bitmap-clearpixel!

(bitmap-clearpixel! <bitmap> <row> <column>) sets the pixel at the given row and column to zero (white). The bitmap is modified and returned.

[1] (define bitmap (bitmap-create 1 1))
bitmap
[2] (bitmap-clearpixel! bitmap 0 0)
#<bitmap orow:-1 ocol:-1 xres:-1 yres:-1 h:1 w:1>
[3] (bitmap-clearpixel! bitmap 0 1)

ERROR!
  message   : error (dimension?)
  irritant  : #<primitive-procedure bitmap-clearpixel!>
  expression: 1
  continue  : possible, continue with value as value from primitive

Error (? for help) >>