Date: Thu, 16 Oct 2008 20:27:34 +0400 From: "Ilya Kasnacheev" <ilya.kasnacheev@gmail.com> To: sdl@lists.libsdl.org Subject: [SDL] SDL for Windows CE: a few GAPI patches Hi *! I've just ported a POWDER roguelike ( http://www.zincland.com/powder/ ) to Windows CE (PDAs, Windows Mobile/Pocket PC). To do that, I had to get libsdl working. Thanks for the awesome project files, it built without a hitch. Nevertheless, I've found quite a few bugs in Windows CE (GAPI) SDL implementation, which I've solved and now present as a serie of patches. I'll try carefully annotate them. Please annotate them so I can work toward accepting them into the main source tree since without them SDL isn't really working on Windows CE (I wonder why nobody fixed them before, btw: why isn't SDL popular as a way to develop Windows CE games? Where are no ports?) These changes can't be considered flawless, but they can be considered working because I've yet to hear complains about things I fixed and POWDER build for Windows CE is now considered stable. Note: my comments start with !!, delete them before applying. diff -bru SDL-1.2.13/src/video/gapi/SDL_gapivideo.c SDL-1.2.13-new/src/video/gapi/SDL_gapivideo.c --- SDL-1.2.13/src/video/gapi/SDL_gapivideo.c 2007-12-31 07:48:00.000000000 +0300 +++ SDL-1.2.13-new/src/video/gapi/SDL_gapivideo.c 2008-10-16 20:02:11.000000000 +0400 @@ -643,6 +643,7 @@ } gapi->userOrientation = SDL_ORIENTATION_UP; + gapi->systemOrientation = SDL_ORIENTATION_UP; video->flags = SDL_FULLSCREEN; /* Clear flags, GAPI supports fullscreen only */ /* GAPI or VGA? */ @@ -661,18 +662,21 @@ } /* detect user landscape mode */ - if( (width > height) && (GetSystemMetrics(SM_CXSCREEN) < GetSystemMetrics(SM_CYSCREEN))) + if( (width > height) && (gapi->gxProperties.cxWidth < gapi->gxProperties.cyHeight)) gapi->userOrientation = SDL_ORIENTATION_RIGHT; + if(GetSystemMetrics(SM_CYSCREEN) < GetSystemMetrics(SM_CXSCREEN)) + gapi->systemOrientation = SDL_ORIENTATION_RIGHT; + /* shall we apply hires fix? for example when we do not use hires resource */ gapi->hiresFix = 0; - if( gapi->userOrientation == SDL_ORIENTATION_RIGHT ) + if( gapi->systemOrientation == gapi->userOrientation ) { - if( (width > GetSystemMetrics(SM_CYSCREEN)) || (height > GetSystemMetrics(SM_CXSCREEN))) + if( (width > GetSystemMetrics(SM_CXSCREEN)) || (height > GetSystemMetrics(SM_CYSCREEN))) gapi->hiresFix = 1; } else - if( (width > GetSystemMetrics(SM_CXSCREEN)) || (height > GetSystemMetrics(SM_CYSCREEN))) - if( !((width == GetSystemMetrics(SM_CYSCREEN)) && (height == GetSystemMetrics(SM_CXSCREEN)))) // user portrait, device landscape + if( (width > GetSystemMetrics(SM_CYSCREEN)) || (height > GetSystemMetrics(SM_CXSCREEN))) +// if( !((width == gapi->gxProperties.cyHeight) && (height == gapi->gxProperties.cxWidth))) // user portrait, device landscape gapi->hiresFix = 1; switch( gapi->userOrientation ) !! It used to query system metrics which return dimensions according to screen !! orientation, which can really be portrait, left landscape or right landscape. !! This is presumably incorrect because we couldn't care less about user mode !! dimensions - all we want are the GAPI framebuffer dimensions, which only match !! user dimensions in one of possible orientations. !! There's a fair dose of cargo cult programming involved in this fix, but it !! used to work only in one orientation (portrait for PDAs, where frame-buffer !! have same orientation as user screen), and now it works on all orientations. @@ -742,21 +746,30 @@ WIN_FlushMessageQueue(); /* Open GAPI display */ - if( !gapi->useVga && this->hidden->useGXOpenDisplay ) + if( !gapi->useVga && this->hidden->useGXOpenDisplay && !this->hidden->alreadyGXOpened ) + { + this->hidden->alreadyGXOpened = 1; if( !gapi->gxFunc.GXOpenDisplay(SDL_Window, GX_FULLSCREEN) ) { SDL_SetError("Couldn't initialize GAPI"); return(NULL); } + } #if REPORT_VIDEO_INFO printf("Video properties:\n"); printf("display bpp: %d\n", gapi->gxProperties.cBPP); printf("display width: %d\n", gapi->gxProperties.cxWidth); printf("display height: %d\n", gapi->gxProperties.cyHeight); + printf("system display width: %d\n", GetSystemMetrics(SM_CXSCREEN)); + printf("system display height: %d\n", GetSystemMetrics(SM_CYSCREEN)); printf("x pitch: %d\n", gapi->gxProperties.cbxPitch); printf("y pitch: %d\n", gapi->gxProperties.cbyPitch); printf("gapi flags: 0x%x\n", gapi->gxProperties.ffFormat); + printf("user orientation: %d\n", gapi->userOrientation); + printf("system orientation: %d\n", gapi->userOrientation); + printf("gapi orientation: %d\n", gapi->gapiOrientation); + if( !gapi->useVga && this->hidden->useGXOpenDisplay && gapi->needUpdate) { !! Previous version used to call gapi->gxFunc.GXOpenDisplay each time the video !! mode would be changed. You shouldn't, because this call has a meaning "Lock the !! GAPI framebuffer, designate it as busy", so the second call will fail (it is !! already locked/busy). !! Testing might not find that because most programs set up the video mode only !! once, but POWDER does this once in a while, so it crashed when in 320x240 mode !! (640x480 mode doesn't use that code, it worked fine). diff -bru SDL-1.2.13/src/video/gapi/SDL_gapivideo.h SDL-1.2.13-new/src/video/gapi/SDL_gapivideo.h --- SDL-1.2.13/src/video/gapi/SDL_gapivideo.h 2007-12-31 07:48:00.000000000 +0300 +++ SDL-1.2.13-new/src/video/gapi/SDL_gapivideo.h 2008-10-16 20:02:11.000000000 +0400 @@ -132,12 +132,17 @@ #define NUM_MODELISTS 4 /* 8, 16, 24, and 32 bits-per-pixel */ int SDL_nummodes[NUM_MODELISTS]; SDL_Rect **SDL_modelist[NUM_MODELISTS]; + // The orientation of the video mode user wants to get + // Probably restricted to UP and RIGHT enum SDL_ScreenOrientation userOrientation; int invert; char hiresFix; // using hires mode without defining hires resource // -------------- int useGXOpenDisplay; /* use GXOpenDispplay */ + int alreadyGXOpened; int w, h; + // The orientation of GAPI framebuffer. + // Never changes on the same device. enum SDL_ScreenOrientation gapiOrientation; void *buffer; // may be 8, 16, 24, 32 bpp @@ -153,6 +158,10 @@ int startOffset; // in bytes int useVga; int suspended; // do not pu anything into video memory + // The orientation of the system, as defined by SM_CXSCREEN and SM_CYSCREEN + // User can change it by using 'screen layout' in system options + // Restricted to UP or RIGHT + enum SDL_ScreenOrientation systemOrientation; }; !! This is a flag variable, see the previous comment !! And yet another orientation: now we have to keep three of them in mind. diff -bru SDL-1.2.13/src/video/wincommon/SDL_sysevents.c SDL-1.2.13-new/src/video/wincommon/SDL_sysevents.c --- SDL-1.2.13/src/video/wincommon/SDL_sysevents.c 2007-12-31 07:48:02.000000000 +0300 +++ SDL-1.2.13-new/src/video/wincommon/SDL_sysevents.c 2008-10-16 20:02:12.000000000 +0400 @@ -160,10 +160,22 @@ #endif */ } break; + // FIXME: Older version used just SDL_VideoSurface->(w, h) + // w and h are "clipped" while x and y are "raw", which caused + // x in former and y in latter case to be clipped in a wrong direction, + // thus offsetting the coordinate on 2 x clip pixels + // (like, 128 for 640 -> 512 clipping). + // We will now try to extract and use raw values. + // The way to do that RIGHT is do (orientation-dependent) clipping before + // doing this transform, but it's hardly possible. + + // SEE SDL_mouse.c /ClipOffset to understand these calculations. case SDL_ORIENTATION_RIGHT: if (!SDL_VideoSurface) break; - rotatedX = SDL_VideoSurface->w - *y; + rotatedX = (2 * ((SDL_VideoSurface->offset%SDL_VideoSurface->pitch)/ + SDL_VideoSurface->format->BytesPerPixel)) + + SDL_VideoSurface->w - *y; rotatedY = *x; *x = rotatedX; *y = rotatedY; @@ -172,7 +184,8 @@ if (!SDL_VideoSurface) break; rotatedX = *y; - rotatedY = SDL_VideoSurface->h - *x; + rotatedY = (2 * (SDL_VideoSurface->offset/SDL_VideoSurface->pitch)) + + SDL_VideoSurface->h - *x; *x = rotatedX; *y = rotatedY; break; !! That's the