Vertex shader example

attribute vec3 vertex;
attribute vec3 normal;

uniform mat4 _mvProj;
uniform mat3 _norm;

varying vec3 vColor;
varying vec3 localPos;

#pragma include "light.glsl"

// constants
vec3 materialColor = vec3(1.0,0.7,0.8);
vec3 specularColor = vec3(1.0,1.0,1.0);

void main(void) {
    // compute position
    gl_Position = _mvProj * vec4(vertex, 1.0);
    
    localPos = vertex;
    
    // compute light info
    vec3 n = normalize(_norm * normal);
    vec3 diffuse;
    float specular;
    float glowingSpecular = 50.0;
    getDirectionalLight(n, _dLight, glowingSpecular, diffuse, specular);
    vColor = max(diffuse,_ambient.xyz)*materialColor+specular*specularColor+_ambient;
}

Fragment shader example

#ifdef GL_ES
precision highp float;
#endif

uniform vec3 BrickColor, MortarColor;
uniform vec3 BrickSize;
uniform vec3 BrickPct;

varying vec3 vColor;
varying vec3 localPos;
void main()
{
    vec3 color;
	vec3 position, useBrick;
	

	position = localPos / BrickSize.xyz;

	if (fract(position.y * 0.5) > 0.5){
		position.x += 0.5;
        position.z += 0.5;
	}
    
	position = fract(position);

	useBrick = step(position, BrickPct.xyz);

	color = mix(MortarColor, BrickColor, useBrick.x * useBrick.y * useBrick.z);
	color *= vColor;

	gl_FragColor = vec4(color, 1.0);
}