tornavis/source/blender/blenlib/BLI_dial_2d.h

61 lines
1.8 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#pragma once
/** \file
* \ingroup bli
*
* \note dials act similar to old rotation based phones and output an angle.
*
* They just are initialized with the center of the dial and a threshold value as input.
*
* When the distance of the current position of the dial from the center
* exceeds the threshold, this position is used to calculate the initial direction.
* After that, the angle from the initial direction is calculated based on
* current and previous directions of the digit, and returned to the user.
*
* Usage examples:
*
* \code{.c}
* float start_position[2] = {0.0f, 0.0f};
* float current_position[2];
* float threshold = 0.5f;
* float angle;
* Dial *dial;
*
* dial = BLI_dial_init(start_position, threshold);
*
* angle = BLI_dial_angle(dial, current_position);
*
* MEM_freeN(dial);
* \endcode
*/
#ifdef __cplusplus
extern "C" {
#endif
typedef struct Dial Dial;
Dial *BLI_dial_init(const float start_position[2], float threshold);
float BLI_dial_angle(Dial *dial, const float current_position[2]);
#ifdef __cplusplus
}
#endif