Method GenerateAutotiles

src/tilemap_layer.cpp:634–670

}

BitmapRef TilemapLayer::GenerateAutotiles(int count, const std::unordered_map<uint32_t, TileXY>& map) {
	int rows = (count + TILES_PER_ROW - 1) / TILES_PER_ROW;
	BitmapRef tiles = Bitmap::Create(TILES_PER_ROW * TILE_SIZE, rows * TILE_SIZE);
	tiles->Clear();
	Rect rect(0, 0, TILE_SIZE/2, TILE_SIZE/2);

	for (auto& p: map) {
		uint32_t quarters_hash = p.first;
		TileXY dst = p.second;

		// unpack the quarters data
		for (int j = 0; j < 2; j++) {
			for (int i = 0; i < 2; i++) {
				constexpr int mask = ~(0xFu << 28);

				int x = quarters_hash >> 28;
				quarters_hash &= mask;
				quarters_hash <<= 4;

				int y = quarters_hash >> 28;
				quarters_hash &= mask;
				quarters_hash <<= 4;

				rect.x = (x * 2 + i) * (TILE_SIZE/2);
				rect.y = (y * 2 + j) * (TILE_SIZE/2);

				tiles->BlitFast((dst.x * 2 + i) * (TILE_SIZE / 2), (dst.y * 2 + j) * (TILE_SIZE / 2), *chipset, rect, 255);
			}
		}
	}

	if (rows > 0) {
		tiles->CheckPixels(Bitmap::Flag_Chipset | Bitmap::Flag_ReadOnly);
	}

	return tiles;
}

void TilemapLayer::SetChipset(BitmapRef const& nchipset) {
	chipset = nchipset;