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.

Macros
#define	SYNTHESIZE_TOUCH_TO_MOUSE   1

Functions
int	SDL_TouchInit (void)
int	SDL_GetNumTouchDevices (void)
	Get the number of registered touch devices. More...
SDL_TouchID	SDL_GetTouchDevice (int index)
	Get the touch ID with the given index, or 0 if the index is invalid. More...
static int	SDL_GetTouchIndex (SDL_TouchID id)
SDL_Touch *	SDL_GetTouch (SDL_TouchID id)
SDL_TouchDeviceType	SDL_GetTouchDeviceType (SDL_TouchID id)
	Get the type of the given touch device. More...
static int	SDL_GetFingerIndex (const SDL_Touch *touch, SDL_FingerID fingerid)
static SDL_Finger *	SDL_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. More...
SDL_Finger *	SDL_GetTouchFinger (SDL_TouchID touchID, int index)
	Get the finger object of the given touch, with the given index. More...
int	SDL_AddTouch (SDL_TouchID touchID, SDL_TouchDeviceType type, 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
static SDL_bool	finger_touching = SDL_FALSE
static SDL_FingerID	track_fingerid
static SDL_TouchID	track_touchid

Macro Definition Documentation

SYNTHESIZE_TOUCH_TO_MOUSE

#define SYNTHESIZE_TOUCH_TO_MOUSE   1

Definition at line 36 of file SDL_touch.c.

Function Documentation

SDL_AddFinger()

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

static

Definition at line 198 of file SDL_touch.c.

{
    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;
}

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_AddTouch()

int SDL_AddTouch	(	SDL_TouchID	touchID,
		SDL_TouchDeviceType	type,
		const char *	name
	)

Definition at line 155 of file SDL_touch.c.

{
    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;
 
    SDL_touchDevices[index] = (SDL_Touch *) SDL_malloc(sizeof(*SDL_touchDevices[index]));
    if (!SDL_touchDevices[index]) {
        return SDL_OutOfMemory();
    }
 
    /* Added touch to list */
    ++SDL_num_touch;
 
    /* we're setting the touch properties */
    SDL_touchDevices[index]->id = touchID;
    SDL_touchDevices[index]->type = type;
    SDL_touchDevices[index]->num_fingers = 0;
    SDL_touchDevices[index]->max_fingers = 0;
    SDL_touchDevices[index]->fingers = NULL;
 
    /* Record this touch device for gestures */
    /* We could do this on the fly in the gesture code if we wanted */
    SDL_GestureAddTouch(touchID);
 
    return index;
}

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, SDL_realloc, SDL_touchDevices, and SDL_Touch::type.

Referenced by SDL_MouseTouchEventsChanged().

SDL_DelFinger()

static int SDL_DelFinger ( SDL_Touch *  touch, SDL_FingerID  fingerid  )

static

Definition at line 225 of file SDL_touch.c.

{
    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;
}

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

Referenced by SDL_SendTouch().

SDL_DelTouch()

void SDL_DelTouch

(

SDL_TouchID

id

)

Definition at line 449 of file SDL_touch.c.

{
    int i;
    int index = SDL_GetTouchIndex(id);
    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);
 
    SDL_num_touch--;
    SDL_touchDevices[index] = SDL_touchDevices[SDL_num_touch];
 
    /* Delete this touch device for gestures */
    SDL_GestureDelTouch(id);
}

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

Referenced by SDL_TouchQuit().

SDL_GetFinger()

static SDL_Finger* SDL_GetFinger ( const SDL_Touch *  touch, SDL_FingerID  id  )

static

Definition at line 121 of file SDL_touch.c.

{
    int index = SDL_GetFingerIndex(touch, id);
    if (index < 0 || index >= touch->num_fingers) {
        return NULL;
    }
    return touch->fingers[index];
}

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

Referenced by SDL_SendTouch(), and SDL_SendTouchMotion().

SDL_GetFingerIndex()

static int SDL_GetFingerIndex ( const SDL_Touch *  touch, SDL_FingerID  fingerid  )

static

Definition at line 109 of file SDL_touch.c.