trickest part, hence the long comment. !! GAPI would really support only 320x240 or 640x480 mode, if application !! requested the different screen size (as POWDER did, wishing 256x192), then SDL !! is going to grab the first mode that fits the requested, and pad the screen !! with black bars (as they do with wide-screen films). !! It would also get, say, 240x320 mode, and to turn it into 256x192 it would !! need to rotate mouse clicks. !! It worked, but one bug slipped through: it would receive mouse clicks !! unpadded, then rotate them, and then pad the black bars. The problem is: rotate !! is done by GAPI driver while padding is done by SDL core. SDL core doesn't know !! anything about rotating, so it would pad one of dimensions incorrectly. I understand that some of my claims (or code) might seem unbacked, but you can always grab the POWDER binary, compile your own libsdl with one or more of those fixes turned off, and see how weird it would misbehave. I can even supply you with those custom builds of libsdl if you don't want to set up the build environment for windows ce, you'll just need a PDA or a smartphone with it. I plan to take care of SDL on Windows CE as long as I maintain the POWDER port. POWDER is good for that because it: Employs both padded (with centered image, black bars) and unpadded (image occupies full screen) graphics; initializes video more than once; uses both 320x240 and 640x480 video; uses both stylus and buttons. There's still a list of unresolved issues which I'm planning to fix: 1) Arrow buttons on PDA return weird scancodes compared to PC, this caused the game to misbehave before I've fixed that. You can see it on those diagrams: http://wrar.name/upload/powder-htc.png http://wrar.name/upload/powder-pda.png 2) SDL (or underlying windows) doesn't care to rotate arrow presses when we're in a low-res GAPI mode, but it will rotate them in VGA mode (because of different screen orientations, the same arrow buttons can suddently mean different directions). Solution: we should stick to GAPI user orientation (the orientation the program supposedly wants) and rotate the keys on our own. _______________________________________________ SDL mailing list SDL@lists.libsdl.org http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org

These are test programs for the SDL library:

	checkkeys	Watch the key events to check the keyboard
	graywin		Display a gray gradient and center mouse on spacebar
	loopwave	Audio test -- loop playing a WAV file
	testalpha	Display an alpha faded icon -- paint with mouse
	testbitmap	Test displaying 1-bit bitmaps
	testblitspeed	Tests performance of SDL's blitters and converters.
	testcdrom	Sample audio CD control program
	testcursor	Tests custom mouse cursor
	testdyngl	Tests dynamically loading OpenGL library
	testerror	Tests multi-threaded error handling
	testfile	Tests RWops layer
	testgamma	Tests video device gamma ramp
	testgl		A very simple example of using OpenGL with SDL
	testhread	Hacked up test of multi-threading
	testiconv	Tests international string conversion
	testjoystick	List joysticks and watch joystick events
	testkeys	List the available keyboard keys
	testloadso	Tests the loadable library layer
	testlock	Hacked up test of multi-threading and locking
	testoverlay	Tests the software/hardware overlay functionality.
	testoverlay2	Tests the overlay flickering/scaling during playback.
	testpalette	Tests palette color cycling
	testplatform	Tests types, endianness and cpu capabilities
	testsem		Tests SDL's semaphore implementation
	testsprite	Example of fast sprite movement on the screen
	testtimer	Test the timer facilities
	testver		Check the version and dynamic loading and endianness
	testvidinfo	Show the pixel format of the display and perfom the benchmark
	testwin		Display a BMP image at various depths
	testwm		Test window manager -- title, icon, events
	threadwin	Test multi-threaded event handling
	torturethread	Simple test for thread creation/destruction