The SDL forums have moved to discourse.libsdl.org.
This is just a read-only archive of the previous forums, to keep old links working.

After debugging testautomation_surface, I have concluded that SW blending doesn't work at least for me (big endian AmigaOS platform).

For example, if sR is 0 and dR is 255, we will get -255*sA casted to an unsigned value. Basically results are quite large numbers instead of the expected 0-255 range. Am I missing something here?

Reference: https://hg.libsdl.org/SDL/file/d11daa346140/src/video/SDL_blit.h#l455

I think that was just trying to promote Uint8 to a larger type. Does it work if you replace (unsigned) with (int)?

On Tue, Jan 3, 2017 at 12:44 PM, capehill wrote:

Yes, replacing unsigned with int makes "testBlit" case work on my platform.

Okay, can you try this?https://hg.libsdl.org/SDL/rev/6285a56f6729



On Wed, Jan 4, 2017 at 11:39 AM, capehill wrote:

Unfortunately it doesn't work for me. You probably have to cast sA to int, at least that helps here. Perhaps compiler promotes result to unsigned because sA's type is unsigned? (SDL_blit_A.c)

Can you provide a patch on the bug?

On Fri, Jan 6, 2017 at 11:26 AM, capehill wrote:

Following patch worked for me: https://sourceforge.net/p/sdl2-amigaos4/code/157/

Okay, I think I got it.

Thanks!


On Sat, Jan 7, 2017 at 7:16 AM, capehill wrote: