make your own graphics libary?

[tomdacat]

For a while now i have been wondering just how opengl and sdl rely
draw graphics to the screen
and how could you do it yourself?
is it rely that hard to make a function to put a pixel
at cord 50, 60?

if anyone knows how to make a very simple graphics libary
then please post a reply
thanks in advance!!

 

[xwb]

Writing to a pixel position: depends on what the hardware is. Sometimes it is just writing values to a couple of ports, sometimes it can be to memory mapped ports. It is probably the same setting the colours. You'll have to talk to the person who designed the hardware.

The graphics library depends on the hardware. Some hardware can draw lines and ellipses, others you have to apply Bresenham's algo to draw the lines and ellipses. On some, you can just write a value to a specific port and it will clear the screen. On others, you have to write to every single pixel.

If you want a simple graphics library, have a look for the Zortech C/C++ compiler. It used to come with the sources for a graphics library.