using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class BurRenderPassFeature : ScriptableRendererFeature
{
    public float Value=1;
 
    class BurRenderPass : ScriptableRenderPass
    {

        public float Value;
        private readonly int BurTexture = Shader.PropertyToID("_BurTexture");
        private readonly int BurTemp = Shader.PropertyToID("BurTemp");
        private Material mat;
        private Vector4 H = new Vector4(1, 0, 0, 0);
        private Vector4 V = new Vector4(0, 1, 0, 0);

        // This method is called before executing the render pass.
        // It can be used to configure render targets and their clear state. Also to create temporary render target textures.
        // When empty this render pass will render to the active camera render target.
        // You should never call CommandBuffer.SetRenderTarget. Instead call <c>ConfigureTarget</c> and <c>ConfigureClear</c>.
        // The render pipeline will ensure target setup and clearing happens in a performant manner.
        public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
        {
            if (mat == null) mat = CoreUtils.CreateEngineMaterial("Unlit URP Shader/Bur");
            //if(bur==null)
            //var dp = renderingData.cameraData.cameraTargetDescriptor;
            //dp.msaaSamples = 1;
            //cmd.GetTemporaryRT(BurTexture, dp);
            //bur = RTHandles.Alloc(BurTexture);
        }

        // Here you can implement the rendering logic.
        // Use <c>ScriptableRenderContext</c> to issue drawing commands or execute command buffers
        // https://docs.unity3d.com/ScriptReference/Rendering.ScriptableRenderContext.html
        // You don't have to call ScriptableRenderContext.submit, the render pipeline will call it at specific points in the pipeline.
        public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
        {
            CommandBuffer cmd = CommandBufferPool.Get("Bur");
            var dp = renderingData.cameraData.cameraTargetDescriptor;
            dp.msaaSamples = 1;
            dp.width /= 2;
            dp.height /= 2;
            cmd.GetTemporaryRT(BurTemp, dp);
            cmd.GetTemporaryRT(BurTexture, dp);
            //cmd.DisableShaderKeyword("UNITY_SHADER_EDITOR");
            cmd.Blit(renderingData.cameraData.renderer.cameraColorTarget,BurTemp);
            //mat.SetFloat("_Value",Value);
            cmd.SetGlobalVector("HorV",H);
            //cmd.SetRenderTarget(BurTexture);
            //cmd.ClearRenderTarget(false,true,Color.black);
            cmd.Blit(BurTemp,BurTexture,mat,0);
            cmd.SetGlobalVector("HorV",V);
            cmd.Blit(BurTexture,BurTemp,mat,0);
            cmd.Blit(BurTemp,BurTexture,mat,1);
            cmd.Blit(BurTexture,BurTemp,mat,1);
            cmd.Blit(BurTemp,BurTexture,mat,1);
            cmd.SetRenderTarget(renderingData.cameraData.renderer.cameraColorTarget);
            cmd.ReleaseTemporaryRT(BurTemp);
            cmd.ReleaseTemporaryRT(BurTexture);
           
            context.ExecuteCommandBuffer(cmd);
            cmd.Release();
        }

        // Cleanup any allocated resources that were created during the execution of this render pass.
        public override void OnCameraCleanup(CommandBuffer cmd)
        {
        }

        public void Disop()
        {
            if(mat!=null)
            CoreUtils.Destroy(mat);
        }
    }

    BurRenderPass m_ScriptablePass;

    /// <inheritdoc/>
    public override void Create()
    {
        m_ScriptablePass = new BurRenderPass();

        // Configures where the render pass should be injected.

    }

    // Here you can inject one or multiple render passes in the renderer.
    // This method is called when setting up the renderer once per-camera.
    public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
    {
        if (renderingData.cameraData.camera.cameraType != CameraType.SceneView)
        {
            m_ScriptablePass.renderPassEvent = RenderPassEvent.BeforeRenderingTransparents;
            Shader.EnableKeyword("UNITY_SHADER_EDITOR");
        }
        else
        {
            m_ScriptablePass.renderPassEvent = RenderPassEvent.BeforeRenderingPostProcessing;
            Shader.DisableKeyword("UNITY_SHADER_EDITOR");
        }

        m_ScriptablePass.Value = Value;
        if (renderingData.cameraData.camera.cameraType != CameraType.SceneView &&
            renderingData.cameraData.camera.name == "Camera")
        {
            renderer.EnqueuePass(m_ScriptablePass);
        }
    }

    protected override void Dispose(bool disposing)
    {
        m_ScriptablePass.Disop();
    }
}