vue3组件
javascript
<v-stage
id="konva_stage"
:config="konvaConfig"
ref="konvaStageRef"
@wheel="wheelForScale($event)"
>
<v-layer>
<v-group :config="group">
<v-image
:config="{
image: pgmImage,
}"
/>
</v-group>
</v-layer>
</v-stage>- Blob 对象（推荐）
javascript
if (data instanceof Blob) {
const url = URL.createObjectURL(data);
pgmImage.value = new Image();
pgmImage.value.src = url;
pgmImage.value.onload = function () {
console.log("pgmImage.width", pgmImage.value.naturalWidth);
console.log("pgmImage.height", pgmImage.value.naturalHeight);
};
}2.base64(此种方式，读取图片内容转换成base64格式会比原图片大大概1/3)
javascript
const base64Str = imgData; // imgData 从后端接口或者websocket 上报数据
pgmImage.value = new Image();
pgmImage.value.src = base64Str;
pgmImage.value.onload = ()=> {
// 获取图片参数 参与逻辑操作
}- pgm 这种非常不推荐pgm本身比其他图片格式大，且不能压缩处理，对图片较大情况下非常不友好！
解析接口传递过来的pgm 数据
javascript
const MapImage = function (data) {
let exp = /^(\S+)\s+(\#.*?\n)*\s*(\d+)\s+(\d+)\s+(\d+)?\s*/;
let match = data && data.match(exp);
if (match) {
let width = (this.width = parseInt(match[3], 10));
let height = (this.height = parseInt(match[4], 10));
let maxVal = parseInt(match[5], 10);
let bytes = maxVal < 256 ? 1 : 2;
let imgData = data.substr(match[0].length);
switch (match[1]) {
case "P1":
this._parser = new ASCIIParser(maxVal + " " + imgData, bytes);
this._formatter = new PBMFormatter(width, height);
break;
case "P2":
this._parser = new ASCIIParser(imgData, bytes);
this._formatter = new PGMFormatter(width, height, maxVal);
break;
case "P3":
this._parser = new ASCIIParser(imgData, bytes);
this._formatter = new PPMFormatter(width, height, maxVal);
break;
case "P4":
this._parser = new BinaryParser(imgData, bytes);
this._formatter = new PBMFormatter(width, height);
break;
case "P5":
this._parser = new BinaryParser(imgData, bytes);
this._formatter = new PGMFormatter(width, height, maxVal);
break;
case "P6":
this._parser = new BinaryParser(data, bytes);
this._formatter = new PPMFormatter(width, height, maxVal);
break;
default:
throw new TypeError(
"Sorry, your file format is not supported. [" + match[1] + "]"
);
}
} else {
throw new TypeError("Sorry, file does not appear to be a Netpbm file.");
}
};
MapImage.prototype.getInitMap = function (type = "image") {
let canvas = this._formatter.getPainting(this._parser, type);
return canvas;
};
const BinaryParser = function (data, bytes) {
this._data = data;
this._bytes = bytes;
this._pointer = 0;
};
BinaryParser.prototype.getNextSample = function () {
if (this._pointer >= this._data.length) return false;
let val = 0;
for (let i = 0; i < this._bytes; i++) {
val = val * 255 + this._data.charCodeAt(this._pointer++);
}
return val;
};
const ASCIIParser = function (data, bytes) {
this._data = data.split(/\s+/);
this._bytes = bytes;
this._pointer = 0;
};
ASCIIParser.prototype.getNextSample = function () {
if (this._pointer >= this._data.length) return false;
let val = 0;
for (let i = 0; i < this._bytes; i++) {
val = val * 255 + parseInt(this._data[this._pointer++], 10);
}
return val;
};
const PPMFormatter = function (width, height, maxVal) {
this._width = width;
this._height = height;
this._maxVal = maxVal;
};
PPMFormatter.prototype.getPainting = function (parser, type) {
let paintData = null;
let canvas = null;
let ctx = null;
let img = null;
if (type === "canvas") {
canvas = document.createElement("canvas");
ctx = canvas.getContext("2d");
canvas.width = ctx.width = this._width;
canvas.height = ctx.height = this._height;
paintData = ctx.getImageData(0, 0, this._width, this._height);
} else {
