// AMS_Circle
// Mikiex
// PS 2.0
// Circle Maker Example.

//#CROSS-SAMPLING : changes Tex.xy.
//#PARAM float Cwidth 0.1 : Circle line width : Circle line width.
//#PARAM float edgefuzz 0.01 : edgefuzz : Fuzzyness of the edges.

// Parameter variables
float Cwidth;
float edgefuzz;

// Foreground texture
texture ForegroundTexture;

// Foreground sampler
sampler2D foreground = sampler_state {
    Texture = (ForegroundTexture);
    MinFilter = Linear;
    MagFilter = Linear;
    MipFilter = Linear;
};

// Increments 1 per frame
float frameCounter;

//These are all constants from Construct
float boxLeft;
float boxRight;
float boxTop;
float boxBottom;
float pixelWidth;
float pixelHeight;
float hotspotX;
float hotspotY;
float boxWidth;
float boxHeight;
float angle;

// Effect function
float4 EffectProcess( float2 Tex : TEXCOORD0 ) : COLOR0
{

//    float4 jj = tex2D(foreground, Tex.xy); //we just ignore the original image
	float tx = (Tex.x-boxLeft)/boxWidth; // make the box into U coords from 0 to 1
	float ty = (Tex.y-boxTop)/boxHeight; // make the box into V coords from 0 to 1
	float res = distance(0.5,float2(tx,ty)); // Use the distance function to create what looks like a radial gradient
	float xfuzz = boxWidth*edgefuzz; // how fuzzy do we want the x edges
	float yfuzz = boxHeight*edgefuzz; // how fuzzy do we want the y edges
	
	float SS1 = 0.5; // this sets the smoothstep position
	float SS2 = 0.5-Cwidth; // this is the inside smoothstep position
	
	res = smoothstep(SS1,SS1-xfuzz,res)*smoothstep(SS2-yfuzz,SS2,res); // the magic of smoothstep!
 
  	
  	float4 resr = {res,0,0,res}; // we pass the result to just the red channel and the alpha channel

    return resr;
}

// ConstructEffect
technique ConstructEffect
{
    pass p0
    {
        VertexShader = null;
        PixelShader = compile ps_2_0 EffectProcess();
    }
}[/code:3skzwxbh]