i965 Gen4/5: clip: correctly handle flat varyings

Previously we only gave special treatment to the builtin color varyings.
This patch adds support for arbitrary flat-shaded varyings, which is
required for GLSL 1.30.

Based on Olivier Galibert's patch from last year:
http://lists.freedesktop.org/archives/mesa-dev/2012-July/024340.html

V5: Move key.do_flat_shading to brw_clip_compile.has_flat_shading
V6: Real bools.

[V1-2]: Signed-off-by: Olivier Galibert <galibert at pobox.com>
Signed-off-by: Chris Forbes <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

6 files changed, 30 insertions, 54 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_clip.c b/src/mesa/drivers/dri/i965/brw_clip.c
index 7621675969d..1c2a4bc6eb8 100644
--- a/src/mesa/drivers/dri/i965/brw_clip.c
+++ b/src/mesa/drivers/dri/i965/brw_clip.c
@@ -70,6 +70,9 @@ static void compile_clip_prog( struct brw_context *brw,
    c.key = *key;
    c.vue_map = brw->vue_map_geom_out;
 
+   c.has_flat_shading =
+      brw_any_flat_varyings(&key->interpolation_mode);
+
    /* nr_regs is the number of registers filled by reading data from the VUE.
     * This program accesses the entire VUE, so nr_regs needs to be the size of
     * the VUE (measured in pairs, since two slots are stored in each
@@ -149,8 +152,8 @@ brw_upload_clip_prog(struct brw_context *brw)
    key.primitive = brw->reduced_primitive;
    /* BRW_NEW_VUE_MAP_GEOM_OUT */
    key.attrs = brw->vue_map_geom_out.slots_valid;
+
    /* _NEW_LIGHT */
-   key.do_flat_shading = (ctx->Light.ShadeModel == GL_FLAT);
    key.pv_first = (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION);
    /* _NEW_TRANSFORM (also part of VUE map)*/
    key.nr_userclip = _mesa_bitcount_64(ctx->Transform.ClipPlanesEnabled);
diff --git a/src/mesa/drivers/dri/i965/brw_clip.h b/src/mesa/drivers/dri/i965/brw_clip.h
index e0d75b0e555..ecbf7416439 100644
--- a/src/mesa/drivers/dri/i965/brw_clip.h
+++ b/src/mesa/drivers/dri/i965/brw_clip.h
@@ -46,7 +46,6 @@ struct brw_clip_prog_key {
    struct interpolation_mode_map interpolation_mode;
    GLuint primitive:4;
    GLuint nr_userclip:4;
-   GLuint do_flat_shading:1;
    GLuint pv_first:1;
    GLuint do_unfilled:1;
    GLuint fill_cw:2;		/* includes cull information */
@@ -121,6 +120,8 @@ struct brw_clip_compile {
    bool need_direction;
 
    struct brw_vue_map vue_map;
+
+   bool has_flat_shading;
 };
 
 /**
@@ -173,8 +174,8 @@ void brw_clip_kill_thread(struct brw_clip_compile *c);
 struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c );
 struct brw_reg brw_clip_plane0_address( struct brw_clip_compile *c );
 
-void brw_clip_copy_colors( struct brw_clip_compile *c,
-			   GLuint to, GLuint from );
+void brw_clip_copy_flatshaded_attributes( struct brw_clip_compile *c,
+                                          GLuint to, GLuint from );
 
 void brw_clip_init_clipmask( struct brw_clip_compile *c );
 
diff --git a/src/mesa/drivers/dri/i965/brw_clip_line.c b/src/mesa/drivers/dri/i965/brw_clip_line.c
index 9ce80b83b9f..9001d36cd0f 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_line.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_line.c
@@ -272,11 +272,11 @@ void brw_emit_line_clip( struct brw_clip_compile *c )
    brw_clip_line_alloc_regs(c);
    brw_clip_init_ff_sync(c);
 
-   if (c->key.do_flat_shading) {
+   if (c->has_flat_shading) {
       if (c->key.pv_first)
-         brw_clip_copy_colors(c, 1, 0);
+         brw_clip_copy_flatshaded_attributes(c, 1, 0);
       else
-         brw_clip_copy_colors(c, 0, 1);
+         brw_clip_copy_flatshaded_attributes(c, 0, 1);
    }
                 
    clip_and_emit_line(c);
diff --git a/src/mesa/drivers/dri/i965/brw_clip_tri.c b/src/mesa/drivers/dri/i965/brw_clip_tri.c
index bea08530ec0..19179c1fc9d 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_tri.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_tri.c
@@ -190,8 +190,8 @@ void brw_clip_tri_flat_shade( struct brw_clip_compile *c )
 
    brw_IF(p, BRW_EXECUTE_1);
    {
-      brw_clip_copy_colors(c, 1, 0);
-      brw_clip_copy_colors(c, 2, 0);
+      brw_clip_copy_flatshaded_attributes(c, 1, 0);
+      brw_clip_copy_flatshaded_attributes(c, 2, 0);
    }
    brw_ELSE(p);
    {
@@ -203,19 +203,19 @@ void brw_clip_tri_flat_shade( struct brw_clip_compile *c )
 		 brw_imm_ud(_3DPRIM_TRIFAN));
 	 brw_IF(p, BRW_EXECUTE_1);
 	 {
-	    brw_clip_copy_colors(c, 0, 1);
-	    brw_clip_copy_colors(c, 2, 1);
+	    brw_clip_copy_flatshaded_attributes(c, 0, 1);
+	    brw_clip_copy_flatshaded_attributes(c, 2, 1);
 	 }
 	 brw_ELSE(p);
 	 {
-	    brw_clip_copy_colors(c, 1, 0);
-	    brw_clip_copy_colors(c, 2, 0);
+	    brw_clip_copy_flatshaded_attributes(c, 1, 0);
+	    brw_clip_copy_flatshaded_attributes(c, 2, 0);
 	 }
 	 brw_ENDIF(p);
       }
       else {
-         brw_clip_copy_colors(c, 0, 2);
-         brw_clip_copy_colors(c, 1, 2);
+         brw_clip_copy_flatshaded_attributes(c, 0, 2);
+         brw_clip_copy_flatshaded_attributes(c, 1, 2);
       }
    }
    brw_ENDIF(p);
@@ -645,7 +645,7 @@ void brw_emit_tri_clip( struct brw_clip_compile *c )
     * flatshading, need to apply the flatshade here because we don't
     * respect the PV when converting to trifan for emit:
     */
-   if (c->key.do_flat_shading) 
+   if (c->has_flat_shading)
       brw_clip_tri_flat_shade(c); 
       
    if ((c->key.clip_mode == BRW_CLIPMODE_NORMAL) ||
diff --git a/src/mesa/drivers/dri/i965/brw_clip_unfilled.c b/src/mesa/drivers/dri/i965/brw_clip_unfilled.c
index e211b95ec82..af327d68ce7 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_unfilled.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_unfilled.c
@@ -501,7 +501,7 @@ void brw_emit_unfilled_clip( struct brw_clip_compile *c )
 
    /* Need to do this whether we clip or not:
     */
-   if (c->key.do_flat_shading)
