Add retained paints and shared text selection

tests/color_space.rs

@@ -0,0 +1,178 @@
+#![recursion_limit = "256"]
+
+use iris::{harness::Harness, prelude::*};
+use pollster::FutureExt;
+use std::sync::OnceLock;
+use wgpu::TextureFormat;
+
+const SIZE: Vec2 = Vec2::new(2.0, 1.0);
+const SOLID: Srgba8 = Srgba8::rgb(17, 127, 231);
+const CHANGED_SOLID: Srgba8 = Srgba8::rgb(243, 139, 168);
+const IMAGE: Srgba8 = Srgba8::rgb(205, 214, 244);
+
+/// Covers the whole colour path rather than a conversion helper: an sRGB
+/// literal enters the linear paint buffer, an sRGB image is sampled as
+/// linear, the Iris shader returns both, and the sRGB attachment encodes the
+/// stored bytes. Replacing only the paint-table entry also proves that a
+/// theme change reaches an already-retained primitive.
+#[test]
+fn solid_paints_and_images_round_trip_through_an_srgb_target() {
+    let gpu = Gpu::open();
+    let mut harness = Harness::new(SIZE, 1.0);
+    let solid = harness.rsc.ui.paints.add(SOLID);
+    let bitmap = image::DynamicImage::ImageRgba8(image::RgbaImage::from_pixel(
+        1,
+        1,
+        image::Rgba([IMAGE.r, IMAGE.g, IMAGE.b, IMAGE.a]),
+    ));
+    let bitmap = image::<iris::harness::HarnessRsc>(bitmap)(&mut harness.rsc);
+    let root = (rect(solid.clone()).sized((1, 1)), bitmap)
+        .span(Dir::RIGHT)
+        .add_strong(&mut harness.rsc)
+        .any();
+    harness.state.set_root(root);
+    harness.frame(0);
+
+    let mut renderer =
+        UiRenderNode::new(&gpu.device, &gpu.queue, TextureFormat::Rgba8UnormSrgb, SIZE)
+            .expect("the Iris pipeline should accept an sRGB render target");
+    let first = render(&gpu, &mut renderer, &mut harness);
+    assert_pixel(first[0], SOLID, "linear paint buffer -> sRGB attachment");
+    assert_pixel(first[1], IMAGE, "sRGB texture -> shader -> sRGB attachment");
+
+    harness.rsc.ui.paints.set(&solid, CHANGED_SOLID);
+    let changed = render(&gpu, &mut renderer, &mut harness);
+    assert_pixel(
+        changed[0],
+        CHANGED_SOLID,
+        "updated paint table -> retained primitive",
+    );
+    assert_pixel(changed[1], IMAGE, "unchanged image after paint update");
+}
+
+fn render(gpu: &Gpu, renderer: &mut UiRenderNode, harness: &mut Harness) -> [[u8; 4]; 2] {
+    renderer.update(
+        &gpu.device,
+        &gpu.queue,
+        &mut harness.rsc.ui,
+        &mut harness.render,
+    );
+    let texture = gpu.device.create_texture(&wgpu::TextureDescriptor {
+        label: Some("Iris colour-space target"),
+        size: wgpu::Extent3d {
+            width: 2,
+            height: 1,
+            depth_or_array_layers: 1,
+        },
+        mip_level_count: 1,
+        sample_count: 1,
+        dimension: wgpu::TextureDimension::D2,
+        format: wgpu::TextureFormat::Rgba8UnormSrgb,
+        usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::COPY_SRC,
+        view_formats: &[],
+    });
+    let view = texture.create_view(&Default::default());
+    let readback = gpu.device.create_buffer(&wgpu::BufferDescriptor {
+        label: Some("Iris colour-space readback"),
+        size: 256,
+        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
+        mapped_at_creation: false,
+    });
+    let mut encoder = gpu.device.create_command_encoder(&Default::default());
+    {
+        let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+            label: Some("Iris colour-space pass"),
+            color_attachments: &[Some(wgpu::RenderPassColorAttachment {
+                view: &view,
+                depth_slice: None,
+                resolve_target: None,
+                ops: wgpu::Operations {
+                    load: wgpu::LoadOp::Clear(LinearRgba::BLACK.to_wgpu()),
+                    store: wgpu::StoreOp::Store,
+                },
+            })],
+            depth_stencil_attachment: None,
+            timestamp_writes: None,
+            occlusion_query_set: None,
+            multiview_mask: None,
+        });
+        renderer.draw(&mut pass);
+    }
+    encoder.copy_texture_to_buffer(
+        texture.as_image_copy(),
+        wgpu::TexelCopyBufferInfo {
+            buffer: &readback,
+            layout: wgpu::TexelCopyBufferLayout {
+                offset: 0,
+                bytes_per_row: Some(256),
+                rows_per_image: Some(1),
+            },
+        },
+        wgpu::Extent3d {
+            width: 2,
+            height: 1,
+            depth_or_array_layers: 1,
+        },
+    );
+    gpu.queue.submit([encoder.finish()]);
+
+    let slice = readback.slice(..);
+    slice.map_async(wgpu::MapMode::Read, |result| {
+        result.expect("mapping the colour-space readback")
+    });
+    gpu.device
+        .poll(wgpu::PollType::wait_indefinitely())
+        .expect("waiting for the colour-space readback");
+    let mapped = slice
+        .get_mapped_range()
+        .expect("reading the mapped colour-space buffer");
+    let pixels = [
+        mapped[0..4].try_into().unwrap(),
+        mapped[4..8].try_into().unwrap(),
+    ];
+    drop(mapped);
+    readback.unmap();
+    pixels
+}
+
+fn assert_pixel(got: [u8; 4], want: Srgba8, path: &str) {
+    let want = [want.r, want.g, want.b, want.a];
+    assert!(
+        got.into_iter()
+            .zip(want)
+            .all(|(got, want)| got.abs_diff(want) <= 1),
+        "{path}: stored {got:?}, expected {want:?} (within one code value)",
+    );
+}
+
+fn vulkan_instance() -> &'static wgpu::Instance {
+    static INSTANCE: OnceLock<wgpu::Instance> = OnceLock::new();
+    INSTANCE.get_or_init(wgpu::Instance::default)
+}
+
+struct Gpu {
+    device: wgpu::Device,
+    queue: wgpu::Queue,
+}
+
+impl Gpu {
+    fn open() -> Self {
+        let adapter = vulkan_instance()
+            .request_adapter(&wgpu::RequestAdapterOptions::default())
+            .block_on()
+            .expect("no wgpu adapter, so Iris's colour-space pipeline went unchecked");
+        let info = adapter.get_info();
+        eprintln!(
+            "color_space: {} ({:?}, {})",
+            info.name, info.backend, info.driver
+        );
+        let (device, queue) = adapter
+            .request_device(&wgpu::DeviceDescriptor {
+                required_limits: iris_core::device_limits(),
+                ..Default::default()
+            })
+            .block_on()
+            .expect("could not get a device from the adapter");
+        Self { device, queue }
+    }
+}