/*+
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    SDL - Simple DirectMedia Layer+
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    Copyright (C) 1997-2010 Sam Lantinga+
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+
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    This library is free software; you can redistribute it and/or+
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    modify it under the terms of the GNU Lesser General Public+
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    License as published by the Free Software Foundation; either+
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    version 2.1 of the License, or (at your option) any later version.+
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+
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    This library is distributed in the hope that it will be useful,+
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    but WITHOUT ANY WARRANTY; without even the implied warranty of+
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU+
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    Lesser General Public License for more details.+
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+
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    You should have received a copy of the GNU Lesser General Public+
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    License along with this library; if not, write to the Free Software+
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    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA+
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+
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    Sam Lantinga+
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    slouken@libsdl.org+
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*/+
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#include "SDL_config.h"+
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+
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#include <unistd.h>+
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#include <sys/time.h>+
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#include <ctype.h>+
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+
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#include "SDL_stdinc.h"+
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#include "SDL_fbvideo.h"+
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#include "SDL_fbelo.h"+
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+
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/*+
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	calibration default values+
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	values are read from the following environment variables:+
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+
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	SDL_ELO_MIN_X+
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	SDL_ELO_MAX_X+
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	SDL_ELO_MIN_Y+
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	SDL_ELO_MAX_Y+
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*/+
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+
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static int ELO_MIN_X = 400;+
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static int ELO_MAX_X = 3670;+
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static int ELO_MIN_Y = 500;+
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static int ELO_MAX_Y = 3540;+
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+
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#define ELO_SNAP_SIZE 6+
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#define ELO_TOUCH_BYTE		'T'+
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#define ELO_ID			'I'+
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#define ELO_MODE		'M'+
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#define ELO_PARAMETER		'P'+
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#define ELO_REPORT		'B'+
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#define ELO_ACK			'A'+
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+
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#define ELO_INIT_CHECKSUM	0xAA+
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+
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#define ELO_BTN_PRESS		0x01+
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#define ELO_STREAM		0x02+
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#define ELO_BTN_RELEASE		0x04+
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+
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#define ELO_TOUCH_MODE		0x01+
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#define ELO_STREAM_MODE		0x02+
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#define ELO_UNTOUCH_MODE	0x04+
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#define ELO_RANGE_CHECK_MODE	0x40+
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#define ELO_TRIM_MODE		0x02+
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#define ELO_CALIB_MODE		0x04+
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#define ELO_SCALING_MODE	0x08+
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#define ELO_TRACKING_MODE	0x40+
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+
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#define ELO_SERIAL_MASK		0xF8+
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+
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#define ELO_SERIAL_IO		'0'+
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+
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#define ELO_MAX_TRIALS	3+
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#define ELO_MAX_WAIT		100000+
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#define ELO_UNTOUCH_DELAY	5+
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#define ELO_REPORT_DELAY	1+
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+
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/*	eloParsePacket+
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*/+
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int+
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eloParsePacket(unsigned char *mousebuf, int *dx, int *dy, int *button_state)+
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{+
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    static int elo_button = 0;+
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    static int last_x = 0;+
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    static int last_y = 0;+
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    int x, y;+
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+
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    /* Check if we have a touch packet */+
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    if (mousebuf[1] != ELO_TOUCH_BYTE) {+
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        return 0;+
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    }+
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+
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    x = ((mousebuf[4] << 8) | mousebuf[3]);+
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    y = ((mousebuf[6] << 8) | mousebuf[5]);+
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+
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    if ((SDL_abs(x - last_x) > ELO_SNAP_SIZE)+
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        || (SDL_abs(y - last_y) > ELO_SNAP_SIZE)) {+
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        *dx = ((mousebuf[4] << 8) | mousebuf[3]);+
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        *dy = ((mousebuf[6] << 8) | mousebuf[5]);+
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    } else {+
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        *dx = last_x;+
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        *dy = last_y;+
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    }+
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+
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    last_x = *dx;+
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    last_y = *dy;+
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+
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    if ((mousebuf[2] & 0x07) == ELO_BTN_PRESS) {+
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        elo_button = 1;+
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    }+
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    if ((mousebuf[2] & 0x07) == ELO_BTN_RELEASE) {+
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        elo_button = 0;+
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    }+
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+
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    *button_state = elo_button;+
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    return 1;+
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}+
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+
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/*	Convert the raw coordinates from the ELO controller+
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	to a screen position.+
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*/+
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void+
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eloConvertXY(_THIS, int *dx, int *dy)+
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{+
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    int input_x = *dx;+
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    int input_y = *dy;+
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    int width = ELO_MAX_X - ELO_MIN_X;+
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    int height = ELO_MAX_Y - ELO_MIN_Y;+
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+
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    *dx =+
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        ((int) cache_vinfo.xres -+
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         ((int) cache_vinfo.xres * (input_x - ELO_MIN_X)) / width);+
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    *dy = (cache_vinfo.yres * (input_y - ELO_MIN_Y)) / height;+
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}+
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+
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+
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/*	eloGetPacket+
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*/+
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int+
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eloGetPacket(unsigned char *buffer, int *buffer_p, int *checksum, int fd)+
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{+
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    int num_bytes;+
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    int ok;+
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+
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    if (fd == 0) {+
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        num_bytes = ELO_PACKET_SIZE;+
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    } else {+
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        num_bytes = read(fd,+
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                         (char *) (buffer + *buffer_p),+
