[waffle] [PATCH 1/3] glx: don't use ARB_create_context with pre 3.0 contexts

[Jose Fonseca]

On 05/04/16 22:45, Emil Velikov wrote:
> This way if the user requests GL pre 3.0 context which lacks the
> flags/extra bits which require ARB_create_context one can safely fall
> back to the normal/legacy entry point.
>
> This resolves piglits on non 3.0 capable drivers such as classic swrast,
> nouveau_vieux and alike.
>
> Cc: Jose Fonseca <jfonseca at vmware.com>
> Cc: Ilia Mirkin <imirkin at alum.mit.edu>
> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> ---
>   src/waffle/glx/glx_config.c  |  7 ++++---
>   src/waffle/glx/glx_context.c | 12 +++++++++++-
>   src/waffle/glx/glx_context.h | 16 ++++++++++++++++
>   3 files changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/src/waffle/glx/glx_config.c b/src/waffle/glx/glx_config.c
> index 7792aa0..5d02bc3 100644
> --- a/src/waffle/glx/glx_config.c
> +++ b/src/waffle/glx/glx_config.c
> @@ -32,6 +32,7 @@
>   #include "wcore_error.h"
>
>   #include "glx_config.h"
> +#include "glx_context.h"
>   #include "glx_display.h"
>   #include "glx_platform.h"
>   #include "glx_wrappers.h"
> @@ -70,11 +71,11 @@ glx_config_check_context_attrs(struct glx_display *dpy,
>
>       switch (attrs->context_api) {
>           case WAFFLE_CONTEXT_OPENGL:
> -            if (!wcore_config_attrs_version_eq(attrs, 10) && !dpy->ARB_create_context) {
> +            if (glx_context_needs_arb_create_context(attrs) &&
> +                !dpy->ARB_create_context) {
>                   wcore_errorf(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");
> +                             "request an OpenGL version greater or equal than 3.0");
>                   return false;
>               }
>               else if (wcore_config_attrs_version_ge(attrs, 32) && !dpy->ARB_create_context_profile) {
> diff --git a/src/waffle/glx/glx_context.c b/src/waffle/glx/glx_context.c
> index 1f9290b..8d532d3 100644
> --- a/src/waffle/glx/glx_context.c
> +++ b/src/waffle/glx/glx_context.c
> @@ -169,7 +169,17 @@ glx_context_create_native(struct glx_config *config,
>       struct glx_display *dpy = glx_display(config->wcore.display);
>       struct glx_platform *platform = glx_platform(dpy->wcore.platform);
>
> -    if (dpy->ARB_create_context) {
> +    // Use ARB_create_context when we have
> +    // - OpenGL version 1.0, or
> +    // - OpenGL version 3.0 or greater, or
> +    // - OpenGL with fwd_compat, or
> +    // - Debug context
> +    //
> +    // The first one of the four is optional, the remainder hard requirement
> +    // for the use of ARB_create_context.
> +    if (dpy->ARB_create_context &&
> +        (wcore_config_attrs_version_eq(&config->wcore.attrs, 10) ||
> +         glx_context_needs_arb_create_context(&config->wcore.attrs))) {
>           bool ok;
>
>           // Choose a large size to prevent accidental overflow.
> diff --git a/src/waffle/glx/glx_context.h b/src/waffle/glx/glx_context.h
> index bb2a4dd..b471b0e 100644
> --- a/src/waffle/glx/glx_context.h
> +++ b/src/waffle/glx/glx_context.h
> @@ -29,6 +29,7 @@
>
>   #include <GL/glx.h>
>
> +#include "wcore_config_attrs.h"
>   #include "wcore_context.h"
>   #include "wcore_util.h"
>
> @@ -55,3 +56,18 @@ glx_context_destroy(struct wcore_context *wc_self);
>
>   union waffle_native_context*
>   glx_context_get_native(struct wcore_context *wc_self);
> +
> +
> +static inline bool
> +glx_context_needs_arb_create_context(const struct wcore_config_attrs *attrs)
> +{
> +    if (attrs->context_api == WAFFLE_CONTEXT_OPENGL &&
> +        (wcore_config_attrs_version_ge(attrs, 30) ||
> +         attrs->context_forward_compatible))
> +        return true;
> +
> +    if (attrs->context_debug)
> +        return true;
> +
> +    return false;
> +}
>


Looks good to me.  Thanks.

Reviewed-by: Jose Fonseca <jfonseca at vmware.com>