[nostalgia/core] Get TileSheetSet working with 8bpp setting

src/nostalgia/modules/core/include/nostalgia/core/gfx.hpp

@@ -23,6 +23,7 @@ struct Sprite {
 	unsigned spriteShape = 0;
 	unsigned spriteSize = 0;
 	unsigned flipX = 0;
+	unsigned bpp = 0;
 	/**
 	 * Valid priorities: 0-3
 	 */
@@ -38,6 +39,7 @@ oxModelBegin(Sprite)
 	oxModelField(spriteShape)
 	oxModelField(spriteSize)
 	oxModelField(flipX)
+	oxModelField(bpp)
 	oxModelField(priority)
 oxModelEnd()
 

src/nostalgia/modules/core/src/gba/gfx.cpp

@@ -60,6 +60,25 @@ constexpr ox::Error model(auto *io, ox::CommonPtrWith<GbaPaletteTarget> auto *t)
 	}
 }
 
+[[nodiscard]]
+static bool loadPixel(TileSheetSetEntry const&setEntry, size_t &sectionIdx, int tileIdx) noexcept {
+	if (setEntry.sections.size() <= sectionIdx) {
+		return false;
+	}
+	auto &section = setEntry.sections[sectionIdx];
+	if (tileIdx < section.begin) {
+		return false;
+	}
+	if (tileIdx > section.end()) {
+		if (sectionIdx >= setEntry.sections.size()) {
+			return false;
+		}
+		++sectionIdx;
+		return tileIdx > section.begin && tileIdx <= section.end();
+	}
+	return true;
+}
+
 constexpr ox::Error model(auto *io, ox::CommonPtrWith<GbaTileMapTarget> auto *t) noexcept {
 	oxReturnError(io->template setTypeInfo<CompactTileSheet>());
 	oxReturnError(io->field("bpp", &t->bpp));
@@ -71,43 +90,27 @@ constexpr ox::Error model(auto *io, ox::CommonPtrWith<GbaTileMapTarget> auto *t)
 		return OxError(1, "Cannot load an 8 BPP tilesheet into a 4 BPP CBB");
 	}
 	ox::Error out{};
-	uint16_t intermediate = 0;
 	if (t->setEntry) {
 		// The following code is atrocious, but it works.
 		// It might be possible to clean it up a little, but it probably
 		// cannot be seriously optimized without preloading TileSheets.
-		// Consider building an array of bitmaps (Array<uint64_t, 4>)
+		size_t sectionIdx = 0;
-		// so this can be done with a single bitmap look up.
 		if (t->targetBpp == t->bpp) {
 			TileSheetSetEntrySection const*section = &t->setEntry->sections[0];
-			size_t sectionIdx = 1;
 			size_t writeIt = 0;
+			uint16_t intermediate = 0;
 			size_t const fourBpp = t->bpp == 4;
 			const auto handleTileMap = [t, &intermediate, &section, &sectionIdx, &writeIt, fourBpp]
-					(std::size_t i, uint8_t const *tile) {
+					(std::size_t i, uint8_t const*tile) {
-				if (!section) {
-					return ox::Error{};
-				}
 				auto const tileIdx = static_cast<int>((i * (2 * fourBpp)) / PixelsPerTile);
-				if (tileIdx < section->begin) {
+				if (!loadPixel(*t->setEntry, sectionIdx, tileIdx)) {
 					return ox::Error{};
 				}
-				if (tileIdx > section->end()) {
+				if (writeIt & 1) { // i is odd
-					if (sectionIdx >= t->setEntry->sections.size()) {
-						section = nullptr;
-						return ox::Error{};
-					}
-					section = &t->setEntry->sections[sectionIdx];
-					++sectionIdx;
-					if (tileIdx < section->begin || tileIdx > section->end()) {
-						return ox::Error{};
-					}
-				}
-				if (writeIt & 1) { // writeIt is odd
 					intermediate |= static_cast<uint16_t>(*tile) << 8;
 					t->tileMap[writeIt / 2] = intermediate;
 					++t->tileWriteIdx;
-				} else { // writeIt is even
+				} else { // i is even
 					intermediate = *tile & 0x00ff;
 				}
 				++writeIt;
@@ -115,31 +118,30 @@ constexpr ox::Error model(auto *io, ox::CommonPtrWith<GbaTileMapTarget> auto *t)
 			};
 			out = io->template field<uint8_t, decltype(handleTileMap)>("tileMap", handleTileMap);
 		} else if (t->targetBpp > t->bpp) { // 4 -> 8 bits
-			const auto handleTileMap = [t, &intermediate](std::size_t i, uint8_t const *tile) {
+			const auto handleTileMap = [t, &sectionIdx](std::size_t writeIt, uint8_t const*tile) {
-				if (i & 1) { // i is odd
+				auto constexpr BytesPerTile4Bpp = 32;
-					intermediate |= static_cast<uint16_t>(*tile) << 8;
+				auto const tileIdx = static_cast<int>(writeIt / BytesPerTile4Bpp);
-					// write 4 pixels from intermediate
+				if (!loadPixel(*t->setEntry, sectionIdx, tileIdx)) {
-					t->tileMap[i - 3] = (intermediate & 0b0000'0000'0000'1111) >> 0;
+					return ox::Error{};
-					t->tileMap[i - 2] = (intermediate & 0b0000'0000'1111'0000) >> 4;
-					t->tileMap[i - 1] = (intermediate & 0b0000'1111'0000'0000) >> 8;
-					t->tileMap[i - 0] = (intermediate & 0b1111'0000'0000'0000) >> 14;
-					++t->tileWriteIdx;
-				} else { // i is even
-					intermediate = *tile & 0x00ff;
 				}
+				uint16_t const px1 = *tile & 0xf;
+				uint16_t const px2 = *tile >> 4;
+				t->tileMap[t->tileWriteIdx] = static_cast<uint16_t>(px1 | (px2 << 8));
+				++t->tileWriteIdx;
 				return ox::Error{};
 			};
 			out = io->template field<uint8_t, decltype(handleTileMap)>("tileMap", handleTileMap);
 		}
 	} else {
-		const auto handleTileMap = [t, &intermediate](std::size_t i, const uint8_t *tile) {
+		uint16_t intermediate = 0;
+		const auto handleTileMap = [t, &intermediate](std::size_t i, const uint8_t*tile) {
 			if (i & 1) { // i is odd
 				intermediate |= static_cast<uint16_t>(*tile) << 8;
 				t->tileMap[i / 2] = intermediate;
 			} else { // i is even
 				intermediate = *tile & 0x00ff;
 			}
-			return OxError(0);
+			return ox::Error{};
 		};
 		out = io->template field<uint8_t, decltype(handleTileMap)>("tileMap", handleTileMap);
 	}
@@ -181,7 +183,6 @@ ox::Error loadSpritePalette(
 
