SCI: Removed usec_sleep from gfx_driver_t (call OSystem::delayMillis directly instead); added remarks that busy-waiting like this with delayMillis is maybe not the best way, and that gfx_driver_t should be either removed or turned into a class

svn-id: r38851

3 files changed, 14 insertions, 30 deletions

diff --git a/engines/sci/gfx/gfx_driver.cpp b/engines/sci/gfx/gfx_driver.cpp
index b3bb8813f1..a142de162c 100644
--- a/engines/sci/gfx/gfx_driver.cpp
+++ b/engines/sci/gfx/gfx_driver.cpp
@@ -463,11 +463,6 @@ static sci_event_t scummvm_get_event(gfx_driver_t *drv) {
 	return input;
 }
 
-static int scummvm_usec_sleep(gfx_driver_t *drv, long usecs) {
-	g_system->delayMillis(usecs / 1000);
-	return GFX_OK;
-}
-
 gfx_driver_t gfx_driver_scummvm = {
 	NULL,
 	0, 0,
@@ -486,7 +481,6 @@ gfx_driver_t gfx_driver_scummvm = {
 	scummvm_set_pointer,
 	scummvm_set_palette,
 	scummvm_get_event,
-	scummvm_usec_sleep,
 	NULL
 };
 
diff --git a/engines/sci/gfx/gfx_driver.h b/engines/sci/gfx/gfx_driver.h
index 3ecdaa80cf..343d0199d0 100644
--- a/engines/sci/gfx/gfx_driver.h
+++ b/engines/sci/gfx/gfx_driver.h
@@ -31,11 +31,11 @@
 
 namespace Sci {
 
-typedef enum {
+enum gfx_buffer_t {
 	GFX_BUFFER_FRONT = 0,
 	GFX_BUFFER_BACK = 1,
 	GFX_BUFFER_STATIC = 2
-} gfx_buffer_t;
+};
 
 
 /* graphics driver hints */
@@ -71,6 +71,7 @@ typedef enum {
 ** must use a reasonable default value.
 */
 
+// FIXME: Turn this into a class, or get rid of it completely.
 struct gfx_driver_t { /* Graphics driver */
 
 	gfx_mode_t *mode; /* Currently active mode, NULL if no mode is active */
@@ -302,17 +303,6 @@ struct gfx_driver_t { /* Graphics driver */
 	**                           queue, or the null event if there is none.
 	*/
 
-	int (*usec_sleep)(gfx_driver_t *drv, long usecs);
-	/* Sleeps the specified amount of microseconds, or until the mouse moves
-	** Parameters: (gfx_driver_t *) drv: The relevant driver
-	**             (long) usecs: Amount of microseconds to sleep
-	** Returns   : (int) GFX_OK or GFX_FATAL
-	** This function returns when the specified amount of microseconds has
-	** elapsed, or when the mouse pointer has been moved and needs to be redrawn.
-	** Only targets that can handle colored mouse pointers may choose to handle
-	** all mouse management internally.
-	*/
-
 	void *state; /* Reserved for internal use */
 
 };
diff --git a/engines/sci/gfx/operations.cpp b/engines/sci/gfx/operations.cpp
index d4190353a1..26b0207695 100644
--- a/engines/sci/gfx/operations.cpp
+++ b/engines/sci/gfx/operations.cpp
@@ -1363,24 +1363,24 @@ static int _gfxop_full_pointer_refresh(gfx_state_t *state) {
 }
 
 int gfxop_usleep(gfx_state_t *state, long usecs) {
-	uint32 time, wakeup_time;
-	int retval = GFX_OK;
-
 	BASIC_CHECKS(GFX_FATAL);
 
-	wakeup_time = g_system->getMillis() + usecs / 1000;
+	uint32 time;
+	const uint32 wakeup_time = g_system->getMillis() + usecs / 1000;
 
-	do {
+	while (true) {
 		GFXOP_FULL_POINTER_REFRESH;
 		time = g_system->getMillis();
-		usecs = 1000 * ((long)wakeup_time - (long)time);
-	} while ((usecs > 0) && !(retval = state->driver->usec_sleep(state->driver, usecs)));
-
-	if (retval) {
-		GFXWARN("Waiting failed\n");
+		if (time >= wakeup_time)
+			break;
+		// FIXME: Busy waiting like this is usually not a good idea if it is for
+		// more than a few milliseconds. One should invoke OSystem::pollEvent during longer
+		// waits, else the mouse cursor might not be updated properly, and the system
+		// will seem sluggish to the user.
+		g_system->delayMillis(wakeup_time - time);
 	}
 
-	return retval;
+	return GFX_OK;
 }
 
 int _gfxop_set_pointer(gfx_state_t *state, gfx_pixmap_t *pxm) {