Mercurial > sdl-ios-xcode
view README.Porting @ 3485:e77a69aae239
Mason Wheeler to sdl
I updated SDL, and suddenly my SDL frames stopped working. They'd "initialize" full of gibberish, and I couldn't render anything to them. After a bit of digging, I found a problem: the renderer initialization routine in my SDL frame code wasn't getting called anymore.
procedure TSdlFrame.Paint;
begin
if SDL_SelectRenderer(FWindowID) = -1 then
CreateRenderer;
SDL_RenderPresent;
end;
function TSdlFrame.CreateRenderer: boolean;
const
pf: tagPIXELFORMATDESCRIPTOR = (nSize: sizeof(pf); nVersion: 1;
dwFlags: PFD_DRAW_TO_WINDOW or PFD_SUPPORT_OPENGL or PFD_DOUBLEBUFFER;
iPixelType: PFD_TYPE_RGBA; cColorBits: 24; cAlphaBits: 8;
iLayerType: PFD_MAIN_PLANE);
RENDERERS: array[TRendererType] of AnsiString = ('software', 'gdi', 'opengl', 'd3d');
var
pFormat: integer;
begin
if (SDL_SelectRenderer(FWindowID) = 0) then
begin
result := true;
Exit;
end;
if FRendererType = rtOpenGL then
begin
pFormat := ChoosePixelFormat(canvas.Handle, @pf);
if not SetPixelFormat(canvas.Handle, pFormat, @pf) then
outputDebugString(PChar(SysErrorMessage(GetLastError)));
if wglCreateContext(canvas.Handle) = 0 then
outputDebugString(PChar(SysErrorMessage(GetLastError)));
end;
if (SDL_CreateRenderer(FWindowID, SDL_RendererIndex(RENDERERS[FRendererType]), [sdlrPresentFlip3, sdlrAccelerated]) = 0) then
begin
SDL_ShowWindow(FWindowID);
assert(SDL_SetRenderDrawColor(0, 0, 0, 255) = 0);
FFlags := SDL_GetWindowFlags(FWindowID);
if assigned(FOnAvailable) then
FOnAvailable(self);
end
else outputDebugString(pChar(format('SDL_CreateRenderer failed: %s', [sdl_GetError])));
result := SDL_SelectRenderer(FWindowID) = 0;
end;
This is a critical issue. The Paint method gets called when the control receives a WM_PAINT message from Windows. I can't create the renderer before then, or it will fail and cause trouble. And when I do create it, it needs to be created with certain parameters. So imagine my surprise when I started debugging into the DLL and found that SDL_SelectRenderer was trying to be "helpful" by creating the renderer for me if it didn't already exist! Now not only does my initialization code not get called, I end up with the wrong renderer and so things don't render as expected when I try to use the window.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 24 Nov 2009 04:48:12 +0000 |
parents | 103760c3a5dc |
children |
line wrap: on
line source
* Porting To A New Platform The first thing you have to do when porting to a new platform, is look at include/SDL_platform.h and create an entry there for your operating system. The standard format is __PLATFORM__, where PLATFORM is the name of the OS. Ideally SDL_platform.h will be able to auto-detect the system it's building on based on C preprocessor symbols. There are two basic ways of building SDL at the moment: 1. The "UNIX" way: ./configure; make; make install If you have a GNUish system, then you might try this. Edit configure.in, take a look at the large section labelled: "Set up the configuration based on the target platform!" Add a section for your platform, and then re-run autogen.sh and build! 2. Using an IDE: If you're using an IDE or other non-configure build system, you'll probably want to create a custom SDL_config.h for your platform. Edit SDL_config.h, add a section for your platform, and create a custom SDL_config_{platform}.h, based on SDL_config.h.minimal and SDL_config.h.in Add the top level include directory to the header search path, and then add the following sources to the project: src/*.c src/audio/*.c src/cdrom/*.c src/cpuinfo/*.c src/events/*.c src/file/*.c src/joystick/*.c src/stdlib/*.c src/thread/*.c src/timer/*.c src/video/*.c src/audio/disk/*.c src/audio/dummy/*.c src/video/dummy/*.c src/joystick/dummy/*.c src/cdrom/dummy/*.c src/thread/generic/*.c src/timer/dummy/*.c src/loadso/dummy/*.c Once you have a working library without any drivers, you can go back to each of the major subsystems and start implementing drivers for your platform. If you have any questions, don't hesitate to ask on the SDL mailing list: http://www.libsdl.org/mailing-list.php Enjoy! Sam Lantinga (slouken@libsdl.org)