Current status of EGL spec

[Brian Paul]

Jon Smirl wrote:
> On 8/10/05, Brian Paul <brian.paul at tungstengraphics.com> wrote:
> 
>>Jon Smirl wrote:
>>
>>>I pretty have a working EGL implementation on radeon DRI now. The code
>>>is checked into the mesa tree. Is it time to push the spec on to
>>>khronos?
>>
>>I haven't had time to finalize the spec.  There's still a number of
>>open issues that should be addressed.
>>
>>
>>
>>>Some minor issues I had...
>>>
>>>1) Would it make sense to eliminate modes and just add an attribute to
>>>configs marking them as displayable? Something like EGL_SCREEN_BIT.
>>
>>No.  Modes have the following attributes: width, height, refresh rate,
>>interlaced.  It wouldn't be good to tie configs (pixel formats) to
>>those attributes.  For example, you'd need separate pixel formats and
>>rendering context to draw to two surfaces which only differed in width
>>and height.
>>
>>
>>
>>>2) Given eglQueryScreenSurfaceMESA and eglCreateScreenSurfaceMESA, for
>>>symmetry should eglShowSurfaceMESA instead be
>>>eglShowScreenSurfaceMESA?
>>
>>That would be OK with me.
>>
>>
>>
>>>3) Should eglScreenPositionMESA(EGLDisplay dpy, EGLScreenMESA screen,
>>>EGLint x, EGLint y) instead use EGLint *x, EGLint *y. That would allow
>>>hardwar
>>
>>You got chopped off there, but I think I know what you're getting at
>>(return the actual position in case 1-pixel positioning isn't supported).
>>
>>First, OpenGL conventionally doesn't use in/out parameters like that.
>>  Second, how common is it that hardware can't support 1-pixel
>>positioning?  If it's not a common problem, I'd defer for a future
>>extension which would allow you to query the positioning granularity.
> 
> 
> We could add a GetScreenPosition call which would take care of this.

Already present: eglQueryScreenMESA(dpy, scrn, 
EGL_SCREEN_POSITION_MESA, pos)


> I'm not sure but it looks like the radeon hardware can only be
> positioned in 8 bit increments. Can someone more familiar with the
> hardware verify this?

Easily done by decreasing the current resolution in X with CTRL-ALT-+ 
then scrolling with the mouse.

-Brian