#include <world/chunk.h>

#include <glad/glad.h>
#include <stddef.h>

void tc_upload_chunk(tc_chunk_s *chunk)
{
    // If the chunk has no mesh, it's probably only air.
    if(chunk->num_vertices == 0)
    {
        return;
    }
    
    if(chunk->vao != 0)             glDeleteVertexArrays(1, &chunk->vao);
    if(chunk->vbo != 0)             glDeleteBuffers(1, &chunk->vbo);
    
    glGenVertexArrays(1, &chunk->vao);
    glBindVertexArray(chunk->vao);
    
    glGenBuffers(1, &chunk->vbo);
    glBindBuffer(GL_ARRAY_BUFFER, chunk->vbo);
    
    glBufferData(GL_ARRAY_BUFFER, chunk->num_vertices * 5 * sizeof(float), NULL, GL_STATIC_DRAW);
    glBufferSubData(GL_ARRAY_BUFFER, 0,
        chunk->num_vertices * 3 * sizeof(float),
        chunk->vertex_positions
    );
    glBufferSubData(GL_ARRAY_BUFFER, 
        chunk->num_vertices * 3 * sizeof(float),
        chunk->num_vertices * 2 * sizeof(float),
        chunk->vertex_uvs
    );
    glBindVertexArray(0);
}

void tc_draw_chunkloader_zone(tc_chunkloader_s *loader)
{
    tc_chunklist_s     *list = &loader->chunklist;
    for(tc_chunklist_entry_s *current = list->first; current != NULL; current = current->next)
    {
        if(current->entity == NULL)
        {
            return;
        }
        tc_send_pointer_to_entity(current->entity, "draw", 0);
    }
    
}