修复复杂字体渲染设备端乱序问题

This commit is contained in:
微微一笑
2025-11-04 19:30:47 +08:00
parent 2218ca0650
commit d06cd6cdfd
2 changed files with 100 additions and 43 deletions

View File

@ -59,6 +59,8 @@
* 清除Canvas内容
*/
clearCanvas() {
// 先清除,再用背景色填充,确保无残留
this.ctx.clearRect(0, 0, this.currentCanvasWidth, this.currentCanvasHeight);
this.ctx.setFillStyle(this.bgColor);
this.ctx.fillRect(0, 0, this.currentCanvasWidth, this.currentCanvasHeight);
},
@ -67,6 +69,9 @@
* 复用单个Canvas处理所有文本行
*/
async drawAndGetPixels() {
// 超采样比例(提高分辨率再降采样,减少模糊)
const SCALE = 3;
const PADDING_X = 1 * SCALE; // 左侧预留像素,避免首字裁剪
let binaryToHex = (binaryArray) => {
if (!Array.isArray(binaryArray) || binaryArray.length !== 8) {
throw new Error("输入必须是包含8个元素的二进制数组");
@ -90,25 +95,61 @@
return hexString;
}
let convertCharToMatrix = (imageData, item) => {
let convertCharToMatrix = (drawResult, item) => {
const charWidth = 13;
const charHeight = 12;
const pixels = [];
for (let i = 0; i < imageData.length; i += 4) {
const R = imageData[i];
pixels.push(R < 128 ? 1 : 0);
const { pixelData, width, height } = drawResult;
// 将高分辨率像素降采样为13x12的布尔矩阵
const target = new Array(charWidth * charHeight).fill(0);
const threshold = 0.5; // 每个小块中超过50%深色判为1
// 确保采样区域严格对齐从PADDING_X开始但只采样13列
for (let y = 0; y < charHeight; y++) {
for (let x = 0; x < charWidth; x++) {
let onCount = 0;
let total = 0;
// 采样区域字符从PADDING_X开始绘制每列宽度为SCALE
const startX = PADDING_X + x * SCALE;
const startY = y * SCALE;
for (let sy = 0; sy < SCALE; sy++) {
for (let sx = 0; sx < SCALE; sx++) {
const px = startX + sx;
const py = startY + sy;
if (px < 0 || py < 0 || px >= width || py >= height) {
// 边界外视为背景(白色)
continue;
}
const idx = (py * width + px) * 4;
const R = pixelData[idx];
const G = pixelData[idx + 1];
const B = pixelData[idx + 2];
const A = pixelData[idx + 3] || 255;
// 使用更严格的阈值考虑alpha通道
const luminance = 0.299 * R + 0.587 * G + 0.114 * B;
const alpha = A / 255;
// 只有深色且不透明才计入
if (luminance < 128 && alpha > 0.5) onCount++;
total++;
}
}
// 当深色占比超过阈值时判为1至少需要采样到一些像素
target[y * charWidth + x] = (total > 0 && onCount / total >= threshold) ? 1 : 0;
}
}
const lowBytes = new Array(charWidth).fill(0);
const highBytes = new Array(charWidth).fill(0);
// 按列打包每列12行分成上下两字节
for (let col = 0; col < charWidth; col++) {
for (let row = 0; row < charHeight; row++) {
const pixel = pixels[row * charWidth + col];
const pixel = target[row * charWidth + col];
if (pixel === 1) {
if (row < 8) {
// 低字节0-7行从低位到高位
lowBytes[col] |= (1 << row);
} else {
// 高字节8-11行从低位到高位
highBytes[col] |= (1 << (row - 8));
}
}
@ -121,30 +162,26 @@
let result = {};
let ctx = this.ctx;
// 1. 动态调整Canvas尺寸
this.currentCanvasWidth = 13;
this.currentCanvasHeight = 12;
// 1. 动态调整Canvas尺寸(高分辨率)
this.currentCanvasWidth = 13 * SCALE + PADDING_X;
this.currentCanvasHeight = 12 * SCALE;
// 2. 清空Canvas绘制背景
this.clearCanvas();
// 3. 设置文字样式
// 3. 设置文字样式(整数像素对齐,顶部基线,避免首字裁剪)
ctx.setFillStyle(this.color);
ctx.setTextBaseline('middle');
// ctx.setTextAlign('center')
ctx.setFontSize(this.fontSize);
ctx.font = `${this.fontSize}px "PingFangBold", "PingFang SC", Arial, sans-serif`;
ctx.setTextBaseline('top');
ctx.setTextAlign('left');
const fs = Math.max(1, Math.round(this.fontSize)) * SCALE;
ctx.setFontSize(fs);
ctx.font = `${fs}px "PingFangBold", "PingFang SC", Arial, sans-serif`;
// 4. 绘制当前行文本
let currentX = 0;
let currentY = this.fontSize / 2 + 1;
for (let j = 0; j < textLine.length; j++) {
let char = textLine[j];
ctx.fillText(char, currentX, currentY);
// 按实际字符宽度计算间距
let charWidth = ctx.measureText(char).width;
currentX += charWidth;
}
// 4. 绘制单个字符(每个字符独立绘制在固定位置)
// 确保字符始终从PADDING_X开始绘制Y坐标为0保证采样一致性
const charX = PADDING_X;
const charY = 0;
ctx.fillText(textLine, charX, charY);
// 5. 异步绘制并获取像素数据(串行处理避免冲突)
await new Promise((resolve, reject) => {
@ -156,12 +193,12 @@
width: this.currentCanvasWidth,
height: this.currentCanvasHeight,
success: res => {
result = {
line: textLine,
pixelData: res.data,
width: this.currentCanvasWidth,
height: this.currentCanvasHeight
};
result = {
line: textLine,
pixelData: res.data,
width: this.currentCanvasWidth,
height: this.currentCanvasHeight
};
resolve();
},
fail: err => {
@ -182,8 +219,12 @@
let item = this.validTxts[i];
// console.log("item=", item);
for (var j = 0; j < item.length; j++) {
let result = await drawTxt(item[j]);
linePixls.push(convertCharToMatrix(result.pixelData, item));
let char = item[j];
let result = await drawTxt(char);
let matrix = convertCharToMatrix(result, item);
// 调试:打印每个字符的点阵数据
console.log(`[点阵生成] 字符"${char}" 点阵数据:`, matrix.map(b => '0x' + b.toString(16).padStart(2, '0')).join(' '));
linePixls.push(matrix);
}
// console.log("hexs=", linePixls.join(","));
arr.push(linePixls);