Structure that represents a haptic direction. More...

#include <SDL_haptic.h>

Public Attributes
Uint8	type

Sint32	dir [3]

Detailed Description

Structure that represents a haptic direction.

This is the direction where the force comes from, instead of the direction in which the force is exerted.

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 450 of file SDL_haptic.h.

Member Data Documentation

◆ dir

Sint32 SDL_HapticDirection::dir[3]

The encoded direction.

Definition at line 453 of file SDL_haptic.h.

◆ type

Uint8 SDL_HapticDirection::type

The type of encoding.

Definition at line 452 of file SDL_haptic.h.

The documentation for this struct was generated from the following file:

include/SDL/SDL_haptic.h

Public Attributes

Detailed Description

Member Data Documentation

◆ dir

◆ type