vbo: create a new draw function interface for indirect draws

All indirect draws are passed to the new draw function. By default
there's a fallback implementation which pipes it right back to
draw_prims, but eventually both the fallback and draw_prim's support for
indirect drawing should be removed.

This should allow a backend to properly support ARB_multi_draw_indirect
and ARB_indirect_parameters.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Acked-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

4 files changed, 89 insertions, 75 deletions

diff --git a/src/mesa/vbo/vbo.h b/src/mesa/vbo/vbo.h
index dd9b428..0b8b6a9 100644
--- a/src/mesa/vbo/vbo.h
+++ b/src/mesa/vbo/vbo.h
@@ -110,6 +110,18 @@ typedef void (*vbo_draw_func)( struct gl_context *ctx,
 			       struct gl_buffer_object *indirect);
 
 
+typedef void (*vbo_indirect_draw_func)(
+   struct gl_context *ctx,
+   GLuint mode,
+   struct gl_buffer_object *indirect_data,
+   GLsizeiptr indirect_offset,
+   unsigned draw_count,
+   unsigned stride,
+   struct gl_buffer_object *indirect_params,
+   GLsizeiptr indirect_params_offset,
+   const struct _mesa_index_buffer *ib);
+
+
 
 
 /* Utility function to cope with various constraints on tnl modules or
@@ -179,6 +191,9 @@ void vbo_always_unmap_buffers(struct gl_context *ctx);
 
 void vbo_set_draw_func(struct gl_context *ctx, vbo_draw_func func);
 
+void vbo_set_indirect_draw_func(struct gl_context *ctx,
+                                vbo_indirect_draw_func func);
+
 void vbo_check_buffers_are_unmapped(struct gl_context *ctx);
 
 void vbo_bind_arrays(struct gl_context *ctx);
diff --git a/src/mesa/vbo/vbo_context.c b/src/mesa/vbo/vbo_context.c
index 19b35a4..9f807a1 100644
--- a/src/mesa/vbo/vbo_context.c
+++ b/src/mesa/vbo/vbo_context.c
@@ -135,6 +135,48 @@ static void init_mat_currval(struct gl_context *ctx)
    }
 }
 
+static void
+vbo_draw_indirect_prims(struct gl_context *ctx,
+                        GLuint mode,
+                        struct gl_buffer_object *indirect_data,
+                        GLsizeiptr indirect_offset,
+                        unsigned draw_count,
+                        unsigned stride,
+                        struct gl_buffer_object *indirect_params,
+                        GLsizeiptr indirect_params_offset,
+                        const struct _mesa_index_buffer *ib)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   struct _mesa_prim *prim;
+   GLsizei i;
+
+   prim = calloc(draw_count, sizeof(*prim));
+   if (prim == NULL) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "gl%sDraw%sIndirect%s",
+                  (draw_count > 1) ? "Multi" : "",
+                  ib ? "Elements" : "Arrays",
+                  indirect_params ? "CountARB" : "");
+      return;
+   }
+
+   prim[0].begin = 1;
+   prim[draw_count - 1].end = 1;
+   for (i = 0; i < draw_count; ++i, indirect_offset += stride) {
+      prim[i].mode = mode;
+      prim[i].indexed = !!ib;
+      prim[i].indirect_offset = indirect_offset;
+      prim[i].is_indirect = 1;
+      prim[i].draw_id = i;
+   }
+
+   vbo->draw_prims(ctx, prim, draw_count,
+                   ib, GL_TRUE, 0, ~0,
+                   NULL, 0,
+                   ctx->DrawIndirectBuffer);
+
+   free(prim);
+}
+
 
 GLboolean _vbo_CreateContext( struct gl_context *ctx )
 {
@@ -152,6 +194,7 @@ GLboolean _vbo_CreateContext( struct gl_context *ctx )
    init_legacy_currval( ctx );
    init_generic_currval( ctx );
    init_mat_currval( ctx );
+   vbo_set_indirect_draw_func(ctx, vbo_draw_indirect_prims);
 
    /* Build mappings from VERT_ATTRIB -> VBO_ATTRIB depending on type
     * of vertex program active.
@@ -223,3 +266,10 @@ void vbo_set_draw_func(struct gl_context *ctx, vbo_draw_func func)
    vbo->draw_prims = func;
 }
 
+
+void vbo_set_indirect_draw_func(struct gl_context *ctx,
+                                vbo_indirect_draw_func func)
+{
+   struct vbo_context *vbo = vbo_context(ctx);
+   vbo->draw_indirect_prims = func;
+}
diff --git a/src/mesa/vbo/vbo_context.h b/src/mesa/vbo/vbo_context.h
index 6293a8b..11f9b17 100644
--- a/src/mesa/vbo/vbo_context.h
+++ b/src/mesa/vbo/vbo_context.h
@@ -76,6 +76,12 @@ struct vbo_context {
     * is responsible for initiating any fallback actions required:
     */
    vbo_draw_func draw_prims;
+
+   /* Optional callback for indirect draws. This allows multidraws to not be
+    * broken up, as well as for the actual count to be passed in as a separate
+    * indirect parameter.
+    */
+   vbo_indirect_draw_func draw_indirect_prims;
 };
 
 
diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index 502b288..2589ff4 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -1546,27 +1546,14 @@ vbo_validated_drawarraysindirect(struct gl_context *ctx,
 {
    struct vbo_context *vbo = vbo_context(ctx);
    struct vbo_exec_context *exec = &vbo->exec;
-   struct _mesa_prim prim[1];
 
    vbo_bind_arrays(ctx);
 
