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 rectangle_in_rectangle_by_triangle(Vector2f p1_r1, Vector2f p2_r1,
Vector2f p3_r1, Vector2f p4_r1, Vector2f p1_r2, Vector2f p2_r2,
Vector2f p3_r2, Vector2f p4_r2)
{
Vector2f center_r1 = new Vector2f((p3_r1.x + p1_r1.x) / 2, (p3_r1.y + p1_r1.y) / 2);
Vector2f center_r2 = new Vector2f((p3_r2.x + p1_r2.x) / 2, (p3_r2.y + p1_r2.y) / 2);
Trianglef triangle = new Trianglef();
triangle.v0 = p1_r1;
triangle.v1 = p2_r1;
triangle.v2 = p3_r1;
if (point_in_triangle(center_r2, triangle))
{
return(true);
}
triangle.v0 = p1_r1;
triangle.v1 = p4_r1;
triangle.v2 = p3_r1;
if (point_in_triangle(center_r2, triangle))
{
return(true);
}
triangle.v0 = p1_r2;
triangle.v1 = p2_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(center_r1, triangle))
{
return(true);
}
triangle.v0 = p1_r2;
triangle.v1 = p4_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(center_r1, triangle))
{
return(true);
}
return(false);
}
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);
}
static public bool lineseg_intersect_rectangle_by_triangle(Vector2f p1_l1, Vector2f p2_l1,
Vector2f p1_r2, Vector2f p2_r2,
Vector2f p3_r2, Vector2f p4_r2)
{
Trianglef triangle = new Trianglef();
triangle.v0 = p1_r2;
triangle.v1 = p2_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(p1_l1, triangle))
{
return(true);
}
triangle.v0 = p1_r2;
triangle.v1 = p4_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(p1_l1, triangle))
{
return(true);
}
triangle.v0 = p1_r2;
triangle.v1 = p2_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(p2_l1, triangle))
{
return(true);
}
triangle.v0 = p1_r2;
triangle.v1 = p4_r2;
triangle.v2 = p3_r2;
if (point_in_triangle(p2_l1, triangle))
{
return(true);
}
LineSegf l1 = new LineSegf();
LineSegf l2 = new LineSegf();
l1.vertex0 = p1_l1;
l1.vertex1 = p2_l1;
l2.vertex0 = p1_r2;
l2.vertex1 = p2_r2;
if (lineseg_intersect_lineseg(l1, l2))
{
return(true);
}
l2.vertex0 = p2_r2;
l2.vertex1 = p3_r2;
if (lineseg_intersect_lineseg(l1, l2))
{
return(true);
}
l2.vertex0 = p3_r2;
l2.vertex1 = p4_r2;
if (lineseg_intersect_lineseg(l1, l2))
{
return(true);
}
l2.vertex0 = p4_r2;
l2.vertex1 = p1_r2;
if (lineseg_intersect_lineseg(l1, l2))
{
return(true);
}
return(false);
}
public void printTriangleWireframe(Trianglef triangle, Vec3f color)
{
printLine(new Linef(triangle.v0, triangle.v1), color);
printLine(new Linef(triangle.v1, triangle.v2), color);
printLine(new Linef(triangle.v2, triangle.v0), color);
}
