using System;
using UnityEngine;
using System.Collections;
[ExecuteInEditMode]
public class PartBloom : MonoBehaviour
{
    //采样率
    public int samplerScale = 1;
    //高亮部分提取阈值
    public Color colorThreshold = Color.gray;
    //Bloom泛光颜色
    public Color bloomColor = Color.white;
    //Bloom权值
    [Range(0.0f, 1.0f)]
    public float bloomFactor = 0.5f;

    /// <summary>
    /// Bloom材质球
    /// </summary>
    public Material m_bloom_mat = null;

    /// <summary>
    /// 特定渲染图
    /// </summary>
    [SerializeField]
    private RenderTexture m_R;
    RenderTexture temp1;
    RenderTexture temp2;
    private Camera rt_bloom_camera;
    void Start()
    {
        rt_bloom_camera = GameObject.Find("BloomCamera").GetComponent<Camera>();
        Debug.Log(rt_bloom_camera.name);
    }

    void OnRenderImage(RenderTexture source, RenderTexture destination)
    {
        if (m_bloom_mat != null && rt_bloom_camera != null)
        {   
            m_R = rt_bloom_camera.targetTexture;
            // m_R = RenderTexture.GetTemporary(source.width / 2, source.height / 2, 0);
            temp1 = RenderTexture.GetTemporary(m_R.width, m_R.height, 0);
            temp2 = RenderTexture.GetTemporary(m_R.width, m_R.height, 0);

            //复制泛光图
            Graphics.Blit(m_R, temp1);


            //根据阈值提取高亮部分,使用pass0进行高亮提取
            m_bloom_mat.SetVector("_colorThreshold", colorThreshold);
            Graphics.Blit(temp1, temp2, m_bloom_mat, 0);

            //高斯模糊，两次模糊，横向纵向，使用pass1进行高斯模糊
            m_bloom_mat.SetVector("_offsets", new Vector4(0, samplerScale, 0, 0));
            Graphics.Blit(temp2, temp1, m_bloom_mat, 1);
            m_bloom_mat.SetVector("_offsets", new Vector4(samplerScale, 0, 0, 0));
            Graphics.Blit(temp1, temp2, m_bloom_mat, 1);

            //Bloom，将模糊后的图作为Material的Blur图参数
            m_bloom_mat.SetTexture("_BlurTex", temp2);
            m_bloom_mat.SetVector("_bloomColor", bloomColor);
            m_bloom_mat.SetFloat("_bloomFactor", bloomFactor);

            //使用pass2进行景深效果计算，清晰场景图直接从source输入到shader的_MainTex中
            Graphics.Blit(source, destination, m_bloom_mat, 2);
            rt_bloom_camera.targetTexture = m_R;
            //释放申请的RT
            RenderTexture.ReleaseTemporary(temp1);
            RenderTexture.ReleaseTemporary(temp2);
        }
    }

    public void SetMaterialRT(RenderTexture rt)
    {
        // m_R = rt;
    }
}