using System;

namespace UnityEngine.Rendering.HighDefinition
{
    /// <summary>
    /// Context used when executing custom passes
    /// </summary>
    public struct CustomPassContext
    {
        /// <summary>
        /// Scriptable Render Context, used for any SRP related operations.
        /// </summary>
        public readonly ScriptableRenderContext renderContext;

        /// <summary>
        /// Command Buffer, used to enqueue graphic commands to the GPU.
        /// </summary>
        public readonly CommandBuffer cmd;

        /// <summary>
        /// HdCamera, HDRP data related to the rendering camera. Use the camera property to access the Camera class.
        /// </summary>
        public readonly HDCamera hdCamera;

        /// <summary>
        /// Result of the culling either of the camera or the custom pass if AggregateCullingParameters is used.
        /// </summary>
        public CullingResults cullingResults;

        /// <summary>
        /// Camera culling results, not modified by the custom pass culling.
        /// </summary>
        public readonly CullingResults cameraCullingResults;

        /// <summary>
        /// Camera color buffer.
        /// </summary>
        public readonly RTHandle cameraColorBuffer;

        /// <summary>
        /// Camera depth buffer.
        /// </summary>
        public readonly RTHandle cameraDepthBuffer;

        /// <summary>
        /// Camera normal buffer.
        /// </summary>
        public readonly RTHandle cameraNormalBuffer;

        /// <summary>
        /// Camera motion vectors buffer.
        /// </summary>
        public readonly RTHandle cameraMotionVectorsBuffer;

        /// <summary>
        /// Lazy handle to the custom color buffer, not allocated if not used.
        /// </summary>
        public readonly Lazy<RTHandle> customColorBuffer;

        /// <summary>
        /// Lazy handle to the custom depth buffer, not allocated if not used.
        /// </summary>
        public readonly Lazy<RTHandle> customDepthBuffer;

        /// <summary>
        /// Material Property Block, unique for each custom pass instance.
        /// </summary>
        public readonly MaterialPropertyBlock propertyBlock;

        /// <summary>
        /// Shading rate image buffer for variable shading rate.
        /// </summary>
        public readonly RTHandle shadingRateBuffer;

        internal readonly RTHandle sssBuffer;
        internal readonly RTHandle diffuseLightingBuffer;

        internal readonly CustomPassInjectionPoint injectionPoint;
		// This represent the state of HDRP globals at the point of recording the custom passes.
		// Using GetShaderVariablesGlobals() from HDRP inside the execute of the custom pass would give invalid result
		// because the execute of custom passes is called during the render graph execution, after the recording of all passes.
        internal readonly ShaderVariablesGlobal currentGlobalState;

        internal CustomPassContext(
            ScriptableRenderContext renderContext, CommandBuffer cmd,
            HDCamera hdCamera, CullingResults cullingResults,
            CullingResults cameraCullingResults,
            RTHandle cameraColorBuffer, RTHandle cameraDepthBuffer,
            RTHandle cameraNormalBuffer, RTHandle cameraMotionVectorsBuffer,
            RTHandle sssBuffer, RTHandle diffuseLightingBuffer, Lazy<RTHandle> customColorBuffer,
            Lazy<RTHandle> customDepthBuffer, MaterialPropertyBlock propertyBlock,
            RTHandle shadingRateBuffer,
            CustomPassInjectionPoint injectionPoint, ShaderVariablesGlobal currentGlobalState)
        {
            this.renderContext = renderContext;
            this.cmd = cmd;
            this.hdCamera = hdCamera;
            this.cullingResults = cullingResults;
            this.cameraCullingResults = cameraCullingResults;
            this.cameraColorBuffer = cameraColorBuffer;
            this.cameraDepthBuffer = cameraDepthBuffer;
            this.customColorBuffer = customColorBuffer;
            this.cameraNormalBuffer = cameraNormalBuffer;
            this.cameraMotionVectorsBuffer = cameraMotionVectorsBuffer;
            this.customDepthBuffer = customDepthBuffer;
            this.propertyBlock = propertyBlock;
            this.shadingRateBuffer = shadingRateBuffer;
            this.sssBuffer = sssBuffer;
            this.diffuseLightingBuffer = diffuseLightingBuffer;
            this.injectionPoint = injectionPoint;
            this.currentGlobalState = currentGlobalState;
        }
    }
}