Erik Hofman <[EMAIL PROTECTED]> writes:
> Alex Romosan wrote:
>> or you can add a call to glEnable(GL_POINT_SPRITE):
>
>> + glEnable(GL_POINT_SPRITE);
>> this allowed me to use GL_POINT_SMOOTH on my nvidia card (enhanced
>> lighting works fine now).
>> i think this would be a better solution (tested only on my nvidia
>> card
>> though).
>
> Ok, I've added support for point sprites. I does indeed increase the
> framerate in my PC. I find this a rather peculiar extension though.
> Especially since SGI has always been using point sprites without
> naming them.
i still think we are papering over a real bug in the fgfs display code
when we enable point sprites. the attached program:
#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h> /* Header File For The OpenGL Library */
#include <GL/glu.h> /* Header File For The GLU Library */
#include <GL/glut.h>
#define NB_PIXELS 1000
void GLUTdraw(void)
{
int i;
int done=0;
GLfloat pixels[NB_PIXELS*3];
for(i=0;i<NB_PIXELS;i++)
{
pixels[3*i]=rand()%250-125;
pixels[3*i+1]=rand()%250-125;
pixels[3*i+2]=rand()%250-125;
}
do
{
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glRotatef(2.0,1.0,1.0,1.0);
glRotatef(1.0,0.0,1.0,1.0);
glColor4ub(255,255,255,255);
glBegin(GL_POINTS);
for(i=0;i<NB_PIXELS;i++)
{
glVertex3f(pixels[3*i],pixels[3*i+1],pixels[3*i+2]);
}
glEnd();
glutSwapBuffers();
}
while(!done);
}
int main(int argc,char *argv[])
{
glutInit(&argc, argv); // initialize the toolkit
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL);
glutInitWindowSize(640,480); // set window size
glutInitWindowPosition(100, 150); // set window position on screen
glutCreateWindow("testgl"); // open the screen window
glutDisplayFunc(GLUTdraw);
glViewport(0,0,640,480);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-100,100,-100,100,-500,500);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_POINT_SMOOTH);
glHint(GL_POINT_SMOOTH_HINT,GL_DONT_CARE);
glPointSize(5.0f);
glutMainLoop();
return 0;
}
enables GL_POINT_SMOOTH and runs just fine on my nvidia card without
the need to enable GL_POINT_SPRITE. so it's something else we do
along the way that gets the driver in a very confused state.
btw, if i understand correctly GL_POINT_SMOOTH is supposed to give you
round points instead of square ones (GL_FASTEST/GL_NICEST hints refer
to the most efficient/correct option, while GL_DONT_CARE means the
client has no preference). GL_POINT_SPRITE will also let you map a
texture across a point sprite if GL_COORD_REPLACE is enabled.
still trying to figure out the real reason why the nvidia driver is
slow when we enable GL_POINT_SMOOTH in fgfs (and learning a lot more
about openGL then i ever wanted to know).
--alex--
--
| I believe the moment is at hand when, by a paranoiac and active |
| advance of the mind, it will be possible (simultaneously with |
| automatism and other passive states) to systematize confusion |
| and thus to help to discredit completely the world of reality. |
