IEglApi

Remarks

The same seam as IGlApi, one layer out. What can be wrong about bringing up a context is not the calls — those are transcription — but the sequence: which attribute list is built for a window and which for a pbuffer, what happens when a driver refuses GLES 3.2, whether a half-built context is torn down in the reverse of the order it was built. All of that is decidable from the call stream, and none of it is decidable on a machine with no EGL — which is every machine this repository is developed on except an Android device.

So the calls go through an interface, the loading lives behind NativeEglApi, and the tests drive a recorder.

Booleans rather than EGLBoolean, and nint for every handle. EGL's handle types are opaque pointers and its boolean is an int; carrying either as its own type here would put the binding in the interface. Failure is reported the way EGL reports it — a false return or a null handle, with GetError holding the reason — rather than by throwing, because the caller's response to EGL_BAD_MATCH from eglCreateContext is to ask for less rather than to give up.

Methods (20)

• nint GetDisplay(nint nativeDisplay)

  eglGetDisplay.

• bool Initialise(nint display, out int major, out int minor)

  eglInitialize.

• bool Terminate(nint display)

  eglTerminate.

• bool BindApi(uint api)

  eglBindAPI.

• string? QueryString(nint display, int name)

  eglQueryString.

• bool ChooseConfig(nint display, ReadOnlySpan<int> attributes, Span<nint> configs, out int count)

  eglChooseConfig.

• nint CreateContext(nint display, nint config, nint share, ReadOnlySpan<int> attributes)

  eglCreateContext.

• nint CreateWindowSurface(nint display, nint config, nint window, ReadOnlySpan<int> attributes)

  eglCreateWindowSurface.

• nint CreatePbufferSurface(nint display, nint config, ReadOnlySpan<int> attributes)

  eglCreatePbufferSurface, which is how a device renders with no window.

• bool DestroySurface(nint display, nint surface)

  eglDestroySurface.

• bool DestroyContext(nint display, nint context)

  eglDestroyContext.

• bool QuerySurface(nint display, nint surface, int attribute, out int value)

  eglQuerySurface.

• bool MakeCurrent(nint display, nint draw, nint read, nint context)

  eglMakeCurrent.

• nint GetCurrentContext()

  eglGetCurrentContext.

• bool SwapBuffers(nint display, nint surface)

  eglSwapBuffers.

• bool SwapInterval(nint display, int interval)

  eglSwapInterval.

• bool ReleaseThread()

  eglReleaseThread.

• nint GetProcAddress(string name)

  eglGetProcAddress.

• nint GetClientProcAddress(string name)

  The same symbol in the client library, when there is one to ask.

• uint GetError()

  eglGetError, which clears as it reads.

Used by (3)

• EglContextVixen.Graphics.OpenGL
• NativeEglApiVixen.Graphics.OpenGL
• RecordingEglApiVixen.Graphics.OpenGL.Tests