cristian-5 / pixelfuck

brainfuck dialect for pixel pictures

pixelfuck

⚠️ This is in early stages of development ⚠️
Write programs for a pixel display ❤️.

Specifications

The programs can be written in a stack-based variant of brainfuck 🤬 that I named pixelfuck. The operations are performed on a stack while the output can be displayed in a $16 \times 16$ grid of virtual pixels 🚨.

Colours

The LEDs can range from 0 to F in hexadecimal, mapped to the castpixel-16 color palette from top to bottom, left to right.

Since the memory cells are 8-bits wide, the highest 4 bits will be used for colour transparency. The lowest 4 bits will be used for the colour index. For example, 0x0F is the color F with no transparency (which means is 100% visible), while 0x8E is the color E with 8 / 16 transparency (which means is only 50% visible). If you want to use a solid colour just after the grid has been prepared / reset, you won't need to set a full byte, you can just set the lowest 4 bits like this: E.

The display will be updated on every output operation (.). Display memory wraps around. Any program running for more than 5 seconds will be stopped.

To allow for faster and cooler programs, there are a few extra features allowed as a language extension:

C	Meaning
`	Duplicate stack top.
°	Push stack top colour into current cell.
,	Push 0 onto the stack.
.	Sets the current cell to the specified value.
:	Push value onto the stack.
;	Output a frame on the display.
?	Pushes current cell colour onto the stack.
"	Increment stack top.
'	Decrement stack top.
+	Pops twice and pushes the addition result.
-	Pops twice and pushes the subtraction result.
*	Pops twice and pushes the multiplication result.
/	Pops twice and pushes the division result.
%	Pops twice and pushes the modulus result.
&	Pops twice and pushes the and result.
|	Pops twice and pushes the or result.
!	Flip the current stack top value.
@	Set delay for the next frames to stack top.
$	Pops and discards the top stack value.
#	Pops and sets the current cell pointer.
=	Pops and sets the current cell data.
<	Move display tape head left ($x - 1$).
>	Move display tape head right ($x + 1$).
^	Move display tape head up ($y - 1$).
_	Move display tape head down ($y + 1$).
[	Jump past matching ] if stack top holds 0.
]	Jump back to matching [ if stack top is not 0.
\	Resets the whole grid to the values F0.
§	Halt the program early.

For practical reasons, you can loop with (), [] and {}.

Data and Pointer Manipulation

You can set a cell to a specific value by using . which will pop the value off the stack and set it in the current cell. For example, 0F. will set the current cell to 15. This is done through subsequent 4 bit shifts and or operations.

You can manipulate the current cell pointer by subfixing the hexadecimal pointer with #. For example, A0:# will set the current cell pointer to [ 10, 0 ] where the first value is the x coordinate and the second value is the y coordinate. The display position [ 0, 0 ] is the top left corner.

Delay and Output

The delay operator @ can be used to set the delay between frames. The delay is a hexadecimal value from 0 to F and it will be multiplied by 200ms. For example, F:@ will set the delay to 3.2s.