Simple form with pixel manipulation

[Mohsen Jamali]

Hi guys,
i'm a c programmer and have not work with opengl at all!
i want to create a 800X600 window that just show some circle and be able to manipulate pixels of the form every milisecond and show the result to the user. there is no interaction between user and form(no click, no dblclick,…) it just shows some circles with one color and lines with different pixel colors(each line may have different pixel colors)
also i want to be able to change the coordination system, i mean change it from top-left to the center of the window. could anyone help me do that with some sample code? links? tutorial?
all replies are greatly appreciated.
thanks.

[menzel]

Beside OpenGL you will need a window toolkit to open an OpenGL context, check if your preferred toolkit (win32, GTK, QT, Cocoa) for your OS has OpenGL samples to begin with.

I guess changing the image every millisecond isn't meant literally? Because you would need a very fast display for that, 60Hz TFTs are more common (70Hz TFTs exist, CRTs can often go to 120Hz).


Tutorials:

http://www.arcsynthesis.org/gltut/
http://duriansoftware.com/joe/An-int...-Contents.html

[Mohsen Jamali]

Beside OpenGL you will need a window toolkit to open an OpenGL context, check if your preferred toolkit (win32, GTK, QT, Cocoa) for your OS has OpenGL samples to begin with.

don't these toolkits reduce the performance?

I guess changing the image every millisecond isn't meant literally? Because you would need a very fast display for that, 60Hz TFTs are more common (70Hz TFTs exist, CRTs can often go to 120Hz).

i mean every milisecond some pixels change, a line for example, about 300 pixels

Tutorials:

http://www.arcsynthesis.org/gltut/
http://duriansoftware.com/joe/An-int...-Contents.html

good tutorials, thanks.

[ZbuffeR]

I guess changing the image every millisecond isn't meant literally? Because you would need a very fast display for that, 60Hz TFTs are more common (70Hz TFTs exist, CRTs can often go to 120Hz).

i mean every milisecond some pixels change, a line for example, about 300 pixels

Every millisecond is not possible.
Current LCD screen are 60hz (16.667 ms per frame), 120hz ("3D" screens) cost more (8.333ms).

[menzel]

don't these toolkits reduce the performance?

Not necessarily. Beside: Cou just can't open an 'raw' OpenGL window with no help of any window toolkit.

i mean every milisecond some pixels change, a line for example, about 300 pixels

You might be able to change a buffer every millisecond, but you will only be possible to display 60 different renderings per second.

[Mohsen Jamali]

i mean every milisecond some pixels change, a line for example, about 300 pixels

You might be able to change a buffer every millisecond, but you will only be possible to display 60 different renderings per second. [/QUOTE]

I think you are right, i should change the bauffer, do the window toolkits allow direct acceess to buffer?