thanks to bernard bout and craig boyd, i've updated the code below. in fact it contained a small bug, that was not adjusting the white colors. now it seems to be working nice. thanks !
this runs a little bit slower than the other aproach, but in my tests, the success was 100%.
the function below converts any button image to a bmp to be used in vfp forms.
there are lots of cool and free icons available on the web, but the vast majority are in .ico, gif or png image formats, that are not very familiar and reliable to be used in vfp. for us, the best image format, for a lot of reasons, is the bmp format.
some transformations are needed to make this bmp to show exactly how we desire, specially when converting source images in a png, gif or ico formats.
vfp shows the pure white - rgb(255,255,255) as transparent in our buttons and image objects. the code below first converts the original whites to rgb(254,254,254) that is visually the same, but does not become transparent, and eliminates the need to create a mask image (.msk) and next, converts the background color of the original bitmap to pure white, that will show transparent in vfp forms.
Important Requires VFP9 and GdiplusX to run.
when you compile this program in your executable, please don't forget to remove the locfile() command, and just use a do system.app instead
lparameters tcsourcefile, tcdestfile * tcsourcefile = getpict() * tcdestfile = forceext(tcsourcefile, "bmp") do locfile("system.app") local lobmp as xfcbitmap local logfx as xfcgraphics local loborderclr as xfccolor local lorect as xfcrectangle local loattr as xfcimageattributes local locolormap as xfccolormap local lodestbmp as xfcbitmap with _screen.system.drawing locolormap = .imaging.colormap.new() loattr = .imaging.imageattributes.new() lobmp = .bitmap.fromfile(tcsourcefile) logfx = .graphics.fromimage(lobmp) lodestbmp = .bitmap.new(lobmp.width, lobmp.height, .imaging.pixelformat.format24bpprgb) lodestgfx = .graphics.fromimage(lodestbmp) * clear the new bitmap lodestgfx.clear(.color.white) * by craig boyd - for enhancing the smoothless and quality lodestgfx.smoothingmode = .drawing2d.smoothingmode.highquality lodestgfx.interpolationmode = .drawing2d.interpolationmode.highqualitybicubic lodestgfx.pixeloffsetmode = .drawing2d.pixeloffsetmode.highquality lorect = lobmp.getbounds() * get the top left pixel color, presuming this color is the background color to become transparent * for our bmp case, this will become pure white - rgb(255,255,255) * that becomes transparent when used in vfp objects loborderclr = lobmp.getpixel(0,0) * convert original whites rgb(255,255,255) to off white - rgb(254,254,254) * this way, the whites will remain without the need of a mask locolormap.oldcolor = .color.white locolormap.newcolor = .color.fromargb(255,254,254,254) loattr.setremaptable(locolormap) lodestgfx.drawimage(lobmp, lorect, lorect, .graphicsunit.pixel, loattr) * next step, convert the borders to pure white, rgb(255,255,255) that will become transparent in buttons locolormap.oldcolor = loborderclr locolormap.newcolor = .color.white loattr.setremaptable(locolormap) lodestgfx.drawimage(lodestbmp, lorect, lorect, .graphicsunit.pixel, loattr) lodestbmp.save(tcdestfile, .imaging.imageformat.bmp) endwith