Files
phos-neo/engine/world_generation/src/mesh_generator.rs
Amatsugu 0bcf65b0b1 fixes to uvs
wip on custom chunk shader
2024-04-02 23:31:45 -04:00

150 lines
3.5 KiB
Rust

use crate::hex_utils::HexCoord;
use crate::{
hex_utils::{offset3d_to_world, INNER_RADIUS, OUTER_RADIUS},
prelude::*,
};
use bevy::{
prelude::*,
render::{
mesh::{Indices, PrimitiveTopology},
render_asset::RenderAssetUsages,
},
};
use std::vec::Vec;
const HEX_CORNERS: [Vec3; 6] = [
Vec3::new(0., 0., OUTER_RADIUS),
Vec3::new(INNER_RADIUS, 0., 0.5 * OUTER_RADIUS),
Vec3::new(INNER_RADIUS, 0., -0.5 * OUTER_RADIUS),
Vec3::new(0., 0., -OUTER_RADIUS),
Vec3::new(-INNER_RADIUS, 0., -0.5 * OUTER_RADIUS),
Vec3::new(-INNER_RADIUS, 0., 0.5 * OUTER_RADIUS),
];
pub fn generate_chunk_mesh(chunk: &Chunk, map: &Map) -> Mesh {
let vertex_count: usize = Chunk::SIZE * Chunk::SIZE * 6;
let mut verts = Vec::with_capacity(vertex_count);
let mut uvs = Vec::with_capacity(vertex_count);
let mut indices = Vec::with_capacity(vertex_count);
for z in 0..Chunk::SIZE {
for x in 0..Chunk::SIZE {
let height = chunk.points[x + z * Chunk::SIZE];
let off_pos = Vec3::new(x as f32, height, z as f32);
let tile_pos = offset3d_to_world(off_pos);
let coord = HexCoord::from_offset(
IVec2::new(x as i32, z as i32) + (chunk.chunk_offset * Chunk::SIZE as i32),
);
let n = map.get_neighbors(&coord);
create_tile(
tile_pos,
&n,
&mut verts,
&mut uvs,
&mut indices,
((x + z * Chunk::SIZE) % 32) as u32,
);
}
}
let mesh = Mesh::new(
PrimitiveTopology::TriangleList,
RenderAssetUsages::MAIN_WORLD | RenderAssetUsages::RENDER_WORLD,
)
.with_inserted_attribute(Mesh::ATTRIBUTE_POSITION, verts)
.with_inserted_attribute(Mesh::ATTRIBUTE_UV_0, uvs)
.with_inserted_indices(Indices::U32(indices))
.with_duplicated_vertices()
.with_computed_flat_normals();
return mesh;
}
//TODO: figure out texture index
fn create_tile(
pos: Vec3,
neighbors: &[Option<f32>; 6],
verts: &mut Vec<Vec3>,
uvs: &mut Vec<Vec2>,
indices: &mut Vec<u32>,
texture_index: u32,
) {
let tex_x = texture_index % 11;
let tex_y = texture_index / 11;
let x_min = tex_x as f32 / 11.;
let y_min = tex_y as f32 / 8.;
const TX_UNIT: Vec2 = Vec2::new(1. / 11., 1. / 8.);
let uv_offset = Vec2::new(x_min + TX_UNIT.x / 2., y_min + TX_UNIT.y / 2.);
let idx = verts.len() as u32;
uvs.push(uv_offset);
verts.push(pos);
for i in 0..6 {
let p = pos + HEX_CORNERS[i];
verts.push(p);
let uv = (HEX_CORNERS[i].xz() * TX_UNIT / 2.) + uv_offset;
uvs.push(uv);
indices.push(idx);
indices.push(idx + 1 + i as u32);
indices.push(idx + 1 + ((i as u32 + 1) % 6));
}
for i in 0..neighbors.len() {
let cur_n = neighbors[i];
match cur_n {
Some(n_height) => {
if n_height < pos.y {
create_tile_wall(
pos,
i,
n_height,
verts,
uvs,
indices,
Vec2::new(x_min, y_min),
Vec2::new(x_min + TX_UNIT.x, y_min + TX_UNIT.y),
);
}
}
_ => {}
}
}
}
fn create_tile_wall(
pos: Vec3,
dir: usize,
height: f32,
verts: &mut Vec<Vec3>,
uvs: &mut Vec<Vec2>,
indices: &mut Vec<u32>,
tx_min: Vec2,
tx_max: Vec2,
) {
let p1 = HEX_CORNERS[(dir) % 6] + pos;
let p2 = HEX_CORNERS[(dir + 1) % 6] + pos;
let p3 = Vec3::new(p1.x, height, p1.z);
let p4 = Vec3::new(p2.x, height, p2.z);
let idx = verts.len() as u32;
verts.push(p1);
verts.push(p2);
verts.push(p3);
verts.push(p4);
indices.push(idx);
indices.push(idx + 2);
indices.push(idx + 1);
indices.push(idx + 1);
indices.push(idx + 2);
indices.push(idx + 3);
//TODO: scale texture based on height
uvs.push(tx_min);
uvs.push(Vec2::new(tx_max.x, tx_min.y));
uvs.push(Vec2::new(tx_min.x, tx_max.y));
uvs.push(tx_max);
}