MISC questions about OpenGL

Silvercord · 01-18-2003, 11:56 PM

How long as OpenGL been around for? Who wrote OpenGL? How many years (from start to finish) did it take? Was it written with Assembly or some type of low level programming?

I've been reading up on how John Carmack is doing Shadow volumes, and I am thorougly impressed, but instead of doing all of those different tests and having to draw into the stencil buffer and all that crap, why not just modify the OpenGL api (not like that would be easy or anything) so that when the color of the light is calculated you shoot a ray from the pixel being drawn to all of the light sources. If shadowing is enabled, if the ray intersects other objects before it gets to the light source(s), the color intensities from that blocked light don't enter into the equation that determines the color of that pixel (and of course if all light sources are blocked, it's black, or blended black if smooth shading is being used or something).

Some other graphics-related questions:
How are the colors of the pixels on the monitor controlled? I mean if you are writing a graphics library that is open across all platforms then there must be some sort of embedded system type development that goes into creating those routines that actually light up the pixels, right? I mean lets say I wake up one morning and I'm feeling really horny and I decide I want to try to draw pixels without using ANY existing api (no win32 or ogl or directcrap).

Ok anyone who helps me is cool.

EDIT: OMG I can't find anything on who actually made OpenGL. Whenever I type in anything to the effect of "creators of opengl" or "makers of opengl" or something it always comes up with OTHER frickin people that made games using opengl, not the writers of the api itself!! GOOGLE IS DUM

01-19-2003, 12:20 AM

http://www.opengl.org

Silvercord · 01-19-2003, 12:36 AM

Where does it say who made opengl and how long it took and all those other 800,000 questions I asked? I am looking in the 'about' section but it doesn't get into any of that stuff, although this is interesting nonetheless

EDIT: And all I really care about is the last two thirds of my post (about the shadows and low level pixel commands)

EDIT1: I was able to find taht OpenGL has been around since 1992

RoD · 01-19-2003, 07:45 AM

Hi man, here try this on for size:

OpenGL was originally developed by Silicon Graphics, Inc, (SGI) as a multi-purpose, platform independent graphics API. This was in 1992. Since 1992 the development of OpenGL has been overseen by the OpenGL Architecture Review Board, or ARB.

Silvercord · 01-19-2003, 07:53 AM

Quote:

Hi man, here try this on for size:

OpenGL was originally developed by Silicon Graphics, Inc, (SGI) as a multi-purpose, platform independent graphics API. This was in 1992. Since 1992 the development of OpenGL has been overseen by the OpenGL Architecture Review Board, or ARB.

sweet I didn't know that. It would be wicked cool to work on the ogl ARB! Now how can something be 'truly' platform independant? When you get right down to it it all depends on the library installed on your system, and whether or not you by chance have the correct one that will work with your system. Umm...yeah...I don't know what I'm talking about but thanks!

RoD · 01-19-2003, 08:02 AM

Have a read, grasshopper : )

http://www.linuxfocus.org/English/Ja...article15.html

http://www.opengl.org/developers/code/tutorials.html

http://www.gametutorials.com/Tutorials/opengl

http://www.frii.com/~martz/oglfaq/gettingstarted.htm

http://www.xmission.com/~nate/tutors.html

http://cg.cs.uni-bonn.de/personal-pa...er/opengl.html

http://vblinks.netfirms.com/advance/index.htm

http://www.opengl.org/developers/code/sig99/index.html

Travis Dane · 01-19-2003, 08:21 AM

Yeah, John Carmack did a real good job in making OpenGL
famous, if it wasn't for him who knows (whe might have been
totally switched over to direct3d

).

Basicelly Direct3d 9 can do everything OpenGL can,
so you should pick an API depending on how you like to program.
Choose your style

Google rocks! OpenGL Saves!

RoD · 01-19-2003, 08:24 AM

Welcome to DirectDoodle!

Yea umm ok, opengl forever!

Silvercord · 01-19-2003, 11:31 AM

When you get right down to it the apis have to be more of less the same, because all a graphics api amounts to is determining the colors of pixels, the process to get there may be dfferent. OpenGL naturally seems like a beter choice because they tried to make it cross platform. That and OpenGL has ran faster on every video card I've used.

