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authorMaze Winther <mazewinther@gmail.com>2026-03-25 16:47:22 +0100
committerMaze Winther <mazewinther@gmail.com>2026-03-29 15:48:22 +0200
commit8db3bead13441a5882d8689dfc6a9f09c82375d9 (patch)
treee9d0cafa93904ffcbec3188c37961bcc16c6422d /apps/web/src/lib/text/measure-element.ts
parent39ea298a9ccba3104c549c0ca079c231981811f5 (diff)
downloadopencut-8db3bead13441a5882d8689dfc6a9f09c82375d9.tar.gz
feat: masks, properties refactor, shaders, storage migrations, and more
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+import {
+ CORNER_RADIUS_MIN,
+ FONT_SIZE_SCALE_REFERENCE,
+} from "@/constants/text-constants";
+import { resolveNumberAtTime } from "@/lib/animation";
+import { DEFAULTS } from "@/lib/timeline/defaults";
+import type { TextBackground, TextElement } from "@/lib/timeline";
+import {
+ measureTextBlock,
+ setCanvasLetterSpacing,
+ getTextVisualRect,
+ type TextBlockMeasurement,
+} from "./layout";
+
+export interface ResolvedTextBackground extends TextBackground {
+ paddingX: number;
+ paddingY: number;
+ offsetX: number;
+ offsetY: number;
+ cornerRadius: number;
+}
+
+export interface MeasuredTextElement {
+ scaledFontSize: number;
+ fontString: string;
+ letterSpacing: number;
+ lineHeightPx: number;
+ lines: string[];
+ lineMetrics: TextMetrics[];
+ block: TextBlockMeasurement;
+ fontSizeRatio: number;
+ resolvedBackground: ResolvedTextBackground;
+ visualRect: { left: number; top: number; width: number; height: number };
+}
+
+/**
+ * Shared text measurement used by both the renderer and preview bounds.
+ * Accepts the canvas context to measure on so callers can reuse an existing
+ * context (e.g. the renderer's) rather than creating a throwaway canvas.
+ * The context state is preserved via save/restore.
+ */
+export function measureTextElement({
+ element,
+ canvasHeight,
+ localTime,
+ ctx,
+}: {
+ element: TextElement;
+ canvasHeight: number;
+ localTime: number;
+ ctx: CanvasRenderingContext2D | OffscreenCanvasRenderingContext2D;
+}): MeasuredTextElement {
+ const scaledFontSize =
+ element.fontSize * (canvasHeight / FONT_SIZE_SCALE_REFERENCE);
+ const fontWeight = element.fontWeight === "bold" ? "bold" : "normal";
+ const fontStyle = element.fontStyle === "italic" ? "italic" : "normal";
+ const fontFamily = `"${element.fontFamily.replace(/"/g, '\\"')}"`;
+ const fontString = `${fontStyle} ${fontWeight} ${scaledFontSize}px ${fontFamily}, sans-serif`;
+ const letterSpacing = element.letterSpacing ?? 0;
+ const lineHeightPx =
+ scaledFontSize * (element.lineHeight ?? DEFAULTS.text.lineHeight);
+ const fontSizeRatio = element.fontSize / DEFAULTS.text.element.fontSize;
+ const lines = element.content.split("\n");
+
+ ctx.save();
+ ctx.font = fontString;
+ ctx.textBaseline = "middle";
+ setCanvasLetterSpacing({ ctx, letterSpacingPx: letterSpacing });
+ const lineMetrics = lines.map((line) => ctx.measureText(line));
+ ctx.restore();
+
+ const block = measureTextBlock({
+ lineMetrics,
+ lineHeightPx,
+ fallbackFontSize: scaledFontSize,
+ });
+
+ const bg = element.background;
+ const resolvedBackground: ResolvedTextBackground = {
+ ...bg,
+ paddingX: resolveNumberAtTime({
+ baseValue: bg.paddingX ?? DEFAULTS.text.background.paddingX,
+ animations: element.animations,
+ propertyPath: "background.paddingX",
+ localTime,
+ }),
+ paddingY: resolveNumberAtTime({
+ baseValue: bg.paddingY ?? DEFAULTS.text.background.paddingY,
+ animations: element.animations,
+ propertyPath: "background.paddingY",
+ localTime,
+ }),
+ offsetX: resolveNumberAtTime({
+ baseValue: bg.offsetX ?? DEFAULTS.text.background.offsetX,
+ animations: element.animations,
+ propertyPath: "background.offsetX",
+ localTime,
+ }),
+ offsetY: resolveNumberAtTime({
+ baseValue: bg.offsetY ?? DEFAULTS.text.background.offsetY,
+ animations: element.animations,
+ propertyPath: "background.offsetY",
+ localTime,
+ }),
+ cornerRadius: resolveNumberAtTime({
+ baseValue: bg.cornerRadius ?? CORNER_RADIUS_MIN,
+ animations: element.animations,
+ propertyPath: "background.cornerRadius",
+ localTime,
+ }),
+ };
+
+ const visualRect = getTextVisualRect({
+ textAlign: element.textAlign,
+ block,
+ background: resolvedBackground,
+ fontSizeRatio,
+ });
+
+ return {
+ scaledFontSize,
+ fontString,
+ letterSpacing,
+ lineHeightPx,
+ lines,
+ lineMetrics,
+ block,
+ fontSizeRatio,
+ resolvedBackground,
+ visualRect,
+ };
+}