using UnityEngine;
using System.Collections;


[ExecuteInEditMode]
[RequireComponent (typeof (Camera))]
[AddComponentMenu ("Image Effects/Edge Detection/Edge Detection")]
public class EdgeDetection : PostEffectsBase {
    public enum EdgeDetectMode {
	TriangleDepthNormals = 0,
	RobertsCrossDepthNormals = 1,
	SobelDepth = 2,
	SobelDepthThin = 3,
	TriangleLuminance = 4,
}


	public EdgeDetectMode mode = EdgeDetectMode.SobelDepthThin;
	public float sensitivityDepth = 1.0f;
	public float sensitivityNormals = 1.0f;
	public float lumThreshhold = 0.2f;
	public float edgeExp = 1.0f;
	public float sampleDist = 1.0f;
	public float edgesOnly = 0.0f;
	public Color edgesOnlyBgColor = Color.white;

	public Shader edgeDetectShader;
	private Material edgeDetectMaterial = null;
	private EdgeDetectMode oldMode = EdgeDetectMode.SobelDepthThin;


    public override bool CheckResources (){	
		 CheckSupport (true);
	
		edgeDetectMaterial = CheckShaderAndCreateMaterial (edgeDetectShader,edgeDetectMaterial);
		if (mode != oldMode)
			SetCameraFlag ();

		oldMode = mode;

		if (!isSupported)
			ReportAutoDisable ();
		return isSupported;				
	}


    new void Start (){
		oldMode	= mode;
	}

	void SetCameraFlag (){
		if (mode == EdgeDetectMode.SobelDepth || mode == EdgeDetectMode.SobelDepthThin)
			GetComponent<Camera>().depthTextureMode |= DepthTextureMode.Depth;
		else if (mode == EdgeDetectMode.TriangleDepthNormals || mode == EdgeDetectMode.RobertsCrossDepthNormals)
			GetComponent<Camera>().depthTextureMode |= DepthTextureMode.DepthNormals;			
	}

	void OnEnable (){
		SetCameraFlag();
	}
	
	[ImageEffectOpaque]
	void OnRenderImage ( RenderTexture source ,   RenderTexture destination  ){	
		if (CheckResources () == false) {
			Graphics.Blit (source, destination);
			return;
		}
				
		Vector2 sensitivity = new Vector2 (sensitivityDepth, sensitivityNormals);		
		edgeDetectMaterial.SetVector ("_Sensitivity", new Vector4 (sensitivity.x, sensitivity.y, 1.0f, sensitivity.y));		
		edgeDetectMaterial.SetFloat ("_BgFade", edgesOnly);	
		edgeDetectMaterial.SetFloat ("_SampleDistance", sampleDist);		
		edgeDetectMaterial.SetVector ("_BgColor", edgesOnlyBgColor);	
		edgeDetectMaterial.SetFloat ("_Exponent", edgeExp);
		edgeDetectMaterial.SetFloat ("_Threshold", lumThreshhold);
		
		Graphics.Blit (source, destination, edgeDetectMaterial, (int) mode);
	}
}