[Mesa-dev] [PATCH 11/12] mesa: Only map the necessary buffer range in vbo_get_minmax_index

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

---
 src/mesa/vbo/vbo_exec_array.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index 484e1a8..9e194b1 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -95,10 +95,17 @@ vbo_get_minmax_index(struct gl_context *ctx,
    GLuint i;
 
    if (_mesa_is_bufferobj(ib->obj)) {
-      const GLvoid *map =
-         ctx->Driver.MapBufferRange(ctx, 0, ib->obj->Size, GL_MAP_READ_BIT,
-				    ib->obj);
-      indices = ADD_POINTERS(map, ib->ptr);
+      unsigned map_size;
+
+      switch (ib->type) {
+      case GL_UNSIGNED_INT:   map_size = count * sizeof(GLuint); break;
+      case GL_UNSIGNED_SHORT: map_size = count * sizeof(GLushort); break;
+      case GL_UNSIGNED_BYTE:  map_size = count * sizeof(GLubyte); break;
+      default: assert(0); map_size = 0;
+      }
+
+      indices = ctx->Driver.MapBufferRange(ctx, (GLsizeiptr) ib->ptr, map_size,
+					   GL_MAP_READ_BIT, ib->obj);
    } else {
       indices = ib->ptr;
    }
-- 
1.7.4.4