hint(DISABLE_DEPTH_TEST) question

Core Library Questions

nootropic..

hint(DISABLE_DEPTH_TEST) question

in Core Library Questions • 1 years ago

hello, i'm trying to reproduce hint(DISABLE_DEPTH_TEST) using pure opengl

gl=((PGraphicsOpenGL)g).gl;

gl.glDisable (GL.GL_DEPTH_TEST);

does not work.. some advice?

Replies(8)

amnon.owed

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

Perhaps...

gl.glDepthMask(false);

?

nootropic..

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

no.. it does not reproduce the same result..

PhiLho

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

I don't know well OpenGL, so I look at the source. At hint(), I see:

if (which == DISABLE_DEPTH_TEST) {
gl.glDisable(GL.GL_DEPTH_TEST);
gl.glClear(GL.GL_DEPTH_BUFFER_BIT);
} else if (which == ENABLE_DEPTH_TEST) {
gl.glEnable(GL.GL_DEPTH_TEST);

Perhaps also search the forums (this one and the old one), if not already done.

kooogy

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

that stuff's pretty standard and looks ok to me.

can you post a small sketch showing it not working?

nootropic..

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

here is my sketch! http://www.openprocessing.org/visuals/?visualID=45742

kooogy

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

that's not a lot of use to me - doesn't run on openprocessing.org and the source doesn't run here as it uses libraries i don't have...

but here's a short example that shows depth hint works fine - click to toggle depth test

import processing.opengl.*;
import javax.media.opengl.GL;
boolean depth;
void setup() {
size(400, 400, OPENGL);
}
void mouseClicked() {
depth = !depth;
redraw();
}
void draw() {
translate(width / 2, height / 2);
GL gl=((PGraphicsOpenGL)g).gl;
if (depth) {
gl.glDisable(GL.GL_DEPTH_TEST);
} else {
gl.glEnable(GL.GL_DEPTH_TEST);
}
gl.glClear(GL.GL_DEPTH_BUFFER_BIT);
noStroke();
// intersecting quads - will see all of green quad if depth check is disabled as it's drawn last
beginShape(QUADS);
fill(255, 0, 0); // red
vertex(-100, -100, -100);
vertex(-100, 100, -100);
vertex( 100, 100, 100);
vertex( 100, -100, 100);
fill(0, 255, 0); // green
vertex(-100, -100, 100);
vertex(-100, 100, 100);
vertex( 100, 100, -100);
vertex( 100, -100, -100);
endShape();
noLoop();
}

kooogy

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

actually, i i comment out al the ControlP5 stuff it does run. but i can't see a problem. "does not work" isn't clear. what isn't working? what should it look like? and you're using NoFill() so it's a wireframe model - so how can you tell that the depth testing isn't working?

nootropic..

Re: hint(DISABLE_DEPTH_TEST) question

1 years ago

ok sorry my problem is in drawing lines with alpha.

with "does not work" i mean that i have 2 different output.

here is the image with

gl.glDisable(GL.GL_DEPTH_TEST);
gl.glClear(GL.GL_DEPTH_BUFFER_BIT);

and here the image with

hint(DISABLE_DEPTH_TEST);

the problem, i think, is that in the first image the alpha drawed lines are with depth test and the nearer lines are drawed overriding the existing pixel (no real alpha) of the line that are farest from camera

sorry if my english is not so good and i can't explain well

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