import { CHUNK_SIZE, Dimension } from "$/client/components/dimension.ts";
import { Camera } from "$/client/components/camera.ts";
import { draw_terrain, set_current_texture } from "$/client/renderer/mod.ts";

// solid and cutout terrain, drawn before entities
export function render_dimension_opaque(dimension: Dimension, camera: Camera) {
	dimension.request_meshes(camera);
	dimension.update_translucent_sorting(camera);

	set_current_texture(dimension.image.tex);

	for (const chunk of dimension.chunks.values()) {
		const mesh = chunk.meshes.solid;
		if (mesh) {
			draw_terrain("solid", mesh.vertex_buffer, mesh.quad_count);
		}
	}

	for (const chunk of dimension.chunks.values()) {
		const mesh = chunk.meshes.cutout;
		if (mesh) {
			draw_terrain("cutout", mesh.vertex_buffer, mesh.quad_count);
		}
	}
}

// translucent terrain, drawn after entities so they show through water and glass.
// chunks go back to front, and each chunk's quads are already sorted back to front
export function render_dimension_translucent(dimension: Dimension, camera: Camera) {
	const distance_sq = (x: number, z: number) => {
		const dx = (x + 0.5) * CHUNK_SIZE - camera.x;
		const dz = (z + 0.5) * CHUNK_SIZE - camera.z;
		return dx * dx + dz * dz;
	};
	const chunks = [...dimension.chunks.values()]
		.filter((chunk) => chunk.meshes.translucent)
		.map((chunk) => ({ mesh: chunk.meshes.translucent!, distance: distance_sq(chunk.x, chunk.z) }))
		.sort((a, b) => b.distance - a.distance);

	set_current_texture(dimension.image.tex);

	for (const { mesh } of chunks) {
		draw_terrain("translucent", mesh.vertex_buffer, mesh.quad_count, mesh.index_buffer);
	}
}