​

uniform float time;

​

varying vec2 vTexCoord;

varying vec3 vNormal;

​

void main(){

  //rotateZ is time. so i can multiply them with that

  // fix: pass precomputed sin and cos as array from draw loop so it doesnt have to do them 4 times per pixel (doesnt seem to impact performance rn thooo)

  mat3 rotate = mat3(

    cos(time), sin(time), 0.0, // first column (not row!)

    -sin(time),cos(time), 0.0, // second column

    0.0, 0.0, 1.0  // third column

  );

  mat3 rotx = mat3( //this is just precomputed rotation of 1 rad

    1.0, 0.0,  0.0, 

    0.0, 0.54, -0.84, 

    0.0, 0.84, 0.54  

  );

  vec3 rotNormal = vNormal * rotate * rotx;

  // vec3 color = vec3(vTexCoord, 1.0);

  vec3 color = max(rotNormal,0.0);

  vec3 cmy;

  cmy.r = 1.0 - max(color.r-color.g-color.b, 0.0);

  cmy.g = 1.0 - max(color.g-color.r-color.b, 0.0);

  cmy.b = 1.0 - max(color.b-color.r-color.g, 0.0);

  gl_FragColor = vec4(cmy, 1.0);

  // gl_FragColor = vec4(1.0,0.0,0.0, 1.0);

}