ScreenDeltaToWorld converts a 1-cell screen delta into a world delta, ensuring a non-zero input always moves at least 1 world cell.
(d, zoom int)
| 81 | // ScreenDeltaToWorld converts a 1-cell screen delta into a world delta, |
| 82 | // ensuring a non-zero input always moves at least 1 world cell. |
| 83 | func ScreenDeltaToWorld(d, zoom int) int { |
| 84 | if d == 0 { |
| 85 | return 0 |
| 86 | } |
| 87 | s := zoomScale(zoom) |
| 88 | if s == 0 { |
| 89 | return d |
| 90 | } |
| 91 | v := int(float32(d)/s + 0.5) |
| 92 | if v == 0 { |
| 93 | if d > 0 { |
| 94 | return 1 |
| 95 | } |
| 96 | return -1 |
| 97 | } |
| 98 | return v |
| 99 | } |
| 100 | |
| 101 | // --- Note ------------------------------------------------------------- |
| 102 |