Re: Point Sprites

• Subject: Re: Point Sprites
• From: "Wesley Smith" <email@hidden>
• Date: Wed, 16 May 2007 20:41:26 -0700
• Delivered-to: email@hidden
• Delivered-to: email@hidden
• Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=GcHUMcSBuxZaDrYu2Swbjg8YxgEeKc6IKqK5Ic4tlz3HxLuaAkcOyppVggxamkenYmBg0WtFOkGefA1LVWvlZa5wIBIPjL65NjJh9D+MtdyE5PzKavGhXI+TKGQcLGZzstqizJrFiAAwWcX/TBQorRJJfpBTFvoBoInlEKSabTc=
• Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=sIEAZvE3LYXqd56dtB8/Kdd/70WP9gI/7eZdgNOeILbeOc3AiZcmAhUlf3ZYxuuz/vdc5PnuEhtH0juSoX/yPzgK1G+7IdfzHa2sycX0Mae2dVPn3ET1lIqr/6dioqHJgv5NZjHh0aAOn9dpPOKwNMpB3+dmok7thb/5zP0lzTs=

Forgot to add:

If I have these lines:

glPointParameterfARB( GL_POINT_FADE_THRESHOLD_SIZE_ARB, 60.0f );
	glPointParameterf(GL_POINT_SIZE_MIN_ARB, 1);
	glPointParameterf(GL_POINT_SIZE_MAX_ARB, 100);
	glPointSize(100);
float quadratic[] =  { 1.1f, 0.000000f, 0.000000f };
glPointParameterfvARB( GL_POINT_DISTANCE_ATTENUATION_ARB, quadratic );

All points are of size 1.

If I change the quadratic values to
float quadratic[] =  { 1.0f, 0.000000f, 0.000000f };

all points are 100.  Is this correct behavior?

thanks,
wes

Hi,
I'm on  OSX 10.4.8 and trying to get point sprites to work.  I'm not
seeing any attenuation in size in the sprites.  All I get is
GL_POINT_SIZE_MIN_ARB for all points.  Here's the code.  Is there
something I'm forgetting?

thanks,
wes

 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45., aspect, 0.2, 100);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glTranslatef(0.0, 0.0, -10.);
    glRotatef(-0., 1.0, 0.0, 0.0);

glEnable(GL_POINT_SPRITE);

        glEnable( GL_BLEND );
        glBlendFunc( GL_SRC_ALPHA, GL_ONE );

        glPointSize(100.);
        glPointParameterfARB( GL_POINT_FADE_THRESHOLD_SIZE_ARB, 60.0f );
        glPointParameterf(GL_POINT_SIZE_MIN_ARB, 1);
        glPointParameterf(GL_POINT_SIZE_MAX_ARB, 100);
        glPointSize(100);

        float quadratic[] =  { 1.0f, 0.0f, 0.01f };
    glPointParameterfvARB( GL_POINT_DISTANCE_ATTENUATION_ARB, quadratic );

        ;
        glBegin(GL_POINTS);
        glColor4f(1., 1., 1., 1.);
        for(int j=0; j < data_height; j++) {
                for(int i=0; i < data_width; i++) {
                        glVertex3fv(data + 3*(j*data_width + i));  //a cone
                }
        }
        glEnd();
        glDisable(GL_POINT_SPRITE_ARB);

_______________________________________________
Do not post admin requests to the list. They will be ignored.
Mac-opengl mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/mac-opengl/email@hidden

• Prev by Date: Point Sprites
• Next by Date: Re: Point Sprites
• Previous by thread: Point Sprites
• Next by thread: Re: Point Sprites
• Index(es):
  • Date
  • Thread