paintData = new Uint8ClampedArray(this._width * this._height * 4);
}
let dataArr = type === "canvas" ? paintData.data : paintData;
for (let row = 0; row < this._height; row++) {
for (let col = 0; col < this._width; col++) {
let factor = 255 / this._maxVal;
let r = factor * parser.getNextSample();
let g = factor * parser.getNextSample();
let b = factor * parser.getNextSample();
let pos = (row * this._width + col) * 4;
dataArr[pos] = r;
dataArr[pos + 1] = g;
dataArr[pos + 2] = b;
dataArr[pos + 3] = 255;
}
}
if (type === "canvas") {
ctx.putImageData(paintData, 0, 0);
return canvas;
} else {
img = new ImageData(paintData, this._width, this._height);
return img;
}
};
const PGMFormatter = function (width, height, maxVal) {
this._width = width;
this._height = height;
this._maxVal = maxVal;
};
PGMFormatter.prototype.getPainting = function (parser, type) {
let paintData = null;
let canvas = null;
let ctx = null;
let img = null;
if (type === "canvas") {
canvas = document.createElement("canvas");
ctx = canvas.getContext("2d");
canvas.width = ctx.width = this._width;
canvas.height = ctx.height = this._height;
paintData = ctx.getImageData(0, 0, this._width, this._height);
} else {
paintData = new Uint8ClampedArray(this._width * this._height * 4);
}
let dataArr = type === "canvas" ? paintData.data : paintData;
for (let row = 0; row < this._height; row++) {
for (let col = 0; col < this._width; col++) {
let d = parser.getNextSample() * (255 / this._maxVal);
let pos = (row * this._width + col) * 4;
dataArr[pos] = d;
dataArr[pos + 1] = d;
dataArr[pos + 2] = d;
dataArr[pos + 3] = 255;
}
}
if (type === "canvas") {
ctx.putImageData(paintData, 0, 0);
return canvas;
} else {
img = new ImageData(paintData, this._width, this._height);
return img;
}
};
const PBMFormatter = function (width, height) {
this._width = width;
this._height = height;
};
PBMFormatter.prototype.getPainting = function (parser, type) {
let paintData = null;
let canvas = null;
let ctx = null;
let img = null;
if (type === "canvas") {
canvas = document.createElement("canvas");
ctx = canvas.getContext("2d");
canvas.width = ctx.width = this._width;
canvas.height = ctx.height = this._height;
paintData = ctx.getImageData(0, 0, this._width, this._height);
}
if (parser instanceof BinaryParser) {
let data = "";
let byte = null;
let bytesPerLine = Math.ceil(this._width / 8);
for (let i = 0; i < this._height; i++) {
let line = parser._data.substr(i * bytesPerLine, bytesPerLine);
let lineData = "";
for (let j = 0; j < line.length; j++)
lineData += ("0000000" + line.charCodeAt(j).toString(2)).substr(-8);
data += lineData.substr(0, this._width);
}
while ((byte = parser.getNextSample()) !== false) {
data += ("0000000" + byte.toString(2)).substr(-8);
}
parser = new ASCIIParser(data.split("").join(" "), 1);
}
let dataArr = type === "canvas" ? paintData.data : paintData;
for (let row = 0; row < this._height; row++) {
for (let col = 0; col < this._width; col++) {
let d = (1 - parser.getNextSample()) * 255;
let pos = (row * this._width + col) * 4;
dataArr[pos] = d;
dataArr[pos + 1] = d;
dataArr[pos + 2] = d;
dataArr[pos + 3] = 255;
}
}
if (type === "canvas") {
ctx.putImageData(paintData, 0, 0);
return canvas;
} else {
img = new ImageData(paintData, this._width, this._height);
return img;
}
};
export { MapImage };vue2 使用方式：
javascript
if (pgmImageData) { //pgmImageData 接口返回
let img = new MapImage(pgmImageData);
let canvasImg = img.getInitMap("canvas");
// canvasImg.width, canvasImg.height
this.konvaConfig.pgmImage = new Image();
this.konvaConfig.pgmImage.src = canvasImg.toDataURL();
}