Add image texture

src/image_texture.rs

@@ -0,0 +1,55 @@
+/*
+        let img = image::open("tests/images/jpg/progressive/cat.jpg").unwrap();
+        let rgnbi = img.into_rgb8();
+        rgnbi.get_pixel(0, 0);
+        rgnbi.
+
+ */
+use image::{Pixel, RgbImage};
+use crate::{Color, Point3};
+use crate::texture::Texture;
+
+pub struct ImageTexture {
+    image: Option<RgbImage>
+}
+
+impl ImageTexture {
+    pub fn new(path: &str) -> Self {
+        let image = image::open(path)
+            .map(|i|i.into_rgb8())
+            .ok();
+        Self {
+            image
+        }
+    }
+    fn value_from_image(image: &RgbImage, u: f64, v: f64) -> Color {
+        // Clamp input texture coordinates to [0,1] x [1,0]
+        let u = u.clamp(0.0, 1.0);
+        let v = v.abs().clamp(0.0, 1.0); // Flip V to image coordinates
+
+        let i = match (u * image.width() as f64) as i32 {
+            i if i >= image.width() as i32 => image.width() as i32 - 1,
+            i => i
+        };
+        let j = match (v * image.height() as f64) as i32 {
+            j if j >= image.height() as i32 => image.height() as i32 - 1,
+            j => j
+        };
+        let color_scale = 1.0 / 255.0;
+        let pixel = image.get_pixel(i as u32, j as u32);
+        let x = pixel.0[0] as f64 * color_scale;
+        let y = pixel.0[1] as f64 * color_scale;
+        let z = pixel.0[2] as f64 * color_scale;
+        Color::new(x, y, z)
+    }
+}
+
+impl Texture for ImageTexture {
+    fn value(&self, u: f64, v: f64, _point: &Point3) -> Color {
+        match &self.image {
+            Some(i) => ImageTexture::value_from_image(i, u, v),
+            // If we have no texture data, then return solid cyan as a debugging aid.
+            _ => Color::new(0.0, 1.0, 1.0)
+        }
+    }
+}

src/main.rs

@@ -12,6 +12,7 @@ use rand::distributions::{Distribution, Uniform};
 use rayon::iter::{IntoParallelIterator, ParallelIterator};
 use crate::material::{Dielectric, Lambertian, Material, Metal};
 use crate::aabb::Aabb;
+use crate::image_texture::ImageTexture;
 use crate::noise::NoiseTexture;
 use crate::perlin::Perlin;
 use crate::texture::CheckerTexture;
@@ -27,6 +28,20 @@ mod bvh;
 mod texture;
 mod perlin;
 mod noise;
+mod image_texture;
+
+fn earth() -> HittableList {
+    let mut world:HittableList = Vec::new();
+    let earth_texture = ImageTexture::new("textures/earthmap.jpg");
+    let earth_material = Arc::new(
+        Material::Lambertian(Lambertian::textured(Arc::new(earth_texture))));
+    world.push(Arc::new(Sphere {
+        center: Point3::new(0.0, 0.0, 0.0),
+        radius: 2.0,
+        material: earth_material
+    }));
+    world
+}
 
 fn two_spheres() -> HittableList {
     let mut world:HittableList = Vec::new();
@@ -148,7 +163,7 @@ fn main() {
     const ASPECT_RATIO: f64 = 3.0 / 2.0;
     const IMAGE_WIDTH: usize = 400;
     const IMAGE_HEIGHT: usize = (IMAGE_WIDTH as f64 / ASPECT_RATIO) as usize;
-    const SAMPLES_PER_PIXEL: i32 = 50;
+    const SAMPLES_PER_PIXEL: i32 = 1;
     const MAX_DEPTH: i32 = 50;
 
     let look_from = Point3::new(13.0, 2.0, 3.0);
@@ -168,10 +183,11 @@ fn main() {
     1.0);
 
     // World
-    let scene: u8 = 1;
+    let scene: u8 = 2;
     let world = match scene {
         0 => two_spheres(),
         1 => two_perlin_spheres(),
+        2 => earth(),
         _ => random_scene()
     };
 

src/output.rs

@@ -34,4 +34,4 @@ impl Output for PNG {
             ImageOutputFormat::Png)
             .map_err(|e|  Error::new(ErrorKind::Other, e))
     }
-}
+}