public BasicEnemy(int xPosition, int yPosition)
{
currentHP = HP;
position = new Vector2(xPosition, yPosition);
direction = new Vector2(-1, 0);
speed = 200;
visual = new AnimatedSprite(Renderer.Instance.enemy, 4, 4, 16, 1000, true);
collider = new AABBCollider((int)position.X + 6, (int)position.Y + 7, 50, 50);
}
private static bool AABBCircle(AABBCollider a, CircleCollider c)
{
List <Vector2> AABBVerts = new List <Vector2>();
AABBVerts.Add(new Vector2(0, 0));
AABBVerts.Add(new Vector2(a.Width, 0));
AABBVerts.Add(new Vector2(a.Width, a.Height));
AABBVerts.Add(new Vector2(0, a.Height));
PolygonCollider hax = new PolygonCollider(a.position.X, a.position.Y, AABBVerts);
return(PolygonCircle(hax, c));
}
public BugEnemy(int xPosition, int yPosition)
{
position = new Vector2(xPosition, yPosition);
currentHP = HP;
speed = 150;
visual = new AnimatedSprite(Renderer.Instance.bug, 4, 4, 16, 1000, true);
collider = new AABBCollider((int)position.X + 6, (int)position.Y + 2, 52, 60);
if (Exodos.Instance.random.Next(0, 2) == 1)
{
direction = new Vector2(-1, 1);
}
else
{
direction = new Vector2(1, 1);
}
direction.Normalize();
directionTimer = directionTime;
}
private static bool AABBHalfPlane(AABBCollider a, HalfPlaneCollider hp)
{
// Check if any of the AABB's vertices satisfies the half-plane's equation.
if (hp.A * a.position.X + hp.B * a.position.Y <= hp.C)
{
return(true);
}
if (hp.A * a.position.X + hp.B * (a.position.Y + a.Height) <= hp.C)
{
return(true);
}
if (hp.A * (a.position.X + a.Width) + hp.B * a.position.Y <= hp.C)
{
return(true);
}
if (hp.A * (a.position.X + a.Width) + hp.B * (a.position.Y + a.Height) <= hp.C)
{
return(true);
}
return(false);
}
// Check for collision between two Axis-Aligned Bounding Boxes.
private static bool AABB(AABBCollider a, AABBCollider b)
{
// This is a special case of the Separating Axis Theorem for AABBs.
if (a.position.X > b.position.X + b.Width)
{
return(false);
}
if (a.position.X + a.Width < b.position.X)
{
return(false);
}
if (a.position.Y > b.position.Y + b.Height)
{
return(false);
}
if (a.position.Y + a.Height < b.position.Y)
{
return(false);
}
return(true);
}
// Uses the Separating Axis Theorem, but accounts for one of the colliders being an AABB and thus described in a different way.
private static bool AABBPolygon(AABBCollider a, PolygonCollider p)
{
// Get the AABB's vertices in a format suitable for GatherPolygonProjectionExtents.
List <Vector2> AABBVerts = new List <Vector2>();
AABBVerts.Add(new Vector2(a.position.X, a.position.Y));
AABBVerts.Add(new Vector2(a.position.X + a.Width, a.position.Y));
AABBVerts.Add(new Vector2(a.position.X + a.Width, a.position.Y + a.Height));
AABBVerts.Add(new Vector2(a.position.X, a.position.Y + a.Height));
for (int i = 0; i < p.vertices.Count; i++)
{
Vector2 edge;
if (i != p.vertices.Count - 1)
{
edge = p.vertices[i + 1] - p.vertices[i];
}
else
{
edge = p.vertices[0] - p.vertices[i];
}
Vector2 axis = new Vector2(edge.Y, -edge.X);
axis.Normalize();
float aMin, aMax, bMin, bMax;
GatherPolygonProjectionExtents(axis, p.vertices, out aMin, out aMax);
GatherPolygonProjectionExtents(axis, AABBVerts, out bMin, out bMax);
if (aMin > bMax)
{
return(false);
}
if (aMax < bMin)
{
return(false);
}
}
for (int i = 0; i < AABBVerts.Count; i++)
{
Vector2 edge;
if (i != AABBVerts.Count - 1)
{
edge = AABBVerts[i + 1] - AABBVerts[i];
}
else
{
edge = AABBVerts[0] - AABBVerts[i];
}
Vector2 axis = new Vector2(edge.Y, -edge.X);
axis.Normalize();
float aMin, aMax, bMin, bMax;
GatherPolygonProjectionExtents(axis, p.vertices, out aMin, out aMax);
GatherPolygonProjectionExtents(axis, AABBVerts, out bMin, out bMax);
if (aMin > bMax)
{
return(false);
}
if (aMax < bMin)
{
return(false);
}
}
return(true);
}
