/* Copyright (c) 2023, Mobica Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 the "License";
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#version 450

layout (location = 0) in vec3 inNormal;
layout (location = 1) in vec3 inColor;
layout (location = 2) in vec3 inViewVec;
layout (location = 3) in vec3 inLightVec;

layout (location = 0) out vec4 outFragColor;

void main() 
{
	float ambientStrength = 0.2f;
	vec3 ambient = ambientStrength * vec3(1.0f, 1.0f, 1.0f);

	vec3 N = normalize(inNormal);
	vec3 L = normalize(inLightVec);
	vec3 V = normalize(inViewVec);
	vec3 R = reflect(-L, N);

	vec3 diffuse = max(dot(N,L),0.0f) * vec3(1.0f);

	vec3  specular = pow(max(dot(R, V), 0.0f), 64.0f) * vec3(0.65f);

	vec3 result = (ambient + diffuse) * inColor + specular;
	outFragColor = vec4(result, 1.0f);
}