Files
doodle-mini/miniprogram/englishPages/shared/draw/columnCompareDraw.ts
T

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2.9 KiB
TypeScript

import { BaseDrawService } from '../../../core/draw/baseDraw';
import type {
LetterTracingData,
TracingRow,
} from '../generators/letter-tracing-generator';
import {
calcLetterFontSizes,
drawFourLineGrid,
drawLetterInFourLineGrid,
FOUR_LINE_GRID_H,
TOY_FONT_LETTER,
type LetterFontSizes,
} from './drawTools';
const LETTER_FACE = `${TOY_FONT_LETTER}, Roboto, sans-serif`;
const COLOR_BLACK = '#1a1a1a';
const COLOR_LIGHT_RED = 'rgba(252, 46, 0, 0.3)';
type ColumnCompareData = Extract<
LetterTracingData,
{ mode: 'column-compare' }
>;
/**
* 分栏对照绘制:
* 四线三格横跨整页宽度,字母分左右两侧书写——
* 左半写大写(repetitions 个),右半写小写(repetitions 个),
* 每侧第一个字母黑色,后续浅红色。
*/
export default class ColumnCompareDraw extends BaseDrawService {
private letterSizes: LetterFontSizes =
calcLetterFontSizes(FOUR_LINE_GRID_H);
async draw(data: ColumnCompareData) {
this.prepareDraw();
await this.drawHeaderAndDivider();
this.drawContent(data.leftRows, data.rightRows);
this.drawPrintFooter();
}
private drawContent(leftRows: TracingRow[], rightRows: TracingRow[]) {
const M = 24;
const lineW = this.canvasWidth - M * 2;
const maxR = Math.max(leftRows.length, rightRows.length);
const footerReserve = 56;
const availableH =
this.canvasHeight - this.currentY - footerReserve - 12;
const rowGap = Math.max(
4,
(availableH - maxR * FOUR_LINE_GRID_H) / (maxR + 1),
);
const y0 = this.currentY + rowGap;
const halfW = lineW / 2;
for (let i = 0; i < maxR; i++) {
const y = y0 + i * (FOUR_LINE_GRID_H + rowGap);
drawFourLineGrid(this.ctx, M, y, lineW, FOUR_LINE_GRID_H);
if (i < leftRows.length) {
this.drawLettersInHalf(leftRows[i], M, y, halfW);
}
if (i < rightRows.length) {
this.drawLettersInHalf(rightRows[i], M + halfW, y, halfW);
}
}
}
/**
* 在四线三格的半侧区域内绘制字母。
* 第一个字母黑色,后续字母浅红色。
*/
private drawLettersInHalf(
row: TracingRow,
x: number,
y: number,
halfW: number,
) {
const n = row.cells.length;
if (n === 0) return;
const slotW = halfW / n;
for (let i = 0; i < n; i++) {
const cell = row.cells[i];
const color = i === 0 ? COLOR_BLACK : COLOR_LIGHT_RED;
const cx = x + slotW * i + slotW / 2;
drawLetterInFourLineGrid(
this.ctx,
cell.char,
cx,
y,
FOUR_LINE_GRID_H,
this.letterSizes,
{ fontFamily: LETTER_FACE, color },
);
}
}
}