There are not defined in CommandBuffer.h to break some header
    // dependencies: Ref<Object> needs Object to be defined.

    enum class Command {
        BeginComputePass,
        BeginRenderPass,
        CopyBufferToBuffer,
        CopyBufferToTexture,
        CopyTextureToBuffer,
        Dispatch,
        DrawArrays,
        DrawElements,
        EndComputePass,
        EndRenderPass,
        SetComputePipeline,
        SetRenderPipeline,
        SetPushConstants,
        SetStencilReference,
        SetScissorRect,
        SetBlendColor,
        SetBindGroup,
        SetIndexBuffer,
        SetVertexBuffers,
        TransitionBufferUsage,
        TransitionTextureUsage,
    };

    struct BeginComputePassCmd {};

    struct BeginRenderPassCmd {
        Ref<RenderPassDescriptorBase> info;
    };

    struct BufferCopyLocation {
        Ref<BufferBase> buffer;
        uint32_t offset;
    };

    struct TextureCopyLocation {
        Ref<TextureBase> texture;
        uint32_t x, y, z;
        uint32_t width, height, depth;
        uint32_t level;
    };

    struct CopyBufferToBufferCmd {
        BufferCopyLocation source;
        BufferCopyLocation destination;
        uint32_t size;
    };

    struct CopyBufferToTextureCmd {
        BufferCopyLocation source;
        TextureCopyLocation destination;
        uint32_t rowPitch;
    };

    struct CopyTextureToBufferCmd {
        TextureCopyLocation source;
        BufferCopyLocation destination;
        uint32_t rowPitch;
    };

    struct DispatchCmd {
        uint32_t x;
        uint32_t y;
        uint32_t z;
    };

    struct DrawArraysCmd {
        uint32_t vertexCount;
        uint32_t instanceCount;
        uint32_t firstVertex;
        uint32_t firstInstance;
    };

    struct DrawElementsCmd {
        uint32_t indexCount;
        uint32_t instanceCount;
        uint32_t firstIndex;
        uint32_t firstInstance;
    };

    struct EndComputePassCmd {};

    struct EndRenderPassCmd {};

    struct SetComputePipelineCmd {
        Ref<ComputePipelineBase> pipeline;
    };

    struct SetRenderPipelineCmd {
        Ref<RenderPipelineBase> pipeline;
    };

    struct SetPushConstantsCmd {
        nxt::ShaderStageBit stages;
        uint32_t offset;
        uint32_t count;
    };

    struct SetStencilReferenceCmd {
        uint32_t reference;
    };

    struct SetScissorRectCmd {
        uint32_t x, y, width, height;
    };

    struct SetBlendColorCmd {
        float r, g, b, a;
    };

    struct SetBindGroupCmd {
        uint32_t index;
        Ref<BindGroupBase> group;
    };

    struct SetIndexBufferCmd {
        Ref<BufferBase> buffer;
        uint32_t offset;
    };

    struct SetVertexBuffersCmd {
        uint32_t startSlot;
        uint32_t count;
    };

    struct TransitionBufferUsageCmd {
        Ref<BufferBase> buffer;
        nxt::BufferUsageBit usage;
    };

    struct TransitionTextureUsageCmd {
        Ref<TextureBase> texture;
        uint32_t startLevel;
        uint32_t levelCount;
        nxt::TextureUsageBit usage;
    };

    // This needs to be called before the CommandIterator is freed so that the Ref<> present in
    // the commands have a chance to run their destructor and remove internal references.
    class CommandIterator;
    void FreeCommands(CommandIterator* commands);
    void SkipCommand(CommandIterator* commands, Command type);

}  // namespace backend

#endif  // BACKEND_COMMANDS_H_