src/events/SDL_touch.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"

/* General touch handling code for SDL */

#include "SDL_events.h"
#include "SDL_events_c.h"
#include "../video/SDL_sysvideo.h"

#include <stdio.h>


static int SDL_num_touch = 0;
static SDL_Touch **SDL_touchPads = NULL;


/* Public functions */
int
SDL_TouchInit(void)
{
  return (0);
}

SDL_Touch *
SDL_GetTouch(SDL_TouchID id)
{
    int index = SDL_GetTouchIndexId(id);
    if (index < 0 || index >= SDL_num_touch) {
        return NULL;
    }
    return SDL_touchPads[index];
}

SDL_Touch *
SDL_GetTouchIndex(int index)
{
    if (index < 0 || index >= SDL_num_touch) {
        return NULL;
    }
    return SDL_touchPads[index];
}

int
SDL_GetFingerIndexId(SDL_Touch* touch,SDL_FingerID fingerid)
{
    int i;
    for(i = 0;i < touch->num_fingers;i++)
        if(touch->fingers[i]->id == fingerid)
            return i;
    return -1;
}


SDL_Finger *
SDL_GetFinger(SDL_Touch* touch,SDL_FingerID id)
{
    int index = SDL_GetFingerIndexId(touch,id);
    if(index < 0 || index >= touch->num_fingers)
        return NULL;
    return touch->fingers[index];
}


int
SDL_GetTouchIndexId(SDL_TouchID id)
{
    int index;
    SDL_Touch *touch;

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

int
SDL_AddTouch(const SDL_Touch * touch, char *name)
{
    SDL_Touch **touchPads;
    int index;
    size_t length;

    if (SDL_GetTouchIndexId(touch->id) != -1) {
        SDL_SetError("Touch ID already in use");
    }

    /* Add the touch to the list of touch */
    touchPads = (SDL_Touch **) SDL_realloc(SDL_touchPads,
                                      (SDL_num_touch + 1) * sizeof(*touch));
    if (!touchPads) {
        SDL_OutOfMemory();
        return -1;
    }

    SDL_touchPads = touchPads;
    index = SDL_num_touch++;

    SDL_touchPads[index] = (SDL_Touch *) SDL_malloc(sizeof(*SDL_touchPads[index]));
    if (!SDL_touchPads[index]) {
        SDL_OutOfMemory();
        return -1;
    }
    SDL_memcpy(SDL_touchPads[index], touch, sizeof(*touch));

    /* we're setting the touch properties */
    length = 0;
    length = SDL_strlen(name);
    SDL_touchPads[index]->focus = 0;
    SDL_touchPads[index]->name = SDL_malloc((length + 2) * sizeof(char));
    SDL_strlcpy(SDL_touchPads[index]->name, name, length + 1);   

    SDL_touchPads[index]->num_fingers = 0;
    SDL_touchPads[index]->max_fingers = 1;
    SDL_touchPads[index]->fingers = (SDL_Finger **) SDL_malloc(sizeof(SDL_Finger*));
    SDL_touchPads[index]->fingers[0] = NULL;
    SDL_touchPads[index]->buttonstate = 0;
    SDL_touchPads[index]->relative_mode = SDL_FALSE;
    SDL_touchPads[index]->flush_motion = SDL_FALSE;
    
    SDL_touchPads[index]->xres = (1<<(16-1));
    SDL_touchPads[index]->yres = (1<<(16-1));
    //Do I want this here? Probably
    SDL_GestureAddTouch(SDL_touchPads[index]);

    return index;
}

void
SDL_DelTouch(SDL_TouchID id)
{
    int index = SDL_GetTouchIndexId(id);
    SDL_Touch *touch = SDL_GetTouch(id);

    if (!touch) {
        return;
    }

    
    SDL_free(touch->name);
 
    if (touch->FreeTouch) {
        touch->FreeTouch(touch);
    }
    SDL_free(touch);

    SDL_num_touch--;
    SDL_touchPads[index] = SDL_touchPads[SDL_num_touch];
}

void
SDL_TouchQuit(void)
{
    int i;

    for (i = SDL_num_touch-1; i > 0 ; --i) {
        SDL_DelTouch(i);
    }
    SDL_num_touch = 0;

    if (SDL_touchPads) {
        SDL_free(SDL_touchPads);
        SDL_touchPads = NULL;
    }
}

int
SDL_GetNumTouch(void)
{
    return SDL_num_touch;
}
SDL_Window *
SDL_GetTouchFocusWindow(SDL_TouchID id)
{
    SDL_Touch *touch = SDL_GetTouch(id);

    if (!touch) {
        return 0;
    }
    return touch->focus;
}

void
SDL_SetTouchFocus(SDL_TouchID id, SDL_Window * window)
{
    int index = SDL_GetTouchIndexId(id);
    SDL_Touch *touch = SDL_GetTouch(id);
    int i;
    SDL_bool focus;

