diff -r -u -p glxgears.orig/glxgears.c glxgears/glxgears.c --- glxgears.orig/glxgears.c 2003-11-30 11:18:09.000000000 -0500 +++ glxgears/glxgears.c 2003-11-30 18:38:25.000000000 -0500 @@ -24,8 +24,12 @@ * This is a port of the infamous "gears" demo to straight GLX (i.e. no GLUT) * Port by Brian Paul 23 March 2001 * + * Exact timing added by Behdad Esfahbod to achieve a fixed speed regardless + * of frame rate. November 2003 + * * Command line options: * -info print GL implementation information + * -debug draw only one tooth for each gear * */ @@ -40,35 +44,37 @@ #include -#define BENCHMARK +#define TIMING -#ifdef BENCHMARK +#ifdef TIMING /* XXX this probably isn't very portable */ #include +#include #include +#include /* return current time (in seconds) */ -static int +static long current_time(void) { struct timeval tv; struct timezone tz; (void) gettimeofday(&tv, &tz); - return (int) tv.tv_sec; + return (long) tv.tv_sec * 1000000 + (long) tv.tv_usec; } -#else /*BENCHMARK*/ +#else /*TIMING*/ /* dummy */ -static int +static long current_time(void) { return 0; } -#endif /*BENCHMARK*/ +#endif /*TIMING*/ @@ -76,11 +82,11 @@ current_time(void) #define M_PI 3.14159265 #endif - static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0; static GLint gear1, gear2, gear3; static GLfloat angle = 0.0; - +static GLint speed = 60; +static int debug = 0, paused = 0; /* * @@ -98,13 +104,14 @@ gear(GLfloat inner_radius, GLfloat outer GLint teeth, GLfloat tooth_depth) { GLint i; - GLfloat r0, r1, r2; + GLfloat r0, r1, r2, maxr2, minr2; GLfloat angle, da; GLfloat u, v, len; r0 = inner_radius; r1 = outer_radius - tooth_depth / 2.0; - r2 = outer_radius + tooth_depth / 2.0; + maxr2 = r2 = outer_radius + tooth_depth / 2.0; + minr2 = debug ? r1 : r2; da = 2.0 * M_PI / teeth / 4.0; @@ -128,7 +135,6 @@ gear(GLfloat inner_radius, GLfloat outer /* draw front sides of teeth */ glBegin(GL_QUADS); - da = 2.0 * M_PI / teeth / 4.0; for (i = 0; i < teeth; i++) { angle = i * 2.0 * M_PI / teeth; @@ -138,7 +144,9 @@ gear(GLfloat inner_radius, GLfloat outer width * 0.5); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); + r2 = minr2; } + r2 = maxr2; glEnd(); glNormal3f(0.0, 0.0, -1.0); @@ -169,7 +177,9 @@ gear(GLfloat inner_radius, GLfloat outer -width * 0.5); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); + r2 = minr2; } + r2 = maxr2; glEnd(); /* draw outward faces of teeth */ @@ -187,7 +197,7 @@ gear(GLfloat inner_radius, GLfloat outer glNormal3f(v, -u, 0.0); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5); glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); - glNormal3f(cos(angle), sin(angle), 0.0); + glNormal3f(cos(angle + 1.5 * da), sin(angle + 1.5 * da), 0.0); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5); glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), @@ -199,8 +209,10 @@ gear(GLfloat inner_radius, GLfloat outer width * 0.5); glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); - glNormal3f(cos(angle), sin(angle), 0.0); + glNormal3f(cos(angle + 3.5 * da), sin(angle + 3.5 * da), 0.0); + r2 = minr2; } + r2 = maxr2; glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5); glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5); @@ -262,7 +274,11 @@ reshape(int width, int height) glViewport(0, 0, (GLint) width, (GLint) height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); - glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0); + /* fit width and height */ + if (h >= 1.0) + glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0); + else + glFrustum(-1.0/h, 1.0/h, -1.0, 1.0, 5.0, 60.