nanogui: Thread: Pixmaps

Greg Haerr ####@####.#### writes:

   >    > 		   IMAGEBITS bits[];
   >    > 		   // image data here, optionally followed by color data
   >    > 
   >    > Make it a pointer, not an array.  Otherwise, how can you make a bitmap
   >    > that's part of the screen?
   > 
   > Again, that won't work for bpp < 8.  Fsck fsck fsck.

	   Sure it will.  The imagebits are then just piled in right next to each other,
   as they say "imagebits are imagebits"...  ;-)

Suppose you have a 1-bit depth bitmap.  With a byte-granular quantity
(i.e., line_len, etc.), how can you specify a non-byte-aligned
subbitmap?  You can't.  So if you want to support subbitmaps you have
to use pixel offsets, not byte offsets, which isn't as simple.
-- 
"To the engineer, the world is a toy box full of sub-optimized and
 feature-poor toys." --Scott Adams

> Suppose you have a 1-bit depth bitmap.  With a byte-granular quantity
> (i.e., line_len, etc.), how can you specify a non-byte-aligned
> subbitmap?  You can't.  So if you want to support subbitmaps you have
> to use pixel offsets, not byte offsets, which isn't as simple.
> 

Ah yes, I figured you were going to comment on my quick comment.
This can be solved by adding 

	COORD x,y;

which are the viewpoint's initial starting positions, relative to the bitmap
origin, in pixel units.  This is used to create the starting mask and/or pixel
offset, much like the original bitmap will have to if required to blt to a screen
pixel address...