Hey guys,
I am trying to draw a white triangle using GLX, but for some reason I cannot get it to show…
Here is the code (admittedly not so great). I can’t seem to figure out why it is not drawing the triangle…
Thanks in advance
Edit:
i just noticed that there are some useless override redirect “things” - i have removed them, but still nothing…
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/time.h>
#include <X11/Xlib.h>
#include <GL/gl.h>
#include <GL/glx.h>
#include <GL/glu.h>
#include <X11/keysym.h>
void init ();
void resize (int, int);
void draw ();
void event_loop ();
/* globals */
const char *env_dpy = NULL;
Display *dpy = NULL;
int screen;
Window root, glwin;
int x,y;
int w,h;
XVisualInfo *vinfo = NULL;
GLXContext glctx;
XSetWindowAttributes *attr = NULL;
Colormap cmap;
static int gl_visual_attr[] = {GLX_RGBA, GLX_DOUBLEBUFFER, GLX_RED_SIZE, 4,
GLX_GREEN_SIZE, 4, GLX_BLUE_SIZE, 4,
GLX_DEPTH_SIZE, 16, None};
/* /globals */
int main (void)
{
if (NULL == (env_dpy = getenv("DISPLAY"))) {
printf("no X server available.
");
return 1;
}
dpy = XOpenDisplay(env_dpy);
if (NULL == dpy) {
printf("cannot connect to X server.
");
return 1;
}
screen = DefaultScreen(dpy);
root = RootWindow(dpy, screen);
/* get an OpenGL visual */
vinfo = glXChooseVisual(dpy, DefaultScreen(dpy), gl_visual_attr);
if (NULL == vinfo) {
printf("cannot find appropriate visual.
");
return 1;
}
/* create an OpenGL context */
glctx = glXCreateContext(dpy, vinfo, 0, GL_TRUE);
if (NULL == glctx) {
printf("cannot create an OpenGL context.
");
return 1;
}
/* create a colormap */
cmap = XCreateColormap(dpy, root, vinfo->visual, AllocNone);
if (0 == cmap) {
printf("cannot allocate colormap.
");
return 1;
}
attr = malloc(sizeof(XSetWindowAttributes));
if (NULL == attr) {
printf("out of memory.
");
return 1;
}
attr->colormap = cmap;
attr->border_pixel = 0;
attr->override_redirect = True;
attr->event_mask = ExposureMask | KeyPressMask | KeyReleaseMask |
ButtonPressMask | ButtonReleaseMask | CWOverrideRedirect |
StructureNotifyMask;
x = 100;
y = 100;
w = 400;
h = 400;
glwin = XCreateWindow(dpy, root, x, y, w, h, 0, vinfo->depth, InputOutput,
vinfo->visual, CWBorderPixel | CWColormap |CWEventMask,
attr);
if (0 == glwin) {
printf("cannot create window.
");
return 1;
}
XMapRaised(dpy, glwin);
XSync(dpy, False);
glXMakeCurrent(dpy, glwin, glctx);
init();
resize(w, h);
event_loop();
XCloseDisplay(dpy);
XFree(vinfo);
free(attr);
return 0;
}
void init ()
{
glShadeModel(GL_SMOOTH);
/* window is cleared to black */
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
resize(w, h);
glFlush();
}
void resize (int w, int h)
{
if (0 >= h) h = 1;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glViewport(0, 0, w, h);
gluPerspective(45.0f, (GLfloat)w / (GLfloat)h, 1.0f, 100.0f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void draw ()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, 0.0f);
glColor3f(1.0f, 1.0f, 1.0f);
glBegin(GL_TRIANGLES);
glVertex3f(-10.0f, -10.0f, 0.0f);
glVertex3f(0.0f, 10.0f, 0.0f);
glVertex3f(10.0f, -10.0f, 0.0f);
glEnd();
}
void event_loop ()
{
XEvent xe;
int done = 0;
KeySym ksym;
while (0 == done) {
while (0 < XPending(dpy)) {
XNextEvent(dpy, &xe);
switch (xe.type) {
case Expose:
draw(dpy, glwin);
break;
case ConfigureNotify:
resize(xe.xconfigure.width, xe.xconfigure.height);
break;
case KeyPress:
ksym = XKeycodeToKeysym(dpy, xe.xkey.keycode, 0);
switch(ksym) {
case XK_q:
done = 1;
break;
case XK_i:
if (glXIsDirect(dpy, glctx))
printf("render type: direct.
");
else
printf("render type: indirect.
");
break;
}
break;
default:
break;
}
}
draw();
glXSwapBuffers(dpy,glwin);
}
}
