i965: Add support for ARB_depth_clamp.

src/mesa/drivers/dri/i965/brw_cc.c

@@ -39,12 +39,14 @@
 
 static void prepare_cc_vp( struct brw_context *brw )
 {
+   GLcontext *ctx = &brw->intel.ctx;
    struct brw_cc_viewport ccv;
 
    memset(&ccv, 0, sizeof(ccv));
 
-   ccv.min_depth = 0.0;
-   ccv.max_depth = 1.0;
+   /* _NEW_VIEWPORT */
+   ccv.min_depth = ctx->Viewport.Near;
+   ccv.max_depth = ctx->Viewport.Far;
 
    dri_bo_unreference(brw->cc.vp_bo);
    brw->cc.vp_bo = brw_cache_data( &brw->cache, BRW_CC_VP, &ccv, NULL, 0 );
@@ -52,7 +54,7 @@ static void prepare_cc_vp( struct brw_context *brw )
 
 const struct brw_tracked_state brw_cc_vp = {
    .dirty = {
-      .mesa = 0,
+      .mesa = _NEW_VIEWPORT,
       .brw = BRW_NEW_CONTEXT,
       .cache = 0
    },

src/mesa/drivers/dri/i965/brw_clip_state.c

@@ -43,11 +43,14 @@ struct brw_clip_unit_key {
    unsigned int curbe_offset;
 
    unsigned int nr_urb_entries, urb_size;
+
+   GLboolean depth_clamp;
 };
 
 static void
 clip_unit_populate_key(struct brw_context *brw, struct brw_clip_unit_key *key)
 {
+   GLcontext *ctx = &brw->intel.ctx;
    memset(key, 0, sizeof(*key));
 
    /* CACHE_NEW_CLIP_PROG */
@@ -62,6 +65,9 @@ clip_unit_populate_key(struct brw_context *brw, struct brw_clip_unit_key *key)
    /* BRW_NEW_URB_FENCE */
    key->nr_urb_entries = brw->urb.nr_clip_entries;
    key->urb_size = brw->urb.vsize;
+
+   /* _NEW_TRANSOFORM */
+   key->depth_clamp = ctx->Transform.DepthClamp;
 }
 
 static dri_bo *
@@ -117,6 +123,7 @@ clip_unit_create_from_key(struct brw_context *brw,
    clip.clip5.userclip_enable_flags = 0x7f;
    clip.clip5.userclip_must_clip = 1;
    clip.clip5.guard_band_enable = 0;
+   if (!key->depth_clamp)
       clip.clip5.viewport_z_clip_enable = 1;
    clip.clip5.viewport_xy_clip_enable = 1;
    clip.clip5.vertex_position_space = BRW_CLIP_NDCSPACE;
@@ -168,7 +175,7 @@ static void upload_clip_unit( struct brw_context *brw )
 
 const struct brw_tracked_state brw_clip_unit = {
    .dirty = {
-      .mesa  = 0,
+      .mesa  = _NEW_TRANSFORM,
       .brw   = (BRW_NEW_CURBE_OFFSETS |
 		BRW_NEW_URB_FENCE),
       .cache = CACHE_NEW_CLIP_PROG

src/mesa/drivers/dri/intel/intel_extensions.c

@@ -139,6 +139,7 @@ static const struct dri_extension i915_extensions[] = {
 
 /** i965-only extensions */
 static const struct dri_extension brw_extensions[] = {
+   { "GL_ARB_depth_clamp",                NULL },
    { "GL_ARB_depth_texture",              NULL },
    { "GL_ARB_fragment_program",           NULL },
    { "GL_ARB_fragment_program_shadow",    NULL },