SetCenter positions the space component according to its center instead of its top-left point (this avoids doing the same math each time in your systems)
(p engo.Point)
| 115 | // SetCenter positions the space component according to its center instead of its |
| 116 | // top-left point (this avoids doing the same math each time in your systems) |
| 117 | func (sc *SpaceComponent) SetCenter(p engo.Point) { |
| 118 | xDelta := sc.Width / 2 |
| 119 | yDelta := sc.Height / 2 |
| 120 | // update position according to point being used as our center |
| 121 | if sc.Rotation == 0 { |
| 122 | sc.Position.X = p.X - xDelta |
| 123 | sc.Position.Y = p.Y - yDelta |
| 124 | return |
| 125 | } |
| 126 | sin, cos := math.Sincos(sc.Rotation * math.Pi / 180) |
| 127 | xDelta = (sc.Width*cos - sc.Height*sin) / 2 |
| 128 | yDelta = (sc.Height*cos + sc.Width*sin) / 2 |
| 129 | sc.Position.X = p.X - xDelta |
| 130 | sc.Position.Y = p.Y - yDelta |
| 131 | } |
| 132 | |
| 133 | // Center gets the center position of the space component instead of its |
| 134 | // top-left point (this avoids doing the same math each time in your systems) |