mesa: Introduce a yet unused _DrawVAO.

During the patch series this VAO gets populated with either the currently
bound VAO or an internal VAO that will be used for immediate mode and
dlist rendering.

v2: More comments about the _DrawVAO, filter and enabled mask.
    Rename _DrawVAOEnabled to _DrawVAOEnabledAttribs.
v3: Fix and move comment.

Signed-off-by: Mathias Fröhlich <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 29 insertions, 0 deletions

diff --git a/src/mesa/main/state.c b/src/mesa/main/state.c
index 2fd4fb9d323..6dd7a7ec075 100644
--- a/src/mesa/main/state.c
+++ b/src/mesa/main/state.c
@@ -479,3 +479,32 @@ _mesa_update_vertex_processing_mode(struct gl_context *ctx)
    else
       ctx->VertexProgram._VPMode = VP_MODE_FF;
 }
+
+
+/**
+ * Set the _DrawVAO and the net enabled arrays.
+ * The vao->_Enabled bitmask is transformed due to position/generic0
+ * as stored in vao->_AttributeMapMode. Then the filter bitmask is applied
+ * to filter out arrays unwanted for the currently executed draw operation.
+ * For example, the generic attributes are masked out form the _DrawVAO's
+ * enabled arrays when a fixed function array draw is executed.
+ */
+void
+_mesa_set_draw_vao(struct gl_context *ctx, struct gl_vertex_array_object *vao,
+                   GLbitfield filter)
+{
+   struct gl_vertex_array_object **ptr = &ctx->Array._DrawVAO;
+   if (*ptr != vao) {
+      _mesa_reference_vao_(ctx, ptr, vao);
+      ctx->NewDriverState |= ctx->DriverFlags.NewArray;
+   } else if (vao->NewArrays) {
+      ctx->NewDriverState |= ctx->DriverFlags.NewArray;
+   }
+
+   /* May shuffle the position and generic0 bits around, filter out unwanted */
+   const GLbitfield enabled = filter & _mesa_get_vao_vp_inputs(vao);
+   if (ctx->Array._DrawVAOEnabledAttribs != enabled)
+      ctx->NewDriverState |= ctx->DriverFlags.NewArray;
+   ctx->Array._DrawVAOEnabledAttribs = enabled;
+   _mesa_set_varying_vp_inputs(ctx, enabled);
+}