From 616838dd0acaa3ca106dc9cce76f2645f5572a3a Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 16 Sep 2020 00:10:12 +0200
Subject: [PATCH] - little bit of cleanup on tileImport.

---
 source/build/src/defs.cpp           |  2 +-
 source/core/textures/buildtiles.cpp | 60 +++++++++++++++++++++--------
 source/core/textures/buildtiles.h   |  2 +-
 3 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/source/build/src/defs.cpp b/source/build/src/defs.cpp
index 6f31bb031..7f3387c9f 100644
--- a/source/build/src/defs.cpp
+++ b/source/build/src/defs.cpp
@@ -760,7 +760,7 @@ static int32_t defsparser(scriptfile *script)
                     break;
                 }
             }
-            tileImport(pos, imp);
+            processTileImport("tileimporttexture", pos, imp);
         }
         break;
         case T_COPYTILE:
diff --git a/source/core/textures/buildtiles.cpp b/source/core/textures/buildtiles.cpp
index 8d256bbc2..a34b718ea 100644
--- a/source/core/textures/buildtiles.cpp
+++ b/source/core/textures/buildtiles.cpp
@@ -1069,37 +1069,63 @@ bool PickTexture(int picnum, FGameTexture* tex, int paletteid, TexturePick& pick
 	return true;
 }
 
+//===========================================================================
+// 
+//	Parsing stuff for tile data comes below.
+//
+//===========================================================================
+
+//===========================================================================
+// 
+//	Helpers for tile parsing
+//
+//===========================================================================
+
+bool ValidateTileRange(const char* cmd, int &begin, int& end, FScriptPosition pos)
+{
+	if (end < begin)
+	{
+		pos.Message(MSG_WARNING, "%s: tile range [%d..%d] is backwards. Indices were swapped.", cmd, begin, end);
+		std::swap(begin, end);
+	}
+
+	if ((unsigned)begin >= MAXUSERTILES || (unsigned)end >= MAXUSERTILES)
+	{
+		pos.Message(MSG_ERROR, "%s: Invalid tile range [%d..%d]", cmd, begin, end);
+		return false;
+	}
+
+	return true;
+}
+
+bool ValidateTilenum(const char* cmd, int tile, FScriptPosition pos)
+{
+	if ((unsigned)tile >= MAXUSERTILES)
+	{
+		pos.Message(MSG_ERROR, "%s: Invalid tile number %d", cmd, tile);
+		return false;
+	}
+
+	return true;
+}
+
 //===========================================================================
 // 
 //	Internal worker for tileImportTexture
 //
 //===========================================================================
 
-void tileImport(FScriptPosition& pos, TileImport& imp)
+void processTileImport(const char *cmd, FScriptPosition& pos, TileImport& imp)
 {
-	if (imp.tile == -1)
-	{
-		pos.Message(MSG_ERROR, "missing tile number in import declaration");
+	if (!ValidateTilenum(cmd, imp.tile, pos))
 		return;
-	}
-	if ((unsigned)imp.tile >= MAXUSERTILES)
-	{
-		pos.Message(MSG_ERROR, "Invalid tile number %d in import declaration", imp.tile);
-		return;
-	}
 
 	if (imp.crc32 != INT64_MAX && int(imp.crc32) != tileGetCRC32(imp.tile))
-	{
-		// Only print as developer diagnostic if that mode is enabled.
-		pos.Message(MSG_DEBUGMSG, "CRC32 mismatch for tile %d.", imp.tile);
 		return;
-	}
 
 	if (imp.sizex != INT_MAX && tileWidth(imp.tile) != imp.sizex && tileHeight(imp.tile) != imp.sizey)
-	{
-		pos.Message(MSG_DEBUGMSG, "Size mismatch for tile %d", imp.tile);
 		return;
-	}
+
 	gi->SetTileProps(imp.tile, imp.surface, imp.vox, imp.shade);
 
 	if (imp.fn.IsNotEmpty() && tileImportFromTexture(imp.fn, imp.tile, imp.alphacut, imp.istexture) < 0) return;
diff --git a/source/core/textures/buildtiles.h b/source/core/textures/buildtiles.h
index a89fe0df6..8215c1226 100644
--- a/source/core/textures/buildtiles.h
+++ b/source/core/textures/buildtiles.h
@@ -518,4 +518,4 @@ struct TileImport
 
 };
 
-void tileImport(FScriptPosition& pos, TileImport& imp);
+void processTileImport(const char* cmd, FScriptPosition& pos, TileImport& imp);