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SYS_Math.subtract() method

Calculate the difference of two polygons (polygon1 - polygon2)

Signature

function subtract(
	polygon1: TSYS_MathPolygonInput,
	polygon2: TSYS_MathPolygonInput,
): TSYS_MathPolygonGroup;

Parameters

Parameter	Type	Description
polygon1	TSYS_MathPolygonInput	Minuend polygon
polygon2	TSYS_MathPolygonInput	Subtrahend polygon

Returns

TSYS_MathPolygonGroup

Polygon group of the difference result, preserving the association between outer rings and holes

Example

// 1. 大矩形铺铜区域与一个完全落在其内部的矩形开孔区
const copper = [{ x: 0, y: 0 }, { x: 100, y: 0 }, { x: 100, y: 80 }, { x: 0, y: 80 }];
const hole = [{ x: 30, y: 20 }, { x: 70, y: 20 }, { x: 70, y: 60 }, { x: 30, y: 60 }];

// 2. 挖孔：差集结果的多边形组里，开孔区被记为孔洞
const cut = eda.sys_Math.subtract(copper, hole);
console.log('差集结果多边形个数：', cut.length);
console.log('孔洞数：', cut[0].holes.length);

// 3. 挖孔后的净面积：100 x 80 - 40 x 40 = 6400
console.log('挖孔后的净面积：', eda.sys_Math.calculateArea(cut));

// 4. 减去完全分离的多边形不产生任何变化（结果仍是原形状的等价组）
const far = [{ x: 200, y: 0 }, { x: 280, y: 0 }, { x: 280, y: 40 }, { x: 200, y: 40 }];
const untouched = eda.sys_Math.subtract(copper, far);
console.log('减去分离区域后的面积：', eda.sys_Math.calculateArea(untouched));