GLM Example - GLSL

example.frag

mat4 rotationMatrix(vec3 axis, float angle);

void main(void)
{
  mat4 mrot = rotationMatrix(vec3(0.0,1.0,0.0), radians(45.0)); 
 
  mat4 m1 = mat4(1.0);  
  mat4 m2 = mat4(2.0); 
 
  mat4 m3 = m1 * m2; 

  m3 *= mrot; 

  vec2 uv = gl_FragCoord.xy / iResolution.xy;
  gl_FragColor = m3 * vec4(uv,0.5+0.5*sin(iGlobalTime),1.0);
}

mat4 rotationMatrix(vec3 axis, float angle)
{
    axis = normalize(axis);
    float s = sin(angle);
    float c = cos(angle);
    float oc = 1.0 - c;
    
    return mat4(oc * axis.x * axis.x + c,           oc * axis.x * axis.y - axis.z * s,  oc * axis.z * axis.x + axis.y * s,  0.0,
                oc * axis.x * axis.y + axis.z * s,  oc * axis.y * axis.y + c,           oc * axis.y * axis.z - axis.x * s,  0.0,
                oc * axis.z * axis.x - axis.y * s,  oc * axis.y * axis.z + axis.x * s,  oc * axis.z * axis.z + c,           0.0,
                0.0,                                0.0,                                0.0,                                1.0);
}