add scene and rendering order

game/src/engine/game.rs

@@ -6,19 +6,15 @@ use std::{marker::PhantomData, time::Duration};
 
 use super::error::Error;
 
-pub trait Object<R: Renderer> {
-    fn update(&mut self, delta: Duration);
-    fn render(&mut self, r: &mut R);
-}
-
-pub trait Io<R: Renderer, O: Object<R>> {
-    fn run(&mut self, game: &mut Game<R, O>);
+pub trait Io<R: Renderer, G: Game<R>> {
+    fn run(&mut self, game: &mut G);
 }
 
 pub trait Renderer {
     fn draw_rect(&mut self, pos: V2, size: V2, color: Color);
     fn draw_point(&mut self, pos: V2, color: Color);
     fn draw_line(&mut self, from: V2, to: V2, color: Color);
+    fn draw_triangle(&mut self, triangle: Triangle2, color: Color);
     fn draw_triangles(&mut self, triangles: &[Triangle2], color: Color);
 }
 
@@ -36,34 +32,8 @@ pub enum Event {
     Exit,
 }
 
-pub struct Game<R: Renderer, O: Object<R>> {
-    _phantom_data: PhantomData<R>,
-    objects: Vec<O>,
-}
-
-impl<R: Renderer, O: Object<R>> Game<R, O> {
-    pub fn new() -> Result<Self, Error> {
-        Ok(Self {
-            _phantom_data: PhantomData,
-            objects: Vec::new(),
-        })
-    }
-
-    pub fn spawn(&mut self, object: O) {
-        self.objects.push(object);
-    }
-
-    pub fn update(&mut self, delta_time: Duration) {
-        for object in self.objects.iter_mut() {
-            object.update(delta_time);
-        }
-    }
-
-    pub fn render(&mut self, r: &mut R) {
-        for object in self.objects.iter_mut() {
-            object.render(r);
-        }
-    }
-
-    pub fn event(&mut self, event: Event) {}
+pub trait Game<R: Renderer> {
+    fn update(&mut self, delta_time: Duration);
+    fn render(&mut self, r: &mut R);
+    fn event(&mut self, event: Event);
 }

game/src/engine/math.rs

@@ -31,7 +31,7 @@ impl V3 {
         f64::sqrt(self.0.powi(2) + self.1.powi(2) + self.2.powi(2))
     }
 
-    pub fn unit(&self) -> V3 {
+    pub fn unit(&self) -> Self {
         self.map(|v| v / self.len())
     }
 
@@ -39,10 +39,14 @@ impl V3 {
         V3(func(self.0), func(self.1), func(self.2))
     }
 
-    pub fn rotate(&self, rot: V3) -> Self {
+    pub fn rotate(&self, rot: Self) -> Self {
         M3x3::new_rotate_z(rot.2)
             * (M3x3::new_rotate_y(rot.1) * (M3x3::new_rotate_x(rot.0) * *self))
     }
+
+    pub fn distance(&self, rhs: Self) -> f64 {
+        (*self - rhs).len()
+    }
 }
 
 impl Add for V3 {
@@ -125,6 +129,10 @@ impl Triangle3 {
     pub fn middle(&self) -> V3 {
         (self.0 + self.1 + self.2).map(|v| v / 3.0)
     }
+
+    pub fn points(&self) -> [V3; 3] {
+        [self.0, self.1, self.2]
+    }
 }
 
 struct M3x3([f64; 9]);

game/src/engine/mod.rs

@@ -4,14 +4,14 @@ mod error;
 mod game;
 mod math;
 mod r3d;
+mod scene;
 mod sdl_io;
 mod shapes;
-mod system;
 
 pub use error::*;
 pub use game::*;
 pub use math::*;
 pub use r3d::*;
+pub use scene::*;
 pub use sdl_io::*;
 pub use shapes::*;
-pub use system::*;

