Fix wrong song area height when starting the program with piano disabled

The height was being defined inside the Preferences window, once the 'Show piano' toggle was changed. Moved that to the drawing code, which updates in real time.

Author: Bentroen

scripts/control_draw/control_draw.gml

@@ -78,8 +78,9 @@ if (show_layers) {
 } else {
 	totalcols = floor(rw / 32)
 }
-if show_piano = 1 {
-	rhval = 270
+rhval = 270
+if (!show_piano) {
+	rhval = 130
 }
 totalrows = floor((rh - rhval) / 32)
 if (min(keysmax, floor((rw - 32) / 39)) != keysshow) {

scripts/draw_window_preferences/draw_window_preferences.gml

@@ -142,13 +142,7 @@ if (selected_tab = 0) {
 	if (draw_checkbox(x1 + 40, y1 + 200, fade, "No fading", "Disables transparency animations on note block sprites")) fade = !fade
 	if (draw_checkbox(x1 + 40, y1 + 220, show_layers, "Show layer boxes", "Whether the layer boxes should be\nshown to the right of the workspace.")) show_layers = !show_layers
     draw_areaheader(x1 + 22, y1 + 260, 456, 95, "Piano")
-    if (draw_checkbox(x1 + 40, y1 + 276, show_piano, "Show piano", "Whether the piano should be visible.")) {
-		show_piano=!show_piano
-		rhval=130
-		if show_piano = 1 {
-			rhval=270
-		}
-}
+    if (draw_checkbox(x1 + 40, y1 + 276, show_piano, "Show piano", "Whether the piano should be visible.")) show_piano = !show_piano
     if (draw_checkbox(x1 + 40, y1 + 296, show_keynames, "Show key names", "If the names of the keys should be shown.")) show_keynames=!show_keynames
     if (draw_checkbox(x1 + 40, y1 + 316, show_keyboard, "Show keyboard shortcuts", "Show the keyboard shortcuts of the keys.")) show_keyboard=!show_keyboard
     if (draw_checkbox(x1 + 40, y1 + 336, show_notechart, "Show note chart when hovering over keys", "Whether to show a note chart\nwhen hovering over the keys.")) show_notechart=!show_notechart