From a61927ef1dfc6a42e46181085fb304d46450473f Mon Sep 17 00:00:00 2001
From: flop <flop@cttue.de>
Date: Fri, 22 May 2026 17:53:20 +0200
Subject: [PATCH] feat: image editor support

---
 ts/src/browser.ts | 91 +++++++++++++++++++++++++++++++++++++++++++++++
 ts/style.css      |  8 +++++
 2 files changed, 99 insertions(+)

diff --git a/ts/src/browser.ts b/ts/src/browser.ts
index 0e6fc78..1b008ff 100644
--- a/ts/src/browser.ts
+++ b/ts/src/browser.ts
@@ -424,6 +424,91 @@ function FieldInput(si: number, ei: number, field: ElFieldMeta, el: MonoDisplay.
   }
 }
 
+// ─── Image2D pixel editor ─────────────────────────────────────────────────────
+
+const PIXEL_SCALE = 4;
+
+function getPixelIndex(img: MonoDisplay.MonoFormatPixelImage, x: number, y: number): number {
+  return y * img.width + x;
+}
+
+function drawImage2DCanvas(canvas: HTMLCanvasElement, img: MonoDisplay.MonoFormatPixelImage) {
+  const ctx = canvas.getContext("2d")!;
+  ctx.fillStyle = "#000";
+  ctx.fillRect(0, 0, canvas.width, canvas.height);
+  ctx.fillStyle = "#EC0";
+  for (let y = 0; y < img.height; y++) {
+    for (let x = 0; x < img.width; x++) {
+      if (img.pixels[getPixelIndex(img, x, y)]) {
+        ctx.fillRect(x * PIXEL_SCALE, y * PIXEL_SCALE, PIXEL_SCALE, PIXEL_SCALE);
+      }
+    }
+  }
+}
+
+interface Image2DEditorState {
+  drawing: boolean;
+  drawValue: number; // 0 or 1
+}
+
+const Image2DEditor: m.Component<{ si: number; ei: number; el: MonoDisplay.MonoFormatImage2D }, Image2DEditorState> = {
+  drawing: false,
+  drawValue: 1,
+
+  oncreate({ dom }) {
+    const canvas = dom as HTMLCanvasElement;
+    const el = (canvas as any)._el as MonoDisplay.MonoFormatImage2D;
+    drawImage2DCanvas(canvas, el.image);
+  },
+
+  onupdate({ dom, attrs }) {
+    drawImage2DCanvas(dom as HTMLCanvasElement, attrs.el.image);
+  },
+
+  view({ attrs: { si, ei, el }, state }) {
+    const img = el.image;
+
+    function pixelFromEvent(e: MouseEvent): { x: number; y: number } | null {
+      const canvas = e.currentTarget as HTMLCanvasElement;
+      const rect = canvas.getBoundingClientRect();
+      const scaleX = canvas.width  / rect.width;
+      const scaleY = canvas.height / rect.height;
+      const x = Math.floor((e.clientX - rect.left) * scaleX / PIXEL_SCALE);
+      const y = Math.floor((e.clientY - rect.top)  * scaleY / PIXEL_SCALE);
+      if (x < 0 || x >= img.width || y < 0 || y >= img.height) return null;
+      return { x, y };
+    }
+
+    function paint(e: MouseEvent) {
+      const p = pixelFromEvent(e);
+      if (!p) return;
+      const idx = getPixelIndex(img, p.x, p.y);
+      img.pixels[idx] = state.drawValue;
+      markDirty(); triggerPreview();
+      drawImage2DCanvas(e.currentTarget as HTMLCanvasElement, img);
+    }
+
+    return m("canvas.pixel-editor", {
+      width:  img.width  * PIXEL_SCALE,
+      height: img.height * PIXEL_SCALE,
+      oncreate: ({ dom }: m.VnodeDOM) => {
+        (dom as any)._el = el;
+        drawImage2DCanvas(dom as HTMLCanvasElement, img);
+      },
+      onupdate: ({ dom }: m.VnodeDOM) => drawImage2DCanvas(dom as HTMLCanvasElement, img),
+      onmousedown: (e: MouseEvent) => {
+        state.drawing = true;
+        const p = pixelFromEvent(e);
+        if (p) state.drawValue = img.pixels[getPixelIndex(img, p.x, p.y)] ? 0 : 1;
+        paint(e);
+      },
+      onmousemove: (e: MouseEvent) => { if (state.drawing) paint(e); },
+      onmouseup:   () => { state.drawing = false; },
+      onmouseleave: () => { state.drawing = false; },
+    });
+  },
+};
+
 const ElementItem: m.Component<{ si: number; ei: number; el: MonoDisplay.MonoFormatElement }> = {
   view({ attrs: { si, ei, el } }) {
     const isActive = activeSecIndex === si && activeElIndex === ei;
@@ -473,6 +558,12 @@ const ElementItem: m.Component<{ si: number; ei: number; el: MonoDisplay.MonoFor
             )
           ),
         ) : null,
+        el.type === MonoDisplay.ElementType.Image2D
+          ? m(".field.full",
+              m("label", "Pixels"),
+              m(Image2DEditor, { si, ei, el: el as MonoDisplay.MonoFormatImage2D }),
+            )
+          : null,
       ),
     );
   },
diff --git a/ts/style.css b/ts/style.css
index 103ddd2..184285b 100644
--- a/ts/style.css
+++ b/ts/style.css
@@ -256,6 +256,14 @@ body {
   display: contents;
 }
 
+canvas.pixel-editor {
+  display: block;
+  cursor: crosshair;
+  image-rendering: pixelated;
+  max-width: 100%;
+  border: 1px solid var(--bd-inner);
+}
+
 #sec-meta {
   background: var(--bg-sunken);
   border: 1px solid var(--bd-inner);