Refactor FontUtils Font loading

src/main/java/meteordevelopment/meteorclient/renderer/text/BuiltinFontFace.java

@@ -1,10 +1,14 @@
 package meteordevelopment.meteorclient.renderer.text;
 
 import meteordevelopment.meteorclient.utils.render.FontUtils;
+import org.jspecify.annotations.NullMarked;
 
 import java.io.InputStream;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
 
-public class BuiltinFontFace extends FontFace {
+@NullMarked
+public non-sealed class BuiltinFontFace extends FontFace {
     private final String name;
 
     public BuiltinFontFace(FontInfo info, String name) {
@@ -14,10 +18,12 @@ public BuiltinFontFace(FontInfo info, String name) {
     }
 
     @Override
-    public InputStream toStream() {
-        InputStream in = FontUtils.stream(name);
-        if (in == null) throw new RuntimeException("Failed to load builtin font " + name + ".");
-        return in;
+    public ReadableByteChannel byteChannelForRead() {
+        InputStream inputStream = FontUtils.builtinFontStream(this.name);
+        if (inputStream == null) {
+            throw new IllegalArgumentException("Builtin font '" + this.name + "' not found");
+        }
+        return Channels.newChannel(inputStream);
     }
 
     @Override

src/main/java/meteordevelopment/meteorclient/renderer/text/CustomTextRenderer.java

@@ -8,11 +8,10 @@
 import meteordevelopment.meteorclient.renderer.MeshBuilder;
 import meteordevelopment.meteorclient.renderer.MeshRenderer;
 import meteordevelopment.meteorclient.renderer.MeteorRenderPipelines;
-import meteordevelopment.meteorclient.utils.Utils;
 import meteordevelopment.meteorclient.utils.render.color.Color;
 import net.minecraft.client.MinecraftClient;
-import org.lwjgl.BufferUtils;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 
 public class CustomTextRenderer implements TextRenderer {
@@ -30,11 +29,10 @@ public class CustomTextRenderer implements TextRenderer {
     private double fontScale = 1;
     private double scale = 1;
 
-    public CustomTextRenderer(FontFace fontFace) {
+    public CustomTextRenderer(FontFace fontFace) throws IOException {
         this.fontFace = fontFace;
 
-        byte[] bytes = Utils.readBytes(fontFace.toStream());
-        ByteBuffer buffer = BufferUtils.createByteBuffer(bytes.length).put(bytes).flip();
+        ByteBuffer buffer = fontFace.readToDirectByteBuffer();
 
         fonts = new Font[5];
         for (int i = 0; i < fonts.length; i++) {

src/main/java/meteordevelopment/meteorclient/renderer/text/FontFace.java

@@ -1,15 +1,28 @@
 package meteordevelopment.meteorclient.renderer.text;
 
-import java.io.InputStream;
+import meteordevelopment.meteorclient.utils.files.ByteBufferUtils;
+import org.jspecify.annotations.NullMarked;
+import org.lwjgl.BufferUtils;
 
-public abstract class FontFace {
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.ReadableByteChannel;
+
+@NullMarked
+public abstract sealed class FontFace permits BuiltinFontFace, SystemFontFace {
     public final FontInfo info;
 
     protected FontFace(FontInfo info) {
         this.info = info;
     }
 
-    public abstract InputStream toStream();
+    public abstract ReadableByteChannel byteChannelForRead() throws IOException;
+
+    public final ByteBuffer readToDirectByteBuffer() throws IOException {
+        try (ReadableByteChannel channel = byteChannelForRead()) {
+            return ByteBufferUtils.readFully(channel, BufferUtils::createByteBuffer);
+        }
+    }
 
     @Override
     public String toString() {

src/main/java/meteordevelopment/meteorclient/renderer/text/SystemFontFace.java

@@ -1,11 +1,15 @@
 package meteordevelopment.meteorclient.renderer.text;
 
-import meteordevelopment.meteorclient.utils.render.FontUtils;
+import org.jspecify.annotations.NullMarked;
 
-import java.io.InputStream;
+import java.io.IOException;
+import java.nio.channels.FileChannel;
+import java.nio.channels.ReadableByteChannel;
 import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
 
-public class SystemFontFace extends FontFace {
+@NullMarked
+public final class SystemFontFace extends FontFace {
     private final Path path;
 
     public SystemFontFace(FontInfo info, Path path) {
@@ -15,14 +19,8 @@ public SystemFontFace(FontInfo info, Path path) {
     }
 
     @Override
-    public InputStream toStream() {
-        if (!path.toFile().exists()) {
-            throw new RuntimeException("Tried to load font that no longer exists.");
-        }
-
-        InputStream in = FontUtils.stream(path.toFile());
-        if (in == null) throw new RuntimeException("Failed to load font from " + path + ".");
-        return in;
+    public ReadableByteChannel byteChannelForRead() throws IOException {
+        return FileChannel.open(this.path, StandardOpenOption.READ);
     }
 
