NAME¶

SDL_HapticPeriodic - A structure containing a template for a Periodic effect.

HEADER FILE¶

Defined in SDL3/SDL_haptic.h

SYNOPSIS¶

#include "SDL3/SDL.h"

typedef struct SDL_HapticPeriodic
{
    /* Header */
    Uint16 type;        /**< SDL_HAPTIC_SINE, SDL_HAPTIC_SQUARE
                             SDL_HAPTIC_TRIANGLE, SDL_HAPTIC_SAWTOOTHUP or
                             SDL_HAPTIC_SAWTOOTHDOWN */
    SDL_HapticDirection direction;  /**< Direction of the effect. */

    /* Replay */
    Uint32 length;      /**< Duration of the effect. */
    Uint16 delay;       /**< Delay before starting the effect. */

    /* Trigger */
    Uint16 button;      /**< Button that triggers the effect. */
    Uint16 interval;    /**< How soon it can be triggered again after button. */

    /* Periodic */
    Uint16 period;      /**< Period of the wave. */
    Sint16 magnitude;   /**< Peak value; if negative, equivalent to 180 degrees extra phase shift. */
    Sint16 offset;      /**< Mean value of the wave. */
    Uint16 phase;       /**< Positive phase shift given by hundredth of a degree. */

    /* Envelope */
    Uint16 attack_length;   /**< Duration of the attack. */
    Uint16 attack_level;    /**< Level at the start of the attack. */
    Uint16 fade_length; /**< Duration of the fade. */
    Uint16 fade_level;  /**< Level at the end of the fade. */
} SDL_HapticPeriodic;

DESCRIPTION¶

The struct handles the following effects:

• SDL_HAPTIC_SINE

• SDL_HAPTIC_SQUARE

• SDL_HAPTIC_TRIANGLE

• SDL_HAPTIC_SAWTOOTHUP

• SDL_HAPTIC_SAWTOOTHDOWN

A periodic effect consists in a wave-shaped effect that repeats itself over time. The type determines the shape of the wave and the parameters determine the dimensions of the wave.

Phase is given by hundredth of a degree meaning that giving the phase a value of 9000 will displace it 25% of its period. Here are sample values:

• 0: No phase displacement.

• 9000: Displaced 25% of its period.

• 18000: Displaced 50% of its period.

• 27000: Displaced 75% of its period.

• 36000: Displaced 100% of its period, same as 0, but 0 is preferred.

Examples:

SDL_HAPTIC_SINE
__ __ __ __
/   /   /   /
/ __/ __/ __/

SDL_HAPTIC_SQUARE
__ __ __ __ __
| | | | | | | | | |
| |__| |__| |__| |__| |

SDL_HAPTIC_TRIANGLE
/  /  /  /  / /   /   /   /   /
/

SDL_HAPTIC_SAWTOOTHUP
/| /| /| /| /| /| /|
/ | / | / | / | / | / | / |
/ |/ |/ |/ |/ |/ |/ |

SDL_HAPTIC_SAWTOOTHDOWN
  |  |  |  |  |  |  |
 |  |  |  |  |  |  |

AVAILABILITY¶

This struct is available since SDL 3.0.0.

SEE ALSO¶

SDL_HAPTIC_SINE(3), SDL_HAPTIC_SQUARE(3), SDL_HAPTIC_TRIANGLE(3), SDL_HAPTIC_SAWTOOTHUP(3), SDL_HAPTIC_SAWTOOTHDOWN(3), SDL_HapticEffect(3type)