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                         ELO_PACKET_SIZE - *buffer_p);+
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    }+
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+
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    if (num_bytes < 0) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr,+
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                "System error while reading from Elographics touchscreen.\n");+
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#endif+
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        return 0;+
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    }+
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+
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    while (num_bytes) {+
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        if ((*buffer_p == 0) && (buffer[0] != ELO_START_BYTE)) {+
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            SDL_memcpy(&buffer[0], &buffer[1], num_bytes - 1);+
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        } else {+
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            if (*buffer_p < ELO_PACKET_SIZE - 1) {+
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                *checksum = *checksum + buffer[*buffer_p];+
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                *checksum = *checksum % 256;+
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            }+
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            (*buffer_p)++;+
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        }+
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        num_bytes--;+
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    }+
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+
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    if (*buffer_p == ELO_PACKET_SIZE) {+
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        ok = (*checksum == buffer[ELO_PACKET_SIZE - 1]);+
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        *checksum = ELO_INIT_CHECKSUM;+
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        *buffer_p = 0;+
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+
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        if (!ok) {+
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            return 0;+
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        }+
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+
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        return 1;+
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    } else {+
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        return 0;+
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    }+
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}+
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+
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/* eloSendPacket+
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*/+
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+
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int+
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eloSendPacket(unsigned char *packet, int fd)+
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{+
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    int i, result;+
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    int sum = ELO_INIT_CHECKSUM;+
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+
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    packet[0] = ELO_START_BYTE;+
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    for (i = 0; i < ELO_PACKET_SIZE - 1; i++) {+
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        sum += packet[i];+
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        sum &= 0xFF;+
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    }+
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    packet[ELO_PACKET_SIZE - 1] = sum;+
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+
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    result = write(fd, packet, ELO_PACKET_SIZE);+
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+
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    if (result != ELO_PACKET_SIZE) {+
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#ifdef DEBUG_MOUSE+
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        printf("System error while sending to Elographics touchscreen.\n");+
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#endif+
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        return 0;+
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    } else {+
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        return 1;+
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    }+
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}+
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+
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+
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/*	eloWaitForInput+
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 */+
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int+
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eloWaitForInput(int fd, int timeout)+
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{+
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    fd_set readfds;+
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    struct timeval to;+
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    int r;+
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+
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    FD_ZERO(&readfds);+
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    FD_SET(fd, &readfds);+
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    to.tv_sec = 0;+
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    to.tv_usec = timeout;+
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+
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    r = select(FD_SETSIZE, &readfds, NULL, NULL, &to);+
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    return r;+
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}+
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+
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/*	eloWaitReply+
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 */+
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int+
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eloWaitReply(unsigned char type, unsigned char *reply, int fd)+
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{+
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    int ok;+
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    int i, result;+
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    int reply_p = 0;+
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    int sum = ELO_INIT_CHECKSUM;+
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+
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    i = ELO_MAX_TRIALS;+
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    do {+
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        ok = 0;+
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+
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        result = eloWaitForInput(fd, ELO_MAX_WAIT);+
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+
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        if (result > 0) {+
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            ok = eloGetPacket(reply, &reply_p, &sum, fd);+
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+
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            if (ok && reply[1] != type && type != ELO_PARAMETER) {+
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#ifdef DEBUG_MOUSE+
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                fprintf(stderr, "Wrong reply received\n");+
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#endif+
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                ok = 0;+
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            }+
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        } else {+
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#ifdef DEBUG_MOUSE+
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            fprintf(stderr, "No input!\n");+
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#endif+
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        }+
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+
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        if (result == 0) {+
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            i--;+
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        }+
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    } while (!ok && (i > 0));+
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+
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    return ok;+
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}+
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+
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+
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/*	eloWaitAck+
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 */+
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+
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int+
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eloWaitAck(int fd)+
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{+
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    unsigned char packet[ELO_PACKET_SIZE];+
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    int i, nb_errors;+
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+
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    if (eloWaitReply(ELO_ACK, packet, fd)) {+
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        for (i = 0, nb_errors = 0; i < 4; i++) {+
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            if (packet[2 + i] != '0') {+
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                nb_errors++;+
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            }+
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        }+
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+
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        if (nb_errors != 0) {+
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#ifdef DEBUG_MOUSE+
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            fprintf(stderr,+
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                    "Elographics acknowledge packet reports %d errors\n",+
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                    nb_errors);+
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#endif+
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        }+
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        return 1;+
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    } else {+
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        return 0;+
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    }+
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}+
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+
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+
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/*	eloSendQuery --+
