[Mesa-dev] [PATCH 03/10] mesa: Implement _mesa_array_element by walking enabled arrays.

[Mathias.Froehlich at gmx.net]

From: Mathias Fröhlich <mathias.froehlich at web.de>

In glArrayElement, use the bitmask trick to just walk the enabled
vao arrays. This should be about equivalent in execution time to
walk the prepare aelt_context list. Finally this will allow us to
reduce the _mesa_update_state calls in a few patches.

Signed-off-by: Mathias Fröhlich <Mathias.Froehlich at web.de>
---
 src/mesa/main/api_arrayelt.c | 78 ++++++++++++++++++++++++++++--------
 1 file changed, 61 insertions(+), 17 deletions(-)

diff --git a/src/mesa/main/api_arrayelt.c b/src/mesa/main/api_arrayelt.c
index d46c8d14b68..62f1e73ca4c 100644
--- a/src/mesa/main/api_arrayelt.c
+++ b/src/mesa/main/api_arrayelt.c
@@ -1541,32 +1541,76 @@ _ae_update_state(struct gl_context *ctx)
 }


+static inline attrib_func
+func_nv(const struct gl_vertex_format *vformat)
+{
+   return AttribFuncsNV[vformat->Normalized][vformat->Size-1]
+      [TYPE_IDX(vformat->Type)];
+}
+
+
+static inline attrib_func
+func_arb(const struct gl_vertex_format *vformat)
+{
+   return AttribFuncsARB[NORM_IDX(vformat)][vformat->Size-1]
+      [TYPE_IDX(vformat->Type)];
+}
+
+
+static inline const void *
+attrib_src(const struct gl_vertex_array_object *vao,
+           const struct gl_array_attributes *array, GLint elt)
+{
+   const struct gl_vertex_buffer_binding *binding =
+      &vao->BufferBinding[array->BufferBindingIndex];
+   const GLubyte *src
+      = ADD_POINTERS(binding->BufferObj->Mappings[MAP_INTERNAL].Pointer,
+                     _mesa_vertex_attrib_address(array, binding))
+      + elt * binding->Stride;
+   return src;
+}
+
+
 void
 _mesa_array_element(struct gl_context *ctx,
                     struct _glapi_table *disp, GLint elt)
 {
-   const AEcontext *actx = AE_CONTEXT(ctx);
+   const struct gl_vertex_array_object *vao = ctx->Array.VAO;
+   GLbitfield mask;

-   if (actx->dirty_state)
-      _ae_update_state(ctx);
+   /* emit conventional arrays elements */
+   mask = (VERT_BIT_FF_ALL & ~VERT_BIT_POS) & vao->Enabled;
+   while (mask) {
+      const gl_vert_attrib attrib = u_bit_scan(&mask);
+      const struct gl_array_attributes *array = &vao->VertexAttrib[attrib];
+      const void *src = attrib_src(vao, array, elt);
+      func_nv(&array->Format)(attrib, src);
+   }

    /* emit generic attribute elements */
-   for (const AEattrib *at = actx->attribs; at->func; at++) {
-      const GLubyte *src
-         = ADD_POINTERS(at->binding->BufferObj->Mappings[MAP_INTERNAL].Pointer,
-                        _mesa_vertex_attrib_address(at->array, at->binding))
-         + elt * at->binding->Stride;
-      at->func(at->index, src);
+   mask = (VERT_BIT_GENERIC_ALL & ~VERT_BIT_GENERIC0) & vao->Enabled;
+   while (mask) {
+      const gl_vert_attrib attrib = u_bit_scan(&mask);
+      const struct gl_array_attributes *array = &vao->VertexAttrib[attrib];
+      const void *src = attrib_src(vao, array, elt);
+      func_arb(&array->Format)(attrib - VERT_ATTRIB_GENERIC0, src);
    }

-   /* emit conventional arrays elements */
-   for (const AEarray *aa = actx->arrays; aa->offset != -1 ; aa++) {
-      const GLubyte *src
-         = ADD_POINTERS(aa->binding->BufferObj->Mappings[MAP_INTERNAL].Pointer,
-                        _mesa_vertex_attrib_address(aa->array, aa->binding))
-         + elt * aa->binding->Stride;
-      CALL_by_offset(disp, (array_func), aa->offset, ((const void *) src));
-   }
+   /* finally, vertex position */
+   if (vao->Enabled & VERT_BIT_GENERIC0) {
+      const gl_vert_attrib attrib = VERT_ATTRIB_GENERIC0;
+      const struct gl_array_attributes *array = &vao->VertexAttrib[attrib];
+      const void *src = attrib_src(vao, array, elt);
+      /* Use glVertex(v) instead of glVertexAttrib(0, v) to be sure it's
+       * issued as the last (provoking) attribute).
+       */
+      func_nv(&array->Format)(0, src);
+   } else if (vao->Enabled & VERT_BIT_POS) {
+      const gl_vert_attrib attrib = VERT_ATTRIB_POS;
+      const struct gl_array_attributes *array = &vao->VertexAttrib[attrib];
+      const void *src = attrib_src(vao, array, elt);
+      func_nv(&array->Format)(0, src);
+    }
 }


--
2.20.1