[Math]Check if a point is inside regular hexagon

Keywords: Calculate point location to check if it’s inside hexagon, 计算坐标点是否在六边形内部

Diagram

code:

boolean IsInsideHexagon(float hX, float hY, float d, float pX, float pY) 
{
    float dx = Math.abs(pX - hX) / d;
    float dy = Math.abs(pY - hY) / d;
    float a = 0.25 * Math.sqrt(3.0);
    return (dy <= a) && (a * dx + 0.25 * dy <= 0.5 * a);
}

Explaination

• dy <= a checks that the point is below the horizontal edge.
• a * dx + 0.25 * dy <= 0.5 * a checks that the point is to the left of the sloped right edge.
• For {hX = 0, hY = 0, d = 1}, the corner points would be (±0.25, ±0.43) and (±0.5, 0.0).

Reference: Is a point inside regular hexagon
https://stackoverflow.com/a/5195868/1645289

经历过孤独的日子，我终于喜欢上自己的无知，与它们相处感到惬意，如同它是一炉旺火。这时就该听任火焰的缓缓燃烧，不说一句话表示自己对无论何事的看法。必须在无知中自我更新。——玛格丽特·杜拉斯（MargueriteDuras）