HDB: Added more constants instead of magic numbers

3 files changed, 17 insertions, 13 deletions

diff --git a/engines/hdb/gfx.h b/engines/hdb/gfx.h
index 73fb92a8ae..26b08108c7 100644
--- a/engines/hdb/gfx.h
+++ b/engines/hdb/gfx.h
@@ -32,6 +32,8 @@ namespace HDB {
 enum {
 	kScreenWidth = 640,
 	kScreenHeight = 480,
+	kScreenDrawWidth = (kScreenWidth - 160), // visible pixels wide
+	kScreenDrawHeight = 480,
 	kTileWidth = 32,
 	kTileHeight = 32,
 	kMaxSkies = 10,
diff --git a/engines/hdb/map.cpp b/engines/hdb/map.cpp
index ca8e2a2205..daec9a8a78 100644
--- a/engines/hdb/map.cpp
+++ b/engines/hdb/map.cpp
@@ -1114,39 +1114,39 @@ void Map::centerMapXY(int x, int y) {
 	int minx, miny, maxx, maxy;
 
 	// Scan from centerX to right edge
-	maxx = (_width - (16/2)) * kTileWidth;
-	for (int i = checkx + 1; i <= checkx + (16 / 2); i++) {
+	maxx = (_width - (kScreenTileWidth / 2)) * kTileWidth;
+	for (int i = checkx + 1; i <= checkx + (kScreenTileWidth / 2); i++) {
 		if (!getMapBGTileIndex(i, checky)) {
-			maxx = (i - (16 / 2)) * kTileWidth;
+			maxx = (i - (kScreenTileWidth / 2)) * kTileWidth;
 			break;
 		}
 	}
 
 	// Scan from centerX to left edge
 	minx = 0;
-	for (int i = checkx - 1; i >= checkx - (16 / 2); i--) {
+	for (int i = checkx - 1; i >= checkx - (kScreenTileWidth / 2); i--) {
 		if (!getMapBGTileIndex(i, checky)) {
 			// +1 because we don't want to see one whole tile
-			minx = (1 + i + (16 / 2)) * kTileWidth;
+			minx = (1 + i + (kScreenTileWidth / 2)) * kTileWidth;
 			break;
 		}
 	}
 
 	// Scan from centerY to bottom edge
-	maxy = (_height - (16/2)) * kTileHeight;
-	for (int i = checky + 1; i <= checky + (16 / 2); i++) {
+	maxy = (_height - (kScreenTileHeight / 2)) * kTileHeight;
+	for (int i = checky + 1; i <= checky + (kScreenTileHeight / 2); i++) {
 		if (!getMapBGTileIndex(checkx, i)) {
-			maxy = (i - (16 / 2)) * kTileHeight;
+			maxy = (i - (kScreenTileHeight / 2)) * kTileHeight;
 			break;
 		}
 	}
 
 	// Scan from centerY to top edge
 	miny = 0;
-	for (int i = checky - 1; i >= checkx - (16 / 2); i--) {
+	for (int i = checky - 1; i >= checkx - (kScreenTileHeight / 2); i--) {
 		if (!getMapBGTileIndex(checkx, i)) {
-			// +! because we don't want to see one whole tile
-			miny = (1 + i + (16 / 2)) * kTileHeight;
+			// +1 because we don't want to see one whole tile
+			miny = (1 + i + (kScreenTileHeight / 2)) * kTileHeight;
 			break;
 		}
 	}
@@ -1163,8 +1163,8 @@ void Map::centerMapXY(int x, int y) {
 		y = maxy;
 	}
 
-	x -= (480 / 2);
-	y -= (480 / 2);
+	x -= (kScreenDrawWidth / 2);
+	y -= (kScreenDrawHeight / 2);
 
 	setMapXY(x, y);
 }
diff --git a/engines/hdb/map.h b/engines/hdb/map.h
index 1822c86234..91cecf17bd 100644
--- a/engines/hdb/map.h
+++ b/engines/hdb/map.h
@@ -30,6 +30,8 @@ namespace HDB {
 enum {
 	kScreenXTiles = 17,
 	kScreenYTiles = 16,
+	kScreenTileWidth = 16,
+	kScreenTileHeight = 16,
 	kMaxGratings = 250,
 	kMaxForegrounds = 250
 };