renders the diablo model

src/main.rs

@@ -37,14 +37,23 @@ fn main() {
     let mut framebuffer = TGAImage::new(w, h, TGAFormat::RGB);
     let model = Model::from_obj("diablo3_pose.obj");
 
-    dbg!(model);
+    dbg!(model.verts.len());
+    let mut max_face = 0usize;
+    let mut min_face = usize::MAX;
 
-    framebuffer
-        .write_file("framebuffer.tga", true, true)
-        .unwrap();
+    for f in model.faces.iter() {
+        for &f in f.iter() {
+            max_face = f.max(max_face);
+            min_face = f.min(min_face);
+        }
+    }
+
+    model.render_wireframe(&mut framebuffer);
+
+    framebuffer.write_file("diablo.tga", true, true).unwrap();
 }
 
-fn baseline(framebuffer: &mut TGAImage) {
+fn _baseline(framebuffer: &mut TGAImage) {
     let ax = 7;
     let ay = 3;
     let bx = 12;
@@ -56,9 +65,9 @@ fn baseline(framebuffer: &mut TGAImage) {
     framebuffer.set(bx, by, WHITE);
     framebuffer.set(cx, cy, WHITE);
 
-    let a = Point::new(ax, ay);
-    let b = Point::new(bx, by);
-    let c = Point::new(cx, cy);
+    let a = Point2i::newu(ax, ay);
+    let b = Point2i::newu(bx, by);
+    let c = Point2i::newu(cx, cy);
 
     line(a, b, framebuffer, BLUE);
     line(c, b, framebuffer, GREEN);
@@ -66,17 +75,17 @@ fn baseline(framebuffer: &mut TGAImage) {
     line(a, c, framebuffer, RED);
 }
 
-fn bench(fb: &mut TGAImage) {
+fn _bench(fb: &mut TGAImage) {
     let mut rng = rand::rng();
 
     for _ in 0..1 << 24 {
         let ax = rng.random_range(0..fb.width);
         let ay = rng.random_range(0..fb.height);
-        let a = Point::new(ax, ay);
+        let a = Point2i::newu(ax, ay);
 
         let bx = rng.random_range(0..fb.width);
         let by = rng.random_range(0..fb.height);
-        let b = Point::new(bx, by);
+        let b = Point2i::newu(bx, by);
 
         line(
             a,
@@ -87,7 +96,7 @@ fn bench(fb: &mut TGAImage) {
     }
 }
 
-fn line(mut a: Point, mut b: Point, fb: &mut TGAImage, color: TGAColor) {
+fn line(mut a: Point2i, mut b: Point2i, fb: &mut TGAImage, color: TGAColor) {
     let is_steep = (a.x - b.x).abs() < (a.y - b.y).abs();
     if is_steep {
         std::mem::swap(&mut a.x, &mut a.y);

src/model.rs

@@ -1,13 +1,10 @@
-#[derive(Default, Debug, Clone, Copy, PartialEq, PartialOrd)]
-pub struct Point3 {
-    store: [f32; 3],
-}
+use std::ops::{Deref, DerefMut};
 
-impl From<[f32; 3]> for Point3 {
-    fn from(value: [f32; 3]) -> Self {
-        Self { store: value }
-    }
-}
+use crate::{
+    RED, line,
+    point::{Point2i, Point3f},
+    tga::TGAImage,
+};
 
 #[derive(Default, Debug, Clone, Copy, PartialEq, PartialOrd)]
 pub struct Face {
@@ -20,9 +17,23 @@ impl From<[usize; 3]> for Face {
     }
 }
 
+impl Deref for Face {
+    type Target = [usize; 3];
+
+    fn deref(&self) -> &Self::Target {
+        &self.store
+    }
+}
+
+impl DerefMut for Face {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.store
+    }
+}
+
 #[derive(Default, Debug, Clone, PartialEq, PartialOrd)]
 pub struct Model {
-    pub verts: Vec<Point3>,
+    pub verts: Vec<Point3f>,
     pub faces: Vec<Face>,
 }
 
@@ -49,7 +60,15 @@ impl Model {
                 if *t == "f" {
                     let f: Vec<usize> = line[1..4]
                         .iter()
-                        .map(|l| l.split('/').take(1).next().unwrap().parse().unwrap())
+                        .map(|l| {
+                            l.split('/')
+                                .take(1)
+                                .next()
+                                .unwrap()
+                                .parse::<usize>()
+                                .unwrap()
+                                - 1
+                        })
                         .collect();
                     let f: [usize; 3] = f.try_into().unwrap();
                     faces.push(f.into());
@@ -59,4 +78,25 @@ impl Model {
 
