mesa: fix clip plane enable breakage

Broken by:

commit 00173d91b70ae4dcea7c6324ee4858c498cae14b
Author: Marek Olšák <[email protected]>
Date:   Sat Jun 10 12:09:43 2017 +0200

    mesa: don't flag _NEW_TRANSFORM for st/mesa if possible

It also optimizes the case slightly for GL core.

It doesn't try to fix that glEnable might be a bad place to do the
clip plane transformation.

Reviewed-by: Nicolai Hähnle <[email protected]>
Tested-by: Michel Dänzer <[email protected]>
Reviewed-by: Roland Scheidegger <[email protected]>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/mesa/main/enable.c b/src/mesa/main/enable.c
index e1293f9bf1e..18a288d35c2 100644
--- a/src/mesa/main/enable.c
+++ b/src/mesa/main/enable.c
@@ -361,8 +361,13 @@ _mesa_set_enable(struct gl_context *ctx, GLenum cap, GLboolean state)
 
             if (state) {
                ctx->Transform.ClipPlanesEnabled |= (1 << p);
-               if (ctx->API == API_OPENGL_COMPAT || ctx->API == API_OPENGLES)
+
+               /* The projection matrix transforms the clip plane. */
+               /* TODO: glEnable might not be the best place to do it. */
+               if (ctx->API == API_OPENGL_COMPAT || ctx->API == API_OPENGLES) {
                   _mesa_update_clip_plane(ctx, p);
+                  ctx->NewDriverState |= ctx->DriverFlags.NewClipPlane;
+               }
             }
             else {
                ctx->Transform.ClipPlanesEnabled &= ~(1 << p);