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Aliii
08-17-2014, 07:22 AM
Im trying to get the maximum allowed size for points.



float sizes[2];
glGetFloatv( GL_POINT_SIZE_RANGE, sizes);

It says 1.0 and 63.375. Now thats not true, I can set it to 500 and it works. Why Im I getting 63? Thanks

Ruggero Visitnin
08-22-2014, 03:48 AM
ok i found it in microsoft references:


Not all sizes are supported when point antialiasing is enabled. If an unsupported size is requested, the nearest supported size is used. Only size 1.0 is guaranteed to be supported; others depend on the implementation. The range of supported sizes and the size difference between supported sizes within the range can be queried by calling glGet with arguments GL_POINT_SIZE_RANGE and GL_POINT_SIZE_GRANULARITY.


so if you set 500 the program uses 63 value because is the nearest supported size, hope you learnd ;)

Aliii
08-22-2014, 04:56 AM
I dont really get it. I set it to 500 with glPointSize( 500) ...if I querry the current size, it says 500. Also it draws it 500 pixels wide. It just says that the range is from 1 to 63.

Ruggero Visitnin
08-22-2014, 05:17 AM
I dont really get it. I set it to 500 with glPointSize( 500) ...if I querry the current size, it says 500. Also it draws it 500 pixels wide. It just says that the range is from 1 to 63.

i tried to do what your code have to do and the result is that if i set glPointSize(500.0f) i get i max size of about 189 from glGetFloatv(GL_POINT_SIZE_RANGE, sizes);
so i think the point is that you should not set a size grater then your max size, i suppose. i can't really think an other way to interpret it

ok i fugured out, i read again the reference and i found that GL_POINT_SIZE_RANGE works only when anti-aliasing is applied, so if you want to apply anti_alising, your point' size will be maximum about 63

Aliii
08-22-2014, 06:28 AM
Thanks! Thats OK then, Im using shaders. It was just strange.

Im putting it here if anybody else runs into this:
"Non-antialiased point size may be clamped to an implementation-dependent maximum. Although this maximum cannot be queried, it must be no less than the maximum value for antialiased points, rounded to the nearest integer value."