example-reading.c

This is a simple example demonstrating how to get input from a device.

#include <stdio.h>
#include "scriptel-proscript.h"
 
scriptel_hid_feature_coordinate_range range;
 
void input_callback(scriptel_device* device, scriptel_input_report* report, unsigned char report_id) {
    if(report_id == SCRIPTEL_INPUT_EXTENDEDCOORDINATE) {
        //We got pen input, lets adjust the coordinates into screen aspect.
        double x = device->display_info.width * ((report->extended_coordinate.x - range.x_min) / (double)(range.x_max - range.x_min));
        double y = device->display_info.height * ((report->extended_coordinate.y - range.y_min) / (double)(range.y_max - range.y_min));
 
        printf("Got a coordinate from the device: %4.2f, %4.2f\n", x, y);
    } else if(report_id == SCRIPTEL_INPUT_BUTTONPRESS) {
        //A button was pressed, if it's the OK button we'll close the device.
        char* caption = report->button_press.region->button.caption;
        printf("Button pressed: %s\n", caption);
        if(strcmp(caption, "OK") == 0) {
            //The OK button was hit, close the device.
            scriptel_close_device(device);
        }
    }
}
 
int main() {
    scriptel_device* device;
 
    //Initialize the library.
    scriptel_init();
 
    //List the devices.
    if(scriptel_list_devices(&device) == SCRIPTEL_CODE_SUCCESS) {
        //Test to see if we have more than zero devices.
        if(device != NULL) {
            printf("Found %i devices.\n", scriptel_count_device_list(device));
 
            //Lets open the first device and get some information from it.
            if(scriptel_open_device(device) == SCRIPTEL_CODE_SUCCESS) {
                printf("Successfully connected to %s - %s at: %s\n", device->manufacturer, device->model, device->path);
                
                //Register an input callback, this will be called when we get input from the pad.
                scriptel_register_input_callback(device, input_callback);
 
                //Get the coordinate scaling information we'll need later.
                range = scriptel_get_coordinate_range(device);
 
                //Wait for input from the pad.
                while(device->open) {
                    scriptel_device_read(device);
                }
 
                scriptel_free_device_list(device);
            } else {
                printf("Problem opening device: %s\n", scriptel_get_last_error());
                return 1;
            }
        } else {
            printf("No devices found!\n");
            return 2;
        }
    } else {
        printf("Problem enumerating devices: %s\n", scriptel_get_last_error());
        return 3;
    }
}