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View Full Version : confused pre-opengl beginner question: about OpenGl 2.x vs 4.x



Maleachi
07-13-2013, 01:29 PM
I startet lerning DirectX and wasnīt sadisfied...
So i wanted to switch to OpenGL.

but there are two Questions that i canīt find an Answer for.
1.) if i create a Programm that should have a wide target range, i would use DirectX 9. But on OpenGL, as far as i know, would that be OpenGL 2.x, but the context in writing changed a lot with 3.x... so, should i lern 2.x and start again lerning 3.x/4.x when i decide to write a program with a more modern look?
Or is it possible to use OpenGL 4.3 and write a context that 2.x compatible?

2.) On Windows XP DirectX is limited to version 9, but does this limitation is the same for Opengl?
If the drivers and the Grafikcard are supporting OpenGL 3.x or 4.x, then it should be possible, or am I wrong?

sorry for my bad english... i had an hard day reading... and english isīnt my natural language.

tonyo_au
07-13-2013, 08:04 PM
You should learn the newest version of OpenGL. You are unlikely to find a graphics card now that does not support 3.x; 4.0 is very common but 4.3 is not yet that common. OpenGL is not limited by the operating system (as it is cross-platform). It is limited by the graphics hardware and the driver installed.

GClements
07-14-2013, 05:00 AM
2.) On Windows XP DirectX is limited to version 9, but does this limitation is the same for Opengl?
No. The only limitation is what the hardware and driver support. E.g. the latest nVidia cards support OpenGL 4.3 on Windows XP, Vista, 7 and 8. AMD cards support OpenGL 4.2 on the same platforms.
Eventually the vendors will stop shipping drivers for XP, but as long as the drivers exist, you can expect them to support the same version of OpenGL regardless of the OS version.

Aleksandar
07-14-2013, 05:54 AM
if i create a Programm that should have a wide target range, i would use DirectX 9. But on OpenGL, as far as i know, would that be OpenGL 2.x, but the context in writing changed a lot with 3.x... so, should i lern 2.x and start again lerning 3.x/4.x when i decide to write a program with a more modern look?
At the beginning we should define a wide range of hardware. If we assume NV HW, then all cards up to 7 years back in the past support OpenGL 3.3 (from NV80). Of course, with the drivers not older than few years. If we assume AMD HW, then all cards up to 6 years back in the past support OpenGL 3.3 (from R600). But if we assume Intel's HW, then the situation is much worse. The common denominator for the last 3 years HW is OpenGL 1.4! For example GMA 3150 in Atom D4xxx/D5xxx/N4xxx/N5xxx is such GPU.


Or is it possible to use OpenGL 4.3 and write a context that 2.x compatible?
You cannot use new features if the drivers/hardware don't support it.


On Windows XP DirectX is limited to version 9, but does this limitation is the same for Opengl?
If the drivers and the Grafikcard are supporting OpenGL 3.x or 4.x, then it should be possible, or am I wrong?
As others have already said, on NV HW you can use OpenGL 4.3 if it is Fermi or newer, or 3.3 if it is 8xxx or newer (with most of the features from the newer versions as extensions). On AMD HD 7xxx or newer you can use OpenGL 4.2. On Intel HD2500/4000 or newer, you can use OpenGL 4.0 but only on Windows7/8 as far as I know.

Maleachi
07-14-2013, 10:36 AM
Wow, thanks for the replies! Now i understanding it better.
I will start with 3.3 and see what the future brings.