         Self { verts, faces }
     }
+
+    pub fn render_wireframe(&self, framebuffer: &mut TGAImage) {
+        let width = framebuffer.width;
+        let height = framebuffer.height;
+
+        for face in self.faces.iter() {
+            let a = world2view(self.verts[face[0]], width, height);
+            let b = world2view(self.verts[face[1]], width, height);
+            let c = world2view(self.verts[face[2]], width, height);
+            line(a, b, framebuffer, RED);
+            line(b, c, framebuffer, RED);
+            line(c, a, framebuffer, RED);
+        }
+    }
+}
+
+fn world2view(point: Point3f, width: u32, height: u32) -> Point2i {
+    let point = (point + 1.0) * 0.5;
+    let x = (point.x().min(1.0) * width as f32).round_ties_even() as i32;
+    let y = (point.y().min(1.0) * height as f32).round_ties_even() as i32;
+    Point2i::new(x, y)
 }

src/point.rs

@@ -1,13 +1,16 @@
-use std::ops::{Add, Mul, Sub};
+use std::ops::{Add, Deref, DerefMut, Div, Mul, Sub};
 
 #[derive(Default, Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Point {
+pub struct Point2i {
     pub x: i32,
     pub y: i32,
 }
 
-impl Point {
-    pub fn new(x: u32, y: u32) -> Self {
+impl Point2i {
+    pub fn new(x: i32, y: i32) -> Self {
+        Self { x, y }
+    }
+    pub fn newu(x: u32, y: u32) -> Self {
         Self {
             x: x as i32,
             y: y as i32,
@@ -15,7 +18,7 @@ impl Point {
     }
 }
 
-impl Add for Point {
+impl Add for Point2i {
     type Output = Self;
 
     fn add(self, rhs: Self) -> Self::Output {
@@ -26,7 +29,7 @@ impl Add for Point {
     }
 }
 
-impl Sub for Point {
+impl Sub for Point2i {
     type Output = Self;
 
     fn sub(self, rhs: Self) -> Self::Output {
@@ -37,7 +40,7 @@ impl Sub for Point {
     }
 }
 
-impl Mul for Point {
+impl Mul for Point2i {
     type Output = Self;
 
     fn mul(self, rhs: Self) -> Self::Output {
@@ -47,3 +50,84 @@ impl Mul for Point {
         }
     }
 }
+
+#[derive(Default, Debug, Clone, Copy, PartialEq, PartialOrd)]
+#[repr(transparent)]
+pub struct Point3f {
+    store: [f32; 3],
+}
+
+impl From<[f32; 3]> for Point3f {
+    fn from(value: [f32; 3]) -> Self {
+        Self { store: value }
+    }
+}
+
+impl Deref for Point3f {
+    type Target = [f32; 3];
+
+    fn deref(&self) -> &Self::Target {
+        &self.store
+    }
+}
+
+impl DerefMut for Point3f {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.store
+    }
+}
+
+impl Point3f {
+    pub fn new(x: f32, y: f32, z: f32) -> Self {
+        Self { store: [x, y, z] }
+    }
+
+    pub fn x(&self) -> f32 {
+        self.store[0]
+    }
+
+    pub fn y(&self) -> f32 {
+        self.store[1]
+    }
+
+    pub fn z(&self) -> f32 {
+        self.store[2]
+    }
+}
+
+impl Add<f32> for Point3f {
+    type Output = Self;
+
+    fn add(self, rhs: f32) -> Self::Output {
+        Self {
+            store: [self[0] + rhs, self[1] + rhs, self[2] + rhs],
+        }
+    }
+}
+
+impl Mul<f32> for Point3f {
+    type Output = Self;
+
+    fn mul(self, rhs: f32) -> Self::Output {
+        Self {
+            store: [self[0] * rhs, self[1] * rhs, self[2] * rhs],
+        }
+    }
+}
+
+impl Div<f32> for Point3f {
+    type Output = Self;
+
+    fn div(self, rhs: f32) -> Self::Output {
+        self * (1.0 / rhs)
+    }
+}
+
+impl From<Point3f> for Point2i {
+    fn from(p: Point3f) -> Self {
+        Self {
+            x: p.x().round_ties_even() as i32,
+            y: p.y().round_ties_even() as i32,
+        }
+    }
+}

src/tga.rs

@@ -236,12 +236,12 @@ impl TGAImage {
     }
 
     pub fn set(&mut self, x: u32, y: u32, color: TGAColor) {
-        if self.data.is_empty() || x > self.width || y > self.height {
+        if self.data.is_empty() || x >= self.width || y >= self.height {
             return;
         }
 
         let bpp = self.bytes_per_pixel() as usize;
-        let start = (x + y * self.width) as usize * bpp;
+        let start = (x + (y * self.width)) as usize * bpp;
         let end = start + bpp;
         self.data[start..end].copy_from_slice(&color[0..bpp]);
     }