test: use spacebar as a slow motion hotkey for gles-rgb-cycle-demo

Whenever something goes wrong in high fps mode, it may be interesting
to slow down the demo to check whether the actual background color
matches the expected color (shown in the window title).
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

test/gles-rgb-cycle-demo.c

@@ -97,6 +97,7 @@ static const EGLint context_attribute_list[] = {
 EGLDisplay egl_display;
 EGLSurface egl_surface;
 
+static int slow_motion = 0;
 static int msleep_time = 1000;
 static int fullscreen_state = 1;
 static int framecount = 0;
@@ -128,7 +129,10 @@ Redraw(int width, int height)
 	glClear(GL_COLOR_BUFFER_BIT);
 	eglSwapBuffers(egl_display, egl_surface);
 
-	usleep(msleep_time * 1000);
+	if (slow_motion)
+		usleep(1000 * 1000);
+	else
+		usleep(msleep_time * 1000);
 }
 
 void set_fullscreen_state(int state)
@@ -264,7 +268,8 @@ main(int argc, char *argv[])
 	printf("between red, green and blue (starting with red).\n");
 	printf("The animation speed is %d milliseconds per frame.\n", msleep_time);
 	printf("\n");
-	printf("Press 'f' to toggle between fullscreen and windowed mode.\n\n");
+	printf("Press 'f' to toggle between fullscreen and windowed mode.\n");
+	printf("Press ' ' to toggle between normal speed and slow motion.\n\n");
 
 #ifdef USE_X
 	set_fullscreen_state(fullscreen_state);
@@ -281,6 +286,8 @@ main(int argc, char *argv[])
 				break;
 			if (xev.type == KeyPress && xev.xkey.keycode == 41)
 				set_fullscreen_state(fullscreen_state ^= 1);
+			if (xev.type == KeyPress && xev.xkey.keycode == 65)
+				slow_motion ^= 1;
 		}
 		Redraw(width, height);
 	}