vbo: introduce vbo_get_minmax_indices function

Introduce vbo_get_minmax_indices() function to handle the min/max index
computation for nr_prims(>= 1). The old code just compute the first
prim's min/max index; this would results an error rendering if user
called functions like glMultiDrawElements(). This patch servers as
fixing this issue.

As when nr_prims = 1, we can pass 1 to paramter nr_prims, thus I made
vbo_get_minmax_index() static.

v2: per Roland's suggestion, put the indices address compuation into
    vbo_get_minmax_index() instead.

    Also do comination if possible to reduce map/unmap count

v3: per Brian's suggestion, use a pointer for start_prim to avoid
    structure copy per loop.

Signed-off-by: Yuanhan Liu <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/mesa/vbo/vbo.h b/src/mesa/vbo/vbo.h
index ed8fc1722ae..bf925ab16f3 100644
--- a/src/mesa/vbo/vbo.h
+++ b/src/mesa/vbo/vbo.h
@@ -127,9 +127,9 @@ int
 vbo_sizeof_ib_type(GLenum type);
 
 void
-vbo_get_minmax_index(struct gl_context *ctx, const struct _mesa_prim *prim,
-		     const struct _mesa_index_buffer *ib,
-		     GLuint *min_index, GLuint *max_index);
+vbo_get_minmax_indices(struct gl_context *ctx, const struct _mesa_prim *prim,
+                       const struct _mesa_index_buffer *ib,
+                       GLuint *min_index, GLuint *max_index, GLuint nr_prims);
 
 void vbo_use_buffer_objects(struct gl_context *ctx);