zoom-image-data
Version:
zoom-image-data
109 lines (108 loc) • 3.5 kB
JavaScript
import { TransferToWindow } from 'transfer-to-window';
class ZoomImageData extends TransferToWindow {
constructor(param) {
const cellWH = param.cellWH || 10;
const cellRatio = param.cellRatio || 1;
let cellW = cellWH;
let cellH = cellWH;
if (cellRatio > 1) {
cellH = ~~(cellW / cellRatio);
}
else {
cellW = ~~(cellH * cellRatio);
}
super(Object.assign(Object.assign({}, param), { inw: cellW * param.inw, inh: cellH * param.inh, cellW,
cellH }), true);
const { inw, inh, inData, outData, splitCell, splitCellSize } = param;
this.sourceW = inw;
this.sourceH = inh;
this.sourceData = new Uint32Array(inData);
this.outData = new Uint32Array(outData);
this.splitCell = splitCell || false;
this.splitCellSize = splitCellSize || 2;
this.resize(true);
}
/**
* Update outputData
*/
update() {
const { sourceData, sourceW, sourceH, outData, outw, outh, invScaleX, invScaleY, invDx, invDy, splitCell, splitCellSize, } = this;
const splitX = splitCell && (1 / invScaleX) > splitCellSize;
const splitY = splitCell && (1 / invScaleY) > splitCellSize;
let lr = -1;
for (let i = 0; i < outh; i++) {
const r = Math.floor((i * invScaleY + invDy));
if (r < 0 || r >= sourceH ||
(splitY && lr !== r)) {
outData.fill(0, i * outw, (i + 1) * outw);
lr = r;
continue;
}
lr = r;
let lc = -1;
for (let j = 0; j < outw; j++) {
const c = Math.floor((j * invScaleX + invDx));
let index = i * outw + j;
if (c < 0 || c >= sourceW ||
(splitX && lc !== c)) {
outData[index] = 0;
lc = c;
continue;
}
lc = c;
outData[index] = sourceData[r * sourceW + c];
}
}
}
/**
* Translate on outdata
* @param dx
* @param dy
* @param silent Whether update outData
*/
translate(dx, dy, silent) {
super.translate(dx, dy);
silent || this.update();
}
/**
* Scale ratio multiple at position(cx,cy) on outdata
* @param cx
* @param cy
* @param ratio
* @param silent Whether update outData
*/
zoom(cx, cy, ratio, silent) {
super.zoom(cx, cy, ratio);
silent || this.update();
}
/**
* 以InCoor：(cx,cy)为中心缩放到scale比例
* @param cx
* @param cy
* @param scale
* @param silent 是否更新outData
*/
zoomToByInCoor(cx, cy, scale, silent) {
super.zoomToByInCoor(cx, cy, scale);
silent || this.update();
}
/**
* 将输入数据完整放置于输出窗口的正中间；效果类似于CSS效果：
* background-size: contain;
* background-repeat: no-repeat;
* background-position: center;
* @param silent Whether update outData
*/
resize(silent) {
super.resize();
silent || this.update();
}
/**
* 坐标(x,y)是否位于输入视框内
*/
inCoorIsIn(x, y) {
const { sourceW, sourceH } = this;
return x >= 0 && x < sourceW && y >= 0 && y < sourceH;
}
}
export { ZoomImageData, ZoomImageData as default };