add new formats to test.rs

Author: EmilioLaiso

examples/test.rs

@@ -1,4 +1,4 @@
-use image::{RgbImage, RgbaImage};
+use image::{GrayAlphaImage, GrayImage, RgbImage, RgbaImage};
 use ispc_downsampler::{downsample, Format, Image};
 use stb_image::image::{load, LoadResult};
 use std::path::Path;
@@ -11,10 +11,15 @@ fn main() {
         LoadResult::ImageU8(img) => {
             assert!(!img.data.is_empty());
 
-            let src_fmt = if img.data.len() / (img.width * img.height) == 4 {
+            let num_channels = img.data.len() / (img.width * img.height);
+            let src_fmt = if num_channels == 4 {
                 Format::RGBA8
-            } else {
+            } else if num_channels == 3 {
                 Format::RGB8
+            } else if num_channels == 2 {
+                Format::RG8
+            } else {
+                Format::R8
             };
 
             println!("Loaded image!");
@@ -47,6 +52,22 @@ fn main() {
                         .save("example_outputs/square_test_result.png")
                         .unwrap()
                 }
+                Format::RG8 => {
+                    let save_image =
+                        GrayAlphaImage::from_vec(target_width, target_height, downsampled_pixels)
+                            .unwrap();
+                    save_image
+                        .save("example_outputs/square_test_result.png")
+                        .unwrap()
+                }
+                Format::R8 => {
+                    let save_image =
+                        GrayImage::from_vec(target_width, target_height, downsampled_pixels)
+                            .unwrap();
+                    save_image
+                        .save("example_outputs/square_test_result.png")
+                        .unwrap()
+                }
             }
         }
         _ => panic!("This test only works with 8-bit per channel textures"),