(svn r1571) Feature: Visually enhanced autorail placing

When using the autorail tool, the rail pieces which are going to be build are highlighted.
If a piece is shown in red, this indicates that the slope/rail combination is impossible. It does not tell you if the rail line construction might not be possible because of other obstacles, e.g. houses or water.

2 files changed, 72 insertions, 1 deletions

diff --git a/table/autorail.h b/table/autorail.h
new file mode 100644
index 000000000..f219f1c7d
--- /dev/null
+++ b/table/autorail.h
@@ -0,0 +1,70 @@
+/* Rail selection types (directions):
+ / \    / \    / \    / \   / \   / \
+/  /\  /\  \  /===\  /   \ /|  \ /  |\
+\/  /  \  \/  \   /  \===/ \|  / \  |/
+ \ /    \ /    \ /    \ /   \ /   \ /
+  0      1      2      3     4     5
+*/
+
+// mark invalid tiles red
+#define RED(c) c | PALETTE_SEL_TILE_RED
+
+// table maps each of the six rail directions and tileh combinations to a sprite
+// invalid entries are required to make sure that this array can be quickly accessed
+const int AutorailTilehSprite[31][6] = {
+// type   0        1        2        3        4        5
+	{       0,       8,      16,      25,      34,      42 }, // tileh = 0
+	{       5,      13, RED(22), RED(31),      35,      42 }, // tileh = 1
+	{       5,      10,      16,      26, RED(38), RED(46) }, // tileh = 2
+	{       5,       9, RED(23),      26,      35, RED(46) }, // tileh = 3
+	{       2,      10, RED(19), RED(28),      34,      43 }, // tileh = 4
+	{       1,       9,      17,      26,      35,      43 }, // tileh = 5
+	{       1,      10, RED(20),      26, RED(38),      43 }, // tileh = 6
+	{       1,       9,      17,      26,      35,      43 }, // tileh = 7
+	{       2,      13,      17,      25, RED(40), RED(48) }, // tileh = 8
+	{       1,      13,      17, RED(32),      35, RED(48) }, // tileh = 9
+	{       2,       9,      17,      26,      35,      43 }, // tileh = 10
+	{       1,       9,      17,      26,      35,      43 }, // tileh = 11
+	{       2,       9,      17, RED(29), RED(40),      43 }, // tileh = 12
+	{       1,       9,      17,      26,      35,      43 }, // tileh = 13
+	{       1,       9,      17,      26,      35,      43 }, // tileh = 14
+	{       0,       1,       2,       3,       4,       5 }, // invalid (15)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (16)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (17)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (18)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (19)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (20)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (21)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (22)
+	{  RED(6), RED(11), RED(17), RED(27), RED(39), RED(47) }, // tileh = 23
+	{       0,       1,       2,       3,       4,       5 }, // invalid (24)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (25)
+	{       0,       1,       2,       3,       4,       5 }, // invalid (26)
+	{  RED(7), RED(15), RED(24), RED(33), RED(36), RED(44) }, // tileh = 27
+	{       0,       1,       2,       3,       4,       5 }, // invalid (28)
+	{  RED(3), RED(14), RED(18), RED(26), RED(41), RED(49) }, // tileh = 29
+	{  RED(4), RED(12), RED(21), RED(30), RED(37), RED(45) }, // tileh = 30
+};
+#undef RED
+
+
+// maps each pixel of a tile (16x16) to a selection type
+// (0,0) is the top corner, (16,16) the bottom corner
+const int AutorailPiece[16][16] = {
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 5, 5, 5, 5, 5, 5 },
+	{ 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1 },
+	{ 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1 },
+	{ 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 },
+	{ 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 },
+	{ 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 3, 3, 3, 3, 3, 3 }
+};
diff --git a/table/sprites.h b/table/sprites.h
index d17d2b4b7..88929b4d7 100644
--- a/table/sprites.h
+++ b/table/sprites.h
@@ -44,7 +44,8 @@ enum Sprites {
 	/* Extra graphic spritenumbers */
 	SPR_CANALS_BASE		= 5126,
 	SPR_SLOPES_BASE		= SPR_CANALS_BASE + 70,
-	SPR_OPENTTD_BASE	= SPR_SLOPES_BASE + 74,		//5270
+	SPR_AUTORAIL_BASE		= SPR_SLOPES_BASE + 78,
+	SPR_OPENTTD_BASE	= SPR_AUTORAIL_BASE + 55, // can be lowered once autorail.grf is finalized
 
 	SPR_BLOT = SPR_OPENTTD_BASE + 32, // colored circle (mainly used as vehicle profit marker and for sever compatibility)