RE: [Plib-users] Newbie Question: Mixing SSG & OpenGL

[Stanford N. <st...@th...>]

Thanks for the pointers!

After much digging under the hood of my program, I'm still encountering
problems with mixing SSG & OpenGL.  I've narrowed it down to the
ssgCullAndDraw() call influencing the GL state somehow.  When I comment
out ssgCullAndDraw() in my redraw routine, the draw_water() works fine,
drawing a blue rectangle.  When I leave the call in there, the rectangle
is still drawn, but it is very dark and blends right into the
background.  

I'm trying to puzzle out what ssgCullAndDraw() is doing that would
affect the standard OpenGL stuff... I'm still quite a novice when it
comes to these things.  If someone could explain things, I'd much
appreciate it!  Thanks in advance!

-- stan

<< CODE SNIPPETS FOR REFERENCE >>

void redraw()
{
	update_game() ;

	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	ssgCullAndDraw( scene );
	draw_water();
	draw_text();
	glutPostRedisplay();
	glutSwapBuffers();
}


void draw_water()
{
	glMatrixMode( GL_PROJECTION );
	glPushMatrix();
	glLoadIdentity();

	glMatrixMode( GL_MODELVIEW );
	glPushMatrix();
	glLoadIdentity();
	GLfloat lmodel_ambient[] = { 0.8, 0.8, 0.8, 1.0 };
	glLightModelfv( GL_LIGHT_MODEL_AMBIENT, lmodel_ambient );

	glColor3f( 0.0f, 0.0f, 1.0f );
	
	glBegin( GL_QUADS );
	glVertex3f( 0.3f, 0.3f, 0.0f );
	glVertex3f( -0.3f, 0.3f, 0.0f );
	glVertex3f( -0.3f, -0.3f, 0.0f );
	glVertex3f( 0.3f, -0.3f, 0.0f );
	glEnd();


	glPopMatrix();
	glMatrixMode( GL_PROJECTION );
	glPopMatrix();
}


-----Original Message-----
From: steve [mailto:steve] On Behalf Of Steve Baker
Sent: Friday, May 10, 2002 2:07 PM
To: Stanford Ng
Cc: pli...@li...
Subject: Re: [Plib-users] Newbie Question: Mixing SSG & OpenGL


Stanford Ng wrote:
> 
> Hi everyone!  I just got started with Plib and I like it a lot!  Great

> work, guys!
> 
> I'm stuck with a rather embarrassing problem: I can't seem to mix SSG 
> & my OpenGL code together.  My SSG code loads a model and displays it.

> My OpenGL code draws some colored polys to the screen.  They both work

> individually, but I can't mix and match...
> 
> It seems that the ssgInit() call will setup some GL state that causes 
> the GL calls in my custom code to not render... This is rather 
> perplexing as I have managed to work the 2-d font rendering via an 2-d

> orthogonal projection into the code.  Is this something obvious I'm 
> missing?
> 
> If someone could point me to an example that has both SSG & OpenGL 
> code working together, I'm sure I can figure out what I'm doing wrong.

Well, all of my games do - so check out TuxKart for example.

----------------------------- Steve Baker
-------------------------------
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