ESDL2

SDL2 Erlang NIFs

SDL provides cross-platform low level access to graphics, audio, keyboard, mouseand joystick hardware via OpenGL and Direct3D. This is an Erlang binding. http://www.libsdl.org/

Status

Week-end project. Work in progress.

Building

• Erlang 17.0+ is required
• SDL 2.0.3+ is required (http://www.libsdl.org/download-2.0.php)
• SDL_image is required (https://www.libsdl.org/projects/SDL_image/)
• SDL_ttf is required (https://www.libsdl.org/projects/SDL_ttf/)
• No support for UTF-8 strings, only Latin-1

Tip: configure SDL_image with --disable-webp for not having to install libwebp.

Build using make.

Ideas

The following ideas need to be investigated:

• We may benefit from the reference receive optimization when doing calls
• We may want a way to pipeline draw operations
• Using HiPE mutable bytearrays for "void* pixels" types

The following tasks remain to be done:

• http://hg.libsdl.org/SDL/file/default/include/SDL_hints.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_error.h

  • Anything that can produce errors will have an automatic call to SDL_GetError.
  • I am not sure we need any direct access to those functions.

• http://hg.libsdl.org/SDL/file/default/include/SDL_log.h

  • We already have logging in Erlang. Not sure we need this.

• http://hg.libsdl.org/SDL/file/default/include/SDL_assert.h

  • I am not sure we need this, and we can't use the assert macro directly anyway.

• http://hg.libsdl.org/SDL/file/default/include/SDL_version.h

  • It might be useful to provide access to some of the macros as functions.
  • The SDL_GetRevisionNumber function needs to be implemented.
  • It might be interesting to use the macros to conditionally implement some features, this way we could be compatible with all versions >= 2.0.0.

• http://hg.libsdl.org/SDL/file/default/include/SDL_video.h

  • The SDL_DisplayMode structure and related functions need to be implemented:
    • SDL_GetNumDisplayModes()
    • SDL_GetDisplayMode()
    • SDL_GetDesktopDisplayMode()
    • SDL_GetCurrentDisplayMode()
    • SDL_GetClosestDisplayMode()
    • SDL_SetWindowDisplayMode()
    • SDL_GetWindowDisplayMode()
  • Most other display functions are also not implemented:
    • SDL_GetNumVideoDisplays()
    • SDL_GetDisplayName()
    • SDL_GetDisplayBounds()
    • SDL_GetDisplayDPI()
  • Some window functions need to be implemented:
    • SDL_CreateWindowFrom()
    • SDL_GetWindowData()
    • SDL_SetWindowData()
    • SDL_GetWindowPixelFormat()
    • SDL_GetWindowFromID()
    • SDL_GetWindowSurface()
    • SDL_UpdateWindowSurface()
    • SDL_UpdateWindowSurfaceRects()
    • SDL_GetGrabbedWindow()
    • SDL_SetWindowGammaRamp()
    • SDL_GetWindowGammaRamp()
  • There is an SDL_WINDOW_MOUSE_CAPTURE window flag we need to implement.
  • There are two window pos flags, related to multi monitors, that we don't support:
    • SDL_WINDOWPOS_UNDEFINED_DISPLAY(X)
    • SDL_WINDOWPOS_CENTERED_DISPLAY(X)
  • We do not support OpenGL at all yet:
    • SDL_GLContext
    • SDL_GLattr
    • SDL_GLprofile
    • SDL_GLcontextFlag
    • SDL_GLcontextReleaseFlag
    • SDL_GL_LoadLibrary()
    • SDL_GL_GetProcAddress()
    • SDL_GL_UnloadLibrary()
    • SDL_GL_ExtensionSupported()
    • SDL_GL_ResetAttributes()
    • SDL_GL_SetAttribute()
    • SDL_GL_GetAttribute()
    • SDL_GL_MakeCurrent()
    • SDL_GL_GetCurrentWindow()
    • SDL_GL_GetCurrentContext()
    • SDL_GL_GetDrawableSize()
    • SDL_GL_SetSwapInterval()
    • SDL_GL_GetSwapInterval()
  • We do not support any of the video driver related functions:
    • SDL_GetNumVideoDrivers()
    • SDL_GetVideoDriver()
    • SDL_VideoInit()
    • SDL_VideoQuit()
    • SDL_GetCurrentVideoDriver()
  • Flags and functions relating to SDL_HitTest are not implemented:
    • SDL_HitTestResult
    • SDL_HitTest() callback
    • SDL_SetWindowHitTest()
  • Screensaver related functions are not implemented:
    • SDL_IsScreenSaverEnabled()
    • SDL_EnableScreenSaver()
    • SDL_DisableScreenSaver()

