(This is a repost of an old blog post of mine from Teknik.)

#qtools #qt #common-lisp

I looked for a quick way of turning vectors of uint8s into Qtools's QImages for purpose of displaying them.

This is a quick macro that I hacked up to do the job.

;;; (ql:quickload :qtools)

(defmacro with-qimage-from-vector ((image-var vector width height) &body body)
  "Establishes a lexical environment, in which IMAGE-VAR is bound to a QImage
created from the ARGB contents of VECTOR, with width WIDTH and height HEIGHT."
  (with-gensyms (length v)
    `(let* ((,length (array-dimension ,vector 0))
            (,v (make-static-vector ,length :initial-contents vector)))
       (unwind-protect
            (with-finalizing
                ((,image-var (q+:make-qimage
                              (static-vector-pointer ,v)
                              ,width ,height
                              (q+:qimage.format_argb32))))
              ,@body)
         (free-static-vector ,v)))))