cione-comp-lib
Version:
`$ yarn add cione-comp-lib` 或者 `$ npm i cione-comp-lib -S`
97 lines (96 loc) • 3.39 kB
JavaScript
import { platformApi } from "../../../../zrender/lib/core/platform.mjs";
var GRADIENT_LEVELS = 256;
var HeatmapLayer = function() {
function HeatmapLayer2() {
this.blurSize = 30;
this.pointSize = 20;
this.maxOpacity = 1;
this.minOpacity = 0;
this._gradientPixels = {
inRange: null,
outOfRange: null
};
var canvas = platformApi.createCanvas();
this.canvas = canvas;
}
HeatmapLayer2.prototype.update = function(data, width, height, normalize, colorFunc, isInRange) {
var brush = this._getBrush();
var gradientInRange = this._getGradient(colorFunc, "inRange");
var gradientOutOfRange = this._getGradient(colorFunc, "outOfRange");
var r = this.pointSize + this.blurSize;
var canvas = this.canvas;
var ctx = canvas.getContext("2d");
var len = data.length;
canvas.width = width;
canvas.height = height;
for (var i = 0; i < len; ++i) {
var p = data[i];
var x = p[0];
var y = p[1];
var value = p[2];
var alpha = normalize(value);
ctx.globalAlpha = alpha;
ctx.drawImage(brush, x - r, y - r);
}
if (!canvas.width || !canvas.height) {
return canvas;
}
var imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
var pixels = imageData.data;
var offset = 0;
var pixelLen = pixels.length;
var minOpacity = this.minOpacity;
var maxOpacity = this.maxOpacity;
var diffOpacity = maxOpacity - minOpacity;
while (offset < pixelLen) {
var alpha = pixels[offset + 3] / 256;
var gradientOffset = Math.floor(alpha * (GRADIENT_LEVELS - 1)) * 4;
if (alpha > 0) {
var gradient = isInRange(alpha) ? gradientInRange : gradientOutOfRange;
alpha > 0 && (alpha = alpha * diffOpacity + minOpacity);
pixels[offset++] = gradient[gradientOffset];
pixels[offset++] = gradient[gradientOffset + 1];
pixels[offset++] = gradient[gradientOffset + 2];
pixels[offset++] = gradient[gradientOffset + 3] * alpha * 256;
} else {
offset += 4;
}
}
ctx.putImageData(imageData, 0, 0);
return canvas;
};
HeatmapLayer2.prototype._getBrush = function() {
var brushCanvas = this._brushCanvas || (this._brushCanvas = platformApi.createCanvas());
var r = this.pointSize + this.blurSize;
var d = r * 2;
brushCanvas.width = d;
brushCanvas.height = d;
var ctx = brushCanvas.getContext("2d");
ctx.clearRect(0, 0, d, d);
ctx.shadowOffsetX = d;
ctx.shadowBlur = this.blurSize;
ctx.shadowColor = "#000";
ctx.beginPath();
ctx.arc(-r, r, this.pointSize, 0, Math.PI * 2, true);
ctx.closePath();
ctx.fill();
return brushCanvas;
};
HeatmapLayer2.prototype._getGradient = function(colorFunc, state) {
var gradientPixels = this._gradientPixels;
var pixelsSingleState = gradientPixels[state] || (gradientPixels[state] = new Uint8ClampedArray(256 * 4));
var color = [0, 0, 0, 0];
var off = 0;
for (var i = 0; i < 256; i++) {
colorFunc[state](i / 255, true, color);
pixelsSingleState[off++] = color[0];
pixelsSingleState[off++] = color[1];
pixelsSingleState[off++] = color[2];
pixelsSingleState[off++] = color[3];
}
return pixelsSingleState;
};
return HeatmapLayer2;
}();
var HeatmapLayer$1 = HeatmapLayer;
export { HeatmapLayer$1 as default };