diff options
Diffstat (limited to 'source/blender/blenlib/intern/BLI_dial_2d.c')
| -rw-r--r-- | source/blender/blenlib/intern/BLI_dial_2d.c | 121 |
1 files changed, 59 insertions, 62 deletions
diff --git a/source/blender/blenlib/intern/BLI_dial_2d.c b/source/blender/blenlib/intern/BLI_dial_2d.c index dd983fe7f8f..c6d28e20f35 100644 --- a/source/blender/blenlib/intern/BLI_dial_2d.c +++ b/source/blender/blenlib/intern/BLI_dial_2d.c @@ -24,81 +24,78 @@ #include "MEM_guardedalloc.h" struct Dial { - /* center of the dial */ - float center[2]; + /* center of the dial */ + float center[2]; - /* threshold of the dial. Distance of current position has to be greater - * than the threshold to be used in any calculations */ - float threshold_squared; + /* threshold of the dial. Distance of current position has to be greater + * than the threshold to be used in any calculations */ + float threshold_squared; - /* the direction of the first dial position exceeding the threshold. This - * is later used as the basis against which rotation angle is calculated */ - float initial_direction[2]; + /* the direction of the first dial position exceeding the threshold. This + * is later used as the basis against which rotation angle is calculated */ + float initial_direction[2]; - /* cache the last angle to detect rotations bigger than -/+ PI */ - float last_angle; + /* cache the last angle to detect rotations bigger than -/+ PI */ + float last_angle; - /* number of full rotations */ - int rotations; + /* number of full rotations */ + int rotations; - /* has initial_direction been initialized */ - bool initialized; + /* has initial_direction been initialized */ + bool initialized; }; - Dial *BLI_dial_initialize(const float start_position[2], float threshold) { - Dial *dial = MEM_callocN(sizeof(Dial), "dial"); + Dial *dial = MEM_callocN(sizeof(Dial), "dial"); - copy_v2_v2(dial->center, start_position); - dial->threshold_squared = threshold * threshold; + copy_v2_v2(dial->center, start_position); + dial->threshold_squared = threshold * threshold; - return dial; + return dial; } float BLI_dial_angle(Dial *dial, const float current_position[2]) { - float current_direction[2]; - - sub_v2_v2v2(current_direction, current_position, dial->center); - - /* only update when we have enough precision, - * by having the mouse adequately away from center */ - if (len_squared_v2(current_direction) > dial->threshold_squared) { - float angle; - float cosval, sinval; - - normalize_v2(current_direction); - - if (!dial->initialized) { - copy_v2_v2(dial->initial_direction, current_direction); - dial->initialized = true; - } - - /* calculate mouse angle between initial and final mouse position */ - cosval = dot_v2v2(current_direction, dial->initial_direction); - sinval = cross_v2v2(current_direction, dial->initial_direction); - - /* clamp to avoid nans in acos */ - angle = atan2f(sinval, cosval); - - /* change of sign, we passed the 180 degree threshold. This means we need to add a turn. - * to distinguish between transition from 0 to -1 and -PI to +PI, - * use comparison with PI/2 */ - if ((angle * dial->last_angle < 0.0f) && - (fabsf(dial->last_angle) > (float)M_PI_2)) - { - if (dial->last_angle < 0.0f) { - dial->rotations--; - } - else { - dial->rotations++; - } - } - dial->last_angle = angle; - - return angle + 2.0f * (float)M_PI * dial->rotations; - } - - return dial->last_angle; + float current_direction[2]; + + sub_v2_v2v2(current_direction, current_position, dial->center); + + /* only update when we have enough precision, + * by having the mouse adequately away from center */ + if (len_squared_v2(current_direction) > dial->threshold_squared) { + float angle; + float cosval, sinval; + + normalize_v2(current_direction); + + if (!dial->initialized) { + copy_v2_v2(dial->initial_direction, current_direction); + dial->initialized = true; + } + + /* calculate mouse angle between initial and final mouse position */ + cosval = dot_v2v2(current_direction, dial->initial_direction); + sinval = cross_v2v2(current_direction, dial->initial_direction); + + /* clamp to avoid nans in acos */ + angle = atan2f(sinval, cosval); + + /* change of sign, we passed the 180 degree threshold. This means we need to add a turn. + * to distinguish between transition from 0 to -1 and -PI to +PI, + * use comparison with PI/2 */ + if ((angle * dial->last_angle < 0.0f) && (fabsf(dial->last_angle) > (float)M_PI_2)) { + if (dial->last_angle < 0.0f) { + dial->rotations--; + } + else { + dial->rotations++; + } + } + dial->last_angle = angle; + + return angle + 2.0f * (float)M_PI * dial->rotations; + } + + return dial->last_angle; } |