use crate::render::DrawCall;
use crate::world::World;

pub fn render_system(world: &World) -> Vec<DrawCall>
{
    let all_entities = world.entities.all_entities();

    all_entities
        .iter()
        .filter_map(|&entity| {
            let transform = world.transforms.get(entity)?;
            let mesh_component = world.meshes.get(entity)?;

            Some(DrawCall {
                vertex_buffer: mesh_component.mesh.vertex_buffer.clone(),
                index_buffer: mesh_component.mesh.index_buffer.clone(),
                num_indices: mesh_component.mesh.num_indices,
                model: transform.to_matrix(),
                pipeline: mesh_component.pipeline,
            })
        })
        .collect()
}