Function GetSaveSlopeZ

src/rail_cmd.cpp:1851–1861

* Get surface height in point (x,y) * On tiles with halftile foundations move (x,y) to a safe point wrt. track */

 * On tiles with halftile foundations move (x,y) to a safe point wrt. track
 */
static uint GetSaveSlopeZ(uint x, uint y, Track track)
{
	switch (track) {
		case TRACK_UPPER: x &= ~0xF; y &= ~0xF; break;
		case TRACK_LOWER: x |=  0xF; y |=  0xF; break;
		case TRACK_LEFT:  x |=  0xF; y &= ~0xF; break;
		case TRACK_RIGHT: x &= ~0xF; y |=  0xF; break;
		default: break;
	}
	return GetSlopePixelZ(x, y);
}

static void DrawSingleSignal(TileIndex tile, const RailTypeInfo *rti, Track track, SignalState condition, SignalOffsets image, uint pos)
{