device_null.c File Reference

#include "hid_device_driver.h"

Include dependency graph for device_null.c:

Classes
struct	null_instance

Typedefs
typedef struct null_instance	null_instance_t

Functions
static void *	null_init (void *handle)
static void	null_free (void *data)
static void	null_handle_packet (void *data, uint8_t *buffer, size_t size)
static bool	null_detect (uint16_t vendor_id, uint16_t product_id)
static void *	null_pad_init (void *data, uint32_t slot, hid_driver_t *driver)
static void	null_pad_deinit (void *data)
static void	null_get_buttons (void *data, input_bits_t *state)
static void	null_packet_handler (void *data, uint8_t *packet, uint16_t size)
static void	null_set_rumble (void *data, enum retro_rumble_effect effect, uint16_t strength)
static int16_t	null_get_axis (void *data, unsigned axis)
static const char *	null_get_name (void *data)
static bool	null_button (void *data, uint16_t joykey)

Variables
pad_connection_interface_t	null_pad_connection
hid_device_t	null_hid_device

Typedef Documentation

null_instance_t

typedef struct null_instance null_instance_t

Function Documentation

null_button()

static bool null_button ( void *  data, uint16_t  joykey  )

static

Read the state of a single button.

null_detect()

static bool null_detect ( uint16_t  vendor_id, uint16_t  product_id  )

static

Return true if the passed in VID and PID are supported by the driver.

null_free()

static void null_free ( void *  data )

static

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null_get_axis()

static int16_t null_get_axis ( void *  data, unsigned  axis  )

static

Read analog sticks. If the pad doesn't have any analog axis, just return 0 here.

The return value must conform to the following characteristics:

• (0, 0) is center
• (-32768,-32768) is top-left
• (32767,32767) is bottom-right

null_get_buttons()

static void null_get_buttons ( void *  data, input_bits_t *  state  )

static

Translate the button data from the pad into the input_bits_t format that RetroArch can use.

null_get_name()

static const char* null_get_name ( void *  data )

static

The name the pad will show up as in the UI, also used to auto-assign buttons in input/input_autodetect_builtin.c

null_handle_packet()

static void null_handle_packet ( void *  data, uint8_t *  buffer, size_t  size  )

static

Handle a single packet from the device. For most pads you'd just forward it onto the pad driver (see below). A more complicated example is in the Wii U GC adapter driver.

null_init()

static void* null_init ( void *  handle )

static

Use the HID_ macros (see input/include/hid_driver.h) to send data packets to the device. When this method returns, the device needs to be in a state where we can read data packets from the device. So, if there's any activation packets (see the ds3 and Wii U GameCube adapter drivers for examples), send them here.

While you can allocate the retro pad here, it isn't mandatory (see the Wii U GC adapter).

If initialization fails, return NULL.

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null_packet_handler()

static void null_packet_handler ( void *  data, uint8_t *  packet, uint16_t  size  )

static

Handle a single packet for the pad.

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null_pad_deinit()

static void null_pad_deinit ( void *  data )

static

If you allocate any memory in null_pad_init() above, de-allocate it here.

null_pad_init()

static void* null_pad_init ( void *  data, uint32_t  slot, hid_driver_t *  driver  )

static

This is called via hid_pad_register(). In the common case where the device only controls one pad, you can simply return the data parameter. But if you need to track multiple pads attached to the same HID device (see: Wii U GC adapter), you can allocate that memory here.

null_set_rumble()

static void null_set_rumble ( void *  data, enum retro_rumble_effect  effect, uint16_t  strength  )

static

If the pad doesn't support rumble, then this can just be a no-op.

Variable Documentation

null_hid_device

hid_device_t null_hid_device

Initial value:

= {
  null_init,
  null_free,
  null_handle_packet,
  null_detect,
  "Null HID device"
}

Assign function pointers to the driver structure.

null_pad_connection

pad_connection_interface_t null_pad_connection

Initial value:

= {
   null_pad_init,
   null_pad_deinit,
   null_packet_handler,
   null_set_rumble,
   null_get_buttons,
   null_get_axis,
   null_get_name,
   null_button
}

Fill in the joypad interface