Travis Dane · 01-19-2003, 01:09 PM

Quote:

Originally posted by Silvercord
That and OpenGL has ran faster on every video card I've used.

Compared to Direct3D? Wich Version? And in wich Game?

no-one · 01-19-2003, 04:52 PM

>How long as OpenGL been around for?

technically since 92, but is father so to speak is IrisGL and has been around much longer.

>
Who wrote OpenGL? How many years (from start to finish) did it take?
<

well since theres no one implemention, a lot of different companies did it seperatly, including Microsoft, SGI, ATI, nVidia, 3D-Labs, etc.. etc..

>
Was it written with Assembly or some type of low level programming?
<

ask your videocard vendor. though OpenGL's software render is usually C.

>
I've been reading up on how John Carmack is doing Shadow volumes, and I am thorougly impressed, but instead of doing all of those different tests and having to draw into the stencil buffer and all that crap, why not just modify the OpenGL api (not like that would be easy or anything) so that when the color of the light is calculated you shoot a ray from the pixel being drawn to all of the light sources. If shadowing is enabled, if the ray intersects other objects before it gets to the light source(s), the color intensities from that blocked light don't enter into the equation that determines the color of that pixel (and of course if all light sources are blocked, it's black, or blended black if smooth shading is being used or something).
<

because this would defy one of the design goals of OpenGL(ie. keep it is low level as possible to grant the user the most control of rendering possible. this is why OpenGL supports only primative rendering(ie. points, lines, polygons, ect...)).

>How are the colors of the pixels on the monitor controlled?

honestly i don't feel up to explaining this, just read up on videocards and monitors or something.

>
I mean if you are writing a graphics library that is open across all platforms then there must be some sort of embedded system type development that goes into creating those routines that actually light up the pixels, right?
mean lets say I wake up one morning and I'm feeling really horny and I decide I want to try to draw pixels without using ANY existing api (no win32 or ogl or directcrap).
<

this is done by the vendor through ancient black magic. nah,
this is not a problem in OpenGL since it is implemented by the vendor(ATI, nVidia, etc...) for the platform. OpenGL is just a written standard, there is no standard or one implementation.

edit:

>
When you get right down to it the apis have to be more of less the same, because all a graphics api amounts to is determining the colors of pixels, the process to get there may be dfferent.
<

well yes and NO.

>
OpenGL naturally seems like a beter choice because they tried to make it cross platform.
<

they did, and thats subject to opinion. ie people who like direct-x dont care.

>That and OpenGL has ran faster on every video card I've used.

usually this is the case with a decent renderer, but speed is subject to so many things other than the API it is hard to say per card sometimes.

Silvercord · 01-25-2003, 02:22 PM

Would it make sense for real time shadows to be added in the opengl utilities library in the way that I suggested? It already contains other high level functions that are a part of the api, and shadow casting seems like it should be one of those things that can realistically be added to a graphics api.

I'm not complaining btw, I'm just wondering and questioning. Also, wasn't Irix an operating system? I need to do more reading up on IrisGL.

no-one · 01-25-2003, 04:20 PM

>
Would it make sense for real time shadows to be added in the opengl utilities library in the way that I suggested?
<

Well let me first say i mis-understood your original post so the first response was a little off,

I guess you could use the OpenGL 1.4+ shaders for something like that now, but you have to have a heafty card to use them, not to mention a new one for HW acceleration.

> Also, wasn't Irix an operating system?

yes, and it still is.

