| 2 | #include <cmath> |
| 3 | |
| 4 | static inline double vswipe_process_delta(const double delta, |
| 5 | const double accumulated_dx, |
| 6 | const int vx, const int vw, |
| 7 | const double speed_cap = 0.5, |
| 8 | const bool free_movement = false) |
| 9 | { |
| 10 | // The slowdown below must be applied differently for going out of bounds. |
| 11 | double sdx_offset = free_movement ? |
| 12 | std::copysign(0, accumulated_dx) : accumulated_dx; |
| 13 | if (vx - accumulated_dx < 0.0) |
| 14 | { |
| 15 | sdx_offset = (accumulated_dx - std::floor(accumulated_dx)) + 1.0; |
| 16 | } |
| 17 | |
| 18 | if (vx - accumulated_dx > vw - 1.0) |
| 19 | { |
| 20 | sdx_offset = (accumulated_dx - std::ceil(accumulated_dx)) - 1.0; |
| 21 | } |
| 22 | |
| 23 | // To achieve a "rubberband" resistance effect when going too far, ease-in |
| 24 | // of the whole swiped distance is used as a slowdown factor for the current |
| 25 | // delta. |
| 26 | const double ease = 1.0 - std::pow(std::abs(sdx_offset) - 0.025, 4.0); |
| 27 | |
| 28 | // If we're moving further in the limit direction, slow down all the way |
| 29 | // to extremely slow, but reversing the direction should be easier. |
| 30 | const double slowdown = wf::clamp(ease, |
| 31 | std::signbit(delta) == std::signbit(sdx_offset) ? 0.005 : 0.2, 1.0); |
| 32 | |
| 33 | return wf::clamp(delta, -speed_cap, speed_cap) * slowdown; |
| 34 | } |
| 35 | |
| 36 | static inline int vswipe_finish_target(const double accumulated_dx, |
| 37 | const int vx, const int vw, |