Forum: wxRuby direct painting on bitmap

Hi, All -

I've been getting closer and closer to a raw painting interface (see 
'Inserting
RMagick RVG images in wxRuby' for my starting point) and now what I'm
working on (yes, I'm getting paid to work today; my kids are 3000 miles 
away
so it's a welcome distraction) is drawing on a MemoryDC associated with 
a
bitmap:

        @picture = Bitmap.new( size_x, size_y )
        artist = MemoryDC.new
        artist.select_object @picture
        artist.set_background_mode SOLID
        artist.flood_fill( 160, 200, Colour.new( 240, 0, 0, 255 ) )

... and later:

        paint_bitmap( @picture, client_size.x, client_size.y )

using the definition (part of my Window sub-class):

    def paint_bitmap bitmap, width, height
        bitmap = make_dummy if bitmap == nil # dummies for non-existant
images (like cpu1 if single-thread)
        rescaled_bitmap = Bitmap.from_image(
bitmap.convert_to_image.rescale( width, height ), -1 )
        rescaled_bitmap.save_file( @fname, BITMAP_TYPE_XPM )
        paint do | renderer |
            renderer.draw_bitmap( rescaled_bitmap, 0, 0, false )
        end
        @sized = false
    end

What appears to be happening is that my bitmaps are not taking over from 
the
original contents of the memory arrays, because what I see being 
rendered
appears to be garbage pages from the screen buffer. If I change 
something in
my GUI (like pressing a button, which changes its color to yellow), I 
see
smears of yellow showing up in my bitmaps and getting rendered in my 
GUI.

The Bitmap#draw method referenced in the DC and MemoryDC docs appears to
have gone bye-bye in 2.0, so I'm using the direct instantiation menthod. 
I
finally got my copy of Smart and Hock and it says something about
select_object not working if the bitmap is unpopulated, so my next try 
is to
pull up a base bitmap from a file instead of creating one from new.

Thanks in advance! :D

On Thu, Nov 25, 2010 at 2:57 PM, Don Wilde <dwilde1@gmail.com> wrote:
[snip]

> using the definition (part of my Window sub-class):
>         @sized = false
>     end


[snip]

Bitmap#load_file is also gone, but Bitmap.new has a file option. Never 
rely
on a first-release API to be as documented. ;-)

Changing make_dummy to load a file got rid of the uninitialized bitmaps, 
but
I still can't paint anything on them. The above code should leave me 
with a
screaming red bitmap, but all I get is the white from my blank.png.

On Thu, Nov 25, 2010 at 3:19 PM, Don Wilde <dwilde1@gmail.com> wrote:
[snip]

>         artist.flood_fill( 160, 200, Colour.new( 240, 0, 0, 255 ) )
>>
>> Never mind. I just re-read the flood_fill docs and discovered that the
Colour in the command is the BOUNDARY color, not the painting color.

You can stop laughing now, hope you enjoyed. :D