//Fragment Shader
#version 330 core

in vec3 FragPos;
in vec3 Normal;

uniform vec3 objectColor;
uniform vec3 lightColor;
uniform vec3 lightPos;
uniform vec3 viewPos;

out vec4 FragColor;

void main()
{
//Diffuse calculations..
vec3 norm = normalize(Normal);
vec3 lightDir = normalize(lightPos - FragPos);
float diff = max(dot(norm, lightDir), 0.0);
vec3 diffuse = diff * lightColor;
//Ambient Light
float ambientStrength = 0.5;
vec3 ambient = ambientStrength * lightColor;
//Specular calculations..
float specularStrength = 0.5;
vec3 viewDir = normalize(viewPos - FragPos);
vec3 reflectDir = reflect(-lightDir, norm);
float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
vec3 specular = specularStrength * spec * lightColor;
//result color
vec3 result = (ambient + diffuse + specular) * objectColor;
//push output color
FragColor = vec4(result, 1.0);
}