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glPointPerameterf on Linux

Started by jamwaffles Feb 20, 2009 at 5:26 AM 8 replies 1.3k views

Original Post

Feb 20, 2009 at 5:26 AM

hello all i am writing a particle engine in C++/OpenGL and i am using point sprites (oooh clever). everythign works fine, but i can't get the attenuation (particles vary in size according to distance from camera) to work. i am using Linux, and as far as i can gather i need glext to use the extensions contained within that library. i have included it and i have linked to it from my Makefile with the flag -lglext to no avail. i have looked in /usr/include/GL and glext is there with the stuff i need in it, but i have looked in /usr/lib and there is no libglext or anything like it. maybe i should post this on a linux forum, but if youre reading this its too late :P. in short, how can i get point sprite attenuation to work on linux. thankyou to any replies, helpful, funny or just plain annoying, as there is NO documentation on this. another thing, in this closed post http://www.gamedev.net/community/forums/topic.asp?topic_id=403529 it talks about this, but there is no evidence of an extension library being used. can enyone enlighten me? all the same problem really james waples, 14

HuntsMan

Feb 20, 2009 at 5:31 AM

What kind of problem are you getting? Compile error? Link errors?

You should try #defining GLEXT_PROTOTYPES before including gl.h

jamwaffles

Author

jamwaffles

Feb 20, 2009 at 5:35 AM

wow. thanks for the very quick reply :D

i am getting compile errors that say glPointPerameterf has not been defined here

james

jamwaffles

Author

jamwaffles

Feb 20, 2009 at 5:42 AM

oh, and your define thing didnt work. sorry :P

any other ideas?

james

swiftcoder

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2,296

swiftcoder

Feb 20, 2009 at 5:55 AM

You may need a newer copy of glext, and possibly a newer version of your graphics card drivers. However, I would really recommend that you avoid messing with glext entirely, and let a library such as GLEE do it for you.

jamwaffles

Author

jamwaffles

Feb 20, 2009 at 6:09 AM

looks promising :P

jamwaffles

Author

jamwaffles

Feb 20, 2009 at 7:17 AM

i have got it working, sort of. how can i use glPointParameterfv() with something that isnt a GLfloat, but a number like 2.0f or 60.0f

e.g:

float fAtten[4] = { 0.0f, 0.0f, 0.01f };
glPointParameterfv(GL_POINT_SIZE_MIN, 2.0f);
glPointParameterfv(GL_POINT_SIZE_MAX, 60.0f);
glPointParameterfv(GL_POINT_DISTANCE_ATTENUATION_ARB, fAtten);
glPointParameterfv(GL_POINT_FADE_THRESHOLD_SIZE_ARB, 60.0f);

the errors are

japeEngine.cpp: In member function ‘void japeEmitter::drawParticles()’:
japeEngine.cpp:214: error: invalid conversion from ‘int’ to ‘const GLfloat*’
japeEngine.cpp:215: error: invalid conversion from ‘int’ to ‘const GLfloat*’
japeEngine.cpp:217: error: invalid conversion from ‘int’ to ‘const GLfloat*’

jamwaffles

Author

jamwaffles

Feb 20, 2009 at 9:16 AM

sorry to bother you, but i now have glee working - thankyou very very much. could yout tell me how i can change the sizes of the particles please. actually, dont because i can just search these forums and the net. thanks anyway lol

james

swiftcoder

Mod

2,296

swiftcoder

Feb 20, 2009 at 11:12 AM

Quote:
Original post by jamwaffles
i have got it working, sort of. how can i use glPointParameterfv() with something that isnt a GLfloat, but a number like 2.0f or 60.0f

e.g:

float fAtten[4] = { 0.0f, 0.0f, 0.01f };
glPointParameterfv(GL_POINT_SIZE_MIN, 2.0f);
glPointParameterfv(GL_POINT_SIZE_MAX, 60.0f);
glPointParameterfv(GL_POINT_DISTANCE_ATTENUATION_ARB, fAtten);
glPointParameterfv(GL_POINT_FADE_THRESHOLD_SIZE_ARB, 60.0f);

the errors are

japeEngine.cpp: In member function ‘void japeEmitter::drawParticles()’:
japeEngine.cpp:214: error: invalid conversion from ‘int’ to ‘const GLfloat*’
japeEngine.cpp:215: error: invalid conversion from ‘int’ to ‘const GLfloat*’
japeEngine.cpp:217: error: invalid conversion from ‘int’ to ‘const GLfloat*’

The *fv versions of the function take pointers to floats, you probably want glPointParameterf, instead.

jamwaffles

Author

jamwaffles

Feb 21, 2009 at 3:12 AM

yeah. i managed to sort that out - GLee is working perfectly. thankyou very much for the recomendation, it has sorted everything out for me. now all i have to do is collision detection. hard. ah well, google helps. thanks again

james

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