Mon, 07 Mar 2011 14:06:46 -0800Fixed bug 1161 (Setting GL_ACCELERATED_VISUAL to 1 forces software rendering in Windows XP)
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 14:06:46 -0800] rev 5446
Fixed bug 1161 (Setting GL_ACCELERATED_VISUAL to 1 forces software rendering in Windows XP)

Jesse Anders 2011-03-05 23:30:09 PST

It seems that in Windows XP, setting SDL_GL_ACCELERATED_VISUAL to 1 actually
disables hardware acceleration and puts OpenGL in software mode.

In the source code, the corresponding WGL attribute is first set here:

*iAttr++ = WGL_ACCELERATION_ARB;
*iAttr++ = WGL_FULL_ACCELERATION_ARB;

Later, this code:

if (_this->gl_config.accelerated >= 0) {
*iAttr++ = WGL_ACCELERATION_ARB;
*iAttr++ =
(_this->gl_config.accelerated ? WGL_GENERIC_ACCELERATION_ARB :
WGL_NO_ACCELERATION_ARB);
}

Sets it again if SDL_GL_ACCELERATED_VISUAL has a value other than the default.

More importantly, the documentation I found states that
WGL_GENERIC_ACCELERATION_ARB asks for an MDC driver, which, although I don't
know much about this topic, doesn't seem like the correct choice here. As
mentioned previously, the end effect is that requesting hardware acceleration
in Windows XP actually forces the renderer into software mode (on my system at
least), which I'm guessing isn't the desired behavior.

Mon, 07 Mar 2011 09:58:21 -0800Enabled multi-touch
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:58:21 -0800] rev 5445
Enabled multi-touch

Mon, 07 Mar 2011 09:57:59 -0800Added gesture test program
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:57:59 -0800] rev 5444
Added gesture test program

Mon, 07 Mar 2011 09:35:53 -0800Removed associated source files
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:35:53 -0800] rev 5443
Removed associated source files

Mon, 07 Mar 2011 09:35:26 -0800Removed associated resources
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:35:26 -0800] rev 5442
Removed associated resources

Mon, 07 Mar 2011 09:35:01 -0800Removed old test
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:35:01 -0800] rev 5441
Removed old test

Mon, 07 Mar 2011 09:25:42 -0800Fixed compile error
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 09:25:42 -0800] rev 5440
Fixed compile error

Mon, 07 Mar 2011 01:34:38 -0800Removed the NDS hack for ARGB1555 surfaces, since it's a general problem; added full color expansion for 16 bpp packed pixels.
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 01:34:38 -0800] rev 5439
Removed the NDS hack for ARGB1555 surfaces, since it's a general problem; added full color expansion for 16 bpp packed pixels.

Mon, 07 Mar 2011 00:30:05 -0800Fixed bitmap order interpretation; SDL defaults to MSB ordering so a bitstream corresponds to a pixel stream.
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 00:30:05 -0800] rev 5438
Fixed bitmap order interpretation; SDL defaults to MSB ordering so a bitstream corresponds to a pixel stream.

The bitmap ordering is defined such that the numbering refers to the pixel index from left to right, and the number position refers to the bit position in the byte.

SDL_BITMAPORDER_4321 is the fourth pixel at the high bit and the first pixel at the low bit (LSBFirst)

SDL_BITMAPORDER_1234 is the first pixel at the high bit and the fourth pixel at the low bit (MSBFirst)

Mon, 07 Mar 2011 00:08:23 -0800We explicitly don't know how to handle 1 and 4 bpp pixel formats.
Sam Lantinga <slouken@libsdl.org> [Mon, 07 Mar 2011 00:08:23 -0800] rev 5437
We explicitly don't know how to handle 1 and 4 bpp pixel formats.