.. index:: graphics


Graphics
========


STM32F0xx
---------
Calculation of location in image buffer should be quick but on M0 there is no division opcode in hardware.

Better use
::

 3 RSHIFT
 7 AND

Instead of 
::

 8 /
 8 MOD

Then OR the bits into the image buffer, so that you do not "unset" the adjacent pixels.

Pixels
------
Use CBIS! to write a single pixel in the frame buffer. and CBIC! to clear a single pixel.
::

 not and

is used in cbic! for clearing a bit. xor to toggle it.