Forums > Jitter

Open GL question

March 1, 2006 | 5:59 pm

I know this is remedial but I’m somehow missing the key rendering openn GL in a matrix without enormous amount of flicker. I’ve checked the documentation but perhaps I’m just oblivious to how this works. I’m tryin to render some text via open GL over top of movie clips.
Thanks,
Casey


March 1, 2006 | 6:03 pm

sorry as soon as I posted this I realized that it needed to go in the jitter forum


March 1, 2006 | 6:21 pm

You’re probably better of performance-wise using jit.lcd instead of
opengl to render text over a video.

wes


March 1, 2006 | 6:27 pm

I was using a version of the subtitle patch that is in the examples, however from my reading it seemed that using open gl to render the text would shift the CPU load for the text rendering from my main CPU to my graphics card. Is that true? Also all of the text I get out of the LCD object looks fairly pixelated, regardless of the font. I gues I’m still in the dark as to how to effectively mix the open GL and matrix worlds.


March 1, 2006 | 6:35 pm

Moving this thread to jitter…


March 1, 2006 | 6:45 pm

Depends,
If you want the text back in matrix land, use jit.lcd.

If you want to keep everything in opengl land, use open gl objects to make text.

It’s that simple.

wes


March 1, 2006 | 7:03 pm

Having read your original email, I’m guessing that you were having
trouble with flickering because you were sending a matrix to a
jit.window that was also set as a gl.render destination. This simply
won’t work the way you want it to. In order to get your video into
OpenGL, you will need to connect to a jit.gl.videoplane object. Here is
a simple example that demonstrates this:

#P toggle 378 267 15 0;
#P window setfont "Sans Serif" 9.;
#P window linecount 1;
#P message 378 284 90 196617 color $1 $1 $1 1.;
#P message 236 282 139 196617 size 24 , text "blah blah blah";
#P newex 236 329 223 196617 jit.gl.text2d foo @blend_enable 1 @automatic 0;
#P message 215 184 30 196617 read;
#P newex 206 208 63 196617 jit.qt.movie;
#P newex 206 239 251 196617 jit.gl.videoplane foo @scale 1.333 1. 1.
@automatic 0;
#P toggle 96 128 15 0;
#P newex 42 285 75 196617 jit.window foo;
#P newex 42 262 82 196617 jit.gl.render foo;
#P newex 96 173 74 196617 t b b b b erase;
#P newex 96 149 51 196617 qmetro 5;
#P connect 9 0 8 0;
#P connect 1 1 8 0;
#P connect 10 0 8 0;
#P connect 11 0 10 0;
#P connect 6 0 5 0;
#P connect 1 2 5 0;
#P connect 7 0 6 0;
#P connect 1 3 6 0;
#P connect 1 4 2 0;
#P connect 1 0 2 0;
#P connect 0 0 1 0;
#P connect 4 0 0 0;
#P window clipboard copycount 12;

Take note of the rendering order imposed by turning off @automatic and
using the trigger object.

Cheers,
Andrew B.


March 1, 2006 | 7:26 pm

Thank you Wes and Andrew, what a great resource this forum is, Again Wallace sorry about the wrong forum thing.
Casey


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