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

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

Referenced by SDL_DelFinger(), and SDL_GetFinger().

SDL_GetNumTouchDevices()

int SDL_GetNumTouchDevices

(

void

)

Get the number of registered touch devices.

Definition at line 52 of file SDL_touch.c.

{
    return SDL_num_touch;
}

References SDL_num_touch.

SDL_GetNumTouchFingers()

int SDL_GetNumTouchFingers

(

SDL_TouchID

touchID

)

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

Definition at line 131 of file SDL_touch.c.

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

References SDL_Touch::num_fingers, and SDL_GetTouch().

SDL_GetTouch()

SDL_Touch* SDL_GetTouch

(

SDL_TouchID

id

)

Definition at line 83 of file SDL_touch.c.

{
    int index = SDL_GetTouchIndex(id);
    if (index < 0 || index >= SDL_num_touch) {
        if (SDL_GetVideoDevice()->ResetTouch != NULL) {
            SDL_SetError("Unknown touch id %d, resetting", (int) id);
            (SDL_GetVideoDevice()->ResetTouch)(SDL_GetVideoDevice());
        } else {
            SDL_SetError("Unknown touch device id %d, cannot reset", (int) id);
        }
        return NULL;
    }
    return SDL_touchDevices[index];
}

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

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

SDL_GetTouchDevice()

SDL_TouchID SDL_GetTouchDevice

(

int

index

)

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

Definition at line 58 of file SDL_touch.c.

{
    if (index < 0 || index >= SDL_num_touch) {
        SDL_SetError("Unknown touch device index %d", index);
        return 0;
    }
    return SDL_touchDevices[index]->id;
}

References SDL_Touch::id, SDL_num_touch, SDL_SetError, and SDL_touchDevices.

SDL_GetTouchDeviceType()

SDL_TouchDeviceType SDL_GetTouchDeviceType

(

SDL_TouchID

id

)

Get the type of the given touch device.

Definition at line 99 of file SDL_touch.c.

{
    SDL_Touch *touch = SDL_GetTouch(id);
    if (touch) {
        return touch->type;
    }
    return SDL_TOUCH_DEVICE_INVALID;
}

References SDL_GetTouch(), SDL_TOUCH_DEVICE_INVALID, and SDL_Touch::type.

SDL_GetTouchFinger()

SDL_Finger* SDL_GetTouchFinger	(	SDL_TouchID	touchID,
		int	index
	)

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

Definition at line 141 of file SDL_touch.c.

{
    SDL_Touch *touch = SDL_GetTouch(touchID);
    if (!touch) {
        return NULL;
    }
    if (index < 0 || index >= touch->num_fingers) {
        SDL_SetError("Unknown touch finger");
        return NULL;
    }
    return touch->fingers[index];
}

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

SDL_GetTouchIndex()

static int SDL_GetTouchIndex ( SDL_TouchID  id )

static

Definition at line 68 of file SDL_touch.c.

{
    int index;
    SDL_Touch *touch;
 
    for (index = 0; index < SDL_num_touch; ++index) {
        touch = SDL_touchDevices[index];
        if (touch->id == id) {
            return index;
        }
    }
    return -1;
}

References SDL_Touch::id, SDL_num_touch, and SDL_touchDevices.

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

SDL_SendTouch()

int SDL_SendTouch	(	SDL_TouchID	id,
		SDL_FingerID	fingerid,
		SDL_bool	down,
		float	x,
		float	y,
		float	pressure
	)

Definition at line 242 of file SDL_touch.c.

{
    int posted;
    SDL_Finger *finger;
    SDL_Mouse *mouse;
 
    SDL_Touch* touch = SDL_GetTouch(id);
    if (!touch) {
        return -1;
    }
 
    mouse = SDL_GetMouse();
 
