Mesa (master): mesa: Only map the necessary buffer range in vbo_get_minmax_index

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 655c7d7498390ab69623e308abe5db4a8489a25c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=655c7d7498390ab69623e308abe5db4a8489a25c

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Mon Aug 22 00:14:51 2011 -0700

mesa: Only map the necessary buffer range in vbo_get_minmax_index

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Brian Paul <brianp at vmware.com>
Acked-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/mesa/vbo/vbo_exec_array.c |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index 484e1a8..18719d5 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -95,10 +95,25 @@ 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;
    }