// Taken from http://forums.create.msdn.com/forums/t/7414.aspx?PageIndex=1
public static Shape CreateEllipse(Vector2 position, float semiMajorAxis, float semiMinorAxis, float angleOffset, int sides)
{
Shape s = new Shape();
float max = 2.0f * (float)Math.PI;
float step = max / (float)sides;
float h = 0.0f;
float k = 0.0f;
for (float t = 0.0f; t < max; t += step)
{
// center point: (h,k); add as argument if you want (to circumvent modifying this.Position)
// x = h + a*cos(t) -- a is semimajor axis, b is semiminor axis
// y = k + b*sin(t)
s._vertices.Add(position + new Vector2((float)(h + semiMajorAxis * Math.Cos(t)),
(float)(k + semiMinorAxis * Math.Sin(t))));
}
// then add the first vector again so it's a complete loop
s._vertices.Add(position + new Vector2((float)(h + semiMajorAxis * Math.Cos(step)),
(float)(k + semiMinorAxis * Math.Sin(step))));
// now rotate it as necessary
Matrix m = Matrix.CreateRotationZ(angleOffset);
for (int i = 0; i < s._vertices.Length; i++)
{
s._vertices[i] = Vector2.Transform((Vector2)s._vertices[i], m);
}
return s;
}
// Taken from http://forums.create.msdn.com/forums/t/7414.aspx?PageIndex=1
public static Shape CreateCircle(Vector2 position, float radius, int sides)
{
Shape s = new Shape();
float max = 2 * (float)Math.PI;
float step = max / (float)sides;
for (float theta = 0; theta < max; theta += step)
{
s._vertices.Add(position + new Vector2(radius * (float)Math.Cos((double)theta),
radius * (float)Math.Sin((double)theta)));
}
// then add the first vector again so it's a complete loop
s._vertices.Add(position + new Vector2(radius * (float)Math.Cos(0),
radius * (float)Math.Sin(0)));
return s;
}
public void DrawShape(Shape shape, Color color, float thickness)
{
if (shape.vertices.vertices == null) { return; }
Vector2 v1, v2, position, origin, scale;
float distance, angle;
for (int i = shape.vertices.Length - 1; i >= 1; --i)
{
v1 = shape.vertices[i - 1];
v2 = shape.vertices[i];
distance = Vector2.Distance(v1, v2);
angle = (float)Math.Atan2((double)(v2.Y - v1.Y),
(double)(v2.X - v1.X));
//origin = Vector2.One * 0.5f;
//position = v1 + 0.5f * (v2 - v1);
scale = new Vector2(distance, thickness);
_batch.Draw(_pixelTexture, v1, null, color, angle, new Vector2(0, 0.5f), scale, SpriteEffects.None, 0);
}
}
public static Shape CreateLine(Vector2 start, Vector2 end)
{
Shape s = new Shape();
s._vertices.Add(start);
s._vertices.Add(end);
return s;
}
public static Shape CreateTriangle(Vector2 a, Vector2 b, Vector2 c)
{
Shape s = new Shape();
s._vertices.Add(a);
s._vertices.Add(b);
s._vertices.Add(c);
s._vertices.Add(a);
return s;
}
public static Shape CreateRectangle(AABB aabb)
{
Shape s = new Shape();
s._vertices.Add(aabb.lowerBound);
s._vertices.Add(new Vector2(aabb.upperBound.X, aabb.lowerBound.Y));
s._vertices.Add(aabb.upperBound);
s._vertices.Add(new Vector2(aabb.lowerBound.X, aabb.upperBound.Y));
s._vertices.Add(aabb.lowerBound);
return s;
}
public static Shape CreateRectangle(Rectangle r)
{
Shape s = new Shape();
s._vertices.Add(new Vector2(r.Left, r.Top));
s._vertices.Add(new Vector2(r.Right, r.Top));
s._vertices.Add(new Vector2(r.Right, r.Bottom));
s._vertices.Add(new Vector2(r.Left, r.Bottom));
s._vertices.Add(new Vector2(r.Left, r.Top));
return s;
}
public static Shape CreateLine(LineSegment segment)
{
Shape s = new Shape();
s._vertices.Add(segment.start);
s._vertices.Add(segment.end);
return s;
}
public void DrawShape(Shape shape, Color color)
{
DrawShape(shape, color, 1);
}