     @Override

src/main/java/meteordevelopment/meteorclient/systems/hud/HudRenderer.java

@@ -27,8 +27,8 @@
 import net.minecraft.util.Identifier;
 import org.joml.Quaternionf;
 import org.joml.Vector3f;
-import org.lwjgl.BufferUtils;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.time.Duration;
 import java.util.ArrayList;
@@ -298,10 +298,12 @@ private void onCustomFontChanged(CustomFontChangedEvent event) {
     }
 
     private static FontHolder loadFont(int height) {
-        byte[] data = Utils.readBytes(Fonts.RENDERER.fontFace.toStream());
-        ByteBuffer buffer = BufferUtils.createByteBuffer(data.length).put(data).flip();
-
-        return new FontHolder(new Font(buffer, height));
+        try {
+            ByteBuffer buffer = Fonts.RENDERER.fontFace.readToDirectByteBuffer();
+            return new FontHolder(new Font(buffer, height));
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to load font: " + Fonts.RENDERER.fontFace, e);
+        }
     }
 
     private static class FontHolder {

src/main/java/meteordevelopment/meteorclient/utils/files/ByteBufferUtils.java

@@ -0,0 +1,88 @@
+/*
+ * This file is part of the Meteor Client distribution (https://github.com/MeteorDevelopment/meteor-client).
+ * Copyright (c) Meteor Development.
+ */
+
+package meteordevelopment.meteorclient.utils.files;
+
+import org.jspecify.annotations.NullMarked;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.function.IntFunction;
+
+import static java.nio.file.Files.*;
+
+@NullMarked
+public final class ByteBufferUtils {
+    private ByteBufferUtils() {}
+
+    public static ByteBuffer readFully(Path path, IntFunction<ByteBuffer> allocator) throws IOException {
+        try (FileChannel channel = FileChannel.open(path, StandardOpenOption.READ)) {
+            long size = size(path);
+            if (size > Integer.MAX_VALUE) {
+                throw new IOException("File too large to read into ByteBuffer: " + path);
+            }
+            ByteBuffer buffer = allocator.apply((int) size);
+            while (buffer.hasRemaining()) {
+                int bytesRead = channel.read(buffer);
+                if (bytesRead == -1) break; // EOF
+            }
+            buffer.flip();
+            return buffer;
+        }
+    }
+
+    public static ByteBuffer readFully(ReadableByteChannel channel, IntFunction<ByteBuffer> allocator) throws IOException {
+        ByteBuffer buffer = requireCapacity(allocator.apply(8192), 8192);
+
+        while (true) {
+            int bytesRead = channel.read(buffer);
+
+            if (bytesRead == -1) break;
+
+            if (bytesRead == 0) {
+                // Avoid busy-spin on non-blocking channels.
+                // If buffer is full, grow; otherwise caller should probably be using blocking I/O.
+                if (!buffer.hasRemaining()) {
+                    buffer = grow(buffer, allocator);
+                    continue;
+                }
+                // In a "readFully" API, returning early is usually better than spinning forever.
+                // Alternative: Thread.onSpinWait(); continue;
+                break;
+            }
+
+            if (!buffer.hasRemaining()) {
+                buffer = grow(buffer, allocator);
+            }
+        }
+
+        buffer.flip();
+        return buffer;
+    }
+
+    private static ByteBuffer grow(ByteBuffer buffer, IntFunction<ByteBuffer> allocator) {
+        int oldCap = buffer.capacity();
+        int newCap = oldCap << 1;
+        if (newCap <= 0) throw new OutOfMemoryError("Buffer too large (overflow): " + oldCap);
+
+        ByteBuffer newBuffer = requireCapacity(allocator.apply(newCap), newCap);
+        buffer.flip();
+        newBuffer.put(buffer);
+        return newBuffer;
+    }
+
+    private static ByteBuffer requireCapacity(ByteBuffer buf, int minCap) {
+        if (buf.capacity() < minCap) {
+            throw new IllegalArgumentException("Allocator returned capacity " + buf.capacity() + " < " + minCap);
+        }
+        return buf;
+    }
+
+}

src/main/java/meteordevelopment/meteorclient/utils/render/FontUtils.java

@@ -2,55 +2,86 @@
  * This file is part of the Meteor Client distribution (https://github.com/MeteorDevelopment/meteor-client).
  * Copyright (c) Meteor Development.
  */
-
 package meteordevelopment.meteorclient.utils.render;
 
