feat: 新增幼儿测字表

miniprogram/core/draw/baseDraw.ts

@@ -16,6 +16,37 @@ import drawHeader from './drawHeader';
 const LINE_COLOR = '#BCBAB2'; // 打印友好的深灰线色，避免渐变色
 const LINE_WIDTH = 3;
 
+/** 品牌水印模式：A 右下角醒目；B 页面中央大号旋转浅水印（默认） */
+export type BrandWatermarkMode = 'A' | 'B';
+
+export interface DrawPrintFooterOptions {
+    /** 默认 B */
+    mode?: BrandWatermarkMode;
+    /** 品牌文案，默认「涂鸦丫小程序」 */
+    text?: string;
+    opacity?: number;
+    fontSize?: number;
+}
+
+const BRAND_TEXT = '涂鸦丫小程序';
+const BRAND_COLOR = '#7C766A';
+
+/** 方案 A：右下角单行品牌水印 */
+const FOOTER_MODE_A = {
+    fontSize: 20,
+    opacity: 0.12,
+    marginRight: 24,
+    marginBottom: 20,
+} as const;
+
+/** 方案 B：页面中央大号旋转浅水印，单行居中 */
+const FOOTER_MODE_B = {
+    fontSize: 32,
+    opacity: 0.12,
+    rotationDeg: -25,
+    centerYRatio: 0.52,
+} as const;
+
 export class BaseDrawService {
     canvas: WechatMiniprogram.Canvas;
     ctx: RenderingContext;
@@ -174,24 +205,69 @@ export class BaseDrawService {
     }
 
     /**
-     * 页脚：页面底部居中绘制品牌文案「涂鸦丫小程序」（粗体）。
+     * 品牌水印页脚（默认「涂鸦丫小程序」单行）。
+     * - A：右下角水印，适合有底部页码的页面
+     * - B：页面中央大号旋转浅水印（默认）
      * 请在整页正文绘制完成后调用，避免被内容覆盖。
      */
-    async drawPrintFooter(): Promise<void> {
+    drawPrintFooter(options?: DrawPrintFooterOptions): void {
+        const mode = options?.mode ?? 'A';
+        const text = options?.text ?? BRAND_TEXT;
+
+        if (mode === 'A') {
+            this.drawPrintFooterModeA(text, options);
+        } else {
+            this.drawPrintFooterModeB(text, options);
+        }
+    }
+
+    /** 方案 A：右下角单行品牌水印 */
+    private drawPrintFooterModeA(
+        text: string,
+        options?: DrawPrintFooterOptions,
+    ): void {
         const { ctx, canvasWidth, canvasHeight } = this;
-        const text = '涂鸦丫小程序';
-        const bottomMargin = 12;
-        const fontSize = 13;
+        const fontSize = options?.fontSize ?? FOOTER_MODE_A.fontSize;
+        const opacity = options?.opacity ?? FOOTER_MODE_A.opacity;
+        const { marginRight, marginBottom } = FOOTER_MODE_A;
         const font = `bold ${fontSize}px "Microsoft Yahei", sans-serif`;
-        const textColor = '#7C766A';
 
         ctx.save();
         ctx.font = font;
-        ctx.fillStyle = textColor;
+        ctx.fillStyle = BRAND_COLOR;
+        ctx.globalAlpha = opacity;
+        ctx.textAlign = 'right';
+        ctx.textBaseline = 'bottom';
+        ctx.fillText(
+            text,
+            canvasWidth - marginRight,
+            canvasHeight - marginBottom,
+        );
+        ctx.restore();
+    }
+
+    /** 方案 B：页面中央大号旋转浅水印，单行居中 */
+    private drawPrintFooterModeB(
+        text: string,
+        options?: DrawPrintFooterOptions,
+    ): void {
+        const { ctx, canvasWidth, canvasHeight } = this;
+        const fontSize = options?.fontSize ?? FOOTER_MODE_B.fontSize;
+        const opacity = options?.opacity ?? FOOTER_MODE_B.opacity;
+        const { rotationDeg, centerYRatio } = FOOTER_MODE_B;
+        const font = `bold ${fontSize}px "Microsoft Yahei", sans-serif`;
+        const centerX = canvasWidth / 2;
+        const centerY = canvasHeight * centerYRatio;
+
+        ctx.save();
+        ctx.font = font;
+        ctx.fillStyle = BRAND_COLOR;
+        ctx.globalAlpha = opacity;
         ctx.textAlign = 'center';
         ctx.textBaseline = 'middle';
-        const y = canvasHeight - bottomMargin - fontSize / 2;
-        ctx.fillText(text, canvasWidth / 2, y);
+        ctx.translate(centerX, centerY);
+        ctx.rotate((rotationDeg * Math.PI) / 180);
+        ctx.fillText(text, 0, 0);
         ctx.restore();
     }