use crate::graphics::{
configure_vertex, graphics, resource, BufferBindingTarget, BufferUsage, VertexDescriptor,
};
use crate::{App, Context};
use core::marker::PhantomData;
pub struct Buffer<T: VertexDescriptor> {
_unsend: core::marker::PhantomData<*const ()>,
vbo: resource::Buffer,
vao: resource::VertexArray,
vertices: usize,
phantom: PhantomData<T>,
}
impl<T: VertexDescriptor> Buffer<T> {
pub fn new(_ctx: &Context<impl App>) -> Buffer<T> {
let gl = graphics().gl();
let vao = gl.create_vertex_array();
gl.bind_vertex_array(Some(vao));
let vbo = gl.create_buffer();
gl.bind_buffer(BufferBindingTarget::ArrayBuffer, Some(vbo));
configure_vertex::<T>(&T::ATTRIBUTES, gl);
gl.bind_vertex_array(None);
Buffer {
_unsend: core::marker::PhantomData,
vbo,
vao,
vertices: 0,
phantom: PhantomData,
}
}
pub fn set_data(&mut self, items: &[T]) {
self.vertices = items.len();
let gl = graphics().gl();
gl.bind_buffer(BufferBindingTarget::ArrayBuffer, Some(self.vbo));
gl.buffer_data(BufferBindingTarget::ArrayBuffer, items, BufferUsage::StaticDraw);
}
pub fn draw(&self) {
let gl = graphics().gl();
gl.bind_vertex_array(Some(self.vao));
if T::INSTANCING.is_instanced() {
gl.draw_arrays_instanced(T::DRAW_MODE, 0, T::INSTANCING.count, self.vertices as i32);
} else {
gl.draw_arrays(T::DRAW_MODE, 0, self.vertices as i32);
}
}
}
impl<T: VertexDescriptor> Drop for Buffer<T> {
fn drop(&mut self) {
let gl = graphics().gl();
gl.delete_buffer(self.vbo);
gl.delete_vertex_array(self.vao);
}
}
impl<T: VertexDescriptor> AsRef<Buffer<T>> for Buffer<T> {
fn as_ref(&self) -> &Buffer<T> {
self
}
}