EGL: C syntax

[capnm]

For example
https://github.com/errcw/glow/blob/master/xml/spec/egl.xml#L179
gives
DEFAULT_DISPLAY = ((EGLNativeDisplayType)0)
needs to be rewritten to
DEFAULT_DISPLAY = C.EGLNativeDisplayType(0)

UPDATE:
needs more work
./package.go:120: cannot convert 0 (type int) to type C.EGLNativeDisplayType

[capnm]

CGO needs another headers
38: error: 'EGLClientPixmapHI' undeclared (first use in this function)

relevant cgo bug:
cmd/cgo: request for better error messages
http://code.google.com/p/go/issues/detail?id=8442

[dominikh]

The issue with C.EGLClientPixmapHI (and C.AHardwareBuffer) is that they're declared as struct EGLClientPixmapHI { ... } – note the absence of a typedef – but then used as C.EGLClientPixmapHI instead of C.struct_EGLClientPixmapHI.

And instead of the DEFAULT_DISPLAY = ((EGLNativeDisplayType)0) issue, we now have a DEFAULT_DISPLAY = EGL_CAST(EGLNativeDisplayType, 0) issue. eglplatform.h seems to define EGL_CAST as #define EGL_CAST(type, value) ((type) (value))

[dominikh]

The incorrect struct types boil down to this difference in <param> formats in the GL and EGL specs:

gl.xml: <param group="cl_context"><ptype>struct _cl_context</ptype> *<name>context</name></param>
egl.xml: <param>struct <ptype>EGLClientPixmapHI</ptype> *<name>pixmap</name></param>

The struct is not part of the ptype.

[dominikh]

One final issue is the large number of object types, such as EGLConfig, EGLNativeDisplayType, and many others. I'm reluctant to change all of these to uintptr, but I don't think glow has a mechanism for making these first class types?

[asicerik]

I still cannot get EGL to compile. It is still showing the
could not determine kind of name for C.AHardwareBuffer
could not determine kind of name for C.EGLClientPixmapHI
errors, etc.
This is compiling under Windows. Is this supposed to work now?