-   memset(prim, 0, sizeof(prim));
-   prim[0].begin = 1;
-   prim[0].end = 1;
-   prim[0].mode = mode;
-   prim[0].is_indirect = 1;
-   prim[0].indirect_offset = (GLsizeiptr)indirect;
-
-   /* NOTE: We do NOT want to handle primitive restart here, nor perform any
-    * other checks that require knowledge of the values in the command buffer.
-    * That would defeat the whole purpose of this function.
-    */
-
    check_buffers_are_unmapped(exec->array.inputs);
-   vbo->draw_prims(ctx, prim, 1,
-                   NULL, GL_TRUE, 0, ~0,
-                   NULL, 0,
-                   ctx->DrawIndirectBuffer);
+   vbo->draw_indirect_prims(ctx, mode,
+                            ctx->DrawIndirectBuffer, (GLsizeiptr)indirect,
+                            1 /* draw_count */, 16 /* stride */,
+                            NULL, 0, NULL);
 
    if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
       _mesa_flush(ctx);
@@ -1580,36 +1567,18 @@ vbo_validated_multidrawarraysindirect(struct gl_context *ctx,
 {
    struct vbo_context *vbo = vbo_context(ctx);
    struct vbo_exec_context *exec = &vbo->exec;
-   struct _mesa_prim *prim;
-   GLsizei i;
    GLsizeiptr offset = (GLsizeiptr)indirect;
 
    if (primcount == 0)
       return;
-   prim = calloc(primcount, sizeof(*prim));
-   if (prim == NULL) {
-      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glMultiDrawArraysIndirect");
-      return;
-   }
 
    vbo_bind_arrays(ctx);
 
-   prim[0].begin = 1;
-   prim[primcount - 1].end = 1;
-   for (i = 0; i < primcount; ++i, offset += stride) {
-      prim[i].mode = mode;
-      prim[i].indirect_offset = offset;
-      prim[i].is_indirect = 1;
-      prim[i].draw_id = i;
-   }
-
    check_buffers_are_unmapped(exec->array.inputs);
-   vbo->draw_prims(ctx, prim, primcount,
-                   NULL, GL_TRUE, 0, ~0,
-                   NULL, 0,
-                   ctx->DrawIndirectBuffer);
-
-   free(prim);
+   vbo->draw_indirect_prims(ctx, mode,
+                            ctx->DrawIndirectBuffer, offset,
+                            primcount, stride,
+                            NULL, 0, NULL);
 
    if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
       _mesa_flush(ctx);
@@ -1623,7 +1592,6 @@ vbo_validated_drawelementsindirect(struct gl_context *ctx,
    struct vbo_context *vbo = vbo_context(ctx);
    struct vbo_exec_context *exec = &vbo->exec;
    struct _mesa_index_buffer ib;
-   struct _mesa_prim prim[1];
 
    vbo_bind_arrays(ctx);
 
@@ -1632,19 +1600,12 @@ vbo_validated_drawelementsindirect(struct gl_context *ctx,
    ib.obj = ctx->Array.VAO->IndexBufferObj;
    ib.ptr = NULL;
 
-   memset(prim, 0, sizeof(prim));
-   prim[0].begin = 1;
-   prim[0].end = 1;
-   prim[0].mode = mode;
-   prim[0].indexed = 1;
-   prim[0].indirect_offset = (GLsizeiptr)indirect;
-   prim[0].is_indirect = 1;
-
    check_buffers_are_unmapped(exec->array.inputs);
-   vbo->draw_prims(ctx, prim, 1,
-                   &ib, GL_TRUE, 0, ~0,
-                   NULL, 0,
-                   ctx->DrawIndirectBuffer);
+   vbo->draw_indirect_prims(ctx, mode,
+                            ctx->DrawIndirectBuffer, (GLsizeiptr)indirect,
+                            1 /* draw_count */, 20 /* stride */,
+                            NULL, 0,
+                            &ib);
 
    if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
       _mesa_flush(ctx);
@@ -1659,17 +1620,10 @@ vbo_validated_multidrawelementsindirect(struct gl_context *ctx,
    struct vbo_context *vbo = vbo_context(ctx);
    struct vbo_exec_context *exec = &vbo->exec;
    struct _mesa_index_buffer ib;
-   struct _mesa_prim *prim;
-   GLsizei i;
    GLsizeiptr offset = (GLsizeiptr)indirect;
 
    if (primcount == 0)
       return;
-   prim = calloc(primcount, sizeof(*prim));
-   if (prim == NULL) {
-      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glMultiDrawElementsIndirect");
-      return;
-   }
 
    vbo_bind_arrays(ctx);
 
@@ -1680,23 +1634,12 @@ vbo_validated_multidrawelementsindirect(struct gl_context *ctx,
    ib.obj = ctx->Array.VAO->IndexBufferObj;
    ib.ptr = NULL;
 
-   prim[0].begin = 1;
-   prim[primcount - 1].end = 1;
-   for (i = 0; i < primcount; ++i, offset += stride) {
-      prim[i].mode = mode;
-      prim[i].indexed = 1;
-      prim[i].indirect_offset = offset;
-      prim[i].is_indirect = 1;
-      prim[i].draw_id = i;
-   }
-
    check_buffers_are_unmapped(exec->array.inputs);
-   vbo->draw_prims(ctx, prim, primcount,
-                   &ib, GL_TRUE, 0, ~0,
-                   NULL, 0,
-                   ctx->DrawIndirectBuffer);
-
-   free(prim);
+   vbo->draw_indirect_prims(ctx, mode,
+                            ctx->DrawIndirectBuffer, offset,
+                            primcount, stride,
+                            NULL, 0,
+                            &ib);
 
    if (MESA_DEBUG_FLAGS & DEBUG_ALWAYS_FLUSH)
       _mesa_flush(ctx);