# HG changeset patch
# User frosch <frosch@openttd.org>
# Date 1315753753 0
# Node ID 7338f18ce5e4706d86162c99120ef907cd25bf86
# Parent  3a5a17348a42723d4490783d69caf1dd2b8d0535
(svn r22923) -Codechange: Move application of the construction stage into TileLayoutSpriteGroup::ProcessRegisters().

diff --git a/src/newgrf_commons.h b/src/newgrf_commons.h
--- a/src/newgrf_commons.h
+++ b/src/newgrf_commons.h
@@ -70,6 +70,25 @@
 DECLARE_ENUM_AS_BIT_SET(TileLayoutFlags)
 
 /**
+ * Determines which sprite to use from a spriteset for a specific construction stage.
+ * @param construction_stage Construction stage 0 - 3.
+ * @param num_sprites Number of available sprites to select stage from.
+ * @return Sprite to use
+ */
+static inline uint GetConstructionStageOffset(uint construction_stage, uint num_sprites)
+{
+	assert(num_sprites > 0);
+	if (num_sprites > 4) num_sprites = 4;
+	switch (construction_stage) {
+		case 0: return 0;
+		case 1: return num_sprites > 2 ? 1 : 0;
+		case 2: return num_sprites > 2 ? num_sprites - 2 : 0;
+		case 3: return num_sprites - 1;
+		default: NOT_REACHED();
+	}
+}
+
+/**
  * Additional modifiers for items in sprite layouts.
  */
 struct TileLayoutRegisters {
diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -476,7 +476,6 @@
 		/* Limit the building stage to the number of stages supplied. */
 		const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
 		byte stage = GetHouseBuildingStage(ti->tile);
-		stage = tlgroup->GetConstructionStageOffset(stage);
 		DrawTileLayout(ti, tlgroup, stage, house_id);
 	}
 }
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -263,7 +263,6 @@
 		/* Limit the building stage to the number of stages supplied. */
 		const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
 		byte stage = GetIndustryConstructionStage(ti->tile);
-		stage = tlgroup->GetConstructionStageOffset(stage);
 		IndustryDrawTileLayout(ti, tlgroup, i->random_colour, stage, gfx);
 		return true;
 	}
diff --git a/src/newgrf_spritegroup.cpp b/src/newgrf_spritegroup.cpp
--- a/src/newgrf_spritegroup.cpp
+++ b/src/newgrf_spritegroup.cpp
@@ -236,6 +236,7 @@
  */
 const DrawTileSprites *TileLayoutSpriteGroup::ProcessRegisters(uint8 *stage) const
 {
+	if (stage != NULL) *stage = GetConstructionStageOffset(*stage, this->num_building_stages);
 	if (!this->dts.NeedsPreprocessing()) return &this->dts;
 
 	static DrawTileSprites result;
diff --git a/src/newgrf_spritegroup.h b/src/newgrf_spritegroup.h
--- a/src/newgrf_spritegroup.h
+++ b/src/newgrf_spritegroup.h
@@ -292,25 +292,6 @@
 	NewGRFSpriteLayout dts;
 
 	const DrawTileSprites *ProcessRegisters(uint8 *stage) const;
-
-	/**
-	 * Determines which sprite to use from a spriteset for a specific construction stage.
-	 * @param construction_stage Construction stage 0 - 3.
-	 * @return Sprite to use
-	 */
-	uint GetConstructionStageOffset(uint construction_stage) const
-	{
-		uint num_sprites = this->num_building_stages;
-		assert(num_sprites > 0);
-		if (num_sprites > 4) num_sprites = 4;
-		switch (construction_stage) {
-			case 0: return 0;
-			case 1: return num_sprites > 2 ? 1 : 0;
-			case 2: return num_sprites > 2 ? num_sprites - 2 : 0;
-			case 3: return num_sprites - 1;
-			default: NOT_REACHED();
-		}
-	}
 };
 
 struct IndustryProductionSpriteGroup : SpriteGroup {