#if SYNTHESIZE_TOUCH_TO_MOUSE
    /* SDL_HINT_TOUCH_MOUSE_EVENTS: controlling whether touch events should generate synthetic mouse events */
    {
        if (mouse->touch_mouse_events) {
            /* FIXME: maybe we should only restrict to a few SDL_TouchDeviceType */
            if (id != SDL_MOUSE_TOUCHID) {
                SDL_Window *window = SDL_GetMouseFocus();
                if (window == NULL) {
                    /* Mouse focus may have been lost by e.g. the window resizing
                     * due to device orientation change while the mouse state is
                     * pressed (because its position is now out of the window).
                     * SendMouse* will update mouse focus again after that, but
                     * if those are never called then SDL might think the
                     * 'mouse' has no focus at all. */
                    window = SDL_GetKeyboardFocus();
                }
                if (window) {
                    if (down) {
                        if (finger_touching == SDL_FALSE) {
                            int pos_x = (int)(x * (float)window->w);
                            int pos_y = (int)(y * (float)window->h);
                            if (pos_x < 0) pos_x = 0;
                            if (pos_x > window->w - 1) pos_x = window->w - 1;
                            if (pos_y < 0) pos_y = 0;
                            if (pos_y > window->h - 1) pos_y = window->h - 1;
                            SDL_SendMouseMotion(window, SDL_TOUCH_MOUSEID, 0, pos_x, pos_y);
                            SDL_SendMouseButton(window, SDL_TOUCH_MOUSEID, SDL_PRESSED, SDL_BUTTON_LEFT);
                        }
                    } else {
                        if (finger_touching == SDL_TRUE && track_touchid == id && track_fingerid == fingerid) {
                            SDL_SendMouseButton(window, SDL_TOUCH_MOUSEID, SDL_RELEASED, SDL_BUTTON_LEFT);
                        }
                    }
                }
                if (down) {
                    if (finger_touching == SDL_FALSE) {
                        finger_touching = SDL_TRUE;
                        track_touchid = id;
                        track_fingerid = fingerid;
                    }
                } else {
                    if (finger_touching == SDL_TRUE && track_touchid == id && track_fingerid == fingerid) {
                        finger_touching = SDL_FALSE;
                    }
                }
            }
        }
    }
#endif
 
    /* SDL_HINT_MOUSE_TOUCH_EVENTS: if not set, discard synthetic touch events coming from platform layer */
    if (mouse->mouse_touch_events == 0) {
        if (id == SDL_MOUSE_TOUCHID) {
            return 0;
        }
    }
 
    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;
        if (SDL_GetEventState(SDL_FINGERDOWN) == SDL_ENABLE) {
            SDL_Event event;
            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;
        if (SDL_GetEventState(SDL_FINGERUP) == SDL_ENABLE) {
            SDL_Event event;
            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;
}

References finger_touching, SDL_Mouse::mouse_touch_events, NULL, SDL_AddFinger(), SDL_BUTTON_LEFT, SDL_DelFinger(), SDL_ENABLE, SDL_FALSE, SDL_FINGERDOWN, SDL_FINGERUP, SDL_GetEventState, SDL_GetFinger(), SDL_GetKeyboardFocus, SDL_GetMouse(), SDL_GetMouseFocus, SDL_GetTouch(), SDL_MOUSE_TOUCHID, SDL_PRESSED, SDL_PushEvent, SDL_RELEASED, SDL_SendMouseButton(), SDL_SendMouseMotion(), SDL_TOUCH_MOUSEID, SDL_TRUE, SDL_Mouse::touch_mouse_events, track_fingerid, track_touchid, SDL_Finger::x, and SDL_Finger::y.

Referenced by SDL_PrivateSendMouseButton(), and SDL_SendTouchMotion().

SDL_SendTouchMotion()

int SDL_SendTouchMotion	(	SDL_TouchID	id,
		SDL_FingerID	fingerid,
		float	x,
		float	y,
		float	pressure
	)

Definition at line 364 of file SDL_touch.c.

