diff --git a/src/nostalgia/core/gfx.cpp b/src/nostalgia/core/gfx.cpp
index a3956344..7ad75c8a 100644
--- a/src/nostalgia/core/gfx.cpp
+++ b/src/nostalgia/core/gfx.cpp
@@ -7,7 +7,7 @@
 namespace nostalgia::core {
 
 // map ASCII values to the nostalgia charset
-char charMap[128] = {
+ox::Array<char, 128> charMap = {
 	0,
 	0,
 	0,
diff --git a/src/nostalgia/core/gfx.hpp b/src/nostalgia/core/gfx.hpp
index 5fb9d2a9..8bc1e478 100644
--- a/src/nostalgia/core/gfx.hpp
+++ b/src/nostalgia/core/gfx.hpp
@@ -4,8 +4,10 @@
 
 #pragma once
 
+#include <ox/std/array.hpp>
 #include <ox/std/types.hpp>
 #include <ox/model/def.hpp>
+
 #include <nostalgia/geo/point.hpp>
 #include <nostalgia/geo/size.hpp>
 
@@ -15,7 +17,7 @@
 
 namespace nostalgia::core {
 
-extern char charMap[128];
+extern ox::Array<char, 128> charMap;
 
 class Drawer {
 	public:
@@ -92,7 +94,8 @@ struct TileSheet {
 			other.rows = 0;
 		}
 		constexpr SubSheet(const char *pName, int pColumns, int pRows, int bpp) noexcept:
-			name(pName), columns(pColumns), rows(pRows), pixels(static_cast<std::size_t>(columns * rows * PixelsPerTile) / (bpp == 4 ? 2u : 1u)) {
+			name(pName), columns(pColumns), rows(pRows),
+            pixels(static_cast<std::size_t>(columns * rows * PixelsPerTile) / (bpp == 4 ? 2u : 1u)) {
 		}
 		constexpr SubSheet(const char *pName, int pColumns, int pRows, ox::Vector<uint8_t> pPixels) noexcept:
 			name(pName), columns(pColumns), rows(pRows), pixels(std::move(pPixels)) {
@@ -125,7 +128,7 @@ struct TileSheet {
 		 * Reads all pixels of this sheet or its children into the given pixel list
 		 * @param pixels
 		 */
-		void readPixelsTo(ox::Vector<uint8_t> *pPixels, int8_t bpp) const noexcept {
+		constexpr void readPixelsTo(ox::Vector<uint8_t> *pPixels, int8_t bpp) const noexcept {
 			if (subsheets.size()) {
 				for (auto &s: subsheets) {
 					s.readPixelsTo(pPixels);
@@ -148,7 +151,7 @@ struct TileSheet {
 		 * Reads all pixels of this sheet or its children into the given pixel list
 		 * @param pixels
 		 */
-		void readPixelsTo(ox::Vector<uint8_t> *pPixels) const noexcept {
+		constexpr void readPixelsTo(ox::Vector<uint8_t> *pPixels) const noexcept {
 			if (subsheets.size()) {
 				for (auto &s: subsheets) {
 					s.readPixelsTo(pPixels);
@@ -217,14 +220,19 @@ struct TileSheet {
 
 		constexpr auto walkPixels(int8_t pBpp, auto callback) const noexcept {
 			if (pBpp == 4) {
-				for (std::size_t i = 0; i < pixels.size(); ++i) {
+				const auto pixelCnt = ox::min<std::size_t>(static_cast<std::size_t>(columns * rows * PixelsPerTile) / 2,
+				                                           pixels.size());
+				//oxAssert(pixels.size() == pixelCnt, "Pixel count does not match rows and columns");
+				for (std::size_t i = 0; i < pixelCnt; ++i) {
 					const auto colorIdx1 = pixels[i] & 0xF;
 					const auto colorIdx2 = pixels[i] >> 4;
 					callback(i * 2 + 0, colorIdx1);
 					callback(i * 2 + 1, colorIdx2);
 				}
 			} else {
-				for (std::size_t i = 0; i < pixels.size(); ++i) {
+				const auto pixelCnt = ox::min<std::size_t>(static_cast<std::size_t>(columns * rows * PixelsPerTile),
+				                                           pixels.size());
+				for (std::size_t i = 0; i < pixelCnt; ++i) {
 					const auto p = pixels[i];
 					callback(i, p);
 				}
@@ -334,7 +342,8 @@ struct TileSheet {
 	}
 
 	[[nodiscard]]
-	constexpr static const auto &getSubSheet(const SubSheetIdx &idx, std::size_t idxIt, const SubSheet *pSubsheet) noexcept {
+	constexpr static const auto &getSubSheet(const SubSheetIdx &idx, std::size_t idxIt,
+                                             const SubSheet *pSubsheet) noexcept {
 		if (idxIt == idx.size()) {
 			return *pSubsheet;
 		}
@@ -502,7 +511,8 @@ void setBgCbb(Context *ctx, unsigned bgIdx, unsigned cbb) noexcept;
 /**
  * @param section describes which section of the selected TileSheetSpace to use (e.g. MEM_PALLETE_BG[section])
  */
-ox::Error loadBgTileSheet(Context *ctx, unsigned cbb, const ox::FileAddress &tilesheet, const ox::FileAddress &palette = nullptr) noexcept;
+ox::Error loadBgTileSheet(Context *ctx, unsigned cbb, const ox::FileAddress &tilesheet,
+                          const ox::FileAddress &palette = nullptr) noexcept;
 
 ox::Error loadSpriteTileSheet(Context *ctx,
                               unsigned section,
@@ -517,7 +527,8 @@ void clearTileLayer(Context *ctx, unsigned bgIdx) noexcept;
 
 void hideSprite(Context *ctx, unsigned) noexcept;
 
-void setSprite(Context *ctx, unsigned idx, unsigned x, unsigned y, unsigned tileIdx, unsigned spriteShape = 0, unsigned spriteSize = 0, unsigned flipX = 0) noexcept;
+void setSprite(Context *ctx, unsigned idx, unsigned x, unsigned y, unsigned tileIdx,
+               unsigned spriteShape = 0, unsigned spriteSize = 0, unsigned flipX = 0) noexcept;
 
 void setSprite(Context *ctx, const Sprite &s) noexcept;