[Mesa-dev] [PATCH] xlib: add support for GLX_ARB_create_context

[Roland Scheidegger]

Am 26.03.2016 um 18:45 schrieb Brian Paul:
> This adds the glXCreateContextAttribsARB() function for the xlib/swrast
> driver.  This allows more piglit tests to run with this driver.
> 
> For example, without this patch we get:
> $ bin/fbo-generatemipmap-1d -auto
> piglit: error: waffle_config_choose failed due to WAFFLE_ERROR_UNSUPPORTED_
> ON_PLATFORM: GLX_ARB_create_context is required in order to request an OpenGL
> version not equal to the default value 1.0
> piglit: error: Failed to create waffle_config for OpenGL 2.0 Compatibility Context
> piglit: info: Failed to create any GL context
> PIGLIT: {"result": "skip" }
> ---
>  src/mesa/drivers/x11/fakeglx.c | 52 ++++++++++++++++++++++++++++++++++++++++++
>  src/mesa/drivers/x11/glxapi.c  | 20 ++++++++++++++++
>  src/mesa/drivers/x11/glxapi.h  |  5 ++++
>  3 files changed, 77 insertions(+)
> 
> diff --git a/src/mesa/drivers/x11/fakeglx.c b/src/mesa/drivers/x11/fakeglx.c
> index 9286f71..80b7176 100644
> --- a/src/mesa/drivers/x11/fakeglx.c
> +++ b/src/mesa/drivers/x11/fakeglx.c
> @@ -74,6 +74,7 @@
>     "GLX_MESA_copy_sub_buffer " \
>     "GLX_MESA_pixmap_colormap " \
>     "GLX_MESA_release_buffers " \
> +   "GLX_ARB_create_context " \
>     "GLX_ARB_get_proc_address " \
>     "GLX_EXT_texture_from_pixmap " \
>     "GLX_EXT_visual_info " \
> @@ -2831,6 +2832,56 @@ Fake_glXReleaseTexImageEXT(Display *dpy, GLXDrawable drawable, int buffer)
>  }
>  
>  
> +static GLXContext
> +Fake_glXCreateContextAttribs(Display *dpy, GLXFBConfig config,
> +                             GLXContext share_context, Bool direct,
> +                             const int *attrib_list)
> +{
> +   XMesaContext xmCtx;
> +   XMesaVisual xmvis = (XMesaVisual) config;
> +   int i;
> +   int major = 0, minor = 0, ctxFlags = 0, profileFlags = 0;
> +
> +   for (i = 0; attrib_list[i]; i += 2) {
> +      switch (attrib_list[i]) {
> +      case GLX_CONTEXT_MAJOR_VERSION_ARB:
> +         major = attrib_list[i + 1];
> +         break;
> +      case GLX_CONTEXT_MINOR_VERSION_ARB:
> +         minor = attrib_list[i + 1];
> +         break;
> +      case GLX_CONTEXT_FLAGS_ARB:
> +         ctxFlags = attrib_list[i + 1];
> +         break;
> +      case GLX_CONTEXT_PROFILE_MASK_ARB:
> +         profileFlags = attrib_list[i + 1];
> +         break;
> +      default:
> +         fprintf(stderr, "Bad attribute in glXCreateContextAttribs()\n");
> +         return 0;
> +      }
> +   }
> +
> +   if (major * 10 + minor > 21) {
> +      /* swrast only supports GL 2.1 and earlier */
> +      return 0;
> +   }
> +
> +   /* These are ignored for now.  We'd have to enhance XMesaCreateContext
> +    * to take these flags and the version, at least.
> +    */
> +   (void) ctxFlags;
> +   (void) profileFlags;
> +
> +   /* deallocate unused windows/buffers */
> +   XMesaGarbageCollect(dpy);
> +
> +   xmCtx = XMesaCreateContext(xmvis, (XMesaContext) share_context);
> +
> +   return (GLXContext) xmCtx;
> +}
> +
> +
>  /* silence warning */
>  extern struct _glxapi_table *_mesa_GetGLXDispatchTable(void);
>  
> @@ -2990,5 +3041,6 @@ _mesa_GetGLXDispatchTable(void)
>     glx.BindTexImageEXT = Fake_glXBindTexImageEXT;
>     glx.ReleaseTexImageEXT = Fake_glXReleaseTexImageEXT;
>  
> +   glx.CreateContextAttribs = Fake_glXCreateContextAttribs;
>     return &glx;
>  }
> diff --git a/src/mesa/drivers/x11/glxapi.c b/src/mesa/drivers/x11/glxapi.c
> index a870e94..cc1bb2a 100644
> --- a/src/mesa/drivers/x11/glxapi.c
> +++ b/src/mesa/drivers/x11/glxapi.c
> @@ -1319,6 +1319,9 @@ static struct name_address_pair GLX_functions[] = {
>     { "glXBindTexImageEXT", (__GLXextFuncPtr) glXBindTexImageEXT },
>     { "glXReleaseTexImageEXT", (__GLXextFuncPtr) glXReleaseTexImageEXT },
>  
> +   /*** GLX_ARB_create_context ***/
> +   { "glXCreateContextAttribsARB", (__GLXextFuncPtr) glXCreateContextAttribsARB },
> +
>     { NULL, NULL }   /* end of list */
>  };
>  
> @@ -1370,3 +1373,20 @@ void PUBLIC
>  {
>     return glXGetProcAddressARB(procName);
>  }
> +
> +
> +/**
> + * Added in GLX_ARB_create_context.
> + */
> +GLXContext PUBLIC
> +glXCreateContextAttribsARB(Display *dpy, GLXFBConfig config,
> +                           GLXContext share_context, Bool direct,
> +                           const int *attrib_list)
> +{
> +   struct _glxapi_table *t;
> +   GET_DISPATCH(dpy, t);
> +   if (!t)
> +      return 0;
> +   return (t->CreateContextAttribs)(dpy, config, share_context, direct,
> +                                    attrib_list);
> +}
> diff --git a/src/mesa/drivers/x11/glxapi.h b/src/mesa/drivers/x11/glxapi.h
> index bd6e970..aff38f7 100644
> --- a/src/mesa/drivers/x11/glxapi.h
> +++ b/src/mesa/drivers/x11/glxapi.h
> @@ -201,6 +201,11 @@ struct _glxapi_table {
>     void (*BindTexImageEXT)(Display *dpy, GLXDrawable drawable, int buffer,
>                             const int *attrib_list);
>     void (*ReleaseTexImageEXT)(Display *dpy, GLXDrawable drawable, int buffer);
> +
> +   /*** GLX_ARB_create_context ***/
> +   GLXContext (*CreateContextAttribs)(Display *dpy, GLXFBConfig config,
> +                                      GLXContext share_context, Bool direct,
> +                                      const int *attrib_list);
>  };
>  
>  
> 

The idea looks right to me but I don't really know this code.
Acked-by: Roland Scheidegger <sroland at vmware.com>