[Mesa-dev] [PATCH 14/18] mesa: add compat profile support for ARB_multi_draw_indirect

[Timothy Arceri]

---
 src/mesa/main/extensions_table.h |  2 +-
 src/mesa/vbo/vbo_exec_array.c    | 75 +++++++++++++++++++++++++++++++-
 2 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h
index 1446a4bd421..12b796777df 100644
--- a/src/mesa/main/extensions_table.h
+++ b/src/mesa/main/extensions_table.h
@@ -88,7 +88,7 @@ EXT(ARB_invalidate_subdata                  , dummy_true
 EXT(ARB_map_buffer_alignment                , dummy_true                             , GLL, GLC,  x ,  x , 2011)
 EXT(ARB_map_buffer_range                    , ARB_map_buffer_range                   , GLL, GLC,  x ,  x , 2008)
 EXT(ARB_multi_bind                          , dummy_true                             , GLL, GLC,  x ,  x , 2013)
-EXT(ARB_multi_draw_indirect                 , ARB_draw_indirect                      ,  x , GLC,  x ,  x , 2012)
+EXT(ARB_multi_draw_indirect                 , ARB_draw_indirect                      , GLL, GLC,  x ,  x , 2012)
 EXT(ARB_multisample                         , dummy_true                             , GLL,  x ,  x ,  x , 1994)
 EXT(ARB_multitexture                        , dummy_true                             , GLL,  x ,  x ,  x , 1998)
 EXT(ARB_occlusion_query                     , ARB_occlusion_query                    , GLL,  x ,  x ,  x , 2001)
diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index 0d92de2e3ad..4e24cdcf263 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -1744,7 +1744,36 @@ vbo_exec_MultiDrawArraysIndirect(GLenum mode, const GLvoid *indirect,
 
    /* If <stride> is zero, the array elements are treated as tightly packed. */
    if (stride == 0)
-      stride = 4 * sizeof(GLuint);      /* sizeof(DrawArraysIndirectCommand) */
+      stride = sizeof(DrawArraysIndirectCommand);
+
+   /* From the ARB_draw_indirect spec:
+    *
+    *    "Initially zero is bound to DRAW_INDIRECT_BUFFER. In the
+    *    compatibility profile, this indicates that DrawArraysIndirect and
+    *    DrawElementsIndirect are to source their arguments directly from the
+    *    pointer passed as their <indirect> parameters."
+    */
+   if (ctx->API == API_OPENGL_COMPAT &&
+       !_mesa_is_bufferobj(ctx->DrawIndirectBuffer)) {
+
+      if (!_mesa_valid_draw_indirect_multi(ctx, primcount, stride,
+                                           "glMultiDrawArraysIndirect"))
+         return;
+
+      const ubyte *ptr = (const ubyte *) indirect;
+      for (unsigned i = 0; i < primcount; i++) {
+         DrawArraysIndirectCommand *cmd = (DrawArraysIndirectCommand *) ptr;
+         _mesa_DrawArraysInstanced(mode, cmd->first, cmd->count, cmd->primCount);
+
+         if (stride == 0) {
+            ptr += sizeof(DrawArraysIndirectCommand);
+         } else {
+            ptr += stride;
+         }
+      }
+
+      return;
+   }
 
    FLUSH_FOR_DRAW(ctx);
 
@@ -1783,7 +1812,49 @@ vbo_exec_MultiDrawElementsIndirect(GLenum mode, GLenum type,
 
    /* If <stride> is zero, the array elements are treated as tightly packed. */
    if (stride == 0)
-      stride = 5 * sizeof(GLuint);      /* sizeof(DrawElementsIndirectCommand) */
+      stride = sizeof(DrawElementsIndirectCommand);
+
+
+   /* From the ARB_draw_indirect spec:
+    *
+    *    "Initially zero is bound to DRAW_INDIRECT_BUFFER. In the
+    *    compatibility profile, this indicates that DrawArraysIndirect and
+    *    DrawElementsIndirect are to source their arguments directly from the
+    *    pointer passed as their <indirect> parameters."
+    */
+   if (ctx->API == API_OPENGL_COMPAT &&
+       !_mesa_is_bufferobj(ctx->DrawIndirectBuffer)) {
+      /*
+       * Unlike regular DrawElementsInstancedBaseVertex commands, the indices
+       * may not come from a client array and must come from an index buffer.
+       * If no element array buffer is bound, an INVALID_OPERATION error is
+       * generated.
+       */
+      if (!_mesa_is_bufferobj(ctx->Array.VAO->IndexBufferObj)) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "glMultiDrawElementsIndirect(no buffer bound "
+                     "to GL_ELEMENT_ARRAY_BUFFER)");
+
+         return;
+      }
+
+      if (!_mesa_valid_draw_indirect_multi(ctx, primcount, stride,
+                                           "glMultiDrawArraysIndirect"))
+         return;
+
+      const ubyte *ptr = (const ubyte *) indirect;
+      for (unsigned i = 0; i < primcount; i++) {
+         vbo_exec_DrawElementsIndirect(mode, type, ptr);
+
+         if (stride == 0) {
+            ptr += sizeof(DrawElementsIndirectCommand);
+         } else {
+            ptr += stride;
+         }
+      }
+
+      return;
+   }
 
    FLUSH_FOR_DRAW(ctx);
 
-- 
2.17.1