//
// 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_==_######################@~
#define TAU 6.283185307179586

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform vec2 dimension;
uniform vec2 center[4];
uniform vec3 color[4];
uniform vec4 strength;

uniform int blend;

void main() {
	vec4 distances = vec4(0.);
	float maxDist = 0.;
	int i;
	
	for( i = 0; i < 4; i++ ) {
		float d      = distance(v_vTexcoord, center[i] / dimension);
		distances[i] = d;
		maxDist      = max(maxDist, d);
	}
	
	maxDist *= 2.;
	
	for( i = 0; i < 4; i++ )
		distances[i] = pow((maxDist - distances[i]) / maxDist, strength[i]);
	
	vec4 weights;
	
	     if(blend == 0) weights = distances / (distances[0] + distances[1] + distances[2] + distances[3]);
	else if(blend == 1) weights = normalize(distances);
	
	vec3 clr = color[0] * weights[0] + 
	           color[1] * weights[1] + 
			   color[2] * weights[2] + 
			   color[3] * weights[3];
	
	gl_FragColor = vec4(clr, 1.);
}