T25c Generative: canvas

InpaintCanvas lays a mask over a picture: brush strokes in shares of
the picture, rastered into a 320-column grid where a later stroke wins
and an erasing one clears, painted as merged rectangles snapped to
device pixels. A ring follows the pointer at the brush's size; [ and ]
size the brush and X swaps it when focused. MaskBrush sets paint or
erase and the size, with Undo and Clear waiting for a stroke.

Pointer strokes move to forms::pen, which SignaturePad and the canvas
share.

examples/gallery/pages/generative/canvas.rs

@@ -0,0 +1,66 @@
+use ely_gpui_component::generative::{InpaintCanvas, MaskBrush, MaskStroke};
+use gpui::{App, IntoElement, ParentElement, Styled, Window, div, px};
+
+use crate::{
+    probe::probe,
+    ui::{keep, section, set},
+};
+
+/// A mask over the olive tree, painted before the demo opens.
+fn tree() -> Vec<MaskStroke> {
+    vec![MaskStroke {
+        points: vec![
+            (0.07, 0.18),
+            (0.12, 0.34),
+            (0.09, 0.52),
+            (0.13, 0.7),
+            (0.1, 0.86),
+        ],
+        radius: 0.07,
+        erase: false,
+    }]
+}
+
+pub fn canvas(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let strokes = keep("gen-mask", tree, window, cx);
+    let brush = keep("gen-brush", || (0.05_f32, false), window, cx);
+    let (now, (radius, erase)) = (strokes.read(cx).clone(), *brush.read(cx));
+    let (painted, undone, cleared) = (strokes.clone(), strokes.clone(), strokes);
+    let (keyed, set_brush) = (brush.clone(), brush);
+    let count = now.len();
+    section(
+        "InpaintCanvas / MaskBrush",
+        "A picture to repaint in part: paint a mask where it should change, erase where it went too far; the mask washes over the picture. On the canvas, [ and ] size the brush and X swaps painting for erasing. Undo takes the last stroke, Clear takes them all.",
+        cx,
+    )
+    .child(
+        div()
+            .w(px(460.))
+            .flex()
+            .flex_col()
+            .gap_3()
+            .child(probe(
+                "gen-canvas",
+                div().w(px(460.)).child(
+                    InpaintCanvas::new("gen-canvas", asset!("atrium-olive.jpg"), 1.5, now)
+                        .brush(radius, erase)
+                        .on_stroke(move |stroke, _, cx| {
+                            let mut next = painted.read(cx).clone();
+                            next.push(stroke);
+                            set(&painted, next, cx)
+                        })
+                        .on_brush(move |radius, erase, _, cx| set(&keyed, (radius, erase), cx)),
+                ),
+            ))
+            .child(
+                MaskBrush::new("gen-mask-brush", radius, erase, count)
+                    .on_brush(move |radius, erase, _, cx| set(&set_brush, (radius, erase), cx))
+                    .on_undo(move |_, cx| {
+                        let mut next = undone.read(cx).clone();
+                        next.pop();
+                        set(&undone, next, cx)
+                    })
+                    .on_clear(move |_, cx| set(&cleared, Vec::new(), cx)),
+            ),
+    )
+}

examples/gallery/pages/generative/mod.rs

@@ -1,3 +1,4 @@
+mod canvas;
 mod panel;
 mod results;
 
@@ -28,6 +29,10 @@ const SCRIPT: &[Step] = &[
     Step::UpAt("gen-ab", 181.0, 147.0),
     Step::Wait(300),
     Step::Shot("verdict"),
+    Step::DownAt("gen-canvas", 300.0, 70.0),
+    Step::UpAt("gen-canvas", 390.0, 220.0),
+    Step::Wait(300),
+    Step::Shot("masked"),
 ];
 
 fn render(window: &mut Window, cx: &mut App) -> AnyElement {
@@ -36,5 +41,6 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
         .child(results::queue(window, cx))
         .child(results::results(window, cx))
         .child(results::variations(window, cx))
+        .child(canvas::canvas(window, cx))
         .into_any_element()
 }