Fix everything, it's all ready to go, also autoscrolling works! :DDDDD

src/main/java/btpos/tools/mclowrespackgenerator/ArgHandler.java

@@ -18,6 +18,19 @@
 import java.util.stream.Collectors;
 
 public class ArgHandler {
+	private final boolean isHeadless;
+
+	public ArgHandler(boolean isHeadless) {
+		this.isHeadless = isHeadless;
+	}
+
+	public Args getArgs(String[] args) {
+		if (isHeadless)
+			return checkCliArgs(args);
+		else
+			return getUIArgs();
+	}
+
 	public Args checkCliArgs(String[] args) throws ParseException {
 		Option inputFilesOption = Option.builder("i")
 		                                .required()
@@ -35,12 +48,13 @@ public Args checkCliArgs(String[] args) throws ParseException {
 		                                .type(File.class)
 		                                .build();
 
-		Option widthOption = Option.builder("m")
-		                           .longOpt("max-scale")
-		                           .desc("Maximum size (in pixels) of block and item textures. Accounts for animated textures.\nIf unset, downscales to the minimum size required for the GPU to be able to load all textures.")
-		                           .hasArg()
-		                           .type(Integer.class)
-		                           .build();
+		Option sizeOption = Option.builder("s")
+		                          .longOpt("max-size")
+		                          .desc("Maximum size (in pixels) of block and item textures. Accounts for animated textures.\n" +
+				                                "If unset, downscales all textures to the minimum size required for the GPU to be able to load the texture atlas.")
+		                          .hasArg()
+		                          .type(Integer.class)
+		                          .build();
 
 		Option formatOption = Option.builder("p")
 		                            .longOpt("pack-format")
@@ -51,16 +65,14 @@ public Args checkCliArgs(String[] args) throws ParseException {
 
 		Options o = new Options().addOption(inputFilesOption)
 		                         .addOption(outputFileOption)
-		                         .addOption(widthOption)
+		                         .addOption(sizeOption)
 		                         .addOption(formatOption);
 
 		CommandLine parsed = new DefaultParser().parse(o, args);
 
 		return new Args(
-				parsed.getParsedOptionValue(widthOption),
-				Optional.ofNullable(parsed.getOptionValues(inputFilesOption))
-				        .map(names -> Arrays.stream(names).map(File::new).collect(Collectors.toList()))
-				        .orElse(null),
+				parsed.getParsedOptionValue(sizeOption, (Integer) null),
+				Arrays.stream(parsed.getOptionValues(inputFilesOption)).map(File::new).collect(Collectors.toList()),
 				parsed.getParsedOptionValue(outputFileOption, new File("downscaled.zip"))
 		);
 	}
@@ -70,20 +82,13 @@ public Args getUIArgs() {
 
 		File outputFile = getOutputFile();
 
-		int autoscale = JOptionPane.showOptionDialog(
-				null,
-				"Autoscale textures?",
-				"",
-				JOptionPane.YES_NO_OPTION,
-				JOptionPane.PLAIN_MESSAGE,
-				null,
-				null,
-				null
-		);
+		int autoscale = JOptionPane.showConfirmDialog(null, "Autoscale textures?");
 
 		Integer maxScale = null;
-		if (autoscale != JOptionPane.YES_OPTION) {
+		if (autoscale == JOptionPane.NO_OPTION) {
 			maxScale = getWidth();
+		} else if (autoscale == JOptionPane.CANCEL_OPTION) {
+			System.exit(0);
 		}
 
 		return new Args(maxScale, inputFiles, outputFile);

src/main/java/btpos/tools/mclowrespackgenerator/Main.java

@@ -5,11 +5,7 @@
 import org.apache.commons.io.file.PathUtils;
 
 import javax.imageio.ImageIO;
-import javax.swing.JFrame;
-import javax.swing.JOptionPane;
-import javax.swing.UIManager;
 import java.awt.Dimension;
-import java.awt.EventQueue;
 import java.awt.image.BufferedImage;
 import java.io.File;
 import java.io.IOException;
@@ -36,50 +32,31 @@
 
 public class Main {
 
-	private Args args;
+	private static final Path outDirectory = Files.createTempDirectory("mcdownscaler");
+	private static Args args;
 
 	private static final boolean IS_HEADLESS = java.awt.GraphicsEnvironment.isHeadless();
 
 	private static final int MAX_ATLAS_SIZE = 16384 * 16384;
 
 	private static final String packmcmeta = "{\n\t\"pack\":{\n\t\t\"pack_format\": 15,\n\t\t \"description\": \"Compressed textures\"\n\t}\n}";
 
+	private static final UserInterfaceHandler uiHandler = UserInterfaceHandler.get(IS_HEADLESS);
 
 	public static void main(String[] argsIn) {
-		try {
-			if (System.getProperty("os.name").toLowerCase().contains("windows"))
-				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
-		} catch (Exception ignored) {
-		}
+		uiHandler.onStart();
 
+		args = new ArgHandler(IS_HEADLESS).getArgs(argsIn);
 
