Add support to load TTF TrueType fonts using FreeType

pom.xml

@@ -2,7 +2,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>virtual-cardboard</groupId>
 	<artifactId>nengen</artifactId>
-	<version>0.0.3</version>
+	<version>0.0.4</version>
 
 	<properties>
 		<maven.compiler.source>1.8</maven.compiler.source>
@@ -200,6 +200,11 @@
 			<artifactId>lwjgl-stb</artifactId>
 			<classifier>${lwjgl.natives}</classifier>
 		</dependency>
+		<dependency>
+			<groupId>org.lwjgl</groupId>
+			<artifactId>lwjgl-freetype</artifactId>
+			<version>3.3.6</version>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/common/NengenFileUtil.java

@@ -7,18 +7,29 @@
 import static org.lwjgl.stb.STBImage.stbi_failure_reason;
 import static org.lwjgl.stb.STBImage.stbi_load;
 import static org.lwjgl.stb.STBImage.stbi_set_flip_vertically_on_load;
+import static org.lwjgl.util.freetype.FreeType.FT_New_Face;
+import static visuals.rendering.text.GameFont.getFontIndex;
 
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.IntBuffer;
 
+import org.lwjgl.PointerBuffer;
+import org.lwjgl.freetype.FT_Bitmap;
+import org.lwjgl.freetype.FT_Face;
+import org.lwjgl.freetype.FT_GlyphSlot;
+import org.lwjgl.freetype.FreeType;
 import org.lwjgl.system.MemoryStack;
+import org.lwjgl.util.freetype.FT_Bitmap;
+import org.lwjgl.util.freetype.FT_Face;
+import org.lwjgl.util.freetype.FT_GlyphSlot;
+import org.lwjgl.util.freetype.FreeType;
+
+import javafx.scene.image.Image;
 import visuals.lwjgl.render.Texture;
-import visuals.rendering.text.CharacterData;
 import visuals.rendering.text.GameFont;
-import visuals.rendering.texture.Image;
 
 public class NengenFileUtil {
 
@@ -94,7 +105,7 @@ public static GameFont loadFont(File font, Texture texture) {
 			DEBUG("Characters: " + numCharacters);
 			DEBUG("Kernings: " + kernings);
 
-			GameFont gameFont = new GameFont(name, fontSize, texture);
+			GameFont gameFont = new GameFont(name, fontSize, texture, getFontIndex());
 
 			// Read characters
 			CharacterData[] characters = gameFont.getCharacterDatas();
@@ -111,7 +122,8 @@ public static GameFont loadFont(File font, Texture texture) {
 				short page = (short) fis.read();
 				CharacterData charData = new CharacterData(x, y, width, height, xOffset, yOffset, xAdvance, page);
 				DEBUG("=====================");
-				DEBUG(c + " " + x + " " + y + " " + width + " " + height + " " + xOffset + " " + yOffset + " " + xAdvance + " " + page);
+				DEBUG(c + " " + x + " " + y + " " + width + " " + height + " " + xOffset + " " + yOffset + " "
+						+ xAdvance + " " + page);
 				DEBUG("Character: " + (char) c);
 				DEBUG("X: " + x);
 				DEBUG("Y: " + y);
@@ -124,14 +136,65 @@ public static GameFont loadFont(File font, Texture texture) {
 				characters[c] = charData;
 			}
 			CharacterData space = characters[' '];
-			characters['\t'] = new CharacterData(space.x(), space.y(), space.width(), space.height(), space.xOffset(), space.yOffset(), (short) (space.xAdvance() * 4), space.getPage());
+			characters['\t'] = new CharacterData(space.x(), space.y(), space.width(), space.height(), space.xOffset(),
+					space.yOffset(), (short) (space.xAdvance() * 4), space.getPage());
 
 			return gameFont;
 		} catch (IOException e) {
 			throw new RuntimeException(e);
 		}
 	}
 
+	public static GameFont loadTTF(String ttfFile, int fontSize) {
+		PointerBuffer ftLibrary = PointerBuffer.allocateDirect(10000);
+		FT_Init_FreeType(ftLibrary);
+
+		PointerBuffer ftFaceBuffer = PointerBuffer.allocateDirect(1);
+		ByteBuffer ftFaceByteBuffer = ftFaceBuffer.getByteBuffer(0, 8);
+		FT_Face ftFace = new FT_Face(ftFaceByteBuffer);
+		FT_New_Face(ftLibrary.address(), ttfFile, getFontIndex(), ftFaceBuffer);
+
+		if (false) {
+			throw new RuntimeException("Failed to initialize FreeType library");
+		}
+
+		FreeType.FT_Set_Pixel_Sizes(ftFace, 0, fontSize);
+
+		GameFont gameFont = new GameFont(ttfFile, fontSize, new CharacterData[0], getFontIndex());
+		CharacterData[] characters = gameFont.getCharacterDatas();
+
+		for (int c = 0; c < 128; c++) {
+			if (FreeType.FT_Load_Char(ftFace, c, FreeType.FT_LOAD_RENDER) != 0) {
+				System.err.println("Failed to load Glyph for character: " + (char) c);
+				continue;
+			}
+
+			FT_GlyphSlot glyph = ftFace.glyph();
+			FT_Bitmap bitmap = glyph.bitmap();
+
+			Texture texture = new Texture().dimensions(bitmap.width(), bitmap.rows())
+					.image(new Image().data(bitmap.buffer(100))).load();
+
+			CharacterData charData = new CharacterData(
+					(short) glyph.bitmap_left(),
+					(short) glyph.bitmap_top(),
+					(short) bitmap.width(),
+					(short) bitmap.rows(),
+					(short) glyph.bitmap_left(),
+					(short) glyph.bitmap_top(),
+					(short) glyph.advance().x(),
+					texture);
+			characters[c] = charData;
+		}
+
+		gameFont.characterDatas(characters);
+
+		FreeType.FT_Done_Face(ftFace);
+		FreeType.FT_Done_FreeType(ftLibrary.address());
+
+		return gameFont;
+	}
+
 	private static short readShort(FileInputStream fis) throws IOException {
 		byte b1 = (byte) fis.read();
 		byte b2 = (byte) fis.read();

