2021-32-bit-holiday-jam/src/renderable_model.rs

151 lines
3.9 KiB
Rust

use byteorder::{ByteOrder, LittleEndian};
use std::convert::TryInto;
use std::ffi::c_void;
use crate::gpu_buffers::*;
// Takes ownership of mesh stuff in an opaque way that's abstract
// from the IQM model. IQM is zero-copy, but this is not.
// Since it's opaque, I can drop in a VBO/IBO setup when I'm not lazy.
pub struct RenderableMesh {
first_triangle: usize,
num_triangles: i32,
pub name: Vec <u8>,
}
pub struct RenderableModel {
num_pos: usize,
num_uv: usize,
vertexes: VertexBuffer,
indexes: IndexBuffer,
pub meshes: Vec <RenderableMesh>,
}
unsafe fn vertex_attrib_pointer (id: Option <u32>, num_coords: i32, float_offset: usize) {
const FALSE_U8: u8 = 0;
const FLOAT_SIZE: i32 = 4;
if let Some (id) = id {
gl::VertexAttribPointer (id, num_coords, gl::FLOAT, FALSE_U8, FLOAT_SIZE * num_coords, (float_offset * 4) as *const u8 as *const c_void);
}
}
pub type AttrMap = Vec <Option <u32>>;
pub mod attributes {
use iota::iota;
iota! {
pub const
POS: usize = iota;
, UV
, NORMAL
}
}
impl RenderableModel {
pub fn from_iqm (model: &inter_quake_model::Model) -> RenderableModel {
let pos_bytes = model.get_vertex_slice (inter_quake_model::types::POSITION);
let uv_bytes = model.get_vertex_slice (inter_quake_model::types::TEXCOORD);
let normal_bytes = model.get_vertex_slice (inter_quake_model::types::NORMAL);
let num_pos = pos_bytes.len () / 4;
let num_uv = uv_bytes.len () / 4;
let num_normal = normal_bytes.len () / 4;
let num_vertexes = num_pos / 3;
assert_eq! (num_vertexes * 2, num_uv);
assert_eq! (num_vertexes * 3, num_normal);
let mut vertex_vec = vec! [0.0; num_pos + num_uv + num_normal];
LittleEndian::read_f32_into (pos_bytes, &mut vertex_vec [0..num_pos]);
LittleEndian::read_f32_into (uv_bytes, &mut vertex_vec [num_pos..num_pos + num_uv]);
LittleEndian::read_f32_into (normal_bytes, &mut vertex_vec [num_pos + num_uv..num_pos + num_uv + num_normal]);
let vertexes = VertexBuffer::from_slice (&vertex_vec);
let index_slice = model.get_all_indexes ();
let indexes = IndexBuffer::from_slice_u8 (index_slice);
let max_index: usize = indexes.max ().try_into ().unwrap ();
assert! (max_index * 3 < num_pos);
assert! (max_index * 2 < num_uv);
assert! (max_index * 3 < num_normal);
let meshes = model.meshes.iter ().enumerate ()
.map (|(i, mesh)| RenderableMesh {
first_triangle: mesh.first_triangle.try_into ().unwrap (),
num_triangles: mesh.num_triangles.try_into ().unwrap (),
name: model.get_mesh_name (i).to_owned (),
})
.collect ();
Self {
num_pos,
num_uv,
vertexes,
indexes,
meshes,
}
}
pub fn draw_ranged <F> (&self,
attrs: &AttrMap, callback: F,
start: usize, end: usize
)
where F: Fn (usize) -> bool
{
self.vertexes.bind ();
self.indexes.bind ();
unsafe {
use attributes::*;
vertex_attrib_pointer (attrs [POS], 3, 0);
vertex_attrib_pointer (attrs [UV], 2, self.num_pos);
vertex_attrib_pointer (attrs [NORMAL], 3, self.num_pos + self.num_uv);
}
for mesh_num in start..end {
if ! callback (mesh_num) {
continue;
}
let mesh = &self.meshes [mesh_num];
unsafe {
gl::DrawRangeElements (gl::TRIANGLES, 0, self.indexes.max (), mesh.num_triangles * 3, gl::UNSIGNED_INT, (mesh.first_triangle * 3 * 4) as *const u8 as *const c_void);
}
}
}
pub fn draw_all <F> (&self, attrs: &AttrMap, callback: F)
where F: Fn (usize) -> bool
{
self.draw_ranged (attrs, callback, 0, self.meshes.len ());
}
pub fn draw (&self, attrs: &AttrMap, mesh_num: usize)
{
self.draw_ranged (attrs, |_| true, mesh_num, mesh_num + 1);
}
pub fn num_meshes (&self) -> usize {
self.meshes.len ()
}
}
pub fn renderable_from_iqm_file <P> (filename: P) -> RenderableModel
where P: AsRef <std::path::Path>
{
let data = crate::file::load_small_file (filename, 1024 * 1024).unwrap ();
let model = inter_quake_model::Model::from_slice (&data).unwrap ();
RenderableModel::from_iqm (&model)
}