71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
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#pragma once
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#include<hgl/math/Vector.h>
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namespace hgl
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{
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/*
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* 根据三角形的三边长计算三角形的面积
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*/
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inline const float TriangleArea(const float a,const float b,const float c)
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{
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const float s=(a+b+c)*0.5f;
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return sqrt(s*(s-a)*(s-b)*(s-c));
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}
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inline const float TriangleArea(const Vector2f &a,const Vector2f &b,const Vector2f &c)
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{
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return fabs((a.x-c.x)*(b.y-c.y)-(a.y-c.y)*(b.x-c.x))*0.5f;
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}
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inline const float TriangleArea(const Vector3f &a,const Vector3f &b,const Vector3f &c)
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{
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return glm::length(glm::cross(b-a,c-a))*0.5f;
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}
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inline const float RectangleArea(const float width,const float height)
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{
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return width*height;
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}
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inline const float RectangleArea(const Vector2f &size)
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{
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return size.x*size.y;
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}
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/**
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* 正圆面积计算
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* @param radius 半径
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*/
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inline const float CircleArea(const float radius)
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{
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return HGL_PI*radius*radius;
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}
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/**
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* 椭圆面积计算
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* @param l_radius 长半径
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* @param s_radius 短半径
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*/
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inline const float EllipseArea(const float horizontal_radius,const float vertical_radius)
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{
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return HGL_PI*horizontal_radius*vertical_radius;
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}
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inline const float EllipseArea(const Vector2f &radius)
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{
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return HGL_PI*radius.x*radius.y;
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}
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inline const float SectorArea(const float radius,const float angle)
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{
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return HGL_PI*radius*radius*angle/360.0f;
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}
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inline const float QuadArea(const Vector3f &a,const Vector3f &b,const Vector3f &c,const Vector3f &d)
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{
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return TriangleArea(a,b,c)+TriangleArea(a,c,d);
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}
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}//namespace hgl
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