    if (!touch || (touch->focus == window)) {
        return;
    }

    /* See if the current window has lost focus */
    if (touch->focus) {
        focus = SDL_FALSE;
        for (i = 0; i < SDL_num_touch; ++i) {
            SDL_Touch *check;
            if (i != index) {
                check = SDL_touchPads[i];
                if (check && check->focus == touch->focus) {
                    focus = SDL_TRUE;
                    break;
                }
            }
        }
        if (!focus) {
            SDL_SendWindowEvent(touch->focus, SDL_WINDOWEVENT_LEAVE, 0, 0);
        }
    }

    touch->focus = window;

    if (touch->focus) {
        focus = SDL_FALSE;
        for (i = 0; i < SDL_num_touch; ++i) {
            SDL_Touch *check;
            if (i != index) {
                check = SDL_touchPads[i];
                if (check && check->focus == touch->focus) {
                    focus = SDL_TRUE;
                    break;
                }
            }
        }
        if (!focus) {
            SDL_SendWindowEvent(touch->focus, SDL_WINDOWEVENT_ENTER, 0, 0);
        }
    }
}

int 
SDL_AddFinger(SDL_Touch* touch,SDL_Finger *finger)
{
    int index;
    SDL_Finger **fingers;
    //printf("Adding Finger...\n");
    if (SDL_GetFingerIndexId(touch,finger->id) != -1) {
        SDL_SetError("Finger ID already in use");
        }

    /* Add the touch to the list of touch */
    if(touch->num_fingers  >= touch->max_fingers){
                //printf("Making room for it!\n");
                fingers = (SDL_Finger **) SDL_realloc(touch->fingers,
                                                     (touch->num_fingers + 1) * sizeof(SDL_Finger *));
                touch->max_fingers = touch->num_fingers+1;
                if (!fingers) {
                        SDL_OutOfMemory();
                        return -1;
                } else {
                        touch->max_fingers = touch->num_fingers+1;
                        touch->fingers = fingers;
                }
        }

    index = touch->num_fingers;
    //printf("Max_Fingers: %i Index: %i\n",touch->max_fingers,index);

    touch->fingers[index] = (SDL_Finger *) SDL_malloc(sizeof(SDL_Finger));
    if (!touch->fingers[index]) {
        SDL_OutOfMemory();
        return -1;
    }
    *(touch->fingers[index]) = *finger;
    touch->num_fingers++;

    return index;
}

int
SDL_DelFinger(SDL_Touch* touch,SDL_FingerID fingerid)
{
    int index = SDL_GetFingerIndexId(touch,fingerid);
    SDL_Finger* finger = SDL_GetFinger(touch,fingerid);

    if (!finger) {
        return -1;
    }
 

    SDL_free(finger);
    touch->num_fingers--;
    touch->fingers[index] = touch->fingers[touch->num_fingers];
    return 0;
}


int
SDL_SendFingerDown(SDL_TouchID id, SDL_FingerID fingerid, SDL_bool down, 
                   float xin, float yin, float pressurein)
{
    int posted;
        Uint16 x;
        Uint16 y;
        Uint16 pressure;
        SDL_Finger *finger;

    SDL_Touch* touch = SDL_GetTouch(id);

    if(!touch) {
      return SDL_TouchNotFoundError(id);
    }

    
    //scale to Integer coordinates
    x = (Uint16)((xin+touch->x_min)*(touch->xres)/(touch->native_xres));
    y = (Uint16)((yin+touch->y_min)*(touch->yres)/(touch->native_yres));
    pressure = (Uint16)((yin+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
    
    finger = SDL_GetFinger(touch,fingerid);
    if(down) {
        if(finger == NULL) {
            SDL_Finger nf;
            nf.id = fingerid;
            nf.x = x;
            nf.y = y;
            nf.pressure = pressure;
            nf.xdelta = 0;
            nf.ydelta = 0;
            nf.last_x = x;
            nf.last_y = y;
            nf.last_pressure = pressure;
            nf.down = SDL_FALSE;
            if(SDL_AddFinger(touch,&nf) < 0) return 0;
            finger = SDL_GetFinger(touch,fingerid);
        }
        else if(finger->down) return 0;
        if(xin < touch->x_min || yin < touch->y_min) return 0; //should defer if only a partial input
        posted = 0;
        if (SDL_GetEventState(SDL_FINGERDOWN) == SDL_ENABLE) {
            SDL_Event event;
            event.tfinger.type = SDL_FINGERDOWN;
            event.tfinger.touchId = id;
            event.tfinger.x = x;
            event.tfinger.y = y;
            event.tfinger.pressure = pressure;
            event.tfinger.state = touch->buttonstate;
            event.tfinger.windowID = touch->focus ? touch->focus->id : 0;
            event.tfinger.fingerId = fingerid;
            posted = (SDL_PushEvent(&event) > 0);
        }
        if(posted) finger->down = SDL_TRUE;
        return posted;
    }
    else {
        if(finger == NULL) {
            SDL_SetError("Finger not found.");
            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.state = touch->buttonstate;
            event.tfinger.windowID = touch->focus ? touch->focus->id : 0;
            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;

            if(SDL_DelFinger(touch,fingerid) < 0) return 0;
            posted = (SDL_PushEvent(&event) > 0);
        }        
        return posted;
    }
}

int
SDL_SendTouchMotion(SDL_TouchID id, SDL_FingerID fingerid, int relative, 
                    float xin, float yin, float pressurein)
{
    SDL_Touch *touch;
    SDL_Finger *finger;
    int posted;
    Sint16 xrel, yrel;
    Uint16 x;
    Uint16 y;
    Uint16 pressure;
    
    touch = SDL_GetTouch(id);
    if (!touch) {
      return SDL_TouchNotFoundError(id);
    }

