#version 450
#extension GL_ARB_separate_shader_objects : enable

struct DataTransferObject
{
  vec4 frag_color;
  vec2 frag_texture_coord;
  vec3 normal;
};

layout(location = 0) in DataTransferObject in_dto;

layout(location = 0) out vec4 out_color;

layout(set = 0, binding = 1) uniform UBODirectionalLight
{
  vec3 direction;
  vec4 color;
} ubo_directional_light;

layout(set = 1, binding = 1) uniform sampler2D texture_sampler;

void
main()
{
  float diffuse_factor =
    max(dot(in_dto.normal, -ubo_directional_light.direction), 0.0);

  vec4 diff_samp = texture(texture_sampler, in_dto.frag_texture_coord);
  vec4 ambient = vec4(vec3(in_dto.frag_color), diff_samp.a);
  vec4 diffuse =
    vec4(vec3(ubo_directional_light.color * diffuse_factor), diff_samp.a);

  diffuse *= diff_samp;
  ambient *= diff_samp;

  out_color = (ambient + diffuse);
}