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import meteordevelopment.meteorclient.MeteorClient;
 import meteordevelopment.meteorclient.renderer.Fonts;
 import meteordevelopment.meteorclient.renderer.text.*;
-import meteordevelopment.meteorclient.utils.Utils;
+import meteordevelopment.meteorclient.utils.files.ByteBufferUtils;
 import net.minecraft.util.Util;
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.lwjgl.BufferUtils;
 import org.lwjgl.stb.STBTTFontinfo;
 import org.lwjgl.stb.STBTruetype;
 
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
 import java.nio.charset.StandardCharsets;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-public class FontUtils {
-    private FontUtils() {
+@NullMarked
+public final class FontUtils {
+    private FontUtils() {}
+
+    public static @Nullable FontInfo getSysFontInfo(File file) {
+        return getFontInfo(file);
     }
 
-    public static FontInfo getSysFontInfo(File file) {
-        return getFontInfo(stream(file));
+    public static @Nullable FontInfo getBuiltinFontInfo(String builtin) {
+        return getFontInfo(builtinFontStream(builtin));
     }
 
-    public static FontInfo getBuiltinFontInfo(String builtin) {
-        return getFontInfo(stream(builtin));
+    /**
+     * System font path: avoid heap byte[] by reading the file into a direct buffer.
+     */
+    private static @Nullable FontInfo getFontInfo(@Nullable File file) {
+        if (file == null || !file.isFile()) return null;
+
+        try {
+            return getFontInfo(ByteBufferUtils.readFully(file.toPath(), BufferUtils::createByteBuffer));
+        } catch (Exception e) {
+            MeteorClient.LOG.warn("Failed to read font file: {}", file, e);
+            return null;
+        }
     }
 
-    public static FontInfo getFontInfo(InputStream stream) {
+    /**
+     * Builtin/resource path: stream into a direct buffer (no byte[] intermediate).
+     */
+    public static @Nullable FontInfo getFontInfo(@Nullable InputStream stream) {
         if (stream == null) return null;
 
-        byte[] bytes = Utils.readBytes(stream);
-        if (bytes.length < 5) return null;
+        try (ReadableByteChannel ch = Channels.newChannel(stream)) {
+            ByteBuffer buf = ByteBufferUtils.readFully(ch, BufferUtils::createByteBuffer);
+            return getFontInfo(buf);
+        } catch (Exception e) {
+            MeteorClient.LOG.warn("Failed to read font stream.", e);
+            return null;
+        }
+    }
+
+    /**
+     * Core logic: interpret font data from a ByteBuffer.
+     * NOTE: This preserves your original 5-byte header check exactly.
+     */
+    private static @Nullable FontInfo getFontInfo(ByteBuffer buffer) {
+        if (buffer.remaining() < 5) return null;
 
+        // Preserve existing check: 00 01 00 00 00
         if (
-            bytes[0] != 0 ||
-            bytes[1] != 1 ||
-            bytes[2] != 0 ||
-            bytes[3] != 0 ||
-            bytes[4] != 0
+            buffer.get(0) != 0 ||
+                buffer.get(1) != 1 ||
+                buffer.get(2) != 0 ||
+                buffer.get(3) != 0 ||
+                buffer.get(4) != 0
         ) return null;
 
-        ByteBuffer buffer = BufferUtils.createByteBuffer(bytes.length).put(bytes).flip();
         STBTTFontinfo fontInfo = STBTTFontinfo.create();
         if (!STBTruetype.stbtt_InitFont(fontInfo, buffer)) return null;
 
@@ -65,7 +96,7 @@ public static FontInfo getFontInfo(InputStream stream) {
     }
 
     public static Set<String> getSearchPaths() {
-        Set<String> paths = new HashSet<>();
+        Set<String> paths = new ObjectOpenHashSet<>();
         paths.add(System.getProperty("java.home") + "/lib/fonts");
 
         for (File dir : getUFontDirs()) {
@@ -136,7 +167,7 @@ public static void loadSystem(List<FontFamily> fontList, File dir) {
         }
     }
 
-    public static boolean addFont(List<FontFamily> fontList, FontFace font) {
+    private static boolean addFont(List<FontFamily> fontList, @Nullable FontFace font) {
         if (font == null) return false;
 
         FontInfo info = font.info;
@@ -152,17 +183,8 @@ public static boolean addFont(List<FontFamily> fontList, FontFace font) {
         return family.addFont(font);
     }
 
-    public static InputStream stream(String builtin) {
-        return FontUtils.class.getResourceAsStream("/assets/" + MeteorClient.MOD_ID + "/fonts/" + builtin + ".ttf");
+    public static @Nullable InputStream builtinFontStream(String name) {
+        return FontUtils.class.getResourceAsStream("/assets/" + MeteorClient.MOD_ID + "/fonts/" + name + ".ttf");
     }
 
-    public static InputStream stream(File file) {
-        try {
-            return new FileInputStream(file);
-        }
-        catch (FileNotFoundException e) {
-            e.printStackTrace();
-            return null;
-        }
-    }
 }