using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
[RequireComponent (typeof(Camera))]
public class PostEffectsBase : MonoBehaviour {	
	protected bool  supportHDRTextures = true;
	protected bool  supportDX11 = false;
	protected bool  isSupported = true;


    protected Material CheckShaderAndCreateMaterial ( Shader s ,   Material m2Create  ){
		if (!s) { 
			Debug.Log("Missing shader in " + this.ToString ());
			enabled = false;
			return null;
		}
			
		if (s.isSupported && m2Create && m2Create.shader == s) 
			return m2Create;
		
		if (!s.isSupported) {
			NotSupported ();
			Debug.Log("The shader " + s.ToString() + " on effect "+this.ToString()+" is not supported on this platform!");
			return null;
		}
		else {
			m2Create = new Material (s);	
			m2Create.hideFlags = HideFlags.DontSave;		
			if (m2Create) 
				return m2Create;
			else return null;
		}
	}


    protected Material CreateMaterial ( Shader s ,   Material m2Create  ){
		if (!s) { 
			Debug.Log ("Missing shader in " + this.ToString ());
			return null;
		}
			
		if (m2Create && (m2Create.shader == s) && (s.isSupported)) 
			return m2Create;
		
		if (!s.isSupported) {
			return null;
		}
		else {
			m2Create = new Material (s);	
			m2Create.hideFlags = HideFlags.DontSave;		
			if (m2Create) 
				return m2Create;
			else return null;
		}
	}
	
	void OnEnable (){
		isSupported = true;
	}	

	protected bool CheckSupport (){
		 return CheckSupport (false);
	}


    public virtual bool CheckResources (){
		 Debug.LogWarning ("CheckResources () for " + this.ToString() + " should be overwritten.");
		return isSupported;
	}


    protected void Start (){
		 CheckResources ();
	}	
		
	protected bool CheckSupport ( bool needDepth  ){
		 isSupported = true;
		supportHDRTextures = SystemInfo.SupportsRenderTextureFormat(RenderTextureFormat.ARGBHalf);
		supportDX11 = SystemInfo.graphicsShaderLevel >= 50 && SystemInfo.supportsComputeShaders;
		
		if (!SystemInfo.supportsImageEffects || !SystemInfo.supportsRenderTextures) {
			NotSupported ();
			return false;
		}		
		
		if(needDepth && !SystemInfo.SupportsRenderTextureFormat (RenderTextureFormat.Depth)) {
			NotSupported ();
			return false;
		}
		
		if(needDepth)
			GetComponent<Camera>().depthTextureMode |= DepthTextureMode.Depth;	
		
		return true;
	}

	protected  bool CheckSupport ( bool needDepth ,    bool needHdr  ){
		 if(!CheckSupport(needDepth))
			return false;
		
		if(needHdr && !supportHDRTextures) {
			NotSupported ();
			return false;		
		}
		
		return true;
	}


    public bool Dx11Support (){
		 return supportDX11;
	}


    protected void ReportAutoDisable (){
		Debug.LogWarning ("The image effect " + this.ToString() + " has been disabled as it's not supported on the current platform.");
	}
			
	// deprecated but needed for old effects to survive upgrading
	bool CheckShader ( Shader s  ){
		 Debug.Log("The shader " + s.ToString () + " on effect "+ this.ToString () + " is not part of the Unity 3.2f+ effects suite anymore. For best performance and quality, please ensure you are using the latest Standard Assets Image Effects (Pro only) package.");		
		if (!s.isSupported) {
			NotSupported ();
			return false;
		} 
		else {
			return false;
		}
	}


    protected void NotSupported (){
		enabled = false;
		isSupported = false;
		return;
	}


    protected void DrawBorder ( RenderTexture dest ,   Material material   ){
		float x1;	
		float x2;
		float y1;
		float y2;		
		
		RenderTexture.active = dest;
        bool  invertY = true; // source.texelSize.y < 0.0ff;
        // Set up the simple Matrix
        GL.PushMatrix();
        GL.LoadOrtho();		
        
        for (int i = 0; i < material.passCount; i++)
        {
            material.SetPass(i);
	        
	        float y1_; float y2_;
	        if (invertY)
	        {
	            y1_ = 1.0f; y2_ = 0.0f;
	        }
	        else
	        {
	            y1_ = 0.0f; y2_ = 1.0f;
	        }
	        	        
	        // left	        
	        x1 = 0.0f;
	        x2 = 0.0f + 1.0f/(dest.width*1.0f);
	        y1 = 0.0f;
	        y2 = 1.0f;
	        GL.Begin(GL.QUADS);
	        
	        GL.TexCoord2(0.0f, y1_); GL.Vertex3(x1, y1, 0.1f);
	        GL.TexCoord2(1.0f, y1_); GL.Vertex3(x2, y1, 0.1f);
	        GL.TexCoord2(1.0f, y2_); GL.Vertex3(x2, y2, 0.1f);
	        GL.TexCoord2(0.0f, y2_); GL.Vertex3(x1, y2, 0.1f);
	
	        // right
	        x1 = 1.0f - 1.0f/(dest.width*1.0f);
	        x2 = 1.0f;
	        y1 = 0.0f;
	        y2 = 1.0f;

	        GL.TexCoord2(0.0f, y1_); GL.Vertex3(x1, y1, 0.1f);
	        GL.TexCoord2(1.0f, y1_); GL.Vertex3(x2, y1, 0.1f);
	        GL.TexCoord2(1.0f, y2_); GL.Vertex3(x2, y2, 0.1f);
	        GL.TexCoord2(0.0f, y2_); GL.Vertex3(x1, y2, 0.1f);	        
	
	        // top
	        x1 = 0.0f;
	        x2 = 1.0f;
	        y1 = 0.0f;
	        y2 = 0.0f + 1.0f/(dest.height*1.0f);

	        GL.TexCoord2(0.0f, y1_); GL.Vertex3(x1, y1, 0.1f);
	        GL.TexCoord2(1.0f, y1_); GL.Vertex3(x2, y1, 0.1f);
	        GL.TexCoord2(1.0f, y2_); GL.Vertex3(x2, y2, 0.1f);
	        GL.TexCoord2(0.0f, y2_); GL.Vertex3(x1, y2, 0.1f);
	        
	        // bottom
	        x1 = 0.0f;
	        x2 = 1.0f;
	        y1 = 1.0f - 1.0f/(dest.height*1.0f);
	        y2 = 1.0f;

	        GL.TexCoord2(0.0f, y1_); GL.Vertex3(x1, y1, 0.1f);
	        GL.TexCoord2(1.0f, y1_); GL.Vertex3(x2, y1, 0.1f);
	        GL.TexCoord2(1.0f, y2_); GL.Vertex3(x2, y2, 0.1f);
	        GL.TexCoord2(0.0f, y2_); GL.Vertex3(x1, y2, 0.1f);	
	                	              
	        GL.End();	
        }	
        
        GL.PopMatrix();
	}
}