01_blur_image/
01_blur_image.rs

1use apple_metal::MetalDevice;
2use apple_mps::{feature_channel_format, Image, ImageDescriptor, ImageGaussianBlur};
3
4fn main() {
5    let device = MetalDevice::system_default().expect("no Metal device available");
6    let queue = device
7        .new_command_queue()
8        .expect("failed to create command queue");
9
10    let descriptor = ImageDescriptor::new(256, 256, 1, feature_channel_format::FLOAT32);
11    let src = Image::new(&device, descriptor).expect("failed to allocate source image");
12    let dst = Image::new(&device, descriptor).expect("failed to allocate destination image");
13
14    let mut impulse = vec![0.0_f32; 256 * 256];
15    let center_index = (256 / 2) * 256 + (256 / 2);
16    impulse[center_index] = 1.0;
17    src.write_f32(&impulse)
18        .expect("failed to upload source image");
19
20    let blur = ImageGaussianBlur::new(&device, 2.0).expect("failed to create gaussian blur");
21    let command_buffer = queue
22        .new_command_buffer()
23        .expect("failed to allocate command buffer");
24    blur.encode_image(&command_buffer, &src, &dst);
25    command_buffer.commit();
26    command_buffer.wait_until_completed();
27
28    let output = dst.read_f32().expect("failed to download blurred image");
29    let center_value = output[center_index];
30    let neighbor_value = output[center_index + 1];
31    let corner_value = output[0];
32    let total_energy: f32 = output.iter().sum();
33
34    assert!(
35        center_value < 1.0,
36        "center should have blurred away from impulse"
37    );
38    assert!(
39        neighbor_value > 0.0,
40        "neighbor should receive energy after blur"
41    );
42    assert!(
43        center_value > neighbor_value,
44        "center should remain strongest sample"
45    );
46    assert!(corner_value.abs() < 1.0e-6, "corners should stay at zero");
47    assert!(
48        (total_energy - 1.0).abs() < 1.0e-2,
49        "gaussian blur should preserve energy, got {total_energy}"
50    );
51
52    println!(
53        "blur smoke passed: center={center_value:.6} neighbor={neighbor_value:.6} sum={total_energy:.6}"
54    );
55}
01_blur_image/01_blur_image.rs

01_blur_image/
01_blur_image.rs
