marsxplr-decomp/Game/Assembly - CSHarp - first pass/SSAOEffect.cs

using UnityEngine;

[ExecuteInEditMode]
[RequireComponent(typeof(Camera))]
[AddComponentMenu("Image Effects/SSAO")]
public class SSAOEffect : MonoBehaviour
{
    public enum SSAOSamples
    {
        Low = 0,
        Medium = 1,
        High = 2,
    }

    public float m_Radius = 0.4f;
    public SSAOSamples m_SampleCount = SSAOSamples.Medium;
    public float m_OcclusionIntensity = 1.5f;
    public int m_Blur = 2;
    public int m_Downsampling = 2;
    public float m_OcclusionAttenuation = 1.0f;
    public float m_MinZ = 0.01f;

    public Shader m_SSAOShader;
    private Material m_SSAOMaterial;

    public Texture2D m_RandomTexture;

    private bool m_Supported;
    private bool m_IsOpenGL;

    private static Material CreateMaterial(Shader shader)
    {
        if (!shader)
            return null;
        Material m = new Material(shader);
        m.hideFlags = HideFlags.HideAndDontSave;
        return m;
    }
    private static void DestroyMaterial(Material mat)
    {
        if (mat)
        {
            DestroyImmediate(mat);
            mat = null;
        }
    }


    void OnDisable()
    {
        DestroyMaterial(m_SSAOMaterial);
    }

    void Start()
    {
        if (!SystemInfo.supportsImageEffects || !SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.Depth))
        {
            m_Supported = false;
            enabled = false;
            return;
        }

        CreateMaterials();
        if (!m_SSAOMaterial || m_SSAOMaterial.passCount != 5)
        {
            m_Supported = false;
            enabled = false;
            return;
        }

        //CreateRandomTable (26, 0.2f);

        camera.depthTextureMode = DepthTextureMode.DepthNormals;
        m_Supported = true;
        m_IsOpenGL = SystemInfo.graphicsDeviceVersion.StartsWith("OpenGL");
    }

    private void CreateMaterials()
    {
        if (!m_SSAOMaterial && m_SSAOShader.isSupported)
        {
            m_SSAOMaterial = CreateMaterial(m_SSAOShader);
            m_SSAOMaterial.SetTexture("_RandomTexture", m_RandomTexture);
        }
    }

    void OnRenderImage(RenderTexture source, RenderTexture destination)
    {
        if (!m_Supported || !m_SSAOShader.isSupported)
        {
            enabled = false;
            return;
        }
        CreateMaterials();

        m_Downsampling = Mathf.Clamp(m_Downsampling, 1, 6);
        m_Radius = Mathf.Clamp(m_Radius, 0.05f, 1.0f);
        m_MinZ = Mathf.Clamp(m_MinZ, 0.00001f, 0.5f);
        m_OcclusionIntensity = Mathf.Clamp(m_OcclusionIntensity, 0.5f, 4.0f);
        m_OcclusionAttenuation = Mathf.Clamp(m_OcclusionAttenuation, 0.2f, 2.0f);
        m_Blur = Mathf.Clamp(m_Blur, 0, 4);

        // Render SSAO term into a smaller texture
        RenderTexture rtAO = RenderTexture.GetTemporary(source.width / m_Downsampling, source.height / m_Downsampling, 0);
        float fovY = camera.fieldOfView;
        float far = camera.farClipPlane;
        float y = Mathf.Tan(fovY * Mathf.Deg2Rad * 0.5f) * far;
        float x = y * camera.aspect;
        m_SSAOMaterial.SetVector("_FarCorner", new Vector3(x, y, far));
        int noiseWidth, noiseHeight;
        if (m_RandomTexture)
        {
            noiseWidth = m_RandomTexture.width;
            noiseHeight = m_RandomTexture.height;
        }
        else
        {
            noiseWidth = 1; noiseHeight = 1;
        }
        m_SSAOMaterial.SetVector("_NoiseScale", new Vector3((float)rtAO.width / noiseWidth, (float)rtAO.height / noiseHeight, 0.0f));
        m_SSAOMaterial.SetVector("_Params", new Vector4(
            m_Radius,
            m_MinZ,
            1.0f / m_OcclusionAttenuation,
            m_OcclusionIntensity));

        bool doBlur = m_Blur > 0;
        Graphics.Blit(doBlur ? null : source, rtAO, m_SSAOMaterial, (int)m_SampleCount);

        if (doBlur)
        {
            // Blur SSAO horizontally
            RenderTexture rtBlurX = RenderTexture.GetTemporary(source.width, source.height, 0);
            m_SSAOMaterial.SetVector("_TexelOffsetScale",
                m_IsOpenGL ?
                new Vector4(m_Blur, 0, 1.0f / m_Downsampling, 0) :
                new Vector4((float)m_Blur / source.width, 0, 0, 0));
            m_SSAOMaterial.SetTexture("_SSAO", rtAO);
            Graphics.Blit(null, rtBlurX, m_SSAOMaterial, 3);
            RenderTexture.ReleaseTemporary(rtAO); // original rtAO not needed anymore

            // Blur SSAO vertically
            RenderTexture rtBlurY = RenderTexture.GetTemporary(source.width, source.height, 0);
            m_SSAOMaterial.SetVector("_TexelOffsetScale",
                m_IsOpenGL ?
                new Vector4(0, m_Blur, 1, 0) :
                new Vector4(0, (float)m_Blur / source.height, 0, 0));
            m_SSAOMaterial.SetTexture("_SSAO", rtBlurX);
            Graphics.Blit(source, rtBlurY, m_SSAOMaterial, 3);
            RenderTexture.ReleaseTemporary(rtBlurX); // blurX RT not needed anymore

            rtAO = rtBlurY; // AO is the blurred one now
        }

        // Modulate scene rendering with SSAO
        m_SSAOMaterial.SetTexture("_SSAO", rtAO);
        Graphics.Blit(source, destination, m_SSAOMaterial, 4);

        RenderTexture.ReleaseTemporary(rtAO);
    }

    /*
    private void CreateRandomTable (int count, float minLength)
    {
        Random.seed = 1337;
        Vector3[] samples = new Vector3[count];
        // initial samples
        for (int i = 0; i < count; ++i)
            samples[i] = Random.onUnitSphere;
        // energy minimization: push samples away from others
        int iterations = 100;
        while (iterations-- > 0) {
            for (int i = 0; i < count; ++i) {
                Vector3 vec = samples[i];
                Vector3 res = Vector3.zero;
                // minimize with other samples
                for (int j = 0; j < count; ++j) {
                    Vector3 force = vec - samples[j];
                    float fac = Vector3.Dot (force, force);
                    if (fac > 0.00001f)
                        res += force * (1.0f / fac);
                }
                samples[i] = (samples[i] + res * 0.5f).normalized;
            }
        }
        // now scale samples between minLength and 1.0
        for (int i = 0; i < count; ++i) {
            samples[i] = samples[i] * Random.Range (minLength, 1.0f);
        }		

        string table = string.Format ("#define SAMPLE_COUNT {0}\n", count);
        table += "const float3 RAND_SAMPLES[SAMPLE_COUNT] = {\n";
        for (int i = 0; i < count; ++i) {
            Vector3 v = samples[i];
            table += string.Format("\tfloat3({0},{1},{2}),\n", v.x, v.y, v.z);
        }
        table += "};\n";
        Debug.Log (table);
    }
    */
}