> I need to do more reading up on IrisGL.

there's not a lot of widely available info on it, but there's some interesting history on OpenGL here.

http://www.opengl.org/developers/faq...al/oglhist.txt

01-18-2003, 11:56 PM	#1
Silvercord Banned Join Date: Jan 2003 Posts: 1,708	MISC questions about OpenGL How long as OpenGL been around for? Who wrote OpenGL? How many years (from start to finish) did it take? Was it written with Assembly or some type of low level programming? I've been reading up on how John Carmack is doing Shadow volumes, and I am thorougly impressed, but instead of doing all of those different tests and having to draw into the stencil buffer and all that crap, why not just modify the OpenGL api (not like that would be easy or anything) so that when the color of the light is calculated you shoot a ray from the pixel being drawn to all of the light sources. If shadowing is enabled, if the ray intersects other objects before it gets to the light source(s), the color intensities from that blocked light don't enter into the equation that determines the color of that pixel (and of course if all light sources are blocked, it's black, or blended black if smooth shading is being used or something). Some other graphics-related questions: How are the colors of the pixels on the monitor controlled? I mean if you are writing a graphics library that is open across all platforms then there must be some sort of embedded system type development that goes into creating those routines that actually light up the pixels, right? I mean lets say I wake up one morning and I'm feeling really horny and I decide I want to try to draw pixels without using ANY existing api (no win32 or ogl or directcrap). Ok anyone who helps me is cool. EDIT: OMG I can't find anything on who actually made OpenGL. Whenever I type in anything to the effect of "creators of opengl" or "makers of opengl" or something it always comes up with OTHER frickin people that made games using opengl, not the writers of the api itself!! GOOGLE IS DUM Last edited by Silvercord; 01-19-2003 at 12:11 AM.
Silvercord is offline

01-19-2003, 12:36 AM	#3
Silvercord Banned Join Date: Jan 2003 Posts: 1,708	Where does it say who made opengl and how long it took and all those other 800,000 questions I asked? I am looking in the 'about' section but it doesn't get into any of that stuff, although this is interesting nonetheless EDIT: And all I really care about is the last two thirds of my post (about the shadows and low level pixel commands) EDIT1: I was able to find taht OpenGL has been around since 1992 Last edited by Silvercord; 01-19-2003 at 12:53 AM.
Silvercord is offline

01-19-2003, 07:45 AM	#4
RoD Banned Join Date: Sep 2002 Posts: 6,334	Hi man, here try this on for size: OpenGL was originally developed by Silicon Graphics, Inc, (SGI) as a multi-purpose, platform independent graphics API. This was in 1992. Since 1992 the development of OpenGL has been overseen by the OpenGL Architecture Review Board, or ARB.
RoD is offline

01-19-2003, 08:02 AM	#6
RoD Banned Join Date: Sep 2002 Posts: 6,334	Have a read, grasshopper : ) http://www.linuxfocus.org/English/Ja...article15.html http://www.opengl.org/developers/code/tutorials.html http://www.gametutorials.com/Tutorials/opengl http://www.frii.com/~martz/oglfaq/gettingstarted.htm http://www.xmission.com/~nate/tutors.html http://cg.cs.uni-bonn.de/personal-pa...er/opengl.html http://vblinks.netfirms.com/advance/index.htm http://www.opengl.org/developers/code/sig99/index.html Last edited by RoD; 01-19-2003 at 08:06 AM.
RoD is offline

01-19-2003, 08:21 AM	#7
Travis Dane Registered User Join Date: Sep 2002 Posts: 1,640	Yeah, John Carmack did a real good job in making OpenGL famous, if it wasn't for him who knows (whe might have been totally switched over to direct3d ). Basicelly Direct3d 9 can do everything OpenGL can, so you should pick an API depending on how you like to program. Choose your style Google rocks! OpenGL Saves!
Travis Dane is offline

01-19-2003, 12:20 AM	#2
blah Guest Posts: n/a	http://www.opengl.org

01-19-2003, 08:24 AM	#8
RoD Banned Join Date: Sep 2002 Posts: 6,334	Welcome to DirectDoodle! Yea umm ok, opengl forever!
RoD is offline

01-19-2003, 11:31 AM	#9
Silvercord Banned Join Date: Jan 2003 Posts: 1,708	When you get right down to it the apis have to be more of less the same, because all a graphics api amounts to is determining the colors of pixels, the process to get there may be dfferent. OpenGL naturally seems like a beter choice because they tried to make it cross platform. That and OpenGL has ran faster on every video card I've used.
Silvercord is offline

