javalwjglslick2d

Drawing text to display


I'm trying to draw a text to the screen in LWJGL following this tutorial. The problem is that when ever I draw a text to the screen, it draws perfectly but when I draw a quad with the text, the quad does not show.

Game class

package moa.bermudez;

import static org.lwjgl.opengl.GL11.*;

import java.awt.Font;
import java.io.InputStream;

import moa.bermudez.utils.Artist;

import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.newdawn.slick.TrueTypeFont;

public class Game 
{
public static final int WIDTH = 320;
public static final int HEIGHT = WIDTH * 9 / 16;
public static final int SCALE = 3;
public static final String NAME = "----";
public static final float VERSION = 0.1f;
public static final int MAX_FPS = 60;

private TrueTypeFont font;
private boolean fontAS = true;

public Game() 
{
    try 
    {
        Display.setDisplayMode(new DisplayMode(WIDTH * SCALE, HEIGHT * SCALE));
        Display.setTitle(NAME + " " + VERSION);
        Display.create();
    } catch(LWJGLException e)
    {
        e.printStackTrace();
        Display.destroy();
    }

    init();
    while(!Display.isCloseRequested())
    {
        setCamera();
        update();
        Display.sync(MAX_FPS);
    }

    Display.destroy();
}

public void update()
{       
    glClear(GL_COLOR_BUFFER_BIT);

    font.drawString(0, 0, "This text is showing");
    Artist.drawQuad(0, 0, 100, 100);    // This is not showing.

    Display.update();
}

public void setCamera()
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glViewport(0, 0, WIDTH * SCALE, HEIGHT * SCALE);
    glOrtho(0, WIDTH * SCALE, HEIGHT * SCALE, 0, 1, -1);
    glMatrixMode(GL_MODELVIEW);
    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

public void init()
{
    try {
        InputStream inputStream = moa.bermudez.fonts.Font.DEFAULT_FONT;

        Font awtFont = Font.createFont(Font.TRUETYPE_FONT, inputStream);
        awtFont = awtFont.deriveFont(24f); 
        font = new TrueTypeFont(awtFont, fontAS);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void main(String[] args)
{
    new Game();
}
}

Artist's DrawQuad method

public static void drawQuad(float x, float y, float width, float height)
{
    glBegin(GL_QUADS);

        glColor3d(0, 0, 1);
        glVertex2f(x, y);
        glVertex2f(x + width, y);
        glVertex2f(x + width, y + height);
        glVertex2f(x, y + height);

    glEnd();
}

Solution

  • After searching, I found a solution to this from this stackoverflow post

    Not calling glEnable(GL_BLEND) in initGL but calling glEnable(GL_BLEND) when you draw the text should make it work.

    glEnable(GL_BLEND);
    font.drawString(0, 0, "This is a text that should appear");
    glDisable(GL_BLEND);