SDL Library
SDL_HapticDirection Struct Reference
Structure that represents a haptic direction. More...
#include <SDL_haptic.h>
Data Fields | |
Uint8 | type |
The type of encoding. | |
Sint32 | dir [3] |
The encoded direction. |
Detailed Description
Structure that represents a haptic direction.
Directions can be specified by:
- SDL_HAPTIC_POLAR : Specified by polar coordinates.
- SDL_HAPTIC_CARTESIAN : Specified by cartesian coordinates.
- SDL_HAPTIC_SPHERICAL : Specified by spherical coordinates.
Cardinal directions of the haptic device are relative to the positioning of the device. North is considered to be away from the user.
The following diagram represents the cardinal directions:
.--. |__| .-------. |=.| |.-----.| |--| || || | | |'-----'| |__|~')_____(' [ COMPUTER ] North (0,-1) ^ | | (1,0) West <----[ HAPTIC ]----> East (-1,0) | | v South (0,1) [ USER ] \|||/ (o o) ---ooO-(_)-Ooo---
If type is SDL_HAPTIC_POLAR, direction is encoded by hundredths of a degree starting north and turning clockwise. SDL_HAPTIC_POLAR only uses the first dir
parameter. The cardinal directions would be:
- North: 0 (0 degrees)
- East: 9000 (90 degrees)
- South: 18000 (180 degrees)
- West: 27000 (270 degrees)
If type is SDL_HAPTIC_CARTESIAN, direction is encoded by three positions (X axis, Y axis and Z axis (with 3 axes)). SDL_HAPTIC_CARTESIAN uses the first three dir
parameters. The cardinal directions would be:
- North: 0,-1, 0
- East: -1, 0, 0
- South: 0, 1, 0
- West: 1, 0, 0
The Z axis represents the height of the effect if supported, otherwise it's unused. In cartesian encoding (1, 2) would be the same as (2, 4), you can use any multiple you want, only the direction matters.
If type is SDL_HAPTIC_SPHERICAL, direction is encoded by two rotations. The first two dir
parameters are used. The dir
parameters are as follows (all values are in hundredths of degrees):
- Degrees from (1, 0) rotated towards (0, 1).
- Degrees towards (0, 0, 1) (device needs at least 3 axes).
Example of force coming from the south with all encodings (force coming from the south means the user will have to pull the stick to counteract):
SDL_HapticDirection direction; // Cartesian directions direction.type = SDL_HAPTIC_CARTESIAN; // Using cartesian direction encoding. direction.dir[0] = 0; // X position direction.dir[1] = 1; // Y position // Assuming the device has 2 axes, we don't need to specify third parameter. // Polar directions direction.type = SDL_HAPTIC_POLAR; // We'll be using polar direction encoding. direction.dir[0] = 18000; // Polar only uses first parameter // Spherical coordinates direction.type = SDL_HAPTIC_SPHERICAL; // Spherical encoding direction.dir[0] = 9000; // Since we only have two axes we don't need more parameters.
- See also:
- SDL_HAPTIC_POLAR
- SDL_HAPTIC_CARTESIAN
- SDL_HAPTIC_SPHERICAL
- SDL_HapticEffect
- SDL_HapticNumAxes
Definition at line 439 of file SDL_haptic.h.
Field Documentation
The encoded direction.
Definition at line 442 of file SDL_haptic.h.
The type of encoding.
Definition at line 441 of file SDL_haptic.h.
Generated on Tue Jul 12 2022 15:10:22 by 1.7.2