shader

//
// Simple passthrough fragment shader
//

varying vec2 v_vTexcoord;
varying vec4 v_vColour;

uniform float iTime;
varying vec2 v_vPosition_R;


/* discontinuous pseudorandom uniformly distributed in [-0.5, +0.5]^3 */
vec3 random3(vec3 c) {
    float j = 4096.0*sin(dot(c,vec3(17.0, 59.4, 15.0)));
    vec3 r;
    r.z = fract(512.0*j);
    j *= .125;
    r.x = fract(512.0*j);
    j *= .125;
    r.y = fract(512.0*j);
    return r-0.5;
}

/* skew constants for 3d simplex functions */
const float F3 =  0.3333333;
const float G3 =  0.1666667;

/* 3d simplex noise */
float simplex3d(vec3 p) {
     /* 1. find current tetrahedron T and it's four vertices */
     /* s, s+i1, s+i2, s+1.0 - absolute skewed (integer) coordinates of T vertices */
     /* x, x1, x2, x3 - unskewed coordinates of p relative to each of T vertices*/

     /* calculate s and x */
     vec3 s = floor(p + dot(p, vec3(F3)));
     vec3 x = p - s + dot(s, vec3(G3));

     /* calculate i1 and i2 */
     vec3 e = step(vec3(0.0), x - x.yzx);
     vec3 i1 = e*(1.0 - e.zxy);
     vec3 i2 = 1.0 - e.zxy*(1.0 - e);

     /* x1, x2, x3 */
     vec3 x1 = x - i1 + G3;
     vec3 x2 = x - i2 + 2.0*G3;
     vec3 x3 = x - 1.0 + 3.0*G3;

     /* 2. find four surflets and store them in d */
     vec4 w, d;

     /* calculate surflet weights */
     w.x = dot(x, x);
     w.y = dot(x1, x1);
     w.z = dot(x2, x2);
     w.w = dot(x3, x3);

     /* w fades from 0.6 at the center of the surflet to 0.0 at the margin */
     w = max(0.6 - w, 0.0);

     /* calculate surflet components */
     d.x = dot(random3(s), x);
     d.y = dot(random3(s + i1), x1);
     d.z = dot(random3(s + i2), x2);
     d.w = dot(random3(s + 1.0), x3);

     /* multiply d by w^4 */
     w *= w;
     w *= w;
     d *= w;

     /* 3. return the sum of the four surflets */
     return dot(d, vec4(52.0));
}

/* const matrices for 3d rotation */
const mat3 rot1 = mat3(-0.37, 0.36, 0.85,-0.14,-0.93, 0.34,0.92, 0.01,0.4);
const mat3 rot2 = mat3(-0.55,-0.39, 0.74, 0.33,-0.91,-0.24,0.77, 0.12,0.63);
const mat3 rot3 = mat3(-0.71, 0.52,-0.47,-0.08,-0.72,-0.68,-0.7,-0.45,0.56);

/* directional artifacts can be reduced by rotating each octave */
float simplex3d_fractal(vec3 m) {
    return   0.5333333*simplex3d(m*rot1)
            +0.2666667*simplex3d(2.0*m*rot2)
            +0.1333333*simplex3d(4.0*m*rot3)
            +0.0666667*simplex3d(8.0*m);
}

void main()
{
	vec2 p = v_vPosition_R.xy;
	vec3 p3 = vec3(p, iTime*0.025);

    float value;

    value = simplex3d_fractal(p3*16.0+32.0);
    value = 0.5 + 1.0*value;

	vec4 originalColor = v_vColour * texture2D( gm_BaseTexture, v_vTexcoord);

	if(originalColor.a != 0.0)
	{

	if (value > 0.2 && value <= 0.3)
	{
    gl_FragColor = vec4(0, 255, 255, 0.05);
	}

	if (value > 0.88 && value < 0.92)
	{
    gl_FragColor = vec4(128, 219, 165, 0.8);
	}

	if (value >= 0.92)
	{
    gl_FragColor = vec4(255, 255, 255, 1);
	}
    return;
	}

}