I am trying to write a large X app. I have successfully modified my xorg.conf to setup 4 monitors on an NVIDIA Quatro5200. I am trying to modify a simple hello world application to open a window on three of the four monitors. depending on the changes to loop the window creation section and event handler portion, i get either a Bus Error, Segmentation Fault, or a BadMatch. (Not sure where the BadMatch is coming from) Here is the code.
If I loop the fontinfo and graphical context portion like the rest, I get a Bus Error.
I can run the single version on each of the different screens one at a time, just not all three in one program.
Help!
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <X11/Xlib.h>
int main (int argc, char *argv[])
{
Display *display;
Visual *visual[3];
int depth[3];
int text_x;
int text_y;
XSetWindowAttributes frame_attributes[3];
int screen_num;
int screen_ind, i;
unsigned int display_width[3], display_height[3];
Window frame_window[3];
XFontStruct *fontinfo = NULL;
XGCValues gr_values;
GC graphical_context;
XKeyEvent event;
char hello_string[] = "Hello X";
int hello_string_length=strlen(hello_string);
display = XOpenDisplay(NULL);
for( i = 0; i < 3; i++ )
{
screen_num = i+1;
visual[i] = DefaultVisual(display, screen_num);
depth[i] = DefaultDepth(display, screen_num);
display_width[i] = DisplayWidth(display, screen_num);
display_height[i] = DisplayHeight(display, screen_num);
frame_attributes[i].background_pixel = XBlackPixel(display, screen_num);
frame_attributes[i].override_redirect = 1;
/* create the application window */
frame_window[i] = XCreateWindow(display, XRootWindow(display, screen_num),
0, 0, display_width[i], display_height[i], 0, depth[i],
InputOutput, visual[i], CWBackPixel|CWOverrideRedirect,
&frame_attributes[i]);
XSelectInput(display, frame_window[i], ExposureMask );
if( fontinfo == NULL )
{
fontinfo = XLoadQueryFont(display, "10x20");
if(fontinfo != NULL )
{
gr_values.font = fontinfo->fid;
gr_values.foreground = XWhitePixel(display, screen_num);
graphical_context = XCreateGC(display, frame_window[i],
GCFont+GCForeground, &gr_values);
}
}
XMapWindow(display, frame_window[i]);
}
while ( 1 ) {
fprintf(stdout, "1\n");
fflush(stdout);
XNextEvent(display, (XEvent *)&event);
switch ( event.type ) {
case Expose:
{
XWindowAttributes window_attributes;
int font_direction, font_ascent, font_descent;
XCharStruct text_structure;
if( event.window == frame_window[0] )
{
hello_string[6] = '1';
screen_ind = 0;
}
else if( event.window == frame_window[1] )
{
hello_string[6] = '2';
screen_ind = 1;
}
else if( event.window == frame_window[2] )
{
hello_string[6] = '3';
screen_ind = 2;
}
else
{
printf("event.window = %d\n", (int)event.window );
return(0);
}
fprintf(stdout, "2\n");
fflush(stdout);
XTextExtents(fontinfo, hello_string, hello_string_length,
&font_direction, &font_ascent, &font_descent,
&text_structure);
fprintf(stdout, "3\n");
fflush(stdout);
XGetWindowAttributes(display, frame_window[screen_ind], &window_attributes);
fprintf(stdout, "4\n");
fflush(stdout);
text_x = (window_attributes.width - text_structure.width)/2;
text_y = (window_attributes.height -
(text_structure.ascent+text_structure.descent))/2;
fprintf(stdout, "5\n");
fflush(stdout);
XDrawString(display, frame_window[screen_ind], graphical_context, text_x, text_y, hello_string, hello_string_length);
fprintf(stdout, "6\n");
fflush(stdout);
break;
}
default:
break;
}
}
return(0);
}I can run the single version on each of the different screens one at a time, just not all three in one program.
Help!
