[GLSL] Weird lighting and Bump-Mapping

Newbie & Debugging Questions
#1

So I’ve implemented a lighting engine through GLSL, and it works flawlessly. But I wanted to add a bump-mapping system, only thing is its nothing like the GL_LIGHT system, and most of the tutorials are fitted to that.

How my light works is I make a Quad that takes the whole window, and acts as a canvas for the fragment shader that goes through the light positions, uniforms, and colors, then uses them to create colored lights.

pointLight.vs:

 #version 120
uniform vec2 lightLocation;
uniform vec3 lightColor;

void main(void) {
	float distance = length(lightLocation - gl_FragCoord.xy);
	float attenuation = 1.0 / distance;
	vec4 color = vec4(attenuation, attenuation, attenuation, pow(attenuation, 3)) * vec4(lightColor, 1);
	
	gl_FragColor = color;
}

Steps to run it (basically):

For each light:

  • Enable stencil buffer
  • For each block:
    • Calculate & render shadow to STENCIL BUFFER
  • Disable stencil buffer
  • Draw lighting (using pixel shader) where stencil is empty
    For each block (again):
  • Draw block

I need a way to add bump-mapping to this kind of lighting, any suggestions?