This entire function is kind of a mess and more complicated than needed, but I don't want to refactor it too heavily tonight. May look at improving how the indexes are assigned more significanly later. The way it handles not finding a valid "gamepad" type device is also super broken, it leaves in place the xinput bindings but opens the controller with dinput and ends up with completely wrong mappings, not solving that now, but fixing the bug where we'd very frequently not find a controller due to gaps in assigned player numbers should mostly avoid it.
Andreas
The issue comes down to this line on MSDN:
"TranslateMessage produces WM_CHAR messages only for keys that are mapped to ASCII characters by the keyboard driver."
"WM_KEYDOWN and WM_KEYUP combinations produce a WM_CHAR or WM_DEADCHAR message. WM_SYSKEYDOWN and WM_SYSKEYUP combinations produce a WM_SYSCHAR or WM_SYSDEADCHAR message."
Except for WM_CHAR, none of these messages are used in SDL. Hence TranslateMessage should be dropped entirely and proper handling be included in the WM_KEYDOWN event.
Currently TranslateMessage is called for every message even if it must not be called in certain cases (like "An application should not call TranslateMessage if the TranslateAccelerator function returns a nonzero value.").
WM_CHAR message handling should remain for external processes posting these messages - additionally, WM_UNICHAR should be added.
I made a patch for src/video/windows/SDL_windowsevents.c that seems to work fine. It doesn't solve the "missing" composition for Khmer, but at least input for languages that cannot be mapped to ASCII characters (and for which IME is not used) will now work on Windows.
Jianyu Guan
I found I make a big mistake that when dstA==0, I just simply let *dstp=*srcp and forgot to make dstRGB = srcRGB*srcA.
The if consition "(*dstp & amask) == 0" in BlitRGBtoRGBPixelAlphaMMX and BlitRGBtoRGBPixelAlphaMMX3dNow should be removed.
I see the Remarks of function SDL_BlitSurface shows that "when SDL_BLENDMODE_BLEND, we have dstA = srcA + (dstA * (1-srcA))". however, I tested some pictures but the result implies "dstA=arcA" actually. I stepped into the source code, and found after I set SDL_BLENDMODE_BLEND for the source surface, the final blit function is BlitRGBtoRGBPixelAlphaMMX when I use SDL_BlitSurface on my computer. And I found these codes:
else if (alpha == amask) {
/* opaque alpha -- copy RGB, keep dst alpha */
*dstp = (*srcp & chanmask) | (*dstp & ~chanmask);
The same code is used in BlitRGBtoRGBPixelAlphaMMX3DNOW and BlitRGBtoRGBPixelAlpha. So I think they still keep dst alpha.
Best regards,
Jianyu Guan
Sam Lantinga
Gabriel Jacobo
Ryan C. Gordon
Edward Rudd
Philipp Wiesemann
Andreas Schiffler
J?rgen P. Tjern?