01-19-2003, 04:52 PM	#11
no-one Has a Masters in B.S. Join Date: Aug 2001 Posts: 2,267	>How long as OpenGL been around for? technically since 92, but is father so to speak is IrisGL and has been around much longer. > Who wrote OpenGL? How many years (from start to finish) did it take? < well since theres no one implemention, a lot of different companies did it seperatly, including Microsoft, SGI, ATI, nVidia, 3D-Labs, etc.. etc.. > Was it written with Assembly or some type of low level programming? < ask your videocard vendor. though OpenGL's software render is usually C. > I've been reading up on how John Carmack is doing Shadow volumes, and I am thorougly impressed, but instead of doing all of those different tests and having to draw into the stencil buffer and all that crap, why not just modify the OpenGL api (not like that would be easy or anything) so that when the color of the light is calculated you shoot a ray from the pixel being drawn to all of the light sources. If shadowing is enabled, if the ray intersects other objects before it gets to the light source(s), the color intensities from that blocked light don't enter into the equation that determines the color of that pixel (and of course if all light sources are blocked, it's black, or blended black if smooth shading is being used or something). < because this would defy one of the design goals of OpenGL(ie. keep it is low level as possible to grant the user the most control of rendering possible. this is why OpenGL supports only primative rendering(ie. points, lines, polygons, ect...)). >How are the colors of the pixels on the monitor controlled? honestly i don't feel up to explaining this, just read up on videocards and monitors or something. > I mean if you are writing a graphics library that is open across all platforms then there must be some sort of embedded system type development that goes into creating those routines that actually light up the pixels, right? mean lets say I wake up one morning and I'm feeling really horny and I decide I want to try to draw pixels without using ANY existing api (no win32 or ogl or directcrap). < this is done by the vendor through ancient black magic. nah, this is not a problem in OpenGL since it is implemented by the vendor(ATI, nVidia, etc...) for the platform. OpenGL is just a written standard, there is no standard or one implementation. edit: > When you get right down to it the apis have to be more of less the same, because all a graphics api amounts to is determining the colors of pixels, the process to get there may be dfferent. < well yes and NO. > OpenGL naturally seems like a beter choice because they tried to make it cross platform. < they did, and thats subject to opinion. ie people who like direct-x dont care. >That and OpenGL has ran faster on every video card I've used. usually this is the case with a decent renderer, but speed is subject to so many things other than the API it is hard to say per card sometimes. __________________ ADVISORY: This users posts are rated CP-MA, for Mature Audiences only. Last edited by no-one; 01-19-2003 at 04:57 PM.
no-one is offline

01-25-2003, 02:22 PM	#12
Silvercord Banned Join Date: Jan 2003 Posts: 1,708	Would it make sense for real time shadows to be added in the opengl utilities library in the way that I suggested? It already contains other high level functions that are a part of the api, and shadow casting seems like it should be one of those things that can realistically be added to a graphics api. I'm not complaining btw, I'm just wondering and questioning. Also, wasn't Irix an operating system? I need to do more reading up on IrisGL.
Silvercord is offline

01-25-2003, 04:20 PM	#13
no-one Has a Masters in B.S. Join Date: Aug 2001 Posts: 2,267	> Would it make sense for real time shadows to be added in the opengl utilities library in the way that I suggested? < Well let me first say i mis-understood your original post so the first response was a little off, I guess you could use the OpenGL 1.4+ shaders for something like that now, but you have to have a heafty card to use them, not to mention a new one for HW acceleration. > Also, wasn't Irix an operating system? yes, and it still is. > I need to do more reading up on IrisGL. there's not a lot of widely available info on it, but there's some interesting history on OpenGL here. http://www.opengl.org/developers/faq...al/oglhist.txt __________________ ADVISORY: This users posts are rated CP-MA, for Mature Audiences only.
no-one is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
OpenGl questions	Shadowwoelf	Windows Programming	4	06-20-2007 05:35 PM
lots of questions about opengl	n3v	Game Programming	9	07-01-2006 07:32 AM
OpenGL Window	Morgul	Game Programming	1	05-15-2005 12:34 PM
OpenGL Transparency Questions	Dante Shamest	Game Programming	7	03-26-2005 05:59 PM
OpenGL .dll vs video card dll	Silvercord	Game Programming	14	02-12-2003 07:57 PM