Wrap every place that accesses a dispatch table with a macro. A new script-

generated file, called src/mesa/glapi/dispatch.h, is added.  This file
contains three macros for each API function.  It contains a GET, a SET, and
a CALL.  Each of the macros take a pointer to the context and a pointer to
the dispatch table.

In several threads on mesa3d-dev we discussed replacing _glapi_add_entrypoint
with a new function called _glapi_add_dispatch.  For this discussion, the
important difference between the two is that the caller of _glapi_add_dispatch
does *not* know what the dispatch offset will be at compile time.  Because of
this callers need to track the dispatch offset returned by
_glapi_add_dispatch.

http://marc.theaimsgroup.com/?t=111947074700001&r=1&w=2

The downside is that driver code then has to access the dispatch table two
different ways.  It accesses it using structure tags (e.g., exec->Begin) for
functions with fixed offsets and via a remap table (e.g., exec[
remap->NewExtensionFunction ]) for functions without fixed offsets. Yuck!

Using the macros allows both types of functions to be accessed
identically.  If a driver needs to set a pointer for Begin, it does
'SET_Begin(ctx, exec, my_begin_function)'.  If it needs to set a pointer
for NewExtensionFunction, it does 'SET_NewExtensionFunction(ctx, exec,
my_NewExtensionFunction_function)'.  Furthermore, if at some point in
the future a static offset is assigned for NewExtensionFunction, only
the macros need to change (instead of every single place that accesses a
table for that function).

This code differs slightly from the originally posted patches in that the
CALL, GET, and SET marcos no longer take a context pointer as a parameter.
Brian Paul had suggested that the remap table could be stored as a global
since it would be set at CreateScreen time and would be constant for all
contexts.  This change reflects that feedback.

http://marc.theaimsgroup.com/?t=112087194700001&r=1&w=2

1 files changed, 7 insertions, 6 deletions

diff --git a/src/mesa/tnl/t_array_api.c b/src/mesa/tnl/t_array_api.c
index c8cd22f0c68..1ad77c5a99b 100644
--- a/src/mesa/tnl/t_array_api.c
+++ b/src/mesa/tnl/t_array_api.c
@@ -43,6 +43,7 @@
 #include "t_save_api.h"
 #include "t_context.h"
 #include "t_pipeline.h"
+#include "dispatch.h"
 
 static void fallback_drawarrays( GLcontext *ctx, GLenum mode, GLint start,
 				 GLsizei count )
@@ -52,10 +53,10 @@ static void fallback_drawarrays( GLcontext *ctx, GLenum mode, GLint start,
    assert(!ctx->CompileFlag);
    assert(ctx->Driver.CurrentExecPrimitive == GL_POLYGON+1);
 
-   GL_CALL(Begin)(mode);
+   CALL_Begin(GET_DISPATCH(), (mode));
    for (i = 0; i < count; i++) 
-       GL_CALL(ArrayElement)( start + i );
-   GL_CALL(End)();
+       CALL_ArrayElement(GET_DISPATCH(), ( start + i ));
+   CALL_End(GET_DISPATCH(), ());
 }
 
 
@@ -69,11 +70,11 @@ static void fallback_drawelements( GLcontext *ctx, GLenum mode, GLsizei count,
 
    /* Here, indices will already reflect the buffer object if active */
 
-   GL_CALL(Begin)(mode);
+   CALL_Begin(GET_DISPATCH(), (mode));
    for (i = 0 ; i < count ; i++) {
-      GL_CALL(ArrayElement)( indices[i] );
+      CALL_ArrayElement(GET_DISPATCH(), ( indices[i] ));
    }
-   GL_CALL(End)();
+   CALL_End(GET_DISPATCH(), ());
 }