src/video/vita/SDL_vitatouch.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2022 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_internal.h"

#if SDL_VIDEO_DRIVER_VITA

#include <psp2/kernel/processmgr.h>
#include <psp2/touch.h>

#include "SDL_events.h"
#include "SDL_log.h"
#include "SDL_vitavideo.h"
#include "SDL_vitatouch.h"
#include "../../events/SDL_mouse_c.h"
#include "../../events/SDL_touch_c.h"

SceTouchData touch_old[SCE_TOUCH_PORT_MAX_NUM];
SceTouchData touch[SCE_TOUCH_PORT_MAX_NUM];

SDL_FRect area_info[SCE_TOUCH_PORT_MAX_NUM];

struct{
    float min;
    float range;
} force_info[SCE_TOUCH_PORT_MAX_NUM];

char* disableFrontPoll = NULL;
char* disableBackPoll = NULL;

void 
VITA_InitTouch(void)
{
    disableFrontPoll = SDL_getenv("VITA_DISABLE_TOUCH_FRONT");
    disableBackPoll = SDL_getenv("VITA_DISABLE_TOUCH_BACK");

    sceTouchSetSamplingState(SCE_TOUCH_PORT_FRONT, SCE_TOUCH_SAMPLING_STATE_START);
    sceTouchSetSamplingState(SCE_TOUCH_PORT_BACK, SCE_TOUCH_SAMPLING_STATE_START);
    sceTouchEnableTouchForce(SCE_TOUCH_PORT_FRONT);
    sceTouchEnableTouchForce(SCE_TOUCH_PORT_BACK);

    for(int port = 0; port < SCE_TOUCH_PORT_MAX_NUM; port++) {
        SceTouchPanelInfo panelinfo;
        sceTouchGetPanelInfo(port, &panelinfo);

        area_info[port].x  = (float)panelinfo.minAaX;
        area_info[port].y  = (float)panelinfo.minAaY;
        area_info[port].w  = (float)(panelinfo.maxAaX - panelinfo.minAaX);
        area_info[port].h  = (float)(panelinfo.maxAaY - panelinfo.minAaY);

        force_info[port].min = (float)panelinfo.minForce;
        force_info[port].range = (float)(panelinfo.maxForce - panelinfo.minForce);
    }

    // Support passing both front and back touch devices in events
    SDL_AddTouch((SDL_TouchID)0, SDL_TOUCH_DEVICE_DIRECT, "Front");
    SDL_AddTouch((SDL_TouchID)1, SDL_TOUCH_DEVICE_INDIRECT_ABSOLUTE,  "Back");
}

void 
VITA_QuitTouch(void){
    sceTouchDisableTouchForce(SCE_TOUCH_PORT_FRONT);
    sceTouchDisableTouchForce(SCE_TOUCH_PORT_BACK);
}

void 
VITA_PollTouch(void)
{
    SDL_FingerID finger_id = 0;
    int port;

    // We skip polling touch if no window is created
    if (Vita_Window == NULL)
        return;

    SDL_memcpy(touch_old, touch, sizeof(touch_old));

    for(port = 0; port < SCE_TOUCH_PORT_MAX_NUM; port++) {
        /** Skip polling of Touch Device if environment variable is set **/
        if (((port == 0) && disableFrontPoll) || ((port == 1) && disableBackPoll)) {
            continue;
        }
        sceTouchPeek(port, &touch[port], 1);
        if (touch[port].reportNum > 0) {
            for (int i = 0; i < touch[port].reportNum; i++)
            {
                // adjust coordinates and forces to return normalized values
                // for the front, screen area is used as a reference (for direct touch)
                // e.g. touch_x = 1.0 corresponds to screen_x = 960
                // for the back panel, the active touch area is used as reference
                float x = 0;
                float y = 0;
                float force = (touch[port].report[i].force - force_info[port].min) / force_info[port].range;
                int finger_down = 0;

                if (touch_old[port].reportNum > 0) {
                    for (int j = 0; j < touch_old[port].reportNum; j++) {
                        if (touch[port].report[i].id == touch_old[port].report[j].id ) {
                            finger_down = 1;
                        }
                    }
                }
                
                VITA_ConvertTouchXYToSDLXY(&x, &y, touch[port].report[i].x, touch[port].report[i].y, port);
                finger_id = (SDL_FingerID) touch[port].report[i].id;

                // Skip if finger was already previously down
                if(!finger_down) {
                    // Send an initial touch
                    SDL_SendTouch((SDL_TouchID)port,
                        finger_id,
                        Vita_Window,
                        SDL_TRUE,
                        x,
                        y,
                        force);
                }

                // Always send the motion
                SDL_SendTouchMotion((SDL_TouchID)port,
                    finger_id,
                    Vita_Window,
                    x,
                    y,
                    force);
            }
        }

        // some fingers might have been let go
        if (touch_old[port].reportNum > 0) {
            for (int i = 0; i < touch_old[port].reportNum; i++) {
                int finger_up = 1;
                if (touch[port].reportNum > 0) {
                    for (int j = 0; j < touch[port].reportNum; j++) {
                        if (touch[port].report[j].id == touch_old[port].report[i].id ) {
                            finger_up = 0;
                        }
                    }
                }
                if (finger_up == 1) {
                    float x = 0;
                    float y = 0;
                    float force = (touch_old[port].report[i].force - force_info[port].min) / force_info[port].range;
                    VITA_ConvertTouchXYToSDLXY(&x, &y, touch_old[port].report[i].x, touch_old[port].report[i].y, port);
                    finger_id = (SDL_FingerID) touch_old[port].report[i].id;
                    // Finger released from screen
                    SDL_SendTouch((SDL_TouchID)port,
                        finger_id,
                        Vita_Window,
                        SDL_FALSE,
                        x,
                        y,
                        force);
                }
            }
        }
    }
}

void VITA_ConvertTouchXYToSDLXY(float *sdl_x, float *sdl_y, int vita_x, int vita_y, int port) {
    float x = (vita_x - area_info[port].x) / area_info[port].w;
    float y = (vita_y - area_info[port].y) / area_info[port].h;

    x = SDL_max(x, 0.0);
    x = SDL_min(x, 1.0);

    y = SDL_max(y, 0.0);
    y = SDL_min(y, 1.0);

    *sdl_x = x;
    *sdl_y = y;
}


#endif /* SDL_VIDEO_DRIVER_VITA */

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