-		JFrame jFrame;
-		if (!IS_HEADLESS) {
-			jFrame = UIGenerators.getConsolePanel();
-
-			EventQueue.invokeLater(() -> jFrame.setVisible(true));
-		} else {
-			jFrame = null;
+		if (args.outputFile.exists()) {
+			args.outputFile.createNewFile();
 		}
 
-		new Main().fileLogic(argsIn);
-
-		if (jFrame != null)
-			jFrame.dispose();
+		doCompression();
 	}
 
 
-	public void fileLogic(String[] argsIn) {
-		ArgHandler argHandler = new ArgHandler();
-		if (IS_HEADLESS)
-			args = argHandler.checkCliArgs(argsIn);
-		else
-			args = argHandler.getUIArgs();
-
-		args.outputFile.createNewFile();
-
-		final Path outDirectory = Files.createTempDirectory("mcdownscaler");
-
+	public static void doCompression() {
 		try {
 			List<Pair<String, Supplier<InputStream>>> name_to_stream = args.inputFiles.stream()
 			                                                                          .map(file -> catcher(() -> new ZipFile(file), null, e -> Util.fileBad(file.getName(), e)))
@@ -92,66 +69,41 @@ public void fileLogic(String[] argsIn) {
 			                                                                          })
 			                                                                          .collect(Collectors.toList());
 
-			PriorityQueue<Pair<Integer, Pair<String, Supplier<InputStream>>>> texturesHeap = new PriorityQueue<>(Comparator.comparingInt(Pair<Integer, Pair<String, Supplier<InputStream>>>::getLeft).reversed());
+			// max heap of total size in pixels
+			PriorityQueue<TextureEntry> texturesHeap = new PriorityQueue<>(Comparator.comparingInt(TextureEntry::getTotalSize).reversed());
 
 			AtomicInteger totalSize = new AtomicInteger(0);
 
 			name_to_stream.stream()
-			              .map(name_stream -> {
-				              Dimension pngDimension = catcher(() -> Util.getPngDimension(name_stream.left, name_stream.right.get()), null, (e) -> fileBad(name_stream.left, e));
-				              if (pngDimension == null)
-					              return null;
-				              return new Pair<>(pngDimension, name_stream);
-			              }).filter(Objects::nonNull)
-			              .map(dim_pair -> dim_pair.lmap(dim_pair.left.width * dim_pair.left.height))
-			              .peek(size_pair -> totalSize.addAndGet(size_pair.left))
+			              .map(str_supp -> new TextureEntry(str_supp.left, str_supp.right))
+			              .peek(entry -> totalSize.addAndGet(entry.getTotalSize()))
 			              .forEach(texturesHeap::add);
 
 			boolean hasOperated = false;
 
-			while (!texturesHeap.isEmpty() && totalSize.get() >= MAX_ATLAS_SIZE) {
+			System.out.println("Starting combined texture size (pixels): " + totalSize.get());
+
+
+			while (!texturesHeap.isEmpty() && (!isAutoscale() || totalSize.get() >= MAX_ATLAS_SIZE)) {
 				hasOperated = true;
-				Pair<Integer, Pair<String, Supplier<InputStream>>> tuple = texturesHeap.poll();
-				Integer oldSize = tuple.left;
-				String name = tuple.right.left;
-				Supplier<InputStream> is_get = tuple.right.right;
+				TextureEntry oldEntry = texturesHeap.poll();
+				int oldSize = oldEntry.getTotalSize();
 
+				TextureEntry newEntry;
 				try {
-					BufferedImage img = ImageIO.read(is_get.get());
-					if (img == null) {
-						System.err.println("Image null somehow idk");
-						continue;
-					}
-
-					int square = Util.getClosestPowerOf2(Math.max(img.getWidth(), img.getHeight()));
-
-					System.out.println("Compressing: " + name);
-					img = Thumbnailator.createThumbnail(img, square, square);
-
-					int newSize = img.getHeight() * img.getWidth();
-					totalSize.addAndGet(newSize - oldSize); // update total size
-
-
-					Path outPath = outDirectory.resolve(Paths.get(name));
-					FileUtils.createParentDirectories(outPath.toFile());
-
-					try (OutputStream outFile = Files.newOutputStream(outPath)) {
-						ImageIO.write(img, PathUtils.getExtension(outPath), outFile);
-					}
-
-					texturesHeap.add(new Pair<>(
-							newSize,
-							new Pair<>(
-									name,
-									() -> catcher(() -> Files.newInputStream(outPath), null, e -> fileBad(outPath.toString(), e))
-							)
-					));
-
-				} catch (IOException e) {
-					fileBad(name, e);
+					newEntry = compressTexture(oldEntry);
+				} catch (Exception e) {
+					fileBad(oldEntry.path, e);
+					continue;
 				}
+
+				totalSize.addAndGet(newEntry.getTotalSize() - oldSize); // update total size
+
+				if (isAutoscale())
+					texturesHeap.add(newEntry); // put back on the heap for possible re-resizing if needed
 			}
 
