better square function

Fragment.glsl

@@ -1,4 +1,5 @@
 #version 330 core
+
 out vec4 pixColor;
 
 uniform int iterationCount;
@@ -6,22 +7,22 @@ uniform float divergeThreshold;
 
 in vec2 complexPos;
 
-vec2 mul(in vec2 a, in vec2 b) {
-    return vec2(a.x * b.x - a.y * b.y, a.y * b.x + a.x * b.y);
-}
-
 vec3 getColor(in float value){
     vec3 red = vec3(0.5, 0, 0);
     vec3 blue = vec3(0, 0, 0.5);
     return value * red + (1 - value) * blue;
 }
 
+vec2 square(in vec2 c){
+    return vec2(c.x * c.x - c.y * c.y, 2 * c.x * c.y);
+}
+
 void main(){
 
     vec2 z;
     float stepsNeeded = 0;
     while (stepsNeeded < iterationCount && length(z) < divergeThreshold){
-        z = mul(z, z) + complexPos;
+        z = square(z) + complexPos;
         ++stepsNeeded;
     }