//
// Simple passthrough vertex shader
//
attribute vec3 in_Position;                  // (x,y,z)
//attribute vec3 in_Normal;                  // (x,y,z)     unused in this shader.
attribute vec4 in_Colour;                    // (r,g,b,a)
attribute vec2 in_TextureCoord;              // (u,v)

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

void main()
{
    vec4 object_space_pos = vec4( in_Position.x, in_Position.y, in_Position.z, 1.0);
    gl_Position = gm_Matrices[MATRIX_WORLD_VIEW_PROJECTION] * object_space_pos;
    
    v_vColour = in_Colour;
    v_vTexcoord = in_TextureCoord;
}

//######################_==_YOYO_SHADER_MARKER_==_######################@~
varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform vec2  dimension;

#define TAU 6.283185307179586
#define distance_sample 32.

void main() {
	vec2 tx  = 1. / dimension;
	vec2 px  = v_vTexcoord * dimension;
	vec4 col = texture2D( gm_BaseTexture, v_vTexcoord );
    gl_FragColor = col;
	
	if(col.a == 1.)
		return;
	
	bool samp = false;
	float angular_sample = distance_sample * TAU * 2.;
	
	for(float i = 1.; i <= distance_sample; i++) {
		float base = 1.;
		float top  = 0.;
		float minDist = 9999.;
		
		for(float j = 0.; j <= angular_sample; j++) {
			float ang = j / angular_sample * TAU;
			
			vec2  pxs = floor(px + vec2( cos(ang),  sin(ang)) * i) + 0.5;
			vec2  txs = pxs * tx;
			vec4  sam = texture2D( gm_BaseTexture, txs );
			float dst = distance(px, pxs);
			
			if(sam.a < 1. || dst > minDist) continue;
			
			gl_FragColor = sam;
			// gl_FragColor = vec4(vec3(i / distance_sample), 1.);
			minDist = dst;
			
			samp = true;
		}
		
		if(samp) return;
	}
}