hi, i'm trying to draw pixels in a bitmap. first i'm allocating a NSBitmapImageRep: def awakeFromNib @nsBitmapImageRepObj = NSBitmapImageRep.alloc.initWithBitmapDataPlanes nil, pixelsWide:@nsRectFrameRect.size.width, pixelsHigh:@nsRectFrameRect.size.height, bitsPerSample:8, samplesPerPixel:3, hasAlpha:false, isPlanar:false, colorSpaceName:"NSCalibratedRGBColorSpace", bytesPerRow:0, bitsPerPixel:0 end i can in fact write pixels if i use the setPixel method: def drawBitmap xs = 255.0/@nsRectFrameRect.size.width ys = 255.0/@nsRectFrameRect.size.height 0.upto @nsRectFrameRect.size.height do |y| 0.upto @nsRectFrameRect.size.width do |x| color = [x*xs,y*ys,0] @nsBitmapImageRepObj.setPixel color, atX:x, y:y end end setNeedsDisplay true end however, i can't figure out how to write directly to the bitmap. bitmapData returns a pointer to the allocated memery, but how do i write to it? @nsBitmapImageRepObj.bitmapData[0] = 255 # => can't convert Fixnum into String (TypeError) @nsBitmapImageRepObj.bitmapData[1] = '\255' # => index 1 out of string (IndexError) documentation states that bitmapData returns an unsigned char*, but when ruby seems to think it's a string with length zero. do i need to use the Pointer class? searching for 'pixel' here on the list revelealed this post by julien jassaud back in dec 2009:

I also had a problem with function NSBitmapImageRep. Again, a pointer problem. Having an NSBitmapImageRep, the function bitmapData returns an (unsigned char *) but in MacRuby, it returns an empty string. The workaround was to create the class in an Objective C bundle.

any news on this issue? thanks in advance, emil tin