adafruit/Adafruit-GFX-Library — pull request #9 by schlammbad (2013-02-22 20:09:23+00:00)
Title: Added drawBitmap overload with background color support.

In order to update in-place bitmaps to minimize flickering caused by separate erase and draw cycles, I added a simple overload to the drawBitmap function that accepts a background color as an additional parameter. This allows one bitmap to visual replace another on a screen without first erasing the area.