Enable loading fonts to GUI

api/src/main/java/com/bartlomiejpluta/base/api/game/gui/Font.java

@@ -0,0 +1,9 @@
+package com.bartlomiejpluta.base.api.game.gui;
+
+import java.nio.ByteBuffer;
+
+public interface Font {
+   String getName();
+
+   ByteBuffer getByteBuffer();
+}

api/src/main/java/com/bartlomiejpluta/base/api/game/gui/GUI.java

@@ -14,5 +14,11 @@ public interface GUI extends Renderable, Disposable {
 
    void fillColor(Color color);
 
+   void setFontFace(String fontUid);
+
+   void setFontSize(float size);
+
+   void putText(float x, float y, CharSequence text);
+
    Color createColor(float red, float green, float blue, float alpha);
 }

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/manager/DefaultFontManager.java

@@ -1,29 +1,52 @@
 package com.bartlomiejpluta.base.engine.gui.manager;
 
+import com.bartlomiejpluta.base.api.game.gui.Font;
+import com.bartlomiejpluta.base.engine.error.AppException;
 import com.bartlomiejpluta.base.engine.gui.asset.FontAsset;
-import com.bartlomiejpluta.base.engine.world.tileset.asset.TileSetAsset;
+import com.bartlomiejpluta.base.engine.gui.model.DefaultFont;
+import com.bartlomiejpluta.base.engine.project.config.ProjectConfiguration;
+import com.bartlomiejpluta.base.engine.util.res.ResourcesManager;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
+import java.nio.ByteBuffer;
 import java.util.HashMap;
 import java.util.Map;
 
 @Slf4j
 @Component
+@RequiredArgsConstructor
 public class DefaultFontManager implements FontManager {
-   private final Map<String, TileSetAsset> assets = new HashMap<>();
+   private final Map<String, FontAsset> assets = new HashMap<>();
+   private final Map<String, ByteBuffer> fontBuffers = new HashMap<>();
+   private final ProjectConfiguration configuration;
+   private final ResourcesManager resourcesManager;
 
    @Override
    public void registerAsset(FontAsset asset) {
       log.info("Registering [{}] font asset under UID: [{}]", asset.getSource(), asset.getUid());
+      assets.put(asset.getUid(), asset);
+
    }
 
    @Override
-   public Integer loadObject(String uid) {
-      // TODO(Implement some kind of font object)
-      // The method should return useful resource associated with the font
-      // that can be easily consumed by NanoVG.
-      // Likely it will be just integer with a unique font ID.
-      return null;
+   public Font loadObject(String uid) {
+      var buffer = fontBuffers.get(uid);
+
+      if (buffer == null) {
+         var asset = assets.get(uid);
+
+         if (asset == null) {
+            throw new AppException("The font asset with UID: [%s] does not exist", uid);
+         }
+
+         var source = configuration.projectFile("fonts", asset.getSource());
+         buffer = resourcesManager.loadResourceAsByteBuffer(source);
+         log.info("Loading font from assets to cache under the key: [{}]", uid);
+         fontBuffers.put(uid, buffer);
+      }
+
+      return new DefaultFont(uid, buffer.duplicate());
    }
 }

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/manager/FontManager.java

@@ -1,7 +1,8 @@
 package com.bartlomiejpluta.base.engine.gui.manager;
 
+import com.bartlomiejpluta.base.api.game.gui.Font;
 import com.bartlomiejpluta.base.engine.common.manager.AssetManager;
 import com.bartlomiejpluta.base.engine.gui.asset.FontAsset;
 
-public interface FontManager extends AssetManager<FontAsset, Integer> {
+public interface FontManager extends AssetManager<FontAsset, Font> {
 }

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/model/DefaultFont.java

@@ -0,0 +1,14 @@
+package com.bartlomiejpluta.base.engine.gui.model;
+
+import com.bartlomiejpluta.base.api.game.gui.Font;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+import java.nio.ByteBuffer;
+
+@Getter
+@RequiredArgsConstructor
+public class DefaultFont implements Font {
+   private final String name;
+   private final ByteBuffer byteBuffer;
+}

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/model/NanoVGColorAdapter.java

@@ -1,4 +1,4 @@
-package com.bartlomiejpluta.base.engine.gui.render;
+package com.bartlomiejpluta.base.engine.gui.model;
 
 import com.bartlomiejpluta.base.api.game.gui.Color;
 import com.bartlomiejpluta.base.api.internal.gc.Disposable;

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/render/NanoVGGUI.java

@@ -7,11 +7,15 @@ import com.bartlomiejpluta.base.api.game.gui.Widget;
 import com.bartlomiejpluta.base.api.game.screen.Screen;
 import com.bartlomiejpluta.base.api.internal.render.ShaderManager;
 import com.bartlomiejpluta.base.engine.error.AppException;
+import com.bartlomiejpluta.base.engine.gui.manager.FontManager;
+import com.bartlomiejpluta.base.engine.gui.model.NanoVGColorAdapter;
 import lombok.Getter;
 import lombok.Setter;
 
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 
 import static org.lwjgl.nanovg.NanoVG.*;
 import static org.lwjgl.nanovg.NanoVGGL3.*;
@@ -25,6 +29,13 @@ public class NanoVGGUI implements GUI {
    private Widget root;
 
    private final List<NanoVGColorAdapter> createdColors = new LinkedList<>();
+   private final Set<String> loadedFonts = new HashSet<>();
+
+   private final FontManager fontManager;
+
+   public NanoVGGUI(FontManager fontManager) {
+      this.fontManager = fontManager;
+   }
 
    public void init(Screen screen) {
       context = nvgCreate(NVG_ANTIALIAS | NVG_STENCIL_STROKES);
@@ -61,6 +72,11 @@ public class NanoVGGUI implements GUI {
       nvgFill(context);
    }
 
+   @Override
+   public void putText(float x, float y, CharSequence text) {
+      nvgText(context, x, y, text);
+   }
+
    @Override
    public Color createColor(float red, float green, float blue, float alpha) {
       var color = new NanoVGColorAdapter(red, green, blue, alpha);
@@ -68,8 +84,25 @@ public class NanoVGGUI implements GUI {
       return color;
    }
 
+   @Override
+   public void setFontFace(String fontUid) {
+      if (!loadedFonts.contains(fontUid)) {
+         var font = fontManager.loadObject(fontUid);
+         nvgCreateFontMem(context, fontUid, font.getByteBuffer(), 0);
+         loadedFonts.add(fontUid);
+      }
+
+      nvgFontFace(context, fontUid);
+   }
+
+   @Override
+   public void setFontSize(float size) {
+      nvgFontSize(context, size);
+   }
+
    @Override
    public void dispose() {
       createdColors.forEach(NanoVGColorAdapter::dispose);
+      nvgDelete(context);
    }
 }

engine/src/main/java/com/bartlomiejpluta/base/engine/project/model/RenderableContext.java

@@ -11,6 +11,7 @@ import com.bartlomiejpluta.base.api.internal.gc.Cleanable;
 import com.bartlomiejpluta.base.api.internal.logic.Updatable;
 import com.bartlomiejpluta.base.api.internal.render.Renderable;
 import com.bartlomiejpluta.base.api.internal.render.ShaderManager;
+import com.bartlomiejpluta.base.engine.gui.manager.FontManager;
 import com.bartlomiejpluta.base.engine.gui.render.NanoVGGUI;
 import com.bartlomiejpluta.base.engine.project.loader.ClassLoader;
 import com.bartlomiejpluta.base.engine.world.entity.manager.EntityManager;
@@ -32,6 +33,7 @@ public class RenderableContext implements Context, Updatable, Renderable, Cleana
    private final EntityManager entityManager;
    private final ImageManager imageManager;
    private final MapManager mapManager;
+   private final FontManager fontManager;
    private final ClassLoader classLoader;
 
    @Getter
@@ -70,7 +72,7 @@ public class RenderableContext implements Context, Updatable, Renderable, Cleana
 
    @Override
    public GUI newGUI() {
-      var gui = new NanoVGGUI();
+      var gui = new NanoVGGUI(fontManager);
       guis.add(gui);
       gui.init(screen);
       return gui;