math or library for converting commands into bitmap array

Hi, I'm using a arduino and high speed adc for an oscilloscope. Problem is high speed printing. I can not use a parallel interface to the display as I'm using majority of all the other pins already. I currently use a spark fun GLCD controller. I also just bought some Digole GLCD controllers with the same issues. I used the Digole display controller with a 400 kHz i2c bus which I thought would help but did not. The problem now is the display controller and its abilities.

I can print a whole image faster then I can togglepixel / drawline through a scan cycle.Is there any code or method for creating a Bitmap array by using commands like (drawline, toggle pixel) or simple math?

http://playground.arduino.cc/Code/GLCDks0108