OpenGL GLSL uniform branching against multiple shaders

Question

I read a lot of articles about homogeneous expressions that relate to branching in order to change the behavior of large "shaders" shaders. I started working with uber shader (opengl lwjgl), but then I realized that the simple act of adding an if statement given by the uniform in the fragment shader that performs simple calculations reduced my fps by 5 compared to individual shaders without uniform if statements. I have not set a limit on my fps limit, it just refreshes as quickly as possible. I'm going to add a normal display and a parallax display, and I see two routes:

Uber vertex shader:

#version 400 core

layout(location = 0) in vec3 position;
layout(location = 1) in vec2 textureCoords;
layout(location = 2)in vec3 normal;
**UNIFORM float RenderFlag;** 


void main(void){

if(RenderFlag ==0){
 //Calculate outVariables for normal mapping to the fragment shader
}

if(RenderFlag ==1){
//Calcuate outVariables for parallax mapping to the fragment shader
}

gl_Position = MVPmatrix *vec4(position,1);



}

Uber barcode:

layout(location = 0) in vec3 position;
layout(location = 1) in vec2 textureCoords;
layout(location = 2)in vec3 normal;
**UNIFORM float RenderFlag;** 
**UNIFORM float reflectionFlag;** // if set either of the 2 render modes               
will have some reflection of the skybox added to it, like reflective   
surface.

void main(void){
if(RenderFlag ==0){
  //display normal mapping


  if(reflectionFlag){
     vec4 reflectColor = texture(cube_texture, ReflectDirR) ;
     //add reflection color to final color and output

  }

}
if(RenderFlag ==1){
//display parrallax mapping
if(reflectionFlag){
    vec4 reflectColor = texture(cube_texture, ReflectDirR) ;

   //add reflection color to final color and output
   }
}
gl_Position = MVPmatrix *vec4(position,1);



}

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finalColor = finalColor + reflectionColor * X 
where X = a uniform variable, if none X == 0, if Reflection X==some amount.

Answer 1

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