feat: 英文字母描红开发

miniprogram/core/generators/letter-tracing-generator.ts

@@ -0,0 +1,172 @@
+import {
+    ALPHABET_BY_LETTER,
+    LETTERS_UPPER,
+} from '../data/alphabet';
+
+export type LetterTracingMode =
+    | 'single-letter'
+    | 'full-alphabet'
+    | 'upper-lower-split'
+    | 'two-column';
+
+export type LetterCaseMode = 'upper' | 'lower' | 'both';
+
+export interface LetterTracingGeneratorConfig {
+    mode: LetterTracingMode;
+    letterCase: LetterCaseMode;
+    selectedLetter?: string;
+    repetitions: number;
+    fadePattern: 'gradient' | 'first-only';
+}
+
+export interface TracingCell {
+    char: string;
+    opacity: number;
+    isGuide: boolean;
+}
+
+export interface TracingRow {
+    displayChar: string;
+    cells: TracingCell[];
+}
+
+export interface TeachingBlock {
+    upper: string;
+    lower: string;
+    word: string;
+    sentence: string;
+    emoji: string;
+}
+
+export type LetterTracingData =
+    | {
+          mode: 'single-letter';
+          teaching: TeachingBlock;
+          rows: TracingRow[];
+      }
+    | {
+          mode: 'full-alphabet';
+          rows: TracingRow[];
+      }
+    | {
+          mode: 'upper-lower-split';
+          upperGlyphs: string[];
+          lowerGlyphs: string[];
+      }
+    | {
+          mode: 'two-column';
+          leftRows: TracingRow[];
+          rightRows: TracingRow[];
+      };
+
+function normalizeLetter(c: string): string {
+    const u = c.trim().toUpperCase();
+    return u.length ? u[0] : 'A';
+}
+
+function buildCells(
+    char: string,
+    count: number,
+    fadePattern: 'gradient' | 'first-only',
+): TracingCell[] {
+    const n = Math.max(1, Math.min(12, count));
+    const cells: TracingCell[] = [];
+    for (let i = 0; i < n; i++) {
+        let opacity: number;
+        if (fadePattern === 'first-only') {
+            opacity = i === 0 ? 1 : 0;
+        } else if (n <= 1) {
+            opacity = 1;
+        } else {
+            opacity = Math.max(0.12, 1 - i / (n - 1));
+        }
+        cells.push({ char, opacity, isGuide: i === 0 });
+    }
+    return cells;
+}
+
+function rowForChar(
+    ch: string,
+    repetitions: number,
+    fadePattern: 'gradient' | 'first-only',
+): TracingRow {
+    return {
+        displayChar: ch,
+        cells: buildCells(ch, repetitions, fadePattern),
+    };
+}
+
+export function generateLetterTracing(
+    config: LetterTracingGeneratorConfig,
+): LetterTracingData {
+    const { mode, letterCase, repetitions, fadePattern } = config;
+
+    if (mode === 'single-letter') {
+        const key = normalizeLetter(config.selectedLetter ?? 'A');
+        const meta = ALPHABET_BY_LETTER[key] ?? ALPHABET_BY_LETTER.A;
+        const upper = key;
+        const lower = key.toLowerCase();
+        const teaching: TeachingBlock = {
+            upper,
+            lower,
+            word: meta.word,
+            sentence: `${upper} is for ${meta.word}`,
+            emoji: meta.emoji,
+        };
+        const rows: TracingRow[] = [
+            rowForChar(upper, repetitions, fadePattern),
+            rowForChar(lower, repetitions, fadePattern),
+        ];
+        return { mode: 'single-letter', teaching, rows };
+    }
+
+    if (mode === 'full-alphabet') {
+        const rows = LETTERS_UPPER.map((L) => {
+            const ch = letterCase === 'lower' ? L.toLowerCase() : L;
+            return rowForChar(ch, repetitions, fadePattern);
+        });
+        return { mode: 'full-alphabet', rows };
+    }
+
+    if (mode === 'upper-lower-split') {
+        return {
+            mode: 'upper-lower-split',
+            upperGlyphs: [...LETTERS_UPPER],
+            lowerGlyphs: LETTERS_UPPER.map((L) => L.toLowerCase()),
+        };
+    }
+
+    // two-column
+    const left = LETTERS_UPPER.slice(0, 13);
+    const right = LETTERS_UPPER.slice(13);
+    const mapChar = (L: string) =>
+        letterCase === 'lower' ? L.toLowerCase() : L;
+    const leftRows = left.map((L) =>
+        rowForChar(mapChar(L), repetitions, fadePattern),
+    );
+    const rightRows = right.map((L) =>
+        rowForChar(mapChar(L), repetitions, fadePattern),
+    );
+    return { mode: 'two-column', leftRows, rightRows };
+}
+
+/** 与 WorksheetDefinition.generatorConfig 合并后的运行时配置 */
+export function mergeLetterTracingConfig(
+    base: Partial<LetterTracingGeneratorConfig>,
+    overrides: Partial<LetterTracingGeneratorConfig>,
+): LetterTracingGeneratorConfig {
+    return {
+        mode: (overrides.mode ?? base.mode ?? 'single-letter') as LetterTracingMode,
+        letterCase: (overrides.letterCase ??
+            base.letterCase ??
+            'upper') as LetterCaseMode,
+        selectedLetter: overrides.selectedLetter ?? base.selectedLetter,
+        repetitions: Math.max(
+            1,
+            (overrides.repetitions ?? base.repetitions ?? 5) as number,
+        ),
+        fadePattern: (overrides.fadePattern ??
+            base.fadePattern ??
+            'gradient') as 'gradient' | 'first-only',
+    };
+}