public static Vector2 MovePos(Vector2 position, float width, float height, Vector2 velocity, Room room, out bool collided)
{
collided = false;
if (velocity == Vector2.Zero)
{
return position;
}
while (velocity != Vector2.Zero)
{
Hitbox box = new Hitbox(position, width, height);
CollideLine? collision = GetNextCollision(box, velocity, room);
float distance = collision.HasValue ? collision.Value.distance : velocity.Length();
Vector2 move = velocity;
move.Normalize();
move *= distance;
position += move;
velocity -= move;
if (collision.HasValue)
{
switch (collision.Value.type)
{
case CollideType.X:
velocity.X = 0f;
break;
case CollideType.Y:
velocity.Y = 0f;
break;
}
collided = true;
}
}
return position;
}
private static CollideLine? GetNextCollision(Hitbox box, Vector2 velocity, Room room)
{
CollideLine? xLine = NextXCollision(box, velocity, room);
CollideLine? yLine = NextYCollision(box, velocity, room);
if (!xLine.HasValue)
{
return yLine;
}
if (!yLine.HasValue)
{
return xLine;
}
return xLine.Value.distance < yLine.Value.distance ? xLine : yLine;
}
public bool BoxOnScreen(Hitbox box)
{
if (box.topLeft.X > size.X / 2f + camera.X)
{
return false;
}
if (box.topRight.X < -size.X / 2f + camera.X)
{
return false;
}
if (box.topLeft.Y > size.Y / 2f + camera.Y)
{
return false;
}
if (box.bottomLeft.Y * tileSize < -size.Y / 2f + camera.Y)
{
return false;
}
return true;
}
private static CollideLine? NextXCollision(Hitbox box, Vector2 velocity, Room room)
{
if (velocity.X > 0f)
{
int x = (int)Math.Ceiling(box.topRight.X / tileSize);
x = Math.Max(x, 0);
int end = (int)Math.Floor((box.topRight.X + velocity.X) / tileSize);
while (x <= end && x < room.width)
{
float xDistance = tileSize * x - box.topRight.X;
float yDistance = xDistance / velocity.X * velocity.Y;
int y = (int)Math.Floor((box.topRight.Y + yDistance) / tileSize);
y = Math.Max(y, 0);
int yEnd = (int)Math.Ceiling((box.bottomRight.Y + yDistance) / tileSize) - 1;
while (y <= yEnd && y < room.height)
{
if (SolidTile(room.tiles[x, y]))
{
return new CollideLine
{
type = CollideType.X,
position = x * tileSize,
start = y * tileSize,
end = (y + 1) * tileSize,
distance = (float)Math.Sqrt(xDistance * xDistance + yDistance * yDistance)
};
}
y++;
}
x++;
}
}
else if (velocity.X < 0f)
{
int x = (int)Math.Floor(box.topLeft.X / tileSize);
x = Math.Min(x, room.width);
int end = (int)Math.Ceiling((box.topLeft.X + velocity.X) / tileSize);
while (x >= end && x > 0)
{
float xDistance = tileSize * x - box.topLeft.X;
float yDistance = xDistance / velocity.X * velocity.Y;
int y = (int)Math.Floor((box.topLeft.Y + yDistance) / tileSize);
y = Math.Max(y, 0);
int yEnd = (int)Math.Ceiling((box.bottomLeft.Y + yDistance) / tileSize) - 1;
while (y <= yEnd && y < room.height)
{
if (SolidTile(room.tiles[x - 1, y]))
{
return new CollideLine
{
type = CollideType.X,
position = x * tileSize,
start = y * tileSize,
end = (y + 1) * tileSize,
distance = (float)Math.Sqrt(xDistance * xDistance + yDistance * yDistance)
};
}
y++;
}
x--;
}
}
return null;
}
private static CollideLine? NextYCollision(Hitbox box, Vector2 velocity, Room room)
{
if (velocity.Y > 0f)
{
int y = (int)Math.Ceiling(box.bottomLeft.Y / tileSize);
y = Math.Max(y, 0);
int end = (int)Math.Floor((box.bottomLeft.Y + velocity.Y) / tileSize);
while (y <= end && y < room.height)
{
float yDistance = tileSize * y - box.bottomLeft.Y;
float xDistance = yDistance / velocity.Y * velocity.X;
int x = (int)Math.Floor((box.bottomLeft.X + xDistance) / tileSize);
x = Math.Max(x, 0);
int xEnd = (int)Math.Ceiling((box.bottomRight.X + xDistance) / tileSize) - 1;
while (x <= xEnd && x < room.width)
{
if (SolidTile(room.tiles[x, y]))
{
return new CollideLine
{
type = CollideType.Y,
position = y * tileSize,
start = x * tileSize,
end = (x + 1) * tileSize,
distance = (float)Math.Sqrt(xDistance * xDistance + yDistance * yDistance)
};
}
x++;
}
y++;
}
}
else if (velocity.Y < 0f)
{
int y = (int)Math.Floor(box.topLeft.Y / tileSize);
y = Math.Min(y, room.height);
int end = (int)Math.Ceiling((box.topLeft.Y + velocity.Y) / tileSize);
while (y >= end && y > 0)
{
float yDistance = tileSize * y - box.topLeft.Y;
float xDistance = yDistance / velocity.Y * velocity.X;
int x = (int)Math.Floor((box.bottomLeft.X + xDistance) / tileSize);
x = Math.Max(x, 0);
int xEnd = (int)Math.Ceiling((box.bottomRight.X + xDistance) / tileSize) - 1;
while (x <= xEnd && x < room.width)
{
if (SolidTile(room.tiles[x, y - 1]))
{
return new CollideLine
{
type = CollideType.Y,
position = y * tileSize,
start = x * tileSize,
end = (x + 1) * tileSize,
distance = (float)Math.Sqrt(xDistance * xDistance + yDistance * yDistance)
};
}
x++;
}
y--;
}
}
return null;
}