Codechange: Use sprite table instead of magic number when drawing ground sprite (#15828)

src/clear_cmd.cpp

@@ -53,12 +53,21 @@ static CommandCost ClearTile_Clear(TileIndex tile, DoCommandFlags flags)
 	return price;
 }
 
-void DrawClearLandTile(const TileInfo *ti, uint8_t set)
+/**
+ * Draw a ClearGround::Grass tile.
+ * @param ti The tile to draw.
+ * @param density The density of the dirt -> grass transition to draw.
+ */
+void DrawClearLandTile(const TileInfo *ti, uint8_t density)
 {
-	DrawGroundSprite(SPR_FLAT_BARE_LAND + SlopeToSpriteOffset(ti->tileh) + set * 19, PAL_NONE);
+	DrawGroundSprite(_clear_land_sprites_grass[density] + SlopeToSpriteOffset(ti->tileh), PAL_NONE);
 }
 
-void DrawHillyLandTile(const TileInfo *ti)
+/**
+ * Draw a ClearGround::Rough tile.
+ * @param ti The tile to draw.
+ */
+void DrawRoughLandTile(const TileInfo *ti)
 {
 	if (ti->tileh != SLOPE_FLAT) {
 		DrawGroundSprite(SPR_FLAT_ROUGH_LAND + SlopeToSpriteOffset(ti->tileh), PAL_NONE);
@@ -67,6 +76,10 @@ void DrawHillyLandTile(const TileInfo *ti)
 	}
 }
 
+/**
+ * Draw the fences atop a ClearGround::Fields tile.
+ * @param ti The tile to draw.
+ */
 static void DrawClearLandFence(const TileInfo *ti)
 {
 	/* combine fences into one sprite object */
@@ -138,7 +151,7 @@ static void DrawTile_Clear(TileInfo *ti)
 			break;
 
 		case ClearGround::Rough:
-			DrawHillyLandTile(ti);
+			DrawRoughLandTile(ti);
 			break;
 
 		case ClearGround::Rocks:

src/clear_func.h

@@ -12,7 +12,7 @@
 
 #include "tile_cmd.h"
 
-void DrawHillyLandTile(const TileInfo *ti);
+void DrawRoughLandTile(const TileInfo *ti);
 void DrawClearLandTile(const TileInfo *ti, uint8_t set);
 
 #endif /* CLEAR_FUNC_H */

src/table/clear_land.h

@@ -9,6 +9,7 @@
 
 #include "sprites.h"
 
+/** Sprites of the random variants of rough grass sprites, for flat tiles only. */
 static const SpriteID _landscape_clear_sprites_rough[8] = {
 	SPR_FLAT_ROUGH_LAND,
 	SPR_FLAT_ROUGH_LAND_1,
@@ -20,6 +21,7 @@ static const SpriteID _landscape_clear_sprites_rough[8] = {
 	SPR_FLAT_ROUGH_LAND_2,
 };
 
+/** Sprite offset for sloped fences on the southwest edge of the tile. */
 static const uint8_t _fence_mod_by_tileh_sw[32] = {
 	0, 2, 4, 0, 0, 2, 4, 0,
 	0, 2, 4, 0, 0, 2, 4, 0,
@@ -27,6 +29,7 @@ static const uint8_t _fence_mod_by_tileh_sw[32] = {
 	0, 2, 4, 2, 0, 2, 4, 0,
 };
 
+/** Sprite offset for sloped fences on the southeast edge of the tile. */
 static const uint8_t _fence_mod_by_tileh_se[32] = {
 	1, 1, 5, 5, 3, 3, 1, 1,
 	1, 1, 5, 5, 3, 3, 1, 1,
@@ -34,6 +37,7 @@ static const uint8_t _fence_mod_by_tileh_se[32] = {
 	1, 1, 5, 5, 3, 3, 3, 1,
 };
 
+/** Sprite offset for sloped fences on the northeast edge of the tile. */
 static const uint8_t _fence_mod_by_tileh_ne[32] = {
 	0, 0, 0, 0, 4, 4, 4, 4,
 	2, 2, 2, 2, 0, 0, 0, 0,
@@ -41,6 +45,7 @@ static const uint8_t _fence_mod_by_tileh_ne[32] = {
 	2, 2, 2, 2, 0, 2, 4, 0,
 };
 
+/** Sprite offset for sloped fences on the northwest edge of the tile. */
 static const uint8_t _fence_mod_by_tileh_nw[32] = {
 	1, 5, 1, 5, 1, 5, 1, 5,
 	3, 1, 3, 1, 3, 1, 3, 1,
@@ -48,7 +53,7 @@ static const uint8_t _fence_mod_by_tileh_nw[32] = {
 	3, 1, 3, 5, 3, 3, 3, 1,
 };
 
-
+/** Sprites of the flat tile base for each type of farm field fence. */
 static const SpriteID _clear_land_fence_sprites[7] = {
 	SPR_HEDGE_BUSHES,
 	SPR_HEDGE_BUSHES_WITH_GATE,
@@ -58,6 +63,7 @@ static const SpriteID _clear_land_fence_sprites[7] = {
 	SPR_HEDGE_STONE,
 };
 
+/** Sprites of the flat tile base for each state of farm fields. */
 static const SpriteID _clear_land_sprites_farmland[16] = {
 	SPR_FARMLAND_BARE,
 	SPR_FARMLAND_STATE_1,
@@ -70,7 +76,16 @@ static const SpriteID _clear_land_sprites_farmland[16] = {
 	SPR_FARMLAND_HAYPACKS,
 };
 
-static const SpriteID _clear_land_sprites_snow_desert[8] = {
+/** Sprites of the flat tile base for each density of clear -> grass transition. */
+static const SpriteID _clear_land_sprites_grass[4] = {
+	SPR_FLAT_BARE_LAND,
+	SPR_FLAT_1_THIRD_GRASS_TILE,
+	SPR_FLAT_2_THIRD_GRASS_TILE,
+	SPR_FLAT_GRASS_TILE,
+};
+
+/** Sprites of the flat tile base for each density of grass -> snow/desert transition. */
+static const SpriteID _clear_land_sprites_snow_desert[4] = {
 	SPR_FLAT_1_QUART_SNOW_DESERT_TILE,
 	SPR_FLAT_2_QUART_SNOW_DESERT_TILE,
 	SPR_FLAT_3_QUART_SNOW_DESERT_TILE,

src/tree_cmd.cpp

@@ -645,7 +645,7 @@ static void DrawTile_Trees(TileInfo *ti)
 	switch (GetTreeGround(ti->tile)) {
 		case TreeGround::Shore: DrawShoreTile(ti->tileh); break;
 		case TreeGround::Grass: DrawClearLandTile(ti, GetTreeDensity(ti->tile)); break;
-		case TreeGround::Rough: DrawHillyLandTile(ti); break;
+		case TreeGround::Rough: DrawRoughLandTile(ti); break;
 		default: DrawGroundSprite(_clear_land_sprites_snow_desert[GetTreeDensity(ti->tile)] + SlopeToSpriteOffset(ti->tileh), PAL_NONE); break;
 	}