Add new signal type: no-entry signal

This is only passable in one direction, but does not have a signal
or show an aspect in the opposite direction

Add a setting for whether this is shown in the signal UI.
Off by default.

media/baseset/CMakeLists.txt

@@ -19,6 +19,7 @@ set(BASESET_OTHER_SOURCE_FILES
         ${CMAKE_CURRENT_SOURCE_DIR}/orig_extra.grf
         ${CMAKE_CURRENT_SOURCE_DIR}/innerhighlight.grf
         ${CMAKE_CURRENT_SOURCE_DIR}/progsignals.grf
+        ${CMAKE_CURRENT_SOURCE_DIR}/extra_signals.grf
         ${CMAKE_CURRENT_SOURCE_DIR}/route_step.grf
         ${CMAKE_CURRENT_SOURCE_DIR}/tracerestrict.grf
 )

media/baseset/extra_signals/extra_signals.nfo

@@ -0,0 +1,23 @@
+// Automatically generated by GRFCODEC. Do not modify!
+// (Info version 32)
+// Escapes: 2+ 2- 2< 2> 2u< 2u> 2/ 2% 2u/ 2u% 2* 2& 2| 2^ 2sto = 2s 2rst = 2r 2psto 2ror = 2rot 2cmp 2ucmp 2<< 2u>> 2>>
+// Escapes: 71 70 7= 7! 7< 7> 7G 7g 7gG 7GG 7gg 7c 7C
+// Escapes: D= = DR D+ = DF D- = DC Du* = DM D* = DnF Du<< = DnC D<< = DO D& D| Du/ D/ Du% D%
+// Format: spritenum imagefile depth xpos ypos xsize ysize xrel yrel zoom flags
+    0 sprites/extra_signals.png  8bpp   40   40   20   30   -9  -28 normal
+    1 sprites/extra_signals.png  8bpp   10   40   20   30   -9  -28 normal
+    2 sprites/extra_signals.png  8bpp  100   40   20   30   -9  -28 normal
+    3 sprites/extra_signals.png  8bpp   70   40   20   30   -9  -28 normal
+    4 sprites/extra_signals.png  8bpp  160   40   20   30   -9  -28 normal
+    5 sprites/extra_signals.png  8bpp  130   40   20   30   -9  -28 normal
+    6 sprites/extra_signals.png  8bpp  220   40   20   30   -9  -28 normal
+    7 sprites/extra_signals.png  8bpp  190   40   20   30   -9  -28 normal
+
+    8 sprites/extra_signals.png  8bpp   20   10    4   22   -1  -20 normal
+    9 sprites/extra_signals.png  8bpp   10   10    5   22   -2  -20 normal
+   10 sprites/extra_signals.png  8bpp   40   10    5   22   -1  -20 normal
+   11 sprites/extra_signals.png  8bpp   30   10    4   22   -1  -20 normal
+   12 sprites/extra_signals.png  8bpp   60   10    5   22   -2  -20 normal
+   13 sprites/extra_signals.png  8bpp   50   10    5   22   -1  -20 normal
+   14 sprites/extra_signals.png  8bpp   80   10    6   22   -3  -20 normal
+   15 sprites/extra_signals.png  8bpp   70   10    6   22   -3  -20 normal