mesh loading, broken mesh

src/load_model.rs

@@ -0,0 +1,60 @@
+use anyhow::Result;
+
+use std::fs::File;
+use std::collections::HashMap;
+use std::io::BufReader;
+
+use crate::app_data;
+use crate::vertex;
+
+use cgmath::{vec3, vec2};
+
+pub fn load_model(data: &mut app_data::AppData) -> Result<()> {
+    // Model
+
+    let mut reader = BufReader::new(File::open("./resources/viking_room.obj").expect("file not found"));
+
+    let (models, _) = tobj::load_obj_buf(
+        &mut reader,
+        &tobj::LoadOptions {
+            triangulate: true,
+            ..Default::default()
+        },
+        |_| Ok(Default::default()),
+    )?;
+
+    // Vertices / Indices
+
+    let mut unique_vertices = HashMap::new();
+
+    for model in &models {
+        for index in &model.mesh.indices {
+            let pos_offset = (3 * index) as usize;
+            let tex_coord_offset = (2 * index) as usize;
+
+            let vertex = vertex::Vertex {
+                pos: vec3(
+                    model.mesh.positions[pos_offset],
+                    model.mesh.positions[pos_offset + 1],
+                    model.mesh.positions[pos_offset + 2],
+                ),
+                color: vec3(1.0, 1.0, 1.0),
+                tex_coord: vec2(
+                    model.mesh.texcoords[tex_coord_offset],
+                    1.0 - model.mesh.texcoords[tex_coord_offset + 1],
+                ),
+            };
+
+            if let Some(index) = unique_vertices.get(&vertex) {
+                data.indices.push(*index as u32);
+            } else {
+                let index = data.vertices.len();
+                unique_vertices.insert(vertex, index);
+                data.vertices.push(vertex);
+                data.indices.push(index as u32);
+            }
+        }
+    }
+
+    Ok(())
+}