game/src/engine/scene.rs

@@ -0,0 +1,59 @@
+use crate::engine::{Color, Renderer, Shape, Triangle3, V3};
+
+pub struct DrawnTriangle {
+    triangle: Triangle3,
+    outline_color: Color,
+    fill_color: Color,
+}
+
+pub struct Scene {
+    objects: Vec<DrawnTriangle>,
+}
+
+impl Scene {
+    pub fn new() -> Self {
+        Self {
+            objects: Vec::new(),
+        }
+    }
+
+    pub fn render<R: Renderer>(&mut self, r: &mut R, camera: V3) {
+        self.objects.sort_by(|a, b| {
+            let a = a
+                .triangle
+                .points()
+                .map(|p| p.distance(camera))
+                .into_iter()
+                .min_by(|a, b| a.total_cmp(b))
+                .unwrap();
+            let b = b
+                .triangle
+                .points()
+                .map(|p| p.distance(camera))
+                .into_iter()
+                .min_by(|a, b| a.total_cmp(b))
+                .unwrap();
+            b.total_cmp(&a)
+        });
+
+        let drawn_triangles = self
+            .objects
+            .iter()
+            .map(|v| (v.triangle.project_2d(), v.outline_color, v.fill_color));
+        for (triangle, outline_color, fill_color) in drawn_triangles {
+            r.draw_triangle(triangle.clone(), fill_color);
+            r.draw_line(triangle.0, triangle.1, outline_color);
+            r.draw_line(triangle.0, triangle.2, outline_color);
+        }
+    }
+
+    pub fn draw_shape(&mut self, pos: V3, shape: &Shape, outline_color: Color, fill_color: Color) {
+        for triangle in shape.faces() {
+            self.objects.push(DrawnTriangle {
+                triangle: triangle.translate(pos),
+                outline_color,
+                fill_color,
+            })
+        }
+    }
+}

game/src/engine/sdl_io.rs

@@ -48,7 +48,7 @@ impl SdlIo {
         })
     }
 
-    pub fn run<O: game::Object<Self>>(&mut self, game: &mut game::Game<Self, O>) {
+    pub fn run(&mut self, game: &mut impl game::Game<Self>) {
         let mut event_pump = self.sdl_context.event_pump().unwrap();
 
         let mut time_before = Instant::now();
@@ -154,6 +154,21 @@ impl Renderer for SdlIo {
             .render_geometry(&vertices, None, VertexIndices::Sequential)
             .unwrap();
     }
+
+    fn draw_triangle(&mut self, triangle: Triangle2, color: Color) {
+        let vertices = [triangle.0, triangle.1, triangle.2]
+            .into_iter()
+            .map(|p| self.point_w2s(p))
+            .map(|p| Vertex {
+                position: p.into(),
+                color: color.into(),
+                tex_coord: FPoint::new(0.0, 0.0),
+            })
+            .collect::<Vec<_>>();
+        self.canvas
+            .render_geometry(&vertices, None, VertexIndices::Sequential)
+            .unwrap();
+    }
 }
 
 impl From<V2> for FPoint {

game/src/engine/system.rs

@@ -1,17 +0,0 @@
-use super::error::Error;
-
-
-pub trait System {
-
-    fn on_add(&self) -> Result<(), Error> {
-        Ok(())
-    }
-    
-    fn on_update(&self) -> Result<(), Error> {
-        Ok(())
-    }
-
-    fn on_remove(&self) -> Result<(), Error> {
-        Ok(())
-    }
-}

game/src/main.rs

@@ -1,51 +1,80 @@
 #![allow(dead_code)]
 
-use std::{f64, time::Duration};
+use std::time::Duration;
 
-use crate::engine::{Color, R3d, Shape, V3};
+use crate::engine::{Color, Renderer, Scene, Shape, V3};
 
 mod engine;
 mod vermiparous;
 
-enum MyObject {
-    Player { pos: V3, vel: V3 },
+struct Game {
+    objects: Vec<Object>,
 }
 