• http://hg.libsdl.org/SDL/file/default/include/SDL_render.h

  • The SDL_RendererInfo structure and related functions are not implemented:
    • SDL_GetRenderDriverInfo()
    • SDL_GetRendererInfo()
  • The SDL_TextureAccess enum is not implemented.
  • The SDL_TextureModulate enum is not implemented.
  • A number of other functions are not implemented:
    • SDL_CreateSoftwareRenderer()
    • SDL_GetRenderer()
    • SDL_CreateTexture()
    • SDL_QueryTexture()
    • SDL_UpdateTexture()
    • SDL_UpdateYUVTexture()
    • SDL_LockTexture()
    • SDL_UnlockTexture()
    • SDL_SetRenderTarget()
    • SDL_GetRenderTarget()
    • SDL_RenderIsClipEnabled()
    • SDL_RenderReadPixels()
  • We do not support OpenGL at all yet:
    • SDL_GL_BindTexture()
    • SDL_GL_UnbindTexture()

• http://hg.libsdl.org/SDL/file/default/include/SDL_pixels.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_rect.h

  • We need to implement everything, though we already have points and rects as maps elsewhere.

• http://hg.libsdl.org/SDL/file/default/include/SDL_surface.h

  • We need to implement everything except SDL_FreeSurface().

• http://hg.libsdl.org/SDL/file/default/include/SDL_syswm.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_events.h

  • The following event types need to be implemented:
    • SDL_APP_TERMINATING (iOS and Android)
    • SDL_APP_LOWMEMORY (iOS and Android)
    • SDL_APP_WILLENTERBACKGROUND (iOS and Android)
    • SDL_APP_DIDENTERBACKGROUND (iOS and Android)
    • SDL_APP_WILLENTERFOREGROUND (iOS and Android)
    • SDL_APP_DIDENTERFOREGROUND (iOS and Android)
    • SDL_SYSWMEVENT (SDL_SysWMEvent, SDL_SysWMmsg)
    • SDL_TEXTEDITING (SDL_TEXTEDITINGEVENT_TEXT_SIZE, SDL_TextEditingEvent)
    • SDL_TEXTINPUT (SDL_TEXTINPUTEVENT_TEXT_SIZE, SDL_TextInputEvent)
    • SDL_JOYAXISMOTION (SDL_JoyAxisEvent)
    • SDL_JOYBALLMOTION (SDL_JoyBallEvent)
    • SDL_JOYHATMOTION (SDL_JoyHatEvent)
    • SDL_JOYBUTTONDOWN (SDL_JoyButtonEvent)
    • SDL_JOYBUTTONUP (SDL_JoyButtonEvent)
    • SDL_JOYDEVICEADDED (SDL_JoyDeviceEvent)
    • SDL_JOYDEVICEREMOVED (SDL_JoyDeviceEvent)
    • SDL_CONTROLLERAXISMOTION (SDL_ControllerAxisEvent)
    • SDL_CONTROLLERBUTTONDOWN (SDL_ControllerButtonEvent)
    • SDL_CONTROLLERBUTTONUP (SDL_ControllerButtonEvent)
    • SDL_CONTROLLERDEVICEADDED (SDL_ControllerDeviceEvent)
    • SDL_CONTROLLERDEVICEREMOVED (SDL_ControllerDeviceEvent)
    • SDL_CONTROLLERDEVICEREMAPPED (SDL_ControllerDeviceEvent)
    • SDL_FINGERDOWN (SDL_TouchFingerEvent)
    • SDL_FINGERUP (SDL_TouchFingerEvent)
    • SDL_FINGERMOTION (SDL_TouchFingerEvent)
    • SDL_DOLLARGESTURE (SDL_DollarGestureEvent)
    • SDL_DOLLARRECORD (SDL_DollarGestureEvent)
    • SDL_MULTIGESTURE (SDL_MultiGestureEvent)
    • SDL_CLIPBOARDUPDATE
    • SDL_DROPFILE (SDL_DropEvent)
    • SDL_AUDIODEVICEADDED (SDL_AudioDeviceEvent)
    • SDL_AUDIODEVICEREMOVED (SDL_AudioDeviceEvent)
    • SDL_RENDER_TARGETS_RESET
    • SDL_RENDER_DEVICE_RESET
    • User defined events, from SDL_USEREVENT to SDL_LASTEVENT (SDL_UserEvent)
  • We currently do not handle the SDL_MouseMotionEvent.state value
  • We currently do not handle the SDL_MouseWheelEvent.direction value (SDL >= 2.0.4, unreleased yet)
  • We need to implement the following functions:
    • SDL_PumpEvents()
    • SDL_PeepEvents()
    • SDL_HasEvent()
    • SDL_HasEvents()
    • SDL_FlushEvent()
    • SDL_FlushEvents()
    • SDL_WaitEvent()
    • SDL_WaitEventTimeout()
    • SDL_PushEvent()
    • SDL_SetEventFilter()
    • SDL_GetEventFilter()
    • SDL_AddEventWatch()
    • SDL_DelEventWatch()
    • SDL_FilterEvents()
    • SDL_EventState()
    • SDL_RegisterEvents()

