mesa: Compute effective buffer bindings in the vao.

Compute VAO buffer binding information past the position/generic0 mapping.
Scan for duplicate buffer bindings and collapse them into derived
effective buffer binding index and effective attribute mask variables.
Provide a set of helper functions to access the distilled
information in the VAO. All of them prefixed with _mesa_draw_...
to indicate that they are meant to query draw information.

v2: Also group user space arrays containing interleaved arrays.
    Add _Eff*Offset to be copied on attribute and binding copy.
    Update comments.

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

1 files changed, 186 insertions, 0 deletions

diff --git a/src/mesa/main/arrayobj.h b/src/mesa/main/arrayobj.h
index 8da5c9ffe01..8b11c79bdb9 100644
--- a/src/mesa/main/arrayobj.h
+++ b/src/mesa/main/arrayobj.h
@@ -30,6 +30,7 @@
 #include "glheader.h"
 #include "mtypes.h"
 #include "glformats.h"
+#include "vbo/vbo.h"
 
 struct gl_context;
 
@@ -146,6 +147,191 @@ _mesa_get_vao_vp_inputs(const struct gl_vertex_array_object *vao)
 }
 
 
+/**
+ * Helper functions for consuming backends to walk the
+ * ctx->Array._DrawVAO for driver side array setup.
+ * Note that mesa provides preprocessed minimal binding information
+ * in the VAO. See _mesa_update_vao_derived_arrays for documentation.
+ */
+
+/**
+ * Return enabled vertex attribute bits for draw.
+ */
+static inline GLbitfield
+_mesa_draw_array_bits(const struct gl_context *ctx)
+{
+   return ctx->Array._DrawVAOEnabledAttribs;
+}
+
+
+/**
+ * Return enabled buffer object vertex attribute bits for draw.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLbitfield
+_mesa_draw_vbo_array_bits(const struct gl_context *ctx)
+{
+   const struct gl_vertex_array_object *const vao = ctx->Array._DrawVAO;
+   assert(vao->NewArrays == 0);
+   return vao->_EffEnabledVBO & ctx->Array._DrawVAOEnabledAttribs;
+}
+
+
+/**
+ * Return enabled user space vertex attribute bits for draw.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLbitfield
+_mesa_draw_user_array_bits(const struct gl_context *ctx)
+{
+   const struct gl_vertex_array_object *const vao = ctx->Array._DrawVAO;
+   assert(vao->NewArrays == 0);
+   return ~vao->_EffEnabledVBO & ctx->Array._DrawVAOEnabledAttribs;
+}
+
+
+/**
+ * Return enabled current values attribute bits for draw.
+ */
+static inline GLbitfield
+_mesa_draw_current_bits(const struct gl_context *ctx)
+{
+   return ~ctx->Array._DrawVAOEnabledAttribs & VERT_BIT_ALL;
+}
+
+
+/**
+ * Return vertex buffer binding provided the attribute struct.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline const struct gl_vertex_buffer_binding*
+_mesa_draw_buffer_binding_from_attrib(const struct gl_vertex_array_object *vao,
+                                      const struct gl_array_attributes *attrib)
+{
+   assert(vao->NewArrays == 0);
+   return &vao->BufferBinding[attrib->_EffBufferBindingIndex];
+}
+
+
+/**
+ * Return vertex array attribute provided the attribute number.
+ */
+static inline const struct gl_array_attributes*
+_mesa_draw_array_attrib(const struct gl_vertex_array_object *vao,
+                        gl_vert_attrib attr)
+{
+   assert(vao->NewArrays == 0);
+   const gl_attribute_map_mode map_mode = vao->_AttributeMapMode;
+   return &vao->VertexAttrib[_mesa_vao_attribute_map[map_mode][attr]];
+}
+
+
+/**
+ * Return vertex buffer binding provided an attribute number.
+ */
+static inline const struct gl_vertex_buffer_binding*
+_mesa_draw_buffer_binding(const struct gl_vertex_array_object *vao,
+                          gl_vert_attrib attr)
+{
+   const struct gl_array_attributes *const attrib
+      = _mesa_draw_array_attrib(vao, attr);
+   return _mesa_draw_buffer_binding_from_attrib(vao, attrib);
+}
+
+
+/**
+ * Return vertex attribute bits bound at the provided binding.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLbitfield
+_mesa_draw_bound_attrib_bits(const struct gl_vertex_buffer_binding *binding)
+{
+   return binding->_EffBoundArrays;
+}
+
+
+/**
+ * Return the vertex offset bound at the provided binding.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLintptr
+_mesa_draw_binding_offset(const struct gl_vertex_buffer_binding *binding)
+{
+   return binding->_EffOffset;
+}
+
+
+/**
+ * Return the relative offset of the provided attrib.
+ *
+ * Needs the a fully updated VAO ready for draw.
+ */
+static inline GLushort
+_mesa_draw_attributes_relative_offset(const struct gl_array_attributes *attrib)
+{
+   return attrib->_EffRelativeOffset;
+}
+
+
+/**
+ * Return a current value vertex array attribute provided the attribute number.
+ */
+static inline const struct gl_array_attributes*
+_mesa_draw_current_attrib(const struct gl_context *ctx, gl_vert_attrib attr)
+{
+   return _vbo_current_attrib(ctx, attr);
+}
+
+
+/**
+ * Return true if we have the VERT_ATTRIB_EDGEFLAG array enabled.
+ */
+static inline bool
+_mesa_draw_edge_flag_array_enabled(const struct gl_context *ctx)
+{
+   return ctx->Array._DrawVAOEnabledAttribs & VERT_BIT_EDGEFLAG;
+}
+
+
+/**
+ * Return the attrib for the given attribute.
+ */
+static inline const struct gl_array_attributes*
+_mesa_draw_attrib(const struct gl_context *ctx, gl_vert_attrib attr)
+{
+   if (ctx->Array._DrawVAOEnabledAttribs & VERT_BIT(attr)) {
+      const struct gl_vertex_array_object *vao = ctx->Array._DrawVAO;
+      return _mesa_draw_array_attrib(vao, attr);
+   } else {
+      return _vbo_current_attrib(ctx, attr);
+   }
+}
+
+
+/**
+ * Return the attrib, binding pair for the given attribute.
+ */
+static inline void
+_mesa_draw_attrib_and_binding(const struct gl_context *ctx, gl_vert_attrib attr,
+                              const struct gl_array_attributes **attrib,
+                              const struct gl_vertex_buffer_binding **binding)
+{
+   if (ctx->Array._DrawVAOEnabledAttribs & VERT_BIT(attr)) {
+      const struct gl_vertex_array_object *vao = ctx->Array._DrawVAO;
+      *attrib = _mesa_draw_array_attrib(vao, attr);
+      *binding = _mesa_draw_buffer_binding_from_attrib(vao, *attrib);
+   } else {
+      *attrib = _vbo_current_attrib(ctx, attr);
+      *binding = _vbo_current_binding(ctx);
+   }
+}
+
+
 /*
  * API functions
  */