 static ox::Error loadTileSheetSet(
 		Context &ctx,
-		unsigned &bpp,
 		uint16_t *tileMapTargetMem,
 		TileSheetSet const&set) noexcept {
 	auto &rom = ctx.rom();
@@ -189,10 +190,12 @@ static ox::Error loadTileSheetSet(
 	for (auto const&entry : set.entries) {
 		oxRequire(tsStat, rom.stat(entry.tilesheet));
 		oxRequire(ts, rom.directAccess(entry.tilesheet));
+		unsigned tilesheetBpp{};
 		GbaTileMapTarget target{
-				.bpp = bpp,
+				.bpp = tilesheetBpp,
 				.defaultPalette = {},
 				.tileMap = tileMapTargetMem + tileWriteIdx,
+				.targetBpp = static_cast<unsigned>(set.bpp),
 				.setEntry = &entry,
 		};
 		oxReturnError(ox::readMC(ts, static_cast<std::size_t>(tsStat.size), &target));
@@ -232,9 +235,10 @@ ox::Error loadBgTileSheet(
 		Context &ctx,
 		unsigned cbb,
 		TileSheetSet const&set) noexcept {
-	auto &bpp = ctx.cbbData[cbb].bpp;
+	auto const bpp = static_cast<unsigned>(set.bpp);
-	oxReturnError(loadTileSheetSet(ctx, bpp, MEM_BG_TILES[cbb].data(), set));
+	oxReturnError(loadTileSheetSet(ctx, MEM_BG_TILES[cbb].data(), set));
 	// update bpp of all bgs with the updated cbb
+	ctx.cbbData[cbb].bpp = bpp;
 	teagba::iterateBgCtl([bpp, cbb](volatile BgCtl &bgCtl) {
 		if (teagba::bgCbb(bgCtl) == cbb) {
 			teagba::bgSetBpp(bgCtl, bpp);
@@ -276,8 +280,8 @@ ox::Error loadSpriteTileSheet(
 ox::Error loadSpriteTileSheet(
 		Context &ctx,
 		TileSheetSet const&set) noexcept {
-	unsigned bpp{};
+	auto const bpp = static_cast<unsigned>(set.bpp);
-	oxReturnError(loadTileSheetSet(ctx, bpp, MEM_SPRITE_TILES, set));
+	oxReturnError(loadTileSheetSet(ctx, MEM_SPRITE_TILES, set));
 	setSpritesBpp(bpp);
 	return {};
 }
@@ -340,17 +344,20 @@ void showSprite(Context&, unsigned idx) noexcept {
 
