🚀 go-pugleaf

I've been thinking about how to write a color pixel pattern to VGA
screen AND setting the background color in one pass, so I am posting
this as a challenge.

Objective: write a bicolor pattern to a rectangular area on a VGA
  graphic screen according to a bitmap, where a bitmap value of 1 
  denotes a pixel color of COLOR1 and a bit value of 0 denotes color 
  COLOR0, using the smallest possible number of access to the video 
  memory.

You may make the following assumptions:
  (0) the screen is in 16 color mode;
  (1) the rectangular area does not cross byte boundary;
  (2) the pallette registers are BIOS default, which means you can
use the color values directly as map masks if needed;

Do not make any assumption regarding the actual values of COLOR1
and COLOR0.

You can use everything the standard VGA spec provides, but probably
should restrict yourself to the following registers: map mask, set-reset, 
enable set-reset, data rotate, (write) mode, bit mask and latch.

You probably don't want to post anything that requires two writes
for each 8 pixels for that would be too easy (unless you think it
is genuinely creactive.)

Let the net be the judge (and the work be the reward.)


  Ya-Gui Wei