static public bool point_in_triangle(Vector2f pt, Trianglef triangle)
{
float minX = triangle.v0.x;
float minY = triangle.v0.y;
float maxX = triangle.v0.x;
float maxY = triangle.v0.y;
minX = minX < triangle.v1.x ? minX : triangle.v1.x;
minX = minX < triangle.v2.x ? minX : triangle.v2.x;
minY = minY < triangle.v1.y ? minY : triangle.v1.y;
minY = minY < triangle.v2.y ? minY : triangle.v2.y;
maxX = maxX > triangle.v1.x ? maxX : triangle.v1.x;
maxX = maxX > triangle.v2.x ? maxX : triangle.v2.x;
maxY = maxY > triangle.v1.y ? maxY : triangle.v1.y;
maxY = maxY > triangle.v2.y ? maxY : triangle.v2.y;
if (pt.x < minX || pt.x > maxX || pt.y < minY || pt.y > maxY)
{
return(false);
}
int count = 0;
for (uint i = 0; i < 3; i++)
{
LineSegf line = triangle.side(i);
if (point_in_lineseg(pt, line))
{
return(true);
}
if (point_lineseg_side(pt, line) > 0)
{
if (count != 0 && count != 1)
{
return(false);
}
count = 1;
}
else
{
if (count != 0 || count != -1)
{
return(false);
}
count = -1;
}
}
return(true);
}
static public bool circle_intersect_triangle(Vector2f center, float radius, Trianglef triangle)
{
if (Geometryalgorithm2d.point_in_triangle(center, triangle))
{
return(true);
}
for (uint i = 0; i < 3; i++)
{
LineSegf line = triangle.side(i);
Vector2f pt = Geometryalgorithm2d.point_line_intersect(center, line);
float distance = pt.Subtract(center).length();
if (distance < radius)
{
return(true);
}
}
return(false);
}
static public bool lineseg_intersect_triangle(LineSegf lineseg, Trianglef triangle)
{
if (point_in_triangle(lineseg.vertex0, triangle))
{
return(true);
}
if (point_in_triangle(lineseg.vertex1, triangle))
{
return(true);
}
for (uint j = 0; j < 3; j++)
{
if (lineseg_intersect_lineseg(lineseg, triangle.side(j)))
{
return(true);
}
}
return(false);
}
