我正在编写一个程序，该程序可以打开并打开带有图像的 GL 窗口并连接到我的 android 设备，在该设备上，用户使用该设备作为一种触控板来平移和放大和缩小。一切正常，但是程序卡在 glutMainLoop 中并且不会继续接受来自设备的数据。显然 glutIdleFunc 是我的问题的解决方案但是我看不到如何在我的代码中实现它而不会出现内存错误？有人可以告诉我如何将函数放入我的代码中，以便它运行连接代码以及 opengl 的东西吗？
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <vrpn_Shared.h>
#include <vrpn_Analog.h>
#include <vector>
#include <GL/freeglut.h>
#include <imageviewer.h>
using namespace std;
int done = 0;
int accepted = 0; // Signals that the program should exit
unsigned tracker_stride = 1; // Every nth report will be printed
//-------------------------------------
// This section contains the data structure that holds information on
// the devices that are created. For each named device, a remote of each
// type analog is created.
class device_info {
public:
char *name;
vrpn_Analog_Remote *ana;
};
const unsigned MAX_DEVICES = 2;
//-------------------------------------
// This section contains the data structure that is used to determine how
// often to print a report for each sensor of each tracker. Each element
// contains a counter that is used by the callback routine to keep track
// of how many it has skipped. There is an element for each possible sensor.
// A new array of elements is created for each new tracker object, and a
// pointer to it is passed as the userdata pointer to the callback handlers.
class t_user_callback {
public:
char t_name[vrpn_MAX_TEXT_LEN];
vector<unsigned> t_counts ;
};
//Callback handlers
void VRPN_CALLBACK handle_analog (void *userdata, const vrpn_ANALOGCB a)
{
int i;
const char *name = (const char *)userdata;
printf("Input from %s:\n \n %5.0f", name, a.channel[0]);
for (i = 1; i < a.num_channel; i++) {
printf(" %5.0f \n", a.channel[1]);
}
printf(" \n");
}
int main (int argc, char * argv [])
{
int print_for_tracker = 1; // Print tracker reports?
int print_for_button = 1; // Print button reports?
int print_for_analog = 1; // Print analog reports?
int print_for_dial = 1; // Print dial reports?
int print_for_text = 1; // Print warning/error messages?
device_info device_list[MAX_DEVICES];
unsigned num_devices = 0;
int i;
// Parse arguments, creating objects
for (i = 1; i < argc; i++) {
if (!strcmp(argv[i], "-notracker")) {
print_for_tracker = 0;
} else if (!strcmp(argv[i], "-nobutton")) {
print_for_button = 0;
} else if (!strcmp(argv[i], "-noanalog")) {
print_for_analog = 0;
} else if (!strcmp(argv[i], "-nodial")) {
print_for_dial = 0;
} else if (!strcmp(argv[i], "-notext")) {
print_for_text = 0;
} else if (!strcmp(argv[i], "-trackerstride")) {
if (tracker_stride <= 0) {
fprintf(stderr, "-trackerstride argument must be 1 or greater\n");
return -1;
}
} else { // Create a device and connect to it.
device_info *dev;
// Name the device and open it as everything
dev = &device_list[num_devices];
dev->name = argv[i];
dev->ana = new vrpn_Analog_Remote(dev->name);
if (print_for_analog) {
printf(" Analog");
dev->ana->register_change_handler(dev->name, handle_analog);
}
printf(".\n");
num_devices++;
}
}
// main interactive loop
printf("Press ^C to exit.\n");
while ( ! done ) {
unsigned i;
// Let all the devices do their things
for (i = 0; i < num_devices; i++) {
device_list[i].ana->mainloop();
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowSize(400,300);
glutInitWindowPosition(200,100);
glutCreateWindow("ImageViewer");
init();
glutDisplayFunc(display);
glutMotionFunc(drag);
glutMouseFunc(mouse);
// glutIdleFunc(IdleFunc);
glutMainLoop();
}
}
return 0;
}