{
    SDL_Touch *touch;
    SDL_Finger *finger;
    SDL_Mouse *mouse;
    int posted;
    float xrel, yrel, prel;
 
    touch = SDL_GetTouch(id);
    if (!touch) {
        return -1;
    }
 
    mouse = SDL_GetMouse();
 
#if SYNTHESIZE_TOUCH_TO_MOUSE
    /* SDL_HINT_TOUCH_MOUSE_EVENTS: controlling whether touch events should generate synthetic mouse events */
    {
        if (mouse->touch_mouse_events) {
            if (id != SDL_MOUSE_TOUCHID) {
                SDL_Window *window = SDL_GetMouseFocus();
                if (window) {
                    if (finger_touching == SDL_TRUE && track_touchid == id && track_fingerid == fingerid) {
                        int pos_x = (int)(x * (float)window->w);
                        int pos_y = (int)(y * (float)window->h);
                        if (pos_x < 0) pos_x = 0;
                        if (pos_x > window->w - 1) pos_x = window->w - 1;
                        if (pos_y < 0) pos_y = 0;
                        if (pos_y > window->h - 1) pos_y = window->h - 1;
                        SDL_SendMouseMotion(window, SDL_TOUCH_MOUSEID, 0, pos_x, pos_y);
                    }
                }
            }
        }
    }
#endif
 
    /* SDL_HINT_MOUSE_TOUCH_EVENTS: if not set, discard synthetic touch events coming from platform layer */
    if (mouse->mouse_touch_events == 0) {
        if (id == SDL_MOUSE_TOUCHID) {
            return 0;
        }
    }
 
    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 == 0.0f && yrel == 0.0f && prel == 0.0f) {
#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;
    if (SDL_GetEventState(SDL_FINGERMOTION) == SDL_ENABLE) {
        SDL_Event event;
        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;
}

References finger_touching, SDL_Mouse::mouse_touch_events, SDL_Finger::pressure, SDL_ENABLE, SDL_FINGERMOTION, SDL_GetEventState, SDL_GetFinger(), SDL_GetMouse(), SDL_GetMouseFocus, SDL_GetTouch(), SDL_MOUSE_TOUCHID, SDL_PushEvent, SDL_SendMouseMotion(), SDL_SendTouch(), SDL_TOUCH_MOUSEID, SDL_TRUE, SDL_Mouse::touch_mouse_events, track_fingerid, track_touchid, SDL_Finger::x, and SDL_Finger::y.

Referenced by SDL_PrivateSendMouseMotion().

SDL_TouchInit()

int SDL_TouchInit

(

void

)

Definition at line 46 of file SDL_touch.c.

{
    return (0);
}

Referenced by SDL_VideoInit().

SDL_TouchQuit()

void SDL_TouchQuit

(

void

)

Definition at line 473 of file SDL_touch.c.

{
    int i;
 
    for (i = SDL_num_touch; i--; ) {
        SDL_DelTouch(SDL_touchDevices[i]->id);
    }
    SDL_assert(SDL_num_touch == 0);
 
    SDL_free(SDL_touchDevices);
    SDL_touchDevices = NULL;
    SDL_GestureQuit();
}

References i, NULL, SDL_assert, SDL_DelTouch(), SDL_free, SDL_GestureQuit(), SDL_num_touch, and SDL_touchDevices.

Referenced by SDL_VideoQuit().

Variable Documentation

finger_touching

SDL_bool finger_touching = SDL_FALSE

static

Definition at line 39 of file SDL_touch.c.

Referenced by SDL_SendTouch(), and SDL_SendTouchMotion().

SDL_num_touch

int SDL_num_touch = 0

static

Definition at line 31 of file SDL_touch.c.

Referenced by SDL_AddTouch(), SDL_DelTouch(), SDL_GetNumTouchDevices(), SDL_GetTouch(), SDL_GetTouchDevice(), SDL_GetTouchIndex(), and SDL_TouchQuit().

SDL_touchDevices

SDL_Touch** SDL_touchDevices = NULL

static

Definition at line 32 of file SDL_touch.c.

Referenced by SDL_AddTouch(), SDL_DelTouch(), SDL_GetTouch(), SDL_GetTouchDevice(), SDL_GetTouchIndex(), and SDL_TouchQuit().

track_fingerid

SDL_FingerID track_fingerid

static

Definition at line 40 of file SDL_touch.c.

Referenced by SDL_SendTouch(), and SDL_SendTouchMotion().

track_touchid

SDL_TouchID track_touchid

static

Definition at line 41 of file SDL_touch.c.

Referenced by SDL_SendTouch(), and SDL_SendTouchMotion().