[Mesa-dev] [PATCH 1/3] egl: rework handling EGL_CONTEXT_FLAGS for ES debug contexts

[Matthew Waters]

From: Matthew Waters <ystreet00 at gmail.com>

As of version 15 of the EGL_KHR_create_context spec, debug contexts
are allowed for ES contexts.  We should allow creation instead of
erroring.

Signed-off-by: Matthew Waters <ystreet00 at gmail.com>
---
 src/egl/main/eglcontext.c              | 51 ++++++++++++++++++++++++++++++----
 src/mesa/drivers/dri/common/dri_util.c | 17 ------------
 2 files changed, 45 insertions(+), 23 deletions(-)

diff --git a/src/egl/main/eglcontext.c b/src/egl/main/eglcontext.c
index 514b91a..ab50fe7 100644
--- a/src/egl/main/eglcontext.c
+++ b/src/egl/main/eglcontext.c
@@ -121,12 +121,51 @@ _eglParseContextAttribList(_EGLContext *ctx, _EGLDisplay *dpy,
 
          /* The EGL_KHR_create_context spec says:
           *
-          *     "Flags are only defined for OpenGL context creation, and
-          *     specifying a flags value other than zero for other types of
-          *     contexts, including OpenGL ES contexts, will generate an
-          *     error."
+          *     "If the EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR flag bit is set in
+          *     EGL_CONTEXT_FLAGS_KHR, then a <debug context> will be created.
+          *     [...]
+          *     In some cases a debug context may be identical to a non-debug
+          *     context. This bit is supported for OpenGL and OpenGL ES
+          *     contexts."
+          */
+         if (api != EGL_OPENGL_API && api != EGL_OPENGL_ES_API
+                && (val & EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR)) {
+            err = EGL_BAD_ATTRIBUTE;
+            break;
+         }
+
+         /* The EGL_KHR_create_context spec says:
+          *
+          *     "If the EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR flag bit
+          *     is set in EGL_CONTEXT_FLAGS_KHR, then a <forward-compatible>
+          *     context will be created. Forward-compatible contexts are
+          *     defined only for OpenGL versions 3.0 and later. They must not
+          *     support functionality marked as <deprecated> by that version of
+          *     the API, while a non-forward-compatible context must support
+          *     all functionality in that version, deprecated or not. This bit
+          *     is supported for OpenGL contexts, and requesting a
+          *     forward-compatible context for OpenGL versions less than 3.0
+          *     will generate an error."
+          */
+         if ((val & EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR)
+                && (api != EGL_OPENGL_API || ctx->ClientMajorVersion < 3)) {
+            err = EGL_BAD_ATTRIBUTE;
+            break;
+         }
+
+         /* The EGL_KHR_create_context_spec says:
+          *
+          *     "If the EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR bit is set in
+          *     EGL_CONTEXT_FLAGS_KHR, then a context supporting <robust buffer
+          *     access> will be created. Robust buffer access is defined in the
+          *     GL_ARB_robustness extension specification, and the resulting
+          *     context must also support either the GL_ARB_robustness
+          *     extension, or a version of OpenGL incorporating equivalent
+          *     functionality. This bit is supported for OpenGL contexts.
           */
-         if (api != EGL_OPENGL_API && val != 0) {
+         if ((val & EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR)
+                && (api != EGL_OPENGL_API
+                    || !dpy->Extensions.EXT_create_context_robustness)) {
             err = EGL_BAD_ATTRIBUTE;
             break;
          }
@@ -194,7 +233,7 @@ _eglParseContextAttribList(_EGLContext *ctx, _EGLDisplay *dpy,
             break;
          }
 
-         ctx->Flags = EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR;
+         ctx->Flags |= EGL_CONTEXT_OPENGL_ROBUST_ACCESS_BIT_KHR;
          break;
 
       default:
diff --git a/src/mesa/drivers/dri/common/dri_util.c b/src/mesa/drivers/dri/common/dri_util.c
index 6c78928..7a953ba 100644
--- a/src/mesa/drivers/dri/common/dri_util.c
+++ b/src/mesa/drivers/dri/common/dri_util.c
@@ -376,23 +376,6 @@ driCreateContextAttribs(__DRIscreen *screen, int api,
        return NULL;
     }
 
-    /* The EGL_KHR_create_context spec says:
-     *
-     *     "Flags are only defined for OpenGL context creation, and specifying
-     *     a flags value other than zero for other types of contexts,
-     *     including OpenGL ES contexts, will generate an error."
-     *
-     * The GLX_EXT_create_context_es2_profile specification doesn't say
-     * anything specific about this case.  However, none of the known flags
-     * have any meaning in an ES context, so this seems safe.
-     */
-    if (mesa_api != API_OPENGL_COMPAT
-        && mesa_api != API_OPENGL_CORE
-        && flags != 0) {
-	*error = __DRI_CTX_ERROR_BAD_FLAG;
-	return NULL;
-    }
-
     /* There are no forward-compatible contexts before OpenGL 3.0.  The
      * GLX_ARB_create_context spec says:
      *
-- 
2.1.2