doodle-mini/miniprogram/service/textDrawService.ts

/**
 * 找一找涂色，文字涂色服务
 * 根据文字列表绘制到Canvas
 */

import { BaseDrawService } from '../core/draw/baseDraw';
/**
 * 计算示例区域圆的中心点
 * @param canvasWidth 画布宽度（逻辑像素）
 * @param circleCount 圆的数量
 * @param padding 圆的间距（逻辑像素）
 * @param radius 圆的半径（逻辑像素）
 * @returns 圆的中心点
 */
function calculateCircleCenters(
    canvasWidth: number,
    circleCount: number,
    padding: number,
    radius: number,
) {
    const availableWidth = canvasWidth - 2 * padding;
    const maxSpacing = 5.5 * radius;
    const centers = [];

    if (circleCount === 1) {
        centers.push(canvasWidth / 2);
    } else {
        const requiredSpace = 2 * radius * circleCount;
        const spaceBetween =
            (availableWidth - requiredSpace) / (circleCount - 1);

        if (spaceBetween > maxSpacing) {
            const totalWidth = 2 * radius + (circleCount - 1) * maxSpacing;
            const startX = (canvasWidth - totalWidth) / 2 + radius;

            for (let i = 0; i < circleCount; i++) {
                centers.push(startX + i * maxSpacing);
            }
        } else {
            const startX = padding + radius;

            for (let i = 0; i < circleCount; i++) {
                centers.push(startX + i * (spaceBetween + 2 * radius));
            }
        }
    }

    return centers;
}

class TextDrawService extends BaseDrawService {
    colors: string[];
    characters: string[];

    constructor(
        canvas: Canvas,
        ctx: RenderingContext,
        options?: Record<string, any>,
    ) {
        options = options || {};
        super(canvas, ctx, {
            title: '找一找  涂  色',
            subTitle: '给文字涂上相同的颜色',
            ...options,
        });
        this.colors = ['#000'];
        this.characters = ['王'];
    }

    async draw(list: Array<{ color: string; word: string }>) {
        this.setPrintConfig();

        this.colors = list.map((item) => item.color || '#000');
        this.characters = list.map((item) => item.word || '日');
        this.clear();
        this.setPaper();

        await this.drawHeader();
        this.drawDivider();
        this.drawLegend();
        this.drawContent();
        await this.drawPrintFooter();
    }

    /** 绘制示例
     * 矩形： x、y为左上角
     * 圆形：x、y为圆心
     * 文字：x textAlign 为 start，文本左边缘对齐
     *      y textBaseline 为 alphabetic，y 对应字母基线（类似左下角）
     *
     * 注意：所有尺寸已转换为逻辑像素（除以3）
     *  */
    drawLegend() {
        const { ctx, colors, characters } = this;
        if (characters.length <= 0) return;

        const legendTopY = this.currentY;
        const radius = 22; // 65/3≈22
        const rectWidth = 60; // 180/3=60
        const rectHeight = 27; // 80/3≈27
        const startX = 87 + radius; // (260+65)/3≈108
        const startY = legendTopY + 10 + radius; // (30+65)/3≈32
        const len = characters.length || 4;
        const centers = calculateCircleCenters(
            this.canvasWidth,
            len,
            73,
            radius,
        ); // 220/3≈73

        /** 计算每个圆之间的间距 */
        const spaceWidth =
            len > 3 ? (this.canvasWidth - startX * 2) / (len - 1) : 0;

        ctx.moveTo(startX, startY);
        colors.forEach((color: string, index: number) => {
            const x = centers[index] || startX + index * spaceWidth;
            const y = startY;
            // 绘制圆
            ctx.strokeStyle = '#000';
            ctx.fillStyle = color;
            ctx.lineWidth = 1; // 4/3≈1
            ctx.beginPath();
            ctx.arc(x, y, radius, 0, Math.PI * 2);
            ctx.fill();
            ctx.stroke();
            ctx.closePath();

            // 绘制长方形
            ctx.fillStyle = '#fff';
            ctx.strokeStyle = '#000';
            ctx.lineWidth = 1; // 4/3≈1
            const rectangleX = x - rectWidth / 2;
            const rectangleY = y + radius + 14; // 43/3≈14
            ctx.strokeRect(rectangleX, rectangleY, rectWidth, rectHeight);

            // 绘制字符
            ctx.fillStyle = '#333';
            ctx.font = 'bold 16px "Microsoft Yahei"'; // 48/3=16
            ctx.textBaseline = 'middle';
            ctx.textAlign = 'center';
            ctx.fillText(
                characters[index],
                rectangleX + rectWidth / 2,
                rectangleY + rectHeight / 2,
                rectWidth,
            );
        });

        this.currentY = startY + radius + 14 + rectHeight + 24;
        this.drawDivider();
    }

    drawContent() {
        const { ctx, characters } = this;
        if (characters.length <= 0) return;

        const len = characters.length;
        const rows = 8;
        const radius = 27; // 80/3≈27
        const fontSize = 24; // 72/3=24

        const startY = this.currentY + 10 + radius; // 62/3≈21
        const startX1 = 103 + radius; // 310/3≈103
        const startX2 = 67 + radius; // 200/3≈67
        const spaceWidthFrist = (this.canvasWidth - startX1 * 2) / (5 - 1);
        const spaceWidthSecond = (this.canvasWidth - startX2 * 2) / (6 - 1);
        const spaceHeight = 18; // 54/3=18

        ctx.moveTo(startX1, startY);
        for (let i = 0; i < rows; i++) {
            const cols = i % 2 === 0 ? 5 : 6;

            for (let j = 0; j < cols; j++) {
                const y = startY + i * (spaceHeight + radius * 2);
                const x =
                    i % 2 === 0
                        ? startX1 + j * spaceWidthFrist
                        : startX2 + j * spaceWidthSecond;

                const character = characters[Math.floor(Math.random() * len)];

                ctx.fillStyle = '#fff';
                ctx.strokeStyle = '#000';
                ctx.lineWidth = 1; // 4/3≈1
                ctx.beginPath();
                ctx.arc(x, y, radius, 0, Math.PI * 2);
                ctx.fill();
                ctx.stroke();
                ctx.closePath();

                ctx.fillStyle = '#333';
                ctx.font = `${fontSize}px "Microsoft Yahei"`;
                ctx.textBaseline = 'middle';
                ctx.textAlign = 'center';
                ctx.fillText(character, x, y, radius * 2);
            }
        }
    }

    // drawLine 已由基类的 drawDivider 替代，保留此方法以保持兼容
    drawLine(linY: number) {
        this.drawDivider();
    }
}

export default TextDrawService;