• http://hg.libsdl.org/SDL/file/default/include/SDL_keyboard.h

  • We need to implement the following functions:
    • SDL_GetKeyboardFocus()
    • SDL_GetKeyboardState()
    • SDL_GetModState()
    • SDL_SetModState()
    • SDL_GetKeyFromScancode()
    • SDL_GetScancodeFromKey()
    • SDL_GetScancodeName()
    • SDL_GetScancodeFromName()
    • SDL_GetKeyName()
    • SDL_GetKeyFromName()
    • SDL_SetTextInputRect()
    • SDL_HasScreenKeyboardSupport()
    • SDL_IsScreenKeyboardShown()

• http://hg.libsdl.org/SDL/file/default/include/SDL_keycode.h

  • We probably should make it easy to identify keycodes and scancodes.

• http://hg.libsdl.org/SDL/file/default/include/SDL_scancode.h

  • We probably should make it easy to identify keycodes and scancodes.

• http://hg.libsdl.org/SDL/file/default/include/SDL_mouse.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_joystick.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_gamecontroller.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_haptic.h

  • We need to implement everything.

• http://hg.libsdl.org/SDL/file/default/include/SDL_audio.h

  • We need to implement everything.
  • We might want to implement SDL_mixer first.

• http://hg.libsdl.org/SDL/file/default/include/SDL_thread.h

  • We don't really need this for Erlang, do we?

• http://hg.libsdl.org/SDL/file/default/include/SDL_mutex.h

  • We don't really need this for Erlang, do we?

• http://hg.libsdl.org/SDL/file/default/include/SDL_atomic.h

  • We don't really need this for Erlang, do we?

• http://hg.libsdl.org/SDL/file/default/include/SDL_timer.h

  • We need to implement everything.
  • It's not the most useful to have, but doesn't hurt to have it.

• http://hg.libsdl.org/SDL/file/default/include/SDL_rwops.h

  • We need to implement everything.
  • It's currently unclear if and how this should be implemented.

• http://hg.libsdl.org/SDL/file/default/include/SDL_loadso.h

  • We don't really need this for Erlang, do we?

• http://hg.libsdl.org/SDL/file/default/include/SDL_platform.h

  • We need to implement the one function in there. Can always be useful.

• http://hg.libsdl.org/SDL/file/default/include/SDL_cpuinfo.h

  • The function SDL_HasAVX2() needs to be implemented. (SDL >= 2.0.4, unreleased yet)

• http://hg.libsdl.org/SDL/file/default/include/SDL_endian.h

  • We need to implement everything.
  • It's currently unclear if and how this should be implemented.

• http://hg.libsdl.org/SDL/file/default/include/SDL_bits.h

  • We need to implement everything.
  • It's currently unclear if and how this should be implemented.

• http://hg.libsdl.org/SDL/file/default/include/SDL_system.h

  • We need to implement everything.
  • It's currently unclear if and how this should be implemented.

• http://hg.libsdl.org/SDL/file/default/include/SDL_stdinc.h

  • Nothing except support for SDL_bool was implemented.
  • There might be useful bits and pieces in there, in particular the math or iconv functions.

• SDL_image, SDL_mixer, ... also need to be investigated and implemented.