On 03/11/2012 05:04 PM, Jacob Carlborg wrote:
On 2012-03-11 14:18, Chad J wrote:
On 03/11/2012 09:09 AM, Jacob Carlborg wrote:
On 2012-03-11 03:23, Chad J wrote:
I've been looking for a good way to render font in OpenGL with D.
Back in they day I was very impressed with Tomasz's article on the
subject: http://h3.gd/dmedia/?n=Tutorials.TextRendering1
I was wonder if anyone has ported it.
Just use FreeType?
FreeType is quite cool, but it will only render glyphs onto small
bitmaps. Getting those glyphs onto the screen becomes more complicated
after that: you can't just blit them like in SDL or somesuch. Since
textures don't come in "supersmall" size, it is effective to pack the
glyphs into a larger texture like the article suggests. Then you have to
texture-map correctly to only render the glyphs you want. Somewhere in
there is a bunch of other font-setting stuff like kerning, sub-pixel
anti-aliasing, line offsets, etc. FreeType doesn't do that stuff for
anyone, it just provides the tools necessary to make it possible. It's
fairly complicated; I'd rather just write "Font f = new Font("Courier
New"); f.draw(100, 100, "Hello world!");".
So you mean putting a texture on a font?
No, just getting the font onto the screen at all.
And I want to:
- Be able to size the font smoothly. (No bitmap fonts!)
- Draw glyphs for higher unicode codepoints. (No texture[128]!)
- Have kerning/hinting. (Freetype makes it possible, but does not do it
for you.)
- Have anti-aliasing and maybe even subpixel accuracy.
Tomasz's code does all of this.
Freetype is very low-level. Freetype does not make OpenGL calls. You
give it a font and a codepoint and it gives you a small grayscale bitmap
and a slew of metrics for it. Then it's up to you to figure out where
to put it and how to get it onto the screen.
If this were trivial, Tomasz (and others who have written on the topic,
too) would not have written 5-10 pages of text plus a bunch of D files
full of code. It's just not that easy. It's all in the original link.
It's actually really weird that there isn't much library code out there
to render text in OpenGL. There are a bunch of tutorials that do it
wrong and maybe a few library thingies that I can't use for various reasons.
