SDL  2.0
SDL_touch.c File Reference
#include "../SDL_internal.h"
#include "SDL_assert.h"
#include "SDL_events.h"
#include "SDL_events_c.h"
#include "../video/SDL_sysvideo.h"
+ Include dependency graph for SDL_touch.c:

Go to the source code of this file.

Functions

int SDL_TouchInit (void)
int SDL_GetNumTouchDevices (void)
 Get the number of registered touch devices.
SDL_TouchID SDL_GetTouchDevice (int index)
 Get the touch ID with the given index, or 0 if the index is invalid.
static int SDL_GetTouchIndex (SDL_TouchID id)
SDL_TouchSDL_GetTouch (SDL_TouchID id)
static int SDL_GetFingerIndex (const SDL_Touch *touch, SDL_FingerID fingerid)
static SDL_FingerSDL_GetFinger (const SDL_Touch *touch, SDL_FingerID id)
int SDL_GetNumTouchFingers (SDL_TouchID touchID)
 Get the number of active fingers for a given touch device.
SDL_FingerSDL_GetTouchFinger (SDL_TouchID touchID, int index)
 Get the finger object of the given touch, with the given index.
int SDL_AddTouch (SDL_TouchID touchID, const char *name)
static int SDL_AddFinger (SDL_Touch *touch, SDL_FingerID fingerid, float x, float y, float pressure)
static int SDL_DelFinger (SDL_Touch *touch, SDL_FingerID fingerid)
int SDL_SendTouch (SDL_TouchID id, SDL_FingerID fingerid, SDL_bool down, float x, float y, float pressure)
int SDL_SendTouchMotion (SDL_TouchID id, SDL_FingerID fingerid, float x, float y, float pressure)
void SDL_DelTouch (SDL_TouchID id)
void SDL_TouchQuit (void)

Variables

static int SDL_num_touch = 0
static SDL_Touch ** SDL_touchDevices = NULL

Function Documentation

static int SDL_AddFinger ( SDL_Touch touch,
SDL_FingerID  fingerid,
float  x,
float  y,
float  pressure 
)
static

Definition at line 178 of file SDL_touch.c.

References SDL_Touch::fingers, SDL_Finger::id, SDL_Touch::max_fingers, SDL_Touch::num_fingers, SDL_Finger::pressure, SDL_malloc, SDL_OutOfMemory, SDL_realloc, SDL_Finger::x, and SDL_Finger::y.

Referenced by SDL_SendTouch().

{
SDL_Finger *finger;
if (touch->num_fingers == touch->max_fingers) {
SDL_Finger **new_fingers;
new_fingers = (SDL_Finger **)SDL_realloc(touch->fingers, (touch->max_fingers+1)*sizeof(*touch->fingers));
if (!new_fingers) {
return SDL_OutOfMemory();
}
touch->fingers = new_fingers;
touch->fingers[touch->max_fingers] = (SDL_Finger *)SDL_malloc(sizeof(*finger));
if (!touch->fingers[touch->max_fingers]) {
return SDL_OutOfMemory();
}
touch->max_fingers++;
}
finger = touch->fingers[touch->num_fingers++];
finger->id = fingerid;
finger->x = x;
finger->y = y;
finger->pressure = pressure;
return 0;
}
int SDL_AddTouch ( SDL_TouchID  touchID,
const char *  name 
)

Definition at line 136 of file SDL_touch.c.

References SDL_Touch::fingers, SDL_Touch::id, SDL_Touch::max_fingers, NULL, SDL_Touch::num_fingers, SDL_GestureAddTouch(), SDL_GetTouchIndex(), SDL_malloc, SDL_num_touch, SDL_OutOfMemory, and SDL_realloc.

{
SDL_Touch **touchDevices;
int index;
index = SDL_GetTouchIndex(touchID);
if (index >= 0) {
return index;
}
/* Add the touch to the list of touch */
touchDevices = (SDL_Touch **) SDL_realloc(SDL_touchDevices,
(SDL_num_touch + 1) * sizeof(*touchDevices));
if (!touchDevices) {
return SDL_OutOfMemory();
}
SDL_touchDevices = touchDevices;
index = SDL_num_touch;
if (!SDL_touchDevices[index]) {
return SDL_OutOfMemory();
}
/* Added touch to list */
/* we're setting the touch properties */
SDL_touchDevices[index]->id = touchID;
/* Record this touch device for gestures */
/* We could do this on the fly in the gesture code if we wanted */
return index;
}
static int SDL_DelFinger ( SDL_Touch touch,
SDL_FingerID  fingerid 
)
static

Definition at line 205 of file SDL_touch.c.

References SDL_Touch::fingers, SDL_Touch::num_fingers, and SDL_GetFingerIndex().

Referenced by SDL_SendTouch().

{
SDL_Finger *temp;
int index = SDL_GetFingerIndex(touch, fingerid);
if (index < 0) {
return -1;
}
touch->num_fingers--;
temp = touch->fingers[index];
touch->fingers[index] = touch->fingers[touch->num_fingers];
touch->fingers[touch->num_fingers] = temp;
return 0;
}
void SDL_DelTouch ( SDL_TouchID  id)

Definition at line 337 of file SDL_touch.c.

References SDL_Touch::fingers, i, SDL_Touch::max_fingers, SDL_free, SDL_GestureDelTouch(), SDL_GetTouch(), SDL_GetTouchIndex(), and SDL_num_touch.

Referenced by SDL_TouchQuit().

{
int i;
SDL_Touch *touch = SDL_GetTouch(id);
if (!touch) {
return;
}
for (i = 0; i < touch->max_fingers; ++i) {
SDL_free(touch->fingers[i]);
}
SDL_free(touch->fingers);
SDL_free(touch);
/* Delete this touch device for gestures */
}
static SDL_Finger* SDL_GetFinger ( const SDL_Touch touch,
SDL_FingerID  id 
)
static

Definition at line 102 of file SDL_touch.c.

References SDL_Touch::fingers, NULL, SDL_Touch::num_fingers, and SDL_GetFingerIndex().

Referenced by SDL_SendTouch(), and SDL_SendTouchMotion().

{
int index = SDL_GetFingerIndex(touch, id);
return NULL;
}
return touch->fingers[index];
}
static int SDL_GetFingerIndex ( const SDL_Touch touch,
SDL_FingerID  fingerid 
)
static

Definition at line 90 of file SDL_touch.c.

References SDL_Touch::fingers, SDL_Finger::id, and SDL_Touch::num_fingers.

Referenced by SDL_DelFinger(), and SDL_GetFinger().

{
int index;
for (index = 0; index < touch->num_fingers; ++index) {
if (touch->fingers[index]->id == fingerid) {
return index;
}
}
return -1;
}
int SDL_GetNumTouchDevices ( void  )

Get the number of registered touch devices.

Definition at line 43 of file SDL_touch.c.

References SDL_num_touch.

{
return SDL_num_touch;
}
int SDL_GetNumTouchFingers ( SDL_TouchID  touchID)

Get the number of active fingers for a given touch device.

Definition at line 112 of file SDL_touch.c.

References SDL_Touch::num_fingers, and SDL_GetTouch().

{
SDL_Touch *touch = SDL_GetTouch(touchID);
if (touch) {
return touch->num_fingers;
}
return 0;
}
SDL_Touch* SDL_GetTouch ( SDL_TouchID  id)

Definition at line 74 of file SDL_touch.c.

References NULL, SDL_VideoDevice::ResetTouch, SDL_GetTouchIndex(), SDL_GetVideoDevice(), SDL_num_touch, and SDL_SetError.

Referenced by SDL_DelTouch(), SDL_GetNumTouchFingers(), SDL_GetTouchFinger(), SDL_SendTouch(), and SDL_SendTouchMotion().

{
if (SDL_GetVideoDevice()->ResetTouch != NULL) {
SDL_SetError("Unknown touch id %d, resetting", (int) id);
} else {
SDL_SetError("Unknown touch device id %d, cannot reset", (int) id);
}
return NULL;
}
}
SDL_TouchID SDL_GetTouchDevice ( int  index)

Get the touch ID with the given index, or 0 if the index is invalid.

Definition at line 49 of file SDL_touch.c.

References SDL_Touch::id, SDL_num_touch, and SDL_SetError.

{
SDL_SetError("Unknown touch device index %d", index);
return 0;
}
}
SDL_Finger* SDL_GetTouchFinger ( SDL_TouchID  touchID,
int  index 
)

Get the finger object of the given touch, with the given index.

Definition at line 122 of file SDL_touch.c.

References SDL_Touch::fingers, NULL, SDL_Touch::num_fingers, SDL_GetTouch(), and SDL_SetError.

