[Mesa-dev] [RFC 11/21] mesa: In helpers, only check driver capability for meta

[Nanley Chery]

From: Nanley Chery <nanley.g.chery at intel.com>

Make constext API and version checks done by the helper functions pass
unconditionally while meta is in progress. This transparently makes
extension checks solely dependent on struct gl_extensions while in meta.

Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
---
 src/mesa/drivers/common/meta.c | 11 +++++++++++
 src/mesa/drivers/common/meta.h |  1 +
 src/mesa/main/extensions.h     |  2 +-
 src/mesa/main/mtypes.h         |  6 ++++++
 src/mesa/main/version.c        |  1 +
 5 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index e27489d..0ffcd9c 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -449,6 +449,16 @@ _mesa_meta_begin(struct gl_context *ctx, GLbitfield state)
    save->API = ctx->API;
    ctx->API = API_OPENGL_COMPAT;
 
+   /* Mesa's extension helper functions use the current context's API to look up
+    * the version required by an extension as a step in determining whether or
+    * not it has been advertised. Since meta aims to only be restricted by the
+    * driver capability (and not by whether or not an extension has been
+    * advertised), set the helper functions' Version variable to a value that
+    * will make the checks on the context API and version unconditionally pass.
+    */
+   save->ExtensionsVersion = ctx->Extensions.Version;
+   ctx->Extensions.Version = ~0;
+
    /* Pausing transform feedback needs to be done early, or else we won't be
     * able to change other state.
     */
@@ -1222,6 +1232,7 @@ _mesa_meta_end(struct gl_context *ctx)
    ctx->Meta->SaveStackDepth--;
 
    ctx->API = save->API;
+   ctx->Extensions.Version = save->ExtensionsVersion;
 }
 
 
diff --git a/src/mesa/drivers/common/meta.h b/src/mesa/drivers/common/meta.h
index 23fa209..4351242 100644
--- a/src/mesa/drivers/common/meta.h
+++ b/src/mesa/drivers/common/meta.h
@@ -72,6 +72,7 @@ struct save_state
 
    /* Always saved/restored with meta. */
    gl_api API;
+   GLuint ExtensionsVersion;
 
    /** MESA_META_CLEAR (and others?) */
    struct gl_query_object *CurrentOcclusionObject;
diff --git a/src/mesa/main/extensions.h b/src/mesa/main/extensions.h
index 50456e98..8f106aa 100644
--- a/src/mesa/main/extensions.h
+++ b/src/mesa/main/extensions.h
@@ -88,7 +88,7 @@ enum {
 /** Checks if the context suports a user-facing extension */
 #define EXT(name_str, driver_cap, ...) \
 static inline bool _mesa_has_##name_str(const struct gl_context *ctx) { \
-      return ctx->Extensions.driver_cap && (ctx->Version > \
+      return ctx->Extensions.driver_cap && (ctx->Extensions.Version > \
              extension_table[MESA_EXTENSION_##name_str].version[ctx->API]); \
 }
 #include "extensions_table.h"
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index f7118c1..a67c5c0 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -3824,6 +3824,12 @@ struct gl_extensions
    const GLubyte *String;
    /** Number of supported extensions */
    GLuint Count;
+   /**
+    * The context version which extension helper functions compare against.
+    * By default, the value is equal to ctx->Version. This changes to ~0,
+    * while meta is in progress.
+    */
+   GLuint Version;
 };
 
 
diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
index 5635a64..314b26d 100644
--- a/src/mesa/main/version.c
+++ b/src/mesa/main/version.c
@@ -524,6 +524,7 @@ _mesa_compute_version(struct gl_context *ctx)
       return;
 
    ctx->Version = _mesa_get_version(&ctx->Extensions, &ctx->Const, ctx->API);
+   ctx->Extensions.Version = ctx->Version;
 
    /* Make sure that the GLSL version lines up with the GL version. In some
     * cases it can be too high, e.g. if an extension is missing.
-- 
2.6.1