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)
Frank Zago to SDL
For those interested, here's a snapshot of the current port. I did away with
most of the previous attempt which was based of the sprite engine, because the
support is limited to 128 64x64 sprites. Instead I'm using the gl engine.
The drawback is that either the frame buffer or the gl engine can be used
because there's not that much video memory on a DS.
With minimal changes to their code, it can now run the following tests: ,
testspriteminimal, testscale and testsprite2. The last 2 only run under the
emulator for some reason. The tests are not included in this patch for size
reason.
In 16 bits mode, the 16th bit indicated transparency/opacity. If 0, the color
is not displayed. So I had to patch a few core file to set that bit to 1. See
patch for src/video/SDL_RLEaccel.c and src/video/SDL_blit.h. Is that ok, or is
there a better way ?
The nds also doesn't support windowed mode, so I force the fullscreen in
src/video/SDL_video.c. Is that ok, or is there a better way ?
To get a smaller library, I also tried to not compile the software renderer
when the hardware renderer is compiled in, and define SDL_NO_COMPAT; however
the compilation eventually fails in SDL_surface.c because SDL_SRCCOLORKEY is
defined in SDL_compat.h. Is SDL_NO_COMPAT only for application and not SDL
itself ?
Removed misleading hide/unhide Cocoa notifications.
We have no way of knowing when a Cocoa window is maximized and then restored (right?)
Disabled spamy mouse motion events by default.
Matthias 2011-02-23 09:37:51 PST
Please view the attached source file. Using this minimal program (as attached),
it creates an OpenGL 2.0 context with a cleared color buffer. If I set the
OpenGL version to 3.2, the function SDL_GL_CreateContext fails (or more
specifically, glXMakeCurrent fails) with an X11 BadMatch error:
X Error of failed request: BadMatch (invalid parameter attributes)
Major opcode of failed request: 128 (GLX)
Minor opcode of failed request: 5 (X_GLXMakeCurrent)
Serial number of failed request: 153
Current serial number in output stream: 153
Also note that if I do not specify the alpha buffer size, the program works for
OpenGL 2.0 and OpenGL 3.2.
After some further analysis, I believe I have found the problem. The specific
issue is in:
SDL_x11opengl.c::X11_GL_CreateContext.
Note that for OpenGL 3.2 contexts, the GLXFBConfig to use is chosen as the best
match from glXChooseFBConfig. However, opengl attributes originally set with
SDL_GL_SetAttribute are not mapped to GLX attributes and then passed to the
glXChooseFBConfig function. According to the GLX 1.4 specification, if the
attributes are not specified, the function falls back to defaults (which, in
this particular case, prefer alpha channel size == 0).
For testing purposes, I modified the call to glXChooseFBConfig to look
something like this:
int glxAttribs[] =
{
GLX_RED_SIZE,8,
GLX_GREEN_SIZE,8,
GLX_BLUE_SIZE,8,
GLX_ALPHA_SIZE,8,
None
};
if (!glXChooseFBConfig ||
!(framebuffer_config = glXChooseFBConfig(display, DefaultScreen(display),
glxAttribs, &fbcount)))
{
...
}
The best match GLXFBConfig then supports 8 bit alpha channel. The program then
works as intended.
Hope this helps!