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*/+
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int+
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eloSendQuery(unsigned char *request, unsigned char *reply, int fd)+
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{+
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    int ok;+
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+
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    if (eloSendPacket(request, fd)) {+
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        ok = eloWaitReply(toupper(request[1]), reply, fd);+
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        if (ok) {+
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            ok = eloWaitAck(fd);+
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        }+
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        return ok;+
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    } else {+
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        return 0;+
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    }+
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}+
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+
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+
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/*	eloSendControl+
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*/+
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int+
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eloSendControl(unsigned char *control, int fd)+
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{+
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    if (eloSendPacket(control, fd)) {+
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        return eloWaitAck(fd);+
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    } else {+
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        return 0;+
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    }+
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}+
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+
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/*	eloInitController+
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*/+
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int+
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eloInitController(int fd)+
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{+
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    unsigned char req[ELO_PACKET_SIZE];+
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    unsigned char reply[ELO_PACKET_SIZE];+
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    const char *buffer = NULL;+
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    int result = 0;+
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+
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    struct termios mouse_termios;+
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+
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    /* try to read the calibration values */+
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    buffer = SDL_getenv("SDL_ELO_MIN_X");+
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    if (buffer) {+
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        ELO_MIN_X = SDL_atoi(buffer);+
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    }+
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    buffer = SDL_getenv("SDL_ELO_MAX_X");+
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    if (buffer) {+
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        ELO_MAX_X = SDL_atoi(buffer);+
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    }+
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    buffer = SDL_getenv("SDL_ELO_MIN_Y");+
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    if (buffer) {+
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        ELO_MIN_Y = SDL_atoi(buffer);+
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    }+
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    buffer = SDL_getenv("SDL_ELO_MAX_Y");+
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    if (buffer) {+
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        ELO_MAX_Y = SDL_atoi(buffer);+
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    }+
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#ifdef DEBUG_MOUSE+
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    fprintf(stderr,+
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            "ELO calibration values:\nmin_x: %i\nmax_x: %i\nmin_y: %i\nmax_y: %i\n",+
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            ELO_MIN_X, ELO_MAX_X, ELO_MIN_Y, ELO_MAX_Y);+
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#endif+
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+
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    /* set comm params */+
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    SDL_memset(&mouse_termios, 0, sizeof(mouse_termios));+
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    mouse_termios.c_cflag = B9600 | CS8 | CREAD | CLOCAL;+
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    mouse_termios.c_cc[VMIN] = 1;+
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    result = tcsetattr(fd, TCSANOW, &mouse_termios);+
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+
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    if (result < 0) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr, "Unable to configure Elographics touchscreen port\n");+
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#endif+
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        return 0;+
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    }+
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+
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    SDL_memset(req, 0, ELO_PACKET_SIZE);+
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    req[1] = tolower(ELO_PARAMETER);+
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    if (!eloSendQuery(req, reply, fd)) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr,+
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                "Not at the specified rate or model 2310, will continue\n");+
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#endif+
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    }+
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+
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    SDL_memset(req, 0, ELO_PACKET_SIZE);+
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    req[1] = tolower(ELO_ID);+
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    if (eloSendQuery(req, reply, fd)) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr, "Ok, controller configured!\n");+
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#endif+
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    } else {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr,+
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                "Unable to ask Elographics touchscreen identification\n");+
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#endif+
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        return 0;+
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    }+
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+
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    SDL_memset(req, 0, ELO_PACKET_SIZE);+
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    req[1] = ELO_MODE;+
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    req[3] = ELO_TOUCH_MODE | ELO_STREAM_MODE | ELO_UNTOUCH_MODE;+
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    req[4] = ELO_TRACKING_MODE;+
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    if (!eloSendControl(req, fd)) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr,+
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                "Unable to change Elographics touchscreen operating mode\n");+
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#endif+
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        return 0;+
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    }+
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+
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    SDL_memset(req, 0, ELO_PACKET_SIZE);+
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    req[1] = ELO_REPORT;+
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    req[2] = ELO_UNTOUCH_DELAY;+
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    req[3] = ELO_REPORT_DELAY;+
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    if (!eloSendControl(req, fd)) {+
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#ifdef DEBUG_MOUSE+
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        fprintf(stderr,+
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                "Unable to change Elographics touchscreen reports timings\n");+
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#endif+
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        return 0;+
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    }+
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+
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    return 1;+
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}+
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+
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int+
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eloReadPosition(_THIS, int fd, int *x, int *y, int *button_state, int *realx,+
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                int *realy)+
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{+
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    unsigned char buffer[ELO_PACKET_SIZE];+
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    int pointer = 0;+
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    int checksum = ELO_INIT_CHECKSUM;+
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+
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    while (pointer < ELO_PACKET_SIZE) {+
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        if (eloGetPacket(buffer, &pointer, &checksum, fd)) {+
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            break;+
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        }+
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    }+
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+
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    if (!eloParsePacket(buffer, realx, realy, button_state)) {+
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        return 0;+
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    }+
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+
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    *x = *realx;+
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    *y = *realy;+
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+
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    eloConvertXY(this, x, y);+
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+
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    return 1;+
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}+
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+
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/* vi: set ts=4 sw=4 expandtab: */+
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