diff -r 7079dcc3bd74 -r 929aad02c5f2 ccdemos/common_sdl.h
--- a/ccdemos/common_sdl.h	Fri Dec 14 16:51:22 2007 +0100
+++ b/ccdemos/common_sdl.h	Mon Dec 17 22:03:50 2007 +0100
@@ -17,8 +17,9 @@
 		++fp10s_acc_samples;
 	}
 	t = tnow;
-	printf("\b\b\b\b\b\b\b\b\bfps:%3d.%1d", fp10s/10, fp10s%10);
-	fflush(stdout);
+	char s[40];
+	sprintf(s, "fps:%3d.%1d", fp10s/10, fp10s%10);
+	SDL_WM_SetCaption(s, NULL);
 
 	rt.render(w, h, render_buffer);
 
@@ -50,14 +51,8 @@
 		SDL_UpdateRect(screen, 0, 0, w, h);
 }
 
-void quit()
-{
-	Uint32 fp100s_aver = fp10s_acc*10/fp10s_acc_samples;
-	printf("\naverlage fps: %3d.%2d\n", fp100s_aver/100, fp100s_aver%100);
-	SDL_Quit();
-}
-
-void loop_sdl(Raytracer &rt, Camera &cam)
+void loop_sdl(Raytracer &rt, Camera &cam,
+	void (*update_callback)() = NULL, void (*key_callback)(int, int) = NULL)
 {
 	SDL_Surface *screen;
 	Float *render_buffer;
@@ -69,9 +64,7 @@
 		fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
 		exit(1);
 	}
-	
-	atexit(quit);
-	
+
 	screen = SDL_SetVideoMode(w, h, 32, SDL_SWSURFACE|SDL_DOUBLEBUF|SDL_RESIZABLE);
 	if ( screen == NULL ) {
 		fprintf(stderr, "Unable to set video mode: %s\n", SDL_GetError());
@@ -87,8 +80,8 @@
 		{
 			switch (event.type) {
 				case SDL_VIDEORESIZE:
-					w = event.resize.w;
-					h = event.resize.h;
+					w = (event.resize.w-1) / 8 * 8 + 8;
+					h = (event.resize.h-1) / 8 * 8 + 8;
 					render_buffer = (Float *) realloc(render_buffer, w*h*3*sizeof(Float));
 					screen = SDL_SetVideoMode(w, h, 32, SDL_HWSURFACE|SDL_DOUBLEBUF|SDL_RESIZABLE);
 					break;
@@ -121,6 +114,17 @@
 						move = -0.5;
 						break;
 					}
+					if (event.key.keysym.sym == SDLK_c) {
+						// print camera coordinates
+						cout << "Camera: eye=" << cam.eye
+						<< ", p=" << cam.p
+						<< ", u=" << cam.u
+						<< ", v=" << cam.v
+						<< endl;
+						break;
+					}
+					if (key_callback != NULL)
+						key_callback(event.key.keysym.sym, 1);
 					break;
 				case SDL_KEYUP:
 					if (event.key.keysym.sym == SDLK_LEFT || event.key.keysym.sym == SDLK_RIGHT) {
@@ -132,9 +136,11 @@
 						break;
 					}
 					if (event.key.keysym.sym == SDLK_w || event.key.keysym.sym == SDLK_s) {
-							move = 0.0;
-							break;
-						}
+						move = 0.0;
+						break;
+					}
+					if (key_callback != NULL)
+						key_callback(event.key.keysym.sym, 0);
 					break;
 				case SDL_QUIT:
 					quit = true;
@@ -144,8 +150,15 @@
 		cam.rotate(Quaternion(cos(rotx),cam.u[0]*sin(rotx),0,cam.u[2]*sin(rotx)).normalize());
 		cam.u.y = 0;
 		cam.u.normalize();
-		cam.move(move,0,0);
+		if (move != 0.0)
+			cam.move(move,0,0);
+		if (update_callback != NULL)
+			update_callback();
 		update(rt, screen, render_buffer);
 	}
 	free(render_buffer);
+
+	Uint32 fp100s_aver = fp10s_acc*10/fp10s_acc_samples;
+	printf("averlage fps: %3d.%2d\n\n", fp100s_aver/100, fp100s_aver%100);
+	SDL_Quit();
 }