#type vertex
#version 410 core

layout(location = 0) in vec3 v_position;
layout(location = 1) in vec3 v_normal;
layout(location = 2) in vec2 v_UV;

out vec3 normal;
out vec2 uv;

uniform mat4 u_viewMatrix;
uniform mat4 u_worldMatrix;

void main()
{
    uv = v_UV;
    normal = mat3(u_worldMatrix) * v_normal; // transform normals into world space

    gl_Position = u_viewMatrix * u_worldMatrix * vec4(v_position, 1.0);
}

#type fragment
#version 410 core

layout(location = 0) out vec4 fragColor;
layout(location = 1) out int objectID;

in vec3 normal;
in vec2 uv;

uniform sampler2D u_Texture;
uniform int u_objectID;

void main()
{
    vec3 lightDir = normalize(vec3(1.0, 7.0, 3.0)) * 0.2f + 0.8f;
    float light = clamp(dot(normalize(normal), lightDir), 0.1, 1.0);

    vec4 texColor = texture(u_Texture, uv);

    fragColor = vec4(texColor.rgb * light, texColor.a);
    // fragColor = vec4(uv.r, uv.g, 0, 1);
    objectID = u_objectID;
}