#include "model_vs.glsl"

// lights
#include "light.glsl"

void main() {
    vec3 objPos = get_object_pos();
    
    v_normal_ws = normalize(vec3(att_instanced_matrix * vec4(v_normal, 0.))); // normal to world/model space
    v_normal = normalize(v_normal);
    v_position = att_position;
    v_texcoord = att_texcoord;
    v_texcoord2 = att_texcoord2;
    v_color = att_color;
    mat4 modelView = view * att_instanced_matrix;
    mat4 l_model = att_instanced_matrix;
    v_position_ws = (l_model * vec4( objPos, 1.0 )).xyz;

    setup_billboards(modelView, l_model);
    
    v_position_ws = (l_model * vec4( objPos, 1.0 )).xyz;
    v_tangent = normalize(mat3(att_instanced_matrix) * att_tangent.xyz);

    #if 0
      // compute tangent T and bitangent B
      vec3 Q1 = dFdx(att_position);
      vec3 Q2 = dFdy(att_position);
      vec2 st1 = dFdx(att_texcoord);
      vec2 st2 = dFdy(att_texcoord);

      vec3 T = normalize(Q1*st2.t - Q2*st1.t);
      vec3 B = normalize(-Q1*st2.s + Q2*st1.s);
      vec3 binormal = B;
    #else
        vec3 binormal = cross(att_normal, att_tangent.xyz) * att_tangent.w;
    #endif
    
    v_binormal = normalize(mat3(att_instanced_matrix) * binormal);
    
    vec4 finalPos = modelView * vec4( objPos, 1.0 );
    vec3 to_camera = normalize( -finalPos.xyz );
    v_to_camera = mat3( inv_view ) * to_camera;
    v_vertcolor = lighting();
    gl_Position = P * finalPos;
    do_shadow();
}