Irrlicht Engine

Code: Select all

void main()
{
  vec3 lightDir = (gl_ModelViewMatrix * gl_Vertex 
                   - gl_LightSource[0].position).xyz;

	// if the vertex is lit
	float dt = dot(lightDir, gl_NormalMatrix * gl_Normal);
	if ( dt <0.01 )
	{
		// don't move it
    	gl_Position = ftransform();
	}
	else 
	{
		// move it far, is the light direction
		vec4 fin = gl_ProjectionMatrix * (
                 gl_ModelViewMatrix * gl_Vertex 
                 + vec4(normalize(lightDir) * 100000.0, 0.0)
               );

		// if fin is behind the far plane
		if ( fin.z > fin.w )
      		fin.z = fin.w; // move to the far plane (needed for z-fail algo.)

		gl_Position = fin;
	}
}