-impl<R: engine::Renderer> engine::Object<R> for MyObject {
+impl Game {
+    fn new() -> Self {
+        Self {
+            objects: Vec::new(),
+        }
+    }
+
+    fn spawn(&mut self, object: Object) {
+        self.objects.push(object);
+    }
+}
+
+impl<R: Renderer> engine::Game<R> for Game {
+    fn update(&mut self, delta_time: Duration) {
+        for object in &mut self.objects {
+            object.update(delta_time);
+        }
+    }
+
+    fn render(&mut self, r: &mut R) {
+        let mut scene = Scene::new();
+        for object in &mut self.objects {
+            object.render(&mut scene);
+        }
+        scene.render(r, V3(0.0, 0.0, -1.0));
+    }
+
+    fn event(&mut self, event: engine::Event) {}
+}
+
+enum Object {
+    Player { pos: V3, vel: V3 },
+    Obstacle { pos: V3, vel_z: f64 },
+    Ground { pos: V3, vel_z: f64 },
+}
+
+impl Object {
     fn update(&mut self, delta_time: Duration) {
         match self {
-            MyObject::Player { pos, vel } => {
+            Object::Player { pos, vel } => {
                 *pos += *vel * delta_time.as_secs_f64();
                 if pos.0 >= 2.1 {
                     pos.0 = -2.0;
                 }
             }
+            Object::Obstacle { pos, vel_z } => {
+                pos.2 += *vel_z * delta_time.as_secs_f64();
+            }
+            Object::Ground { pos, vel_z } => {
+                pos.2 += *vel_z * delta_time.as_secs_f64();
+            }
         }
     }
 
-    fn render(&mut self, r: &mut R) {
+    fn render(&mut self, scene: &mut Scene) {
         match self {
-            MyObject::Player { pos, .. } => {
-                let mut r3d = R3d::new(r);
-
-                for z in 0..10 {
-                    for x in -10..10 {
-                        r3d.draw_shape(
-                            V3(x as f64 * 0.1, -0.5, z as f64 * 0.1),
-                            &Shape::new_plane(V3(0.1, 0.0, 0.1)),
-                            Color::Cyan,
-                            Color::Black,
-                        );
-                    }
-                }
-
-                r3d.draw_shape(
+            Object::Player { pos, .. } => {
+                scene.draw_shape(
                     *pos + V3(0.0, 0.2, 0.0),
                     &Shape::new_cube(V3(0.2, 0.1, 0.2)),
                     Color::Green,
                     Color::Black,
                 );
-                r3d.draw_shape(
+                scene.draw_shape(
                     *pos + V3(-0.8, -0.2, 0.0),
                     &Shape::new_cube(V3(0.2, 0.2, 0.2))
                         .translate(V3(-0.1, -0.1, -0.1))
@@ -54,19 +83,37 @@ impl<R: engine::Renderer> engine::Object<R> for MyObject {
                     Color::Black,
                 );
             }
+            Object::Obstacle { pos, vel_z } => todo!(),
+            Object::Ground { pos, .. } => {
+                for z in 0..10 {
+                    for x in -10..10 {
+                        scene.draw_shape(
+                            V3(x as f64 * 0.1 + pos.0, pos.1, z as f64 * 0.1 + pos.2),
+                            &Shape::new_plane(V3(0.1, 0.0, 0.1)),
+                            Color::Cyan,
+                            Color::Black,
+                        );
+                    }
+                }
+            }
         }
     }
 }
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut sdl_io = engine::SdlIo::new()?;
-    let mut game = engine::Game::<engine::SdlIo, MyObject>::new()?;
+    let mut game = Game::new();
 
-    let player = MyObject::Player {
+    let player = Object::Player {
         pos: V3(-1.0, -0.1, 0.0),
         vel: V3(0.4, 0.0, 0.0),
     };
     game.spawn(player);
+    let ground = Object::Ground {
+        pos: V3(0.0, -0.3, -0.5),
+        vel_z: -0.1,
+    };
+    game.spawn(ground);
 
     sdl_io.run(&mut game);
     Ok(())