How to display Gif89a with transparent color other than black
Posted on 2000-02-28
I would like to know how can I display a GIF89a file with tranparent color other than black. The popular browsers do it but I want to do this in my own program written in C++ for Windows 95 (and higher). If transparent color is black I made a mask for image replacing all black pixels by white ones and the others by the white ones and next I used two BitBlt's, the first with the mask and AND ROP-code and the second with the image and the OR ROP-code. But if a transparent color is other than black this method obviously doesn't work. Nevertheless the browsers know how to resolve this problem. Do you know any method for C++ Windows program ?
Thank you in advance for any response