From 11ceb6ebc768f9f8b6c731ec36cad0dc83c2d4b4 Mon Sep 17 00:00:00 2001
From: CDaut <git@cdaut.de>
Date: Fri, 17 Nov 2023 20:44:21 +0100
Subject: [PATCH] main render loop

---
 Cargo.toml      |  5 ++---
 src/geometry.rs | 27 +++++++++++++++++++++++++++
 src/main.rs     | 14 ++++++++++----
 src/renderer.rs | 24 +++++++++++++++++++++++-
 4 files changed, 62 insertions(+), 8 deletions(-)
 create mode 100644 src/geometry.rs

diff --git a/Cargo.toml b/Cargo.toml
index 7665320..c2e914f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,5 @@ edition = "2021"
 [dependencies]
 easy-gltf = "1.1.1"
 clap = { version = "4.4.8", features = ["derive"] }
-
-[alias]
-runx = "run /home/clemens/repositorys/raytrace-rs/scenes/cube_on_plane.glb 0"
\ No newline at end of file
+cgmath = "0.18.0"
+rayon = "1.8.0"
\ No newline at end of file
diff --git a/src/geometry.rs b/src/geometry.rs
new file mode 100644
index 0000000..ad7626f
--- /dev/null
+++ b/src/geometry.rs
@@ -0,0 +1,27 @@
+use cgmath::Vector3;
+use easy_gltf::Camera;
+use easy_gltf::model::Triangle;
+
+pub struct Ray {
+    source: Vector3<f64>,
+    direction: Vector3<f64>,
+}
+
+pub trait Intersectable {
+    /*
+    tests whether the ray intersects the Intersectable.
+    returns: The intersection point or empty if there is none
+     */
+    fn test_isec(&self, ray: &Ray) -> Option<Vector3<f32>>;
+}
+
+impl Intersectable for Triangle {
+    //perform muller trumbore intersection
+    fn test_isec(&self, ray: &Ray) -> Option<Vector3<f32>> {
+        todo!()
+    }
+}
+
+pub fn construct_rays(camera: &Camera) -> Vec<Ray> {
+    todo!()
+}
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 1e49cba..29b1d1b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,21 @@
 mod renderer;
+mod geometry;
 
 use std::string::String;
 use clap::{Parser};
+use easy_gltf::Scene;
 use crate::renderer::render;
 
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None)]
 struct Args {
     gltf_file_path: String,
-    //which scene to use in the gltf file
-    scene_index: u32,
+    /// which scene to use in the gltf file
+    #[arg(short, long)]
+    scene_index: usize,
+    /// which camera to render from
+    #[arg(short, long)]
+    camera_index: usize,
 }
 
 fn main() {
@@ -17,10 +23,10 @@ fn main() {
     let args = Args::parse();
 
     //load gltf scene
-    let scenes = easy_gltf::load(
+    let scenes: &Vec<Scene> = &easy_gltf::load(
         &args.gltf_file_path)
         .expect(&*format!("Failed to load glTF file {}", &args.gltf_file_path));
 
-    render(scenes, args.scene_index)
+    render(scenes, args.scene_index, args.camera_index)
 }
 
diff --git a/src/renderer.rs b/src/renderer.rs
index 1ea7884..401d6b6 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -1,4 +1,26 @@
+use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use easy_gltf::model::{Mode};
 use easy_gltf::Scene;
+use crate::geometry::{construct_rays, Intersectable, Ray};
 
-pub fn render(scenes: Vec<Scene>, scene_idx: u32) {
+
+pub fn render(scenes: &Vec<Scene>, scene_idx: usize, camera_idx: usize) {
+    //construct all rays and cast them all
+    let rays: Vec<Ray> = construct_rays(&scenes[scene_idx].cameras[camera_idx]);
+    rays.into_par_iter().for_each(|ray| {
+        //test intersection with all models in the scene
+        //TODO: Improve, to avoid iterating all models
+        scenes[scene_idx].models.iter().for_each(|model| {
+            match model.mode() {
+                Mode::Triangles => {
+                    //in triangle mode there will always be a triangle vector
+                    let triangles = model.triangles().unwrap();
+                    triangles.iter().for_each(|triangle| {
+                        triangle.test_isec(&ray);
+                    });
+                }
+                _ => { panic!("Unable to render model in mode {:?}", model.mode()) }
+            }
+        });
+    });
 }
\ No newline at end of file