FX circle

This is a quick example of how you could use an effect to replace a sprite with a procedual texture, this fx file makes a circle. This is unfinished in as much as it could be made to do things such as having a consistant line width, allow custom colours etc.

Hope someone finds it useful

// 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]

Hey, that's pretty cool. I like the softening of the edges. Mind if I include it in the next build?

You're welcome to do what you want with it

I wish I had more time to improve it, but I thought I would post it rather than just leave it sitting on my pc doing nothing.

You might be interested in : http://accad.osu.edu/~smay/RManNotes/RegularPatterns/index.html

Its a page about regular patterns using Renderman shaders but they are very similar to HLSL.

Construct is cool btw

I recommend a slight modification to this effect - make it white instead of red. Then when it's paired with the tint effect, it can be made any color.

Modified part: From float4 resr = {res,0,0,res}; // we pass the result to just the red channel and the alpha channel

to

float4 resr = {res,res,res,res}; // we pass the result to all the channels

The edited .fx file:

// 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,res,res,res}; // we pass the result to all the channels

return resr;

}

// ConstructEffect

technique ConstructEffect

{

pass p0

{

VertexShader = null;

PixelShader = compile ps_2_0 EffectProcess();

}

}