Using MC resource provider to get Unifont to allow changing it in resource packs (and code for re-generating char lookup texture accordingly).

src/main/scala/li/cil/oc/client/renderer/font/DynamicFontRenderer.scala

@@ -2,6 +2,8 @@ package li.cil.oc.client.renderer.font
 
 import li.cil.oc.client.renderer.font.DynamicFontRenderer.CharTexture
 import li.cil.oc.util.{FontUtil, RenderState}
+import net.minecraft.client.Minecraft
+import net.minecraft.client.resources.{ReloadableResourceManager, ResourceManager, ResourceManagerReloadListener}
 import org.lwjgl.BufferUtils
 import org.lwjgl.opengl._
 
@@ -11,16 +13,37 @@ import scala.collection.mutable
  * Font renderer that dynamically generates lookup textures by rendering a font
  * to it. It's pretty broken right now, and font rendering looks crappy as hell.
  */
-class DynamicFontRenderer extends TextureFontRenderer {
+class DynamicFontRenderer extends TextureFontRenderer with ResourceManagerReloadListener {
-  private val glyphProvider = new FontParserUnifont()
+  private val glyphProvider: IGlyphProvider = new FontParserUnifont()
 
-  private val textures = mutable.ArrayBuffer(new DynamicFontRenderer.CharTexture(this))
+  private val textures = mutable.ArrayBuffer.empty[CharTexture]
 
   private val charMap = mutable.Map.empty[Char, DynamicFontRenderer.CharIcon]
 
-  var activeTexture: CharTexture = textures(0)
+  private var activeTexture: CharTexture = _
 
+  initialize()
+
+  Minecraft.getMinecraft.getResourceManager match {
+    case reloadable: ReloadableResourceManager => reloadable.registerReloadListener(this)
+    case _ =>
+  }
+
+  def initialize() {
+    for (texture <- textures) {
+      texture.delete()
+    }
+    textures.clear()
+    charMap.clear()
+    textures += new DynamicFontRenderer.CharTexture(this)
+    activeTexture = textures(0)
     generateChars(basicChars.toCharArray)
+  }
+
+  def onResourceManagerReload(manager: ResourceManager) {
+    glyphProvider.initialize()
+    initialize()
+  }
 
   override protected def charWidth = glyphProvider.getGlyphWidth
 
@@ -40,7 +63,7 @@ class DynamicFontRenderer extends TextureFontRenderer {
 
   override protected def drawChar(tx: Float, ty: Float, char: Char) {
     val icon = charMap(char)
-    if (icon.texture == activeTexture) {
+    if (icon != null && icon.texture == activeTexture) {
       icon.draw(tx, ty)
     }
   }
@@ -84,6 +107,10 @@ object DynamicFontRenderer {
 
     private var chars = 0
 
+    def delete() {
+      GL11.glDeleteTextures(id)
+    }
+
     def bind() {
       GL11.glBindTexture(GL11.GL_TEXTURE_2D, id)
     }

src/main/scala/li/cil/oc/client/renderer/font/FontParserUnifont.java

@@ -1,20 +1,40 @@
 package li.cil.oc.client.renderer.font;
 
 import li.cil.oc.OpenComputers;
+import li.cil.oc.Settings;
+import net.minecraft.client.Minecraft;
+import net.minecraft.util.ResourceLocation;
 import org.lwjgl.BufferUtils;
 
 import java.io.BufferedReader;
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.ByteBuffer;
+import java.util.logging.Level;
 
 public class FontParserUnifont implements IGlyphProvider {
-    private final byte[][] glyphs;
+    private static final byte[] b_set = {(byte) 255, (byte) 255, (byte) 255, (byte) 255};
+    private static final byte[] b_unset = {0, 0, 0, 0};
 
-    public FontParserUnifont() throws Exception {
+    private final byte[][] glyphs = new byte[65536][];
+
+    public FontParserUnifont() {
+        initialize();
+    }
+
+    @Override
+    public void initialize() {
+        for (int i = 0; i < glyphs.length; ++i) {
+            glyphs[i] = null;
+        }
+        final InputStream font = Minecraft.getMinecraft().getResourceManager().getResource(new ResourceLocation(Settings.resourceDomain(), "unifont.hex")).getInputStream();
+        if (font == null) {
+            OpenComputers.log().warning("Failed opening unifont file.");
+            return;
+        }
+        try {
             OpenComputers.log().info("Initialized Unifont glyph provider.");
-        glyphs = new byte[65536][];
-        final InputStream font = getClass().getResourceAsStream("/assets/opencomputers/unifont.hex");
             final BufferedReader input = new BufferedReader(new InputStreamReader(font));
             String line;
             int glyphCount = 0;
@@ -29,10 +49,15 @@ public class FontParserUnifont implements IGlyphProvider {
                 glyphs[charCode] = glyph;
             }
             OpenComputers.log().info("Loaded " + glyphCount + " glyphs.");
+        } catch (IOException ex) {
+            OpenComputers.log().log(Level.WARNING, "Failed loading glyphs.", ex);
+        } finally {
+            try {
+                font.close();
+            } catch (IOException ignored) {
+            }
+        }
     }
-
-    private static final byte[] b_set = {(byte) 255, (byte) 255, (byte) 255, (byte) 255};
-    private static final byte[] b_unset = {0, 0, 0, 0};
 
     @Override
     public ByteBuffer getGlyph(int charCode) {

src/main/scala/li/cil/oc/client/renderer/font/IGlyphProvider.java

@@ -3,7 +3,11 @@ package li.cil.oc.client.renderer.font;
 import java.nio.ByteBuffer;
 
 public interface IGlyphProvider {
+    public void initialize();
+
     public ByteBuffer getGlyph(int charCode);
+
     public int getGlyphWidth();
+
     public int getGlyphHeight();
 }