{
SDL_Touch *touch = SDL_GetTouch(touchID);
if (!touch) {
return NULL;
}
SDL_SetError("Unknown touch finger");
return NULL;
}
return touch->fingers[index];
}
static int SDL_GetTouchIndex ( SDL_TouchID  id)
static

Definition at line 59 of file SDL_touch.c.

References SDL_Touch::id, and SDL_num_touch.

Referenced by SDL_AddTouch(), SDL_DelTouch(), and SDL_GetTouch().

{
int index;
SDL_Touch *touch;
for (index = 0; index < SDL_num_touch; ++index) {
if (touch->id == id) {
return index;
}
}
return -1;
}
int SDL_SendTouch ( SDL_TouchID  id,
SDL_FingerID  fingerid,
SDL_bool  down,
float  x,
float  y,
float  pressure 
)

Definition at line 222 of file SDL_touch.c.

References SDL_AddFinger(), SDL_DelFinger(), SDL_ENABLE, SDL_FINGERDOWN, SDL_FINGERUP, SDL_GetEventState, SDL_GetFinger(), SDL_GetTouch(), SDL_PushEvent, SDL_Finger::x, and SDL_Finger::y.

Referenced by SDL_SendTouchMotion().

{
int posted;
SDL_Finger *finger;
SDL_Touch* touch = SDL_GetTouch(id);
if (!touch) {
return -1;
}
finger = SDL_GetFinger(touch, fingerid);
if (down) {
if (finger) {
/* This finger is already down */
return 0;
}
if (SDL_AddFinger(touch, fingerid, x, y, pressure) < 0) {
return 0;
}
posted = 0;
event.tfinger.type = SDL_FINGERDOWN;
event.tfinger.touchId = id;
event.tfinger.fingerId = fingerid;
event.tfinger.x = x;
event.tfinger.y = y;
event.tfinger.dx = 0;
event.tfinger.dy = 0;
event.tfinger.pressure = pressure;
posted = (SDL_PushEvent(&event) > 0);
}
} else {
if (!finger) {
/* This finger is already up */
return 0;
}
posted = 0;
event.tfinger.type = SDL_FINGERUP;
event.tfinger.touchId = id;
event.tfinger.fingerId = fingerid;
/* I don't trust the coordinates passed on fingerUp */
event.tfinger.x = finger->x;
event.tfinger.y = finger->y;
event.tfinger.dx = 0;
event.tfinger.dy = 0;
event.tfinger.pressure = pressure;
posted = (SDL_PushEvent(&event) > 0);
}
SDL_DelFinger(touch, fingerid);
}
return posted;
}
int SDL_SendTouchMotion ( SDL_TouchID  id,
SDL_FingerID  fingerid,
float  x,
float  y,
float  pressure 
)

Definition at line 284 of file SDL_touch.c.

References SDL_Finger::pressure, SDL_ENABLE, SDL_FINGERMOTION, SDL_GetEventState, SDL_GetFinger(), SDL_GetTouch(), SDL_PushEvent, SDL_SendTouch(), SDL_TRUE, SDL_Finger::x, and SDL_Finger::y.

{
SDL_Touch *touch;
SDL_Finger *finger;
int posted;
float xrel, yrel, prel;
touch = SDL_GetTouch(id);
if (!touch) {
return -1;
}
finger = SDL_GetFinger(touch,fingerid);
if (!finger) {
return SDL_SendTouch(id, fingerid, SDL_TRUE, x, y, pressure);
}
xrel = x - finger->x;
yrel = y - finger->y;
prel = pressure - finger->pressure;
/* Drop events that don't change state */
if (!xrel && !yrel && !prel) {
#if 0
printf("Touch event didn't change state - dropped!\n");
#endif
return 0;
}
/* Update internal touch coordinates */
finger->x = x;
finger->y = y;
finger->pressure = pressure;
/* Post the event, if desired */
posted = 0;
event.tfinger.type = SDL_FINGERMOTION;
event.tfinger.touchId = id;
event.tfinger.fingerId = fingerid;
event.tfinger.x = x;
event.tfinger.y = y;
event.tfinger.dx = xrel;
event.tfinger.dy = yrel;
event.tfinger.pressure = pressure;
posted = (SDL_PushEvent(&event) > 0);
}
return posted;
}
int SDL_TouchInit ( void  )

Definition at line 37 of file SDL_touch.c.

Referenced by SDL_VideoInit().

{
return (0);
}
void SDL_TouchQuit ( void  )

Variable Documentation

int SDL_num_touch = 0
static
SDL_Touch** SDL_touchDevices = NULL
static

Definition at line 32 of file SDL_touch.c.