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, 0.0, -40.0); @@ -335,7 +351,7 @@ make_window( Display *dpy, const char *n visinfo = glXChooseVisual( dpy, scrnum, attrib ); if (!visinfo) { - printf("Error: couldn't get an RGB, Double-buffered visual\n"); + fprintf(stderr, "Error: couldn't get an RGB, Double-buffered visual\n"); exit(1); } @@ -365,7 +381,7 @@ make_window( Display *dpy, const char *n ctx = glXCreateContext( dpy, visinfo, NULL, True ); if (!ctx) { - printf("Error: glXCreateContext failed\n"); + fprintf(stderr, "Error: glXCreateContext failed\n"); exit(1); } @@ -410,41 +426,83 @@ event_loop(Display *dpy, Window win) else { r = XLookupString(&event.xkey, buffer, sizeof(buffer), NULL, NULL); - if (buffer[0] == 27) { - /* escape */ - return; + switch (buffer[0]) { + case 27: /* escape */ + case 'q': + return; + case 32: /* space */ + paused = 1 - paused; + break; + case 'a': + if (speed < 360) + speed += 5; + break; + case 'z': + if (speed > -360) + speed -= 5; + break; } } } } } - /* next frame */ - angle += 2.0; - - draw(); - glXSwapBuffers(dpy, win); - - /* calc framerate */ { - static int t0 = -1; - static int frames = 0; - int t = current_time(); + long t = current_time(); + { + /* next frame */ + static long t0 = 0; + long useconds; + + if (!t0) + t0 = t; + + useconds = t - t0; + if (!useconds) /* assume 100FPS if we don't have timer */ + useconds = 10000; + + if (!paused) + angle = angle + ((double)speed * useconds) / 1000000.0; + /*angle = angle + 0.2;*/ + + /* keep angle small so we don't lose precision! */ + if (angle > 360.0) + angle = angle - 360.0; - if (t0 < 0) - t0 = t; + draw(); + glXSwapBuffers(dpy, win); - frames++; - - if (t - t0 >= 5.0) { - GLfloat seconds = t - t0; - GLfloat fps = frames / seconds; - printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds, - fps); t0 = t; - frames = 0; + } + +#ifdef TIMING + { + /* calc framerate */ + static int frames = 0; + static long t0 = 0; + + if (!t0) + t0 = t; + + frames++; + + if (t - t0 >= 5000000) { + GLfloat seconds = (t - t0) / 1000000.0; + GLfloat fps = frames / seconds; + + printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds, + fps); + t0 = t; + frames = 0; + } } } + + /* need to give cpu away in order to get precise timing next cycle, + otherwise, gettimeofday would return almost the same value. */ + sched_yield(); + +#endif /*TIMING*/ } } @@ -467,11 +525,14 @@ main(int argc, char *argv[]) else if (strcmp(argv[i], "-info") == 0) { printInfo = GL_TRUE; } + else if (strcmp(argv[i], "-debug") == 0) { + debug = 1; + } } dpy = XOpenDisplay(dpyName); if (!dpy) { - printf("Error: couldn't open display %s\n", dpyName); + fprintf(stderr, "Error: couldn't open display %s\n", dpyName); return -1; } diff -r -u -p glxgears.orig/glxgears.man glxgears/glxgears.man --- glxgears.orig/glxgears.man 2003-11-30 11:18:09.000000000 -0500 +++ glxgears/glxgears.man 2003-11-30 11:50:03.000000000 -0500 @@ -19,6 +19,9 @@ Print out GL implementation information .TP 8 .BI "\-display " displayname Specify the display to query. +.TP 8 +.B \-debug +Draw a single tooth on each gear. .SH ENVIRONMENT .PP .TP 8 diff -r -u -p glxgears.orig/glxgears._man glxgears/glxgears._man --- glxgears.orig/glxgears._man 2003-11-30 11:18:09.000000000 -0500 +++ glxgears/glxgears._man 2003-11-30 11:50:19.000000000 -0500 @@ -19,6 +19,9 @@ Print out GL implementation information .TP 8 .BI "\-display " displayname Specify the display to query. +.TP 8 +.B \-debug +Draw a single tooth on each gear. .SH ENVIRONMENT .PP .TP 8