fix this shit code

[dataf3l]

Original	Improved	Reason
b	buffer	More descriptive of the data structure.
c	glyph or character	Avoids confusion with standard "C" language keywords/types.
x, y	pos_x, pos_y	Clarifies these are position coordinates.
x_1, y_1	start_x, start_y	Indicates the beginning of a line or path.
x_2, y_2	end_x, end_y	Indicates the conclusion of a line or path.
color	fg_color	Consistency across functions; explicitly denotes foreground.
i, j	row, col	In 2D loops, these clarify which axis is being iterated.
err, e2	error_margin, error_step	Makes Bresenham’s algorithm logic more readable.