#ifdef GL_ES
precision mediump float;
#endif;
attribute vec4 position;
attribute vec4 texcoord;
attribute vec4 normal;
uniform mat4 ModelMatrix;
uniform mat4 ViewMatrix;
uniform mat4 ProjectionMatrix;
uniform mat4 IT_ModelMatrix;
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_SpecualrLight;
varying vec4 V_Color;
void main(){
	//ambient
	vec4 ambientColor = U_AmbientMaterial*U_AmbientLight;

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

	//spacular
	vec4 specularColor = vec4(0.0, 0.0, 0.0, 0.0);
	if(diffuseIntensity > 0) {
		vec3 L = normalize(U_LightPos.xyz - vec3(0)); //ΘλΙδΉβΟί
		vec3 worldPos = (ModelMatrix * position).xyz;
		vec3 vd = normalize(U_CameraPos.xyz - worldPos);
		vec3 halfVector = normalize(L+vd);
		float specularIntensity = pow(max(0.0, dot(halfVector, n)),4.0);
		specularColor = U_SpecularMaterial * U_SpecualrLight * specularIntensity;
	}

	V_Color = ambientColor + diffuseColor + specularColor;

	gl_Position = ProjectionMatrix * ViewMatrix * ModelMatrix * position;
}