varying vec4 diffuse,ambient;
varying vec3 normal,lightDir,halfVector;

void main()
{	
	/* first transform the normal into eye space and normalize the result */
	normal = normalize(gl_NormalMatrix * gl_Normal);
	
	/* now normalize the light's direction. Note that according to the
	OpenGL specification, the light is stored in eye space. Also since 
	we're talking about a directional light, the position field is actually 
	direction */
	lightDir = normalize(vec3(gl_LightSource[0].position));

	/* Normalize the halfVector to pass it to the fragment shader */
	halfVector = normalize(gl_LightSource[0].halfVector.xyz);
	
	/* Compute the diffuse, ambient and globalAmbient terms */
	diffuse = gl_FrontMaterial.diffuse * gl_LightSource[0].diffuse;
	ambient = gl_FrontMaterial.ambient * gl_LightSource[0].ambient;
	ambient += gl_LightModel.ambient * gl_FrontMaterial.ambient;
	
		
	gl_Position = ftransform();	
} 