 void setSprite(Context&, uint_t idx, Sprite const&s) noexcept {
 	//oxAssert(g_spriteUpdates < config::GbaSpriteBufferLen, "Sprite update buffer overflow");
+	uint16_t const eightBpp = s.bpp == 8;
 	teagba::addSpriteUpdate({
 		.attr0 = static_cast<uint16_t>(
 			  (static_cast<uint16_t>(s.y & ox::onMask<uint8_t>(0b111'1111)))
 			| (static_cast<uint16_t>(1) << 10) // enable alpha
+			| (static_cast<uint16_t>(eightBpp) << 13)
 			| (static_cast<uint16_t>(s.spriteShape) << 14)),
 		.attr1 = static_cast<uint16_t>(
 			  (static_cast<uint16_t>(s.x) & ox::onMask<uint8_t>(8))
 			| (static_cast<uint16_t>(s.flipX) << 12)
 			| (static_cast<uint16_t>(s.spriteSize) << 14)),
 		.attr2 = static_cast<uint16_t>(
-			  (static_cast<uint16_t>(s.tileIdx & ox::onMask<uint16_t>(8)))
+			// double tileIdx if 8 bpp
+			  (static_cast<uint16_t>((s.tileIdx * (1 + eightBpp)) & ox::onMask<uint16_t>(8)))
 			| (static_cast<uint16_t>(s.priority & 0b11) << 10)),
 		.idx = static_cast<uint16_t>(idx),
 	});

src/nostalgia/player/app.cpp

@@ -105,16 +105,18 @@ static ox::Error runTileSheetSetTest(turbine::Context &tctx) {
 	core::setBgTile(*cctx, 0, 11, 9, 2);
 	core::setBgTile(*cctx, 0, 13, 9, 4);
 	core::setSprite(*cctx, 16, {
-			.enabled = true,
+		.enabled = true,
-			.x = 12 * 8,
+		.x = 12 * 8,
-			.y = 9 * 8,
+		.y = 9 * 8,
-			.tileIdx = 3,
+		.tileIdx = 3,
+		.bpp = static_cast<unsigned>(set.bpp),
 	});
 	core::setSprite(*cctx, 17, {
 		.enabled = true,
 		.x = 14 * 8,
 		.y = 9 * 8,
 		.tileIdx = 5,
+		.bpp = static_cast<unsigned>(set.bpp),
 	});
 	turbine::setKeyEventHandler(tctx, testKeyEventHandler);
 	return turbine::run(tctx);