+
 			String displayText;
 			if (hasOperated) {
 				File mcmeta = outDirectory.resolve("pack.mcmeta").toFile();
@@ -163,13 +115,45 @@ public void fileLogic(String[] argsIn) {
 				displayText = "Nothing to do!";
 			}
 
-			EventQueue.invokeAndWait(() -> JOptionPane.showMessageDialog(null, displayText));
+			uiHandler.onFinish(displayText);
 		} catch (Exception e) {
 			throw new RuntimeException(e);
 		}
-
 	}
 
+	private static TextureEntry compressTexture(TextureEntry entry) {
+		try (InputStream is = entry.getter.get()) {
+			BufferedImage img = ImageIO.read(is);
+			if (img == null) {
+				throw new IOException("Image read as null: " + entry.path);
+			}
+
+			int square = isAutoscale() ? entry.getBestCap() : args.maxScale;
+
+			System.out.println("Compressing: " + entry.path);
+			img = Thumbnailator.createThumbnail(img, square, square); // does keep the aspect ratio the same
+
+
+			Path outPath = outDirectory.resolve(Paths.get(entry.path));
+			FileUtils.createParentDirectories(outPath.toFile());
+
+			try (OutputStream outFile = Files.newOutputStream(outPath)) {
+				ImageIO.write(img, PathUtils.getExtension(outPath), outFile);
+			}
+
+			return new TextureEntry(
+					entry.path,
+					() -> catcher(() -> Files.newInputStream(outPath), null, e -> fileBad(outPath.toString(), e)),
+					new Dimension(img.getWidth(), img.getHeight())
+			);
+		}
+	}
+
+	private static boolean isAutoscale() {
+		return args.maxScale == null;
+	}
+
+
 	public static void pack(Path sourceDirPath, String zipFilePath) throws IOException {
 		File f = new File(zipFilePath);
 		if (!f.exists())

src/main/java/btpos/tools/mclowrespackgenerator/TextAreaOutputStream.java

@@ -176,6 +176,7 @@ public synchronized void run() {
 				if (don >= 100) {
 					break;
 				}
+				textArea.setCaretPosition(textArea.getDocument().getLength());
 			}
 			if (don == lines.size()) {
 				lines.clear();

src/main/java/btpos/tools/mclowrespackgenerator/TextureEntry.java

@@ -0,0 +1,45 @@
+package btpos.tools.mclowrespackgenerator;
+
+
+import java.awt.Dimension;
+import java.io.InputStream;
+import java.util.function.Supplier;
+
+public class TextureEntry {
+	public final String path;
+	public final Supplier<InputStream> getter;
+	public final Dimension dimension;
+
+	public TextureEntry(String path, Supplier<InputStream> getter) {
+		this(path, getter, null);
+	}
+
+	public TextureEntry(String path, Supplier<InputStream> getter, Dimension dimension) {
+		this.path = path;
+		this.getter = getter;
+		this.dimension = dimension != null ? dimension : findDimension(path, getter);
+	}
+
+	private static Dimension findDimension(String path, Supplier<InputStream> getter) {
+		return Util.getPngDimension(path, getter.get());
+	}
+
+	public int getTotalSize() {
+		return dimension.height * dimension.width;
+	}
+
+	public int getBestCap() {
+		int bigger = Math.max(dimension.height, dimension.width);
+		int smaller = Math.min(dimension.height, dimension.width);
+
+		// handle animated textures that are one block stretched over many
+		if (bigger != smaller
+            && bigger % smaller == 0)
+		{
+			int ratio = bigger / smaller;
+			return Util.getClosestPowerOf2(smaller) * ratio;
+		} else {
+			return Util.getClosestPowerOf2(bigger);
+		}
+	}
+}

src/main/java/btpos/tools/mclowrespackgenerator/UIGenerators.java

@@ -3,19 +3,20 @@
 import javax.swing.JFrame;
 import javax.swing.JScrollPane;
 import javax.swing.JTextArea;
+import javax.swing.text.DefaultCaret;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintStream;
 
 public class UIGenerators {
-	static JFrame getConsolePanel() {
+	public static JFrame enableConsolePanel() {
 		JFrame jFrame = new JFrame();
 		jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		JTextArea jTextArea = new JTextArea();
 		JScrollPane jsp = new JScrollPane(jTextArea, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
-		jsp.getVerticalScrollBar().addAdjustmentListener(e -> jTextArea.select(jTextArea.getHeight() + 1000, 0));
 		jTextArea.setEditable(false);
 
+
 		TextAreaOutputStream tex = new TextAreaOutputStream(jTextArea);
 
 		PrintStream splitConsoleStream = new PrintStream(new OutputStream() {
@@ -32,7 +33,7 @@ public void write(int b) throws IOException {
 		System.setErr(splitConsoleStream);
 
 		jFrame.setSize(500, 300);
-		jFrame.add(jTextArea);
+		jFrame.add(jsp);
 		jFrame.setLocationRelativeTo(null);
 
 		return jFrame;