port: fix sliding doors exploding at non-60fps framerates

src/game/propobj.c

@@ -7671,7 +7671,12 @@ void doorTick(struct prop *doorprop)
 	}
 
 	// Update frac
+#ifdef PLATFORM_N64
 	if (door->lastcalc60 < g_Vars.lvframe60 || g_Vars.lvupdate240 == 0) {
+#else
+	// lastcalc60 actually stores lvframe240
+	if (door->lastcalc60 < g_Vars.lvframe240 || g_Vars.lvupdate240 == 0) {
+#endif
 		doorsCalcFrac(door);
 	}
 
@@ -20333,7 +20338,11 @@ void doorsCalcFrac(struct doorobj *door)
 			func0f08d460(loopdoor);
 		}
 
+#ifdef PLATFORM_N64
 		loopdoor->lastcalc60 = g_Vars.lvframe60;
+#else
+		loopdoor->lastcalc60 = g_Vars.lvframe240; // actually use the 240hz counter for higher framerates
+#endif
 		loopdoor = loopdoor->sibling;
 
 		if (loopdoor == door) {

src/include/types.h

@@ -1523,7 +1523,7 @@ struct doorobj { // objtype 0x01
 	/*0xc4*/ s16 portalnum;
 	/*0xc6*/ s8 soundtype;
 	/*0xc7*/ s8 fadetime60; // counts down
-	/*0xc8*/ s32 lastcalc60;
+	/*0xc8*/ s32 lastcalc60; // port: actually stores 240hz frame number
 	/*0xcc*/ u8 laserfade;
 	/*0xcd*/ u8 unusedmaybe[3];
 	/*0xd0*/ u8 shadeinfo1[4]; // player 1