    //scale to Integer coordinates
    x = (Uint16)((xin+touch->x_min)*(touch->xres)/(touch->native_xres));
    y = (Uint16)((yin+touch->y_min)*(touch->yres)/(touch->native_yres));
    pressure = (Uint16)((yin+touch->pressure_min)*(touch->pressureres)/(touch->native_pressureres));
    if(touch->flush_motion) {
        return 0;
    }
    
    finger = SDL_GetFinger(touch,fingerid);
    if(finger == NULL || !finger->down) {
        return SDL_SendFingerDown(id,fingerid,SDL_TRUE,xin,yin,pressurein);        
    } else {
        /* the relative motion is calculated regarding the last position */
        if (relative) {
            xrel = x;
            yrel = y;
            x = (finger->last_x + x);
            y = (finger->last_y + y);
        } else {
            if(xin < touch->x_min) x = finger->last_x; /*If movement is only in one axis,*/
            if(yin < touch->y_min) y = finger->last_y; /*The other is marked as -1*/
            if(pressurein < touch->pressure_min) pressure = finger->last_pressure;
            xrel = x - finger->last_x;
            yrel = y - finger->last_y;
            //printf("xrel,yrel (%i,%i)\n",(int)xrel,(int)yrel);
        }
        
        /* Drop events that don't change state */
        if (!xrel && !yrel) {
#if 0
            printf("Touch event didn't change state - dropped!\n");
#endif
            return 0;
        }
        
        /* Update internal touch coordinates */
        
        finger->x = x;
        finger->y = y;
        
        /*Should scale to window? Normalize? Maintain Aspect?*/
        //SDL_GetWindowSize(touch->focus, &x_max, &y_max);
        
        /* make sure that the pointers find themselves inside the windows */
        /* only check if touch->xmax is set ! */
        /*
          if (x_max && touch->x > x_max) {
          touch->x = x_max;
          } else if (touch->x < 0) {
          touch->x = 0;
          }
          
          if (y_max && touch->y > y_max) {
          touch->y = y_max;
          } else if (touch->y < 0) {
          touch->y = 0;
          }
        */
        finger->xdelta = xrel;
        finger->ydelta = yrel;
        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;
            event.tfinger.state = touch->buttonstate;
            event.tfinger.windowID = touch->focus ? touch->focus->id : 0;
            posted = (SDL_PushEvent(&event) > 0);
        }
        finger->last_x = finger->x;
        finger->last_y = finger->y;
        finger->last_pressure = finger->pressure;
        return posted;
    }
}

int
SDL_SendTouchButton(SDL_TouchID id, Uint8 state, Uint8 button)
{
    SDL_Touch *touch;
    int posted;
    Uint32 type;

    
    touch = SDL_GetTouch(id);
    if (!touch) {
      return SDL_TouchNotFoundError(id);
    }

    /* Figure out which event to perform */
    switch (state) {
    case SDL_PRESSED:
        if (touch->buttonstate & SDL_BUTTON(button)) {
            /* Ignore this event, no state change */
            return 0;
        }
        type = SDL_TOUCHBUTTONDOWN;
        touch->buttonstate |= SDL_BUTTON(button);
        break;
    case SDL_RELEASED:
        if (!(touch->buttonstate & SDL_BUTTON(button))) {
            /* Ignore this event, no state change */
            return 0;
        }
        type = SDL_TOUCHBUTTONUP;
        touch->buttonstate &= ~SDL_BUTTON(button);
        break;
    default:
        /* Invalid state -- bail */
        return 0;
    }

    /* Post the event, if desired */
    posted = 0;
    if (SDL_GetEventState(type) == SDL_ENABLE) {
        SDL_Event event;
        event.type = type;
        event.tbutton.touchId = touch->id;
        event.tbutton.state = state;
        event.tbutton.button = button;
        event.tbutton.windowID = touch->focus ? touch->focus->id : 0;
        posted = (SDL_PushEvent(&event) > 0);
    }
    return posted;
}

char *
SDL_GetTouchName(SDL_TouchID id)
{
    SDL_Touch *touch = SDL_GetTouch(id);
    if (!touch) {
        return NULL;
    }
    return touch->name;
}

int SDL_TouchNotFoundError(SDL_TouchID id) {
  //int i;
  SDL_SetError("ERROR: Cannot send touch on non-existent device with id: %li make sure SDL_AddTouch has been called\n",id);
#if 0
  printf("ERROR: There are %i touches installed with Id's:\n",SDL_num_touch);
  for(i=0;i < SDL_num_touch;i++) {
    printf("ERROR: %li\n",SDL_touchPads[i]->id);
  }
#endif
  return 0;
}
/* vi: set ts=4 sw=4 expandtab: */