--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/newgrf_canal.cpp	Wed Jun 13 11:45:14 2007 +0000
@@ -0,0 +1,96 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "variables.h"
+#include "landscape.h"
+#include "debug.h"
+#include "newgrf.h"
+#include "newgrf_callbacks.h"
+#include "newgrf_spritegroup.h"
+#include "newgrf_canal.h"
+
+
+/** Table of canal 'feature' sprite groups */
+const SpriteGroup *_canal_sg[CF_END];
+
+
+/* Random bits and triggers are not supported for canals, so the following
+ * three functions are stubs. */
+static uint32 CanalGetRandomBits(const ResolverObject *object)
+{
+	return 0;
+}
+
+
+static uint32 CanalGetTriggers(const ResolverObject *object)
+{
+	return 0;
+}
+
+
+static void CanalSetTriggers(const ResolverObject *object, int triggers)
+{
+	return;
+}
+
+
+static uint32 CanalGetVariable(const ResolverObject *object, byte variable, byte parameter, bool *available)
+{
+	TileIndex tile = object->u.canal.tile;
+
+	switch (variable) {
+		case 0x80:
+			return TileHeight(tile);
+
+		case 0x81:
+			return ((_opt.landscape == LT_ARCTIC && GetTileZ(tile) > GetSnowLine()) ? 4 : 0) |
+			       (_opt.landscape == LT_TROPIC ? GetTropicZone(tile) : 0);
+	}
+
+	DEBUG(grf, 1, "Unhandled canal property 0x%02X", variable);
+
+	*available = false;
+	return 0;
+}
+
+
+static const SpriteGroup *CanalResolveReal(const ResolverObject *object, const SpriteGroup *group)
+{
+	if (group->g.real.num_loaded == 0) return NULL;
+
+	return group->g.real.loaded[0];
+}
+
+
+static void NewCanalResolver(ResolverObject *res, TileIndex tile)
+{
+	res->GetRandomBits = &CanalGetRandomBits;
+	res->GetTriggers   = &CanalGetTriggers;
+	res->SetTriggers   = &CanalSetTriggers;
+	res->GetVariable   = &CanalGetVariable;
+	res->ResolveReal   = &CanalResolveReal;
+
+	res->u.canal.tile = tile;
+
+	res->callback        = 0;
+	res->callback_param1 = 0;
+	res->callback_param2 = 0;
+	res->last_value      = 0;
+	res->trigger         = 0;
+	res->reseed          = 0;
+}
+
+
+SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
+{
+	ResolverObject object;
+	const SpriteGroup *group;
+
+	NewCanalResolver(&object, tile);
+
+	group = Resolve(_canal_sg[feature], &object);
+	if (group == NULL || group->type != SGT_RESULT) return 0;
+
+	return group->g.result.sprite;
+}