How can one draw text?

Newbie & Debugging Questions
#1

I’m really sad. I’m trying to use LWJGL to draw some text on the screen, nothing fancy, I just need to be able to read some info. I find that I’ll need Slick. I get slick. I use this ( http://www.lwjgl.org/wiki/index.php?title=Slick-Util_Library_-Part_3-_TrueType_Fonts_for_LWJGL ) to try and draw something with TrueTypeFont. Doesn’t work, also deprecated. I find that I need to use “UnicodeFont”. I use that, but I get null pointer errors which no one online seems to get (specifically this:)

Exception in thread “Thread-0” java.lang.IllegalStateException: The UnicodeFont must have at least one effect before any glyphs can be loaded.
at org.newdawn.slick.UnicodeFont.loadGlyphs(UnicodeFont.java:340)
at org.newdawn.slick.UnicodeFont.loadGlyphs(UnicodeFont.java:325)
Any API’s I find are dead links.

I have a very simple question. How do I draw text on my screen?

#2

Try this:


Font awtFont = new Font("Default", Font.PLAIN, 14);
font = new UnicodeFont(awtFont);
font.getEffects().add(new ColorEffect(java.awt.Color.white));
font.addAsciiGlyphs();
try { font.loadGlyphs(); }
catch (SlickException e) { 
    e.printStackTrace(); 
}

I’m guessing you don’t have a “font.getEffects().add(…)”.

#3

No dice

Exception in thread “Thread-0” java.lang.NoSuchMethodError: org.newdawn.slick.opengl.renderer.SGL.glTexSubImage2D(IIIIIIIILjava/nio/ByteBuffer;)V
at org.newdawn.slick.font.GlyphPage.renderGlyph(GlyphPage.java:212)
at org.newdawn.slick.font.GlyphPage.loadGlyphs(GlyphPage.java:166)
at org.newdawn.slick.UnicodeFont.loadGlyphs(UnicodeFont.java:376)
at org.newdawn.slick.UnicodeFont.loadGlyphs(UnicodeFont.java:325)

It doesn’t like “try { font.loadGlyphs(); }”

#4

This looks really weird: ???
org.newdawn.slick.opengl.renderer.SGL.glTexSubImage2D(IIIIIIIILjava/nio/ByteBuffer;)V

Are you using the latest version of slick?

EDIT:
also: https://bitbucket.org/kevglass/slick/issue/29/unicodefontloadglyphs-throws

#5

I used the one at ninjacave, that’s the only one i could find
http://slick.cokeandcode.com/

#6

Where can I even get the latest version of Slick?

#7

See my edit above and check your build path, what does it have in it? e.g. for one of my projects which uses font rendering I have lwjgl_util.jar, lwjgl.jar, and slick.jar.

You probably have the latest version.

#8

Here is a picture what my buildpath looks like

#9

From what this said it’s probably an incompatability between you slick.jar and slick_util.jar versions. The latest slick download doesn’t even include slick_util so try removing it, maybe the slick_util stuff was combined with slick in the latest version.

#10

That was a good idea. I no longer have any errors. However, I still cannot see my text.
I load everything like this:

		Font awtFont = new Font("Times New Roman", Font.PLAIN, 14);
		font = new UnicodeFont(awtFont);
		font.getEffects().add(new ColorEffect(java.awt.Color.white));
		font.addAsciiGlyphs();
		try { font.loadGlyphs(); }
		catch (SlickException e) { 
		    e.printStackTrace(); 
		}

And draw it like this:


			font.drawString(0.2f, 0.2f, "efer");

Is there anything else I need to include to get it to draw properly?

Thank you

#11

Do you have other textures drawing before the text? If so, call

TextureImpl.unbind();

Or it could be

TextureImpl.bindNone();

I can’t remember which one :frowning:

#12

How are your matrices set up? e.g. I’m doing:


        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(0, w, h, 0, 1, -1);// w is the screen width and h is the height
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        glEnable(GL_BLEND);
        glDisable(GL_DEPTH_TEST);
        font.drawString(10, 10, "Text");//draws text 10 pixels down and to the right of the top left corner

Maybe your text is getting drawn off-screen? I don’t really know tbh.

#13

That works! The only problem is that is removes everything else drawn from the screen. How can I use different GL settings at different times to overlay them?

#14

Oh yeah, you need to set the matrices back to what they were again afterwards. I think this should work:


        glMatrixMode(GL_PROJECTION);
        glPushMatrix();
        glLoadIdentity();
        glOrtho(0, w, h, 0, 1, -1);// w is the screen width and h is the height
        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        glLoadIdentity();
        glEnable(GL_BLEND);
        glDisable(GL_DEPTH_TEST);
        font.drawString(10, 10, "Text");//draws text 10 pixels down and to the right of the top left corner
        // do rest of text drawing here + any other overlay stuff
        glMatrixMode(GL_PROJECTION);
        glPopMatrix();
        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();
        glEnable(GL_DEPTH_TEST);

Also make sure any overlay type stuff is rendered last because if depth test is disabled it draws in the order of the commands.

#15

It works! Thank you guys so much!

Just one thing, is there a way to make the text look smoother?
I tried to render Courier, but it looks like this

(I have only copied the code found in this thread)

#16

Add glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); somewhere before rendering the text. I thought it got set to that by default.

#17

Excellent, thank you! This was a very confusing block of code.

#18

You can do this the “Notch” way. The almighty Notch’s way. Check out his Ludum Dare entries source code.

#19

My API here also has some basic bitmap text support:

Of course if you want something more robust and cross-platform, you should be using LibGDX. :slight_smile: