canvas/pages/index/transform-matrix.js

57 lines
1.2 KiB
JavaScript

class TransformMatrix {
constructor() {
this.reset();
}
reset() {
this.a = 1; // 水平缩放
this.b = 0; // 垂直倾斜
this.c = 0; // 水平倾斜
this.d = 1; // 垂直缩放
this.tx = 0; // 水平移动
this.ty = 0; // 垂直移动
this.stack = [];
}
translate(dx, dy) {
this.tx += this.a * dx + this.c * dy;
this.ty += this.b * dx + this.d * dy;
}
scale(sx, sy, cx = 0, cy = 0) {
// 移动到中心点
this.translate(cx, cy);
// 应用缩放
this.a *= sx;
this.b *= sx;
this.c *= sy;
this.d *= sy;
// 移回原位置
this.translate(-cx, -cy);
}
toArray() {
return [this.a, this.b, this.c, this.d, this.tx, this.ty];
}
// 用于调试的字符串表示
toString() {
return `[${this.a.toFixed(2)}, ${this.b.toFixed(2)}, ${this.c.toFixed(2)}, ${this.d.toFixed(2)}, ${this.tx.toFixed(1)}, ${this.ty.toFixed(1)}]`;
}
// 克隆方法
clone() {
const clone = new TransformMatrix();
clone.a = this.a;
clone.b = this.b;
clone.c = this.c;
clone.d = this.d;
clone.tx = this.tx;
clone.ty = this.ty;
return clone;
}
}
export default TransformMatrix;