src/main/java/visuals/rendering/text/CharacterData.java

@@ -1,7 +1,10 @@
 package visuals.rendering.text;
 
+import visuals.lwjgl.render.Texture;
+
 /**
- * Information about a character in a bitmap font. The fields are all in pixels, except for {@link CharacterData#page}.
+ * Information about a character in a bitmap font. The fields are all in pixels,
+ * except for {@link CharacterData#page}.
  *
  * @author Jay
  */
@@ -24,12 +27,14 @@ public final class CharacterData {
 	 */
 	private final int height;
 	/**
-	 * The horizontal offset of the character when it is displayed. This is usually a small number.
+	 * The horizontal offset of the character when it is displayed. This is usually
+	 * a small number.
 	 */
 	private final int xOffset;
 	/**
 	 * The vertical offset of the character when it is displayed.
-	 * For example, the letter 'g' has a larger yOffset than 'l' because it is offset downwards.
+	 * For example, the letter 'g' has a larger yOffset than 'l' because it is
+	 * offset downwards.
 	 */
 	private final int yOffset;
 	/**
@@ -39,8 +44,18 @@ public final class CharacterData {
 	private final int xAdvance;
 	/**
 	 * The index of the bitmap image that this character is on. This is usually 0.
+	 * <br>
+	 * <br>
+	 * Mutually exclusive with {@link CharacterData#texture}.
+	 */
+	private int page;
+	/**
+	 * The texture that this character is on.
+	 * <br>
+	 * <br>
+	 * Mutually exclusive with {@link CharacterData#page}.
 	 */
-	private final int page;
+	private Texture texture;
 
 	public CharacterData(int x, int y, int width, int height, int xOffset, int yOffset, int xAdvance, int page) {
 		this.x = x;
@@ -53,10 +68,26 @@ public CharacterData(int x, int y, int width, int height, int xOffset, int yOffs
 		this.page = page;
 	}
 
-	public CharacterData(short x, short y, short width, short height, short xOffset, short yOffset, short xAdvance, short page) {
+	public CharacterData(int x, int y, int width, int height, int xOffset, int yOffset, int xAdvance, Texture texture) {
+		this.x = x;
+		this.y = y;
+		this.width = width;
+		this.height = height;
+		this.xOffset = xOffset;
+		this.yOffset = yOffset;
+		this.xAdvance = xAdvance;
+		this.texture = texture;
+	}
+
+	public CharacterData(short x, short y, short width, short height, short xOffset, short yOffset, short xAdvance,
+			short page) {
 		this(x, y, width, height, xOffset, yOffset, xAdvance, (int) page);
 	}
 
+	public CharacterData(int x, int y, int width, int height, int xOffset, int yOffset, int xAdvance) {
+		this(x, y, width, height, xOffset, yOffset, xAdvance, 0);
+	}
+
 	public int x() {
 		return x;
 	}

src/main/java/visuals/rendering/text/GameFont.java

@@ -4,16 +4,39 @@
 
 public final class GameFont {
 
+	public static long FONT_INDEX = 0;
+
+	/**
+	 * The global index of the font.
+	 */
+	private final long fontIndex;
+
 	private final String name;
 	private final int fontSize;
-	private final CharacterData[] characterDatas;
+	private CharacterData[] characterDatas;
 	private final Texture texture;
 
-	public GameFont(String name, int fontSize, Texture texture) {
+	public GameFont(String name, int fontSize, Texture texture, long fontIndex) {
 		this.name = name;
 		this.fontSize = fontSize;
 		characterDatas = new CharacterData[128];
 		this.texture = texture;
+		this.fontIndex = fontIndex;
+	}
+
+	public GameFont(String name, int fontSize, CharacterData[] characterDatas, long fontIndex) {
+		this.name = name;
+		this.fontSize = fontSize;
+		this.characterDatas = characterDatas;
+		this.texture = null;
+		this.fontIndex = fontIndex;
+	}
+
+	public GameFont(String name, int fontSize, CharacterData[] characterDatas) {
+		this.name = name;
+		this.fontSize = fontSize;
+		this.characterDatas = characterDatas;
+		this.texture = null;
 	}
 
 	public String getName() {
@@ -28,12 +51,22 @@ public CharacterData[] getCharacterDatas() {
 		return characterDatas;
 	}
 
+	public void characterDatas(CharacterData[] characterDatas) {
+		this.characterDatas = characterDatas;
+	}
+
 	public Texture texture() {
 		return texture;
 	}
 
 	public void delete() {
-		texture.delete();
+		if (texture != null) {
+			texture.delete();
+		}
+	}
+
+	public static long getFontIndex() {
+		return FONT_INDEX++;
 	}
 
 }