X-Git-Url: https://git.draconx.ca/gitweb/rrace.git/blobdiff_plain/ee68c7cd53763caeb44de97f1036ebaf014a7292..831e44784dc638f4025269f5a4217ada98602eda:/src/motif_ui.c

diff --git a/src/motif_ui.c b/src/motif_ui.c
index 127de06..fefcfed 100644
--- a/src/motif_ui.c
+++ b/src/motif_ui.c
@@ -323,6 +323,8 @@ static void game_expose(Widget w, void *data, void *cb_data)
 {
 	XmDrawingAreaCallbackStruct *cbs = cb_data;
 	XExposeEvent *e = &cbs->event->xexpose;
+	struct app_state *state = data;
+	uint_least32_t *gp = state->board.game;
 	Dimension width, height;
 	uint_fast32_t mask;
 
@@ -330,8 +332,15 @@ static void game_expose(Widget w, void *data, void *cb_data)
 	if (!(width /= 5) || !(height /= 5))
 		return;
 
-	mask = expose_mask(e->x, e->y, e->width, e->height, width, height);
-	x11_redraw_game(data, mask);
+	/*
+	 * Only draw exposed nonempty tiles; exposed areas are filled with the
+	 * background automatically and thus exposed empty spaces don't need
+	 * to be drawn again.
+	 */
+	mask = gp[0] | gp[1] | gp[2];
+	mask &= expose_mask(e->x, e->y, e->width, e->height, width, height);
+
+	x11_redraw_game(state, mask);
 }
 
 static void goal_expose(Widget w, void *data, void *cb_data)