compute scale for Z24 buffers

diff --git a/src/mesa/pipe/softpipe/sp_quad_depth_test.c b/src/mesa/pipe/softpipe/sp_quad_depth_test.c
index d47c4c42b8f283dbdae745c84aa36d4d5f5f20b9..a26bd51d84616838cf49dd0dbf824e63480ea3ca 100644 (file)
--- a/src/mesa/pipe/softpipe/sp_quad_depth_test.c
+++ b/src/mesa/pipe/softpipe/sp_quad_depth_test.c
@@ -59,6 +59,8 @@ sp_depth_test_quad(struct quad_stage *qs, struct quad_header *quad)
     */
    if (sps->surface.format == PIPE_FORMAT_U_Z16)
       scale = 65535.0;
+   else if (sps->surface.format == PIPE_FORMAT_Z24_S8)
+      scale = (float) ((1 << 24) - 1);
    else
       assert(0);  /* XXX fix this someday */