obj models

src/core/resources.rs

@@ -0,0 +1,124 @@
+use std::io::{BufReader, Cursor};
+use wgpu::util::DeviceExt;
+
+use crate::core::model::{Material, Mesh, Model, ModelVertex};
+use crate::core::texture::Texture;
+
+pub async fn load_string(file_name: &str) -> anyhow::Result<String> {
+    let path = std::path::Path::new(env!("OUT_DIR"))
+        .join("res")
+        .join(file_name);
+    let txt = std::fs::read_to_string(path)?;
+
+    return Ok(txt);
+}
+
+pub async fn load_binary(file_name: &str) -> anyhow::Result<Vec<u8>> {
+    let path = std::path::Path::new(env!("OUT_DIR"))
+        .join("res")
+        .join(file_name);
+    let data = std::fs::read(path)?;
+
+    return Ok(data);
+}
+
+pub async fn load_texture(
+    file_name: &str,
+    device: &wgpu::Device,
+    queue: &wgpu::Queue,
+) -> anyhow::Result<Texture> {
+    let data = load_binary(file_name).await?;
+    Texture::from_bytes(device, queue, &data, file_name)
+}
+
+pub async fn load_model(
+    file_name: &str,
+    device: &wgpu::Device,
+    queue: &wgpu::Queue,
+    layout: &wgpu::BindGroupLayout,
+) -> anyhow::Result<Model> {
+    let obj_text = load_string(file_name).await?;
+    let obj_cursor = Cursor::new(obj_text);
+    let mut obj_reader = BufReader::new(obj_cursor);
+
+    let (models, obj_materials) = tobj::load_obj_buf_async(
+        &mut obj_reader,
+        &tobj::LoadOptions {
+            triangulate: true,
+            single_index: true,
+            ..Default::default()
+        },
+        |p| async move {
+            let mat_text = load_string(&p).await.unwrap();
+            tobj::load_mtl_buf(&mut BufReader::new(Cursor::new(mat_text)))
+        },
+    )
+    .await?;
+
+    let mut materials = Vec::new();
+    for m in obj_materials? {
+        let diffuse_texture = load_texture(&m.diffuse_texture, device, queue).await?;
+        let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
+            layout,
+            entries: &[
+                wgpu::BindGroupEntry {
+                    binding: 0,
+                    resource: wgpu::BindingResource::TextureView(&diffuse_texture.view),
+                },
+                wgpu::BindGroupEntry {
+                    binding: 1,
+                    resource: wgpu::BindingResource::Sampler(&diffuse_texture.sampler),
+                },
+            ],
+            label: None,
+        });
+
+        materials.push(Material {
+            name: m.name,
+            diffuse_texture,
+            bind_group,
+        })
+    }
+
+    let meshes = models
+        .into_iter()
+        .map(|m| {
+            let vertices = (0..m.mesh.positions.len() / 3)
+                .map(|i| ModelVertex {
+                    position: [
+                        m.mesh.positions[i * 3],
+                        m.mesh.positions[i * 3 + 1],
+                        m.mesh.positions[i * 3 + 2],
+                    ],
+                    tex_coords: [m.mesh.texcoords[i * 2], m.mesh.texcoords[i * 2 + 1]],
+                    normal: [
+                        m.mesh.normals[i * 3],
+                        m.mesh.normals[i * 3 + 1],
+                        m.mesh.normals[i * 3 + 2],
+                    ],
+                })
+                .collect::<Vec<_>>();
+
+            let vertex_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+                label: Some(&format!("{:?} Vertex Buffer", file_name)),
+                contents: bytemuck::cast_slice(&vertices),
+                usage: wgpu::BufferUsages::VERTEX,
+            });
+            let index_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
+                label: Some(&format!("{:?} Index Buffer", file_name)),
+                contents: bytemuck::cast_slice(&m.mesh.indices),
+                usage: wgpu::BufferUsages::INDEX,
+            });
+
+            Mesh {
+                name: file_name.to_string(),
+                vertex_buffer,
+                index_buffer,
+                num_elements: m.mesh.indices.len() as u32,
+                material: m.mesh.material_id.unwrap_or(0),
+            }
+        })
+        .collect::<Vec<_>>();
+
+    return Ok(Model { meshes, materials });
+}