Alvin wrote: > matthiasm wrote: > >> >> On 25.07.2008, at 15:23, Alvin wrote: >> >>> According to the the FLTK manual, Fl_Image::color_average() states: >>> "The original image data is not altered by this method" >>> >>> This is great for what I am doing except I do not know how to have >>> the image >>> draw the "original image data". Basically, how can I remove the >>> saturation? >>> >>> This applies to Fl_Image::desaturate(). It makes the same claim >>> about not >>> altering the original image data. >> >> >> Both functions create a new image that you can use instead of the old >> one, for example. You can then simply delete the old image if you like. >> >> To draw an image, either cal someWidget->image(myImage), which will >> make the image part of the label for that widget, or derive your own >> widget and override the draw() function to draw you custom widgets >> with your own ideas on where the images go. >> >> Matthias >> >> >> ---- >> http://robowerk.com/ > > Hmmm, I don't fully understand. I figured it created a new image, but the > old one is stored in Fl_Image somewhere (perhaps data[1]?) The problem is > the Fl_Image::color_average() doesn't have a return value. > > Here's a trivial example: > > Fl_Button *b = new Button(......); // Assume b is global > > Fl_Shared_Image *img = Fl_Shared_Image::get("/path/to/image.png"); > > b->image(img); > > // now later in the code I want to darken the image > > b->image()->color_average(FL_BLACK, 0.4); > > // now even later I want to restore the original image > > b-> ???? > > As a work around, I store the original image in b's user_data(). I then > make a copy of the image and call color_average() on the copy. I then set > b's image() to the darkened, copied image. To restore the image, I move > the pointer from user_data() to b->image() after I clean the darkened, > copied image (delete it). > > I figured that there would be a way to undo the color_average() and > desaturate() since they do not modify the original image. >
Ugh, I (re)discovered Fl_Image::deimage(). For my purposes, this does exactly what I'm trying to do. I simply store the darkened, copied image in deimage(). Then when I deactivate the widget, that image is drawn. Then the original is drawn when the widget is activated. But still, the documentation implies (at least how I read it) that the color_average() and desaturate() can be undone some how. Is this true? -- Alvin _______________________________________________ fltk mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk
