// Fragment Shader: Bump mapping using normal map.
uniform sampler2D decaltex;
uniform sampler2D decalmap;

void main (void)
{
  vec4 mc = texture2D(decalmap,vec2(gl_FragCoord.xy)/4096.0).rgba;
  vec4 dc = texture2D(decaltex,gl_TexCoord[0].xy).rgba;

  mc.rgb = mix(mc.rgb,dc.rgb,dc.a);
  mc.a += dc.a;
  mc.a = clamp(mc.a,0.0,1.0);
    gl_FragColor = mc;
}