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| author | Maze Winther <mazewinther@gmail.com> | 2026-04-20 11:31:17 +0200 |
|---|---|---|
| committer | Maze Winther <mazewinther@gmail.com> | 2026-04-20 11:31:17 +0200 |
| commit | 3e89d2998588f8e35c524e523ba2ee853f0f6475 (patch) | |
| tree | 57221f96c1259b3b07e3ddf8c1adefc502b9d8eb /apps/web/src/graphics/stroke.ts | |
| parent | 729d10592f4e802f91c555c309ff3ba4b119f843 (diff) | |
| download | opencut-3e89d2998588f8e35c524e523ba2ee853f0f6475.tar.gz | |
refactor: restructure files to their domains, new preview overlay system, and dep graph
Diffstat (limited to 'apps/web/src/graphics/stroke.ts')
| -rw-r--r-- | apps/web/src/graphics/stroke.ts | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/apps/web/src/graphics/stroke.ts b/apps/web/src/graphics/stroke.ts new file mode 100644 index 00000000..230d9904 --- /dev/null +++ b/apps/web/src/graphics/stroke.ts @@ -0,0 +1,102 @@ +import type { GraphicStrokeAlign } from "./definitions/shared";
+
+type GraphicRenderContext =
+ | CanvasRenderingContext2D
+ | OffscreenCanvasRenderingContext2D;
+
+function createTempCanvas({
+ width,
+ height,
+}: {
+ width: number;
+ height: number;
+}): OffscreenCanvas | HTMLCanvasElement {
+ try {
+ return new OffscreenCanvas(width, height);
+ } catch {
+ const canvas = document.createElement("canvas");
+ canvas.width = width;
+ canvas.height = height;
+ return canvas;
+ }
+}
+
+function applyStroke({
+ ctx,
+ path,
+ strokeWidth,
+ strokeColor,
+}: {
+ ctx: GraphicRenderContext;
+ path: Path2D;
+ strokeWidth: number;
+ strokeColor: string;
+}) {
+ ctx.strokeStyle = strokeColor;
+ ctx.lineWidth = strokeWidth;
+ ctx.stroke(path);
+}
+
+export function applyAlignedStroke({
+ ctx,
+ path,
+ strokeWidth,
+ strokeAlign,
+ strokeColor,
+}: {
+ ctx: GraphicRenderContext;
+ path: Path2D;
+ strokeWidth: number;
+ strokeAlign: GraphicStrokeAlign;
+ strokeColor: string;
+}): void {
+ if (strokeWidth <= 0) {
+ return;
+ }
+
+ if (strokeAlign === "inside") {
+ ctx.save();
+ ctx.clip(path);
+ applyStroke({
+ ctx,
+ path,
+ strokeWidth: strokeWidth * 2,
+ strokeColor,
+ });
+ ctx.restore();
+ return;
+ }
+
+ if (strokeAlign === "outside") {
+ const strokeCanvas = createTempCanvas({
+ width: ctx.canvas.width,
+ height: ctx.canvas.height,
+ });
+ const strokeCtx = strokeCanvas.getContext("2d") as GraphicRenderContext | null;
+ if (!strokeCtx) {
+ return;
+ }
+
+ applyStroke({
+ ctx: strokeCtx,
+ path,
+ strokeWidth: strokeWidth * 2,
+ strokeColor,
+ });
+
+ // Keep only the outer half of the doubled stroke so alpha fills do not
+ // leave a visible inner stroke behind.
+ strokeCtx.globalCompositeOperation = "destination-out";
+ strokeCtx.fill(path);
+
+ ctx.drawImage(strokeCanvas, 0, 0);
+ return;
+ }
+
+ applyStroke({
+ ctx,
+ path,
+ strokeWidth,
+ strokeColor,
+ });
+}
|