#ifdef GL_ES
precision mediump float;
#endif

uniform vec4 U_AmbientMaterial;
uniform vec4 U_AmbientLight;

uniform vec4 U_LightPos;
uniform vec4 U_DiffuseMaterial;
uniform vec4 U_DiffuseLight;

uniform vec4 U_CameraPos;
uniform vec4 U_SpecularMaterial;
uniform vec4 U_SpecularLight;

varying vec4 V_Normal;
varying vec4 V_WorldPos;
void main()
{
	//ambient
	vec4 ambirntColor = U_AmbientMaterial*U_AmbientLight;

	//diffuse
	vec3 L = normalize(U_LightPos.xyz - vec3(0));
	vec3 n = normalize(V_Normal.xyz);
	float diffuseIntensity = max(0.0, dot(L,n));
	vec4 diffuseColor = U_DiffuseMaterial * U_DiffuseLight * diffuseIntensity;

	//specular
	vec4 specularColor = vec4(0);
	if(diffuseIntensity > 0.0) {
		vec3 sL = normalize(vec3(0) - U_LightPos.xyz); //ΘλΙδΉβΟί
		vec3 rd = normalize(reflect(sL, n));
		vec3 vd = normalize((U_CameraPos - V_WorldPos).xyz);
		float specularIntensity = pow(max(0.0, dot(vd, rd)),32.0);
		specularColor = U_SpecularMaterial * U_SpecularLight * specularIntensity;
	}

	gl_FragColor=ambirntColor + diffuseColor + specularColor;
}