I have loose a point in Opengl, please help me!

[TempodiBasic]

Hi guys
please test and correct my code to get the same result in normal graphic mode and in openg mode-
It seems that with my code I loose some point (I hope not loosing the point) on Opengl.
Please run the code at a first time, then change the value of _glpointsize and run again. Do you see any differences?

Code: QB64: [Select]

1. DIM SHARED GlInit AS INTEGER, s AS SINGLE, Glactive AS INTEGER
2. DIM A AS LONG, i AS SINGLE, r AS SINGLE, x AS SINGLE, y AS SINGLE
3.  
4. A = _NEWIMAGE(800, 600, 32)
5.  
6. SCREEN A
7. GlInit = 0
8. Glactive = 0
9. r = 50
10. x = 400
11. y = 300
12. COLOR _RGB32(200, 200, 10, 255)
13. PRINT "Standard graphic mode"
14. SLEEP 2
15. FOR z = 4 TO 8
16.     CLS
17.     s = _PI(2) / z
18.     FOR i = 0 TO _PI(2) STEP s
19.         cx = (COS(i) * r) + x
20.         cy = (SIN(i) * r) + y
21.         PSET (cx, cy)
22.     NEXT i
23.     '  _DISPLAY
24.     SLEEP 1
25. NEXT z
26. '_AUTODISPLAY
27. PRINT "Opengl graphic mode"
28. _DELAY 2: CLS
29. GlInit = -1
30. Glactive = -1
31. FOR z = 4 TO 8
32.     s = _PI(2) / z
33.     _DELAY 1
34. NEXT
35. PRINT " End of demo"
36. END
37.  
38.  
39.  
40.  
41.  
42. 'area GL --------------------
43. SUB _GL ()
44.     IF NOT Glactive THEN EXIT SUB
45.     IF GlInit THEN
46.         _glViewport 0, 0, _WIDTH, _HEIGHT
47.         _glClearColor 0, 0, 0, 1
48.         GlInit = 0
49.     END IF
50.     _glClear _GL_COLOR_BUFFER_BIT
51.     drawpoint 0.1, 0.2, .4
52.  
53.     _glFlush
54. END SUB
55.  
56. SUB drawpoint (x AS SINGLE, y AS SINGLE, r AS SINGLE)
57.     DIM i, cx AS SINGLE, cy AS SINGLE
58.     _glColor4f 0.8, 8, 0.1, 1.0
59.     _glPointSize 1 ' it works with 2 or more !
60.     _glBegin _GL_POINTS
61.     LOCATE 1, 1
62.     FOR i = 0 TO _PI(2) STEP s
63.         cx = (COS(i) * r) + x
64.         cy = (SIN(i) * r) + y
65.         _glVertex2f cx, cy
66.     NEXT i
67.     _glEnd
68. END SUB
69.  

Can you help me to find my mistake? Thanks for feedbacks

[Kernelpanic]

"glPointSize = 1":
In OpenGL mode, only 4 points are displayed on the first screen and only 2 points on the second.

With "glPointSize = 3" all eight points are there.

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[TempodiBasic]

Interesting results... it seems that _glpoint is dipendent to the video card of the pc on which it is running the program!
Please test also this code to compare the results
https://www.qb64.org/forum/index.php?topic=3254.msg125337#msg125337
Thanks for feedback

[Kernelpanic]

Result see there:

https://www.qb64.org/forum/index.php?topic=3254.msg125337#msg125337

[TempodiBasic]

Thanks
Kernelpanic
I think that these our results can be useful to developers of QB64 that work on Opengl.

[Kernelpanic]

TempoDiBasic, You are welcome. That would be good for development of course.