Pixel-Composer/shaders/sh_polar/sh_polar.fsh

#pragma use(sampler)

#region -- sampler -- [1730686036.7372286]
	uniform int  interpolation;
	uniform vec2 sampleDimension;
	uniform int  sampleMode;

	const float PI = 3.14159265358979323846;
	float sinc ( float x ) { return x == 0.? 1. : sin(x * PI) / (x * PI); }

	vec4 texture2D_bicubic( sampler2D texture, vec2 uv ) {
		uv = uv * sampleDimension + 0.5;
		vec2 iuv = floor( uv );
		vec2 fuv = fract( uv );
		uv = iuv + fuv * fuv * (3.0 - 2.0 * fuv);
		uv = (uv - 0.5) / sampleDimension;
		return texture2D( texture, uv );
	}

	const int RSIN_RADIUS = 1;
	vec4 texture2D_rsin( sampler2D texture, vec2 uv ) {
		vec2 tx = 1.0 / sampleDimension;
		vec2 p  = uv * sampleDimension;
		
		vec4  col = vec4(0.);
		float wei = 0.;
		
		for (int x = -RSIN_RADIUS; x <= RSIN_RADIUS; x++)
		for (int y = -RSIN_RADIUS; y <= RSIN_RADIUS; y++) {
			vec2 sx = vec2(float(x), float(y));
			float a = length(sx) / float(RSIN_RADIUS);
			// if(a > 1.) continue;
			
			vec4 sample = texture2D(texture, uv + sx * tx);
			float w     = sinc(a * PI * tx.x) * sinc(a * PI * tx.y);
			
			col += w * sample;
			wei += w;
		}
		
		col /= wei;
		return col;
	}

	const int LANCZOS_RADIUS = 3;
	float lanczosWeight(float d, float n) { return d == 0.0 ? 1.0 : (d * d < n * n ? sinc(d) * sinc(d / n) : 0.0); }

	vec4 texture2D_lanczos3( sampler2D texture, vec2 uv ) {
		vec2 center = uv - (mod(uv * sampleDimension, 1.0) - 0.5) / sampleDimension;
		vec2 offset = (uv - center) * sampleDimension;
		vec2 tx = 1. / sampleDimension;
		
		vec4  col = vec4(0.);
		float wei = 0.;
		
		for(int x = -LANCZOS_RADIUS; x < LANCZOS_RADIUS; x++)
		for(int y = -LANCZOS_RADIUS; y < LANCZOS_RADIUS; y++) {
			
			float wx = lanczosWeight(float(x) - offset.x, float(LANCZOS_RADIUS));
			float wy = lanczosWeight(float(y) - offset.y, float(LANCZOS_RADIUS));
			float w  = wx * wy;
			
			col += w * texture2D(texture, center + vec2(x, y) * tx);
			wei += w;
		}
		
		col /= wei;
		return col;
	}

	vec4 texture2Dintp( sampler2D texture, vec2 uv ) {
			 if(interpolation <= 2)	return texture2D(          texture, uv );
		else if(interpolation == 3)	return texture2D_bicubic(  texture, uv );
		else if(interpolation == 4)	return texture2D_lanczos3( texture, uv );
		
		return texture2D( texture, uv );
	}

	vec4 sampleTexture( sampler2D texture, vec2 pos) {
		if(pos.x >= 0. && pos.y >= 0. && pos.x <= 1. && pos.y <= 1.)
			return texture2Dintp(texture, pos);
		
			 if(sampleMode <= 1) return vec4(0.);
		else if(sampleMode == 2) return texture2Dintp(texture, clamp(pos, 0., 1.));
		else if(sampleMode == 3) return texture2Dintp(texture, fract(pos));
		else if(sampleMode == 4) return vec4(vec3(0.), 1.);
		
		return vec4(0.);
	}
#endregion -- sampler --

varying vec2  v_vTexcoord;
varying vec4  v_vColour;
uniform int   invert;
uniform int   distMode;
uniform int   swap;
uniform vec2  tile;

uniform vec2      blend;
uniform int       blendUseSurf;
uniform sampler2D blendSurf;
uniform vec2      range;

void main() {
	vec2 center = vec2(0.5, 0.5);
	vec2 coord;
	vec2 til   = tile/* * vec2(1., PI * 2.)*/;
	vec2 _tile = swap == 1? til.yx : til;
	
	float bld = blend.x;
	if(blendUseSurf == 1) {
		vec4 _vMap = texture2Dintp( blendSurf, v_vTexcoord );
		bld = mix(blend.x, blend.y, (_vMap.r + _vMap.g + _vMap.b) / 3.);
	}
	
	float rad0 = radians(range.x);
	float rad1 = radians(range.y);
	float radr = (range.y - range.x) / 360.;
	
	gl_FragColor = vec4(0.);
	
	if(invert == 0) {
		float dist = distance(v_vTexcoord, center) / (sqrt(2.) * .5);
		if(distMode == 1)      dist = sqrt(dist);
		else if(distMode == 2) dist = log(dist);
		
		vec2  cenPos = v_vTexcoord - center;
		float angle	 = atan(cenPos.y, -cenPos.x) + PI;
		
		angle = (angle - rad0) / radr;
		if(angle < rad0 || angle > rad1) return;
		
		angle /= PI * 2.;
		coord = fract(vec2(dist, angle) * _tile);
		
	} else if(invert == 1) {
		float dist = v_vTexcoord.x * 0.5;
		if(distMode == 1)      dist = sqrt(dist);
		else if(distMode == 2) dist = log(dist);
		
		float angle = v_vTexcoord.y * PI * 2.;
		
		angle = (angle - rad0) / radr;
		if(angle < rad0 || angle > rad1) return;
		
		coord = fract(center + vec2(cos(angle), sin(angle)) * dist * _tile);
	}
	
	if(swap == 1) coord.xy = coord.yx;
	
	gl_FragColor = texture2Dintp( gm_BaseTexture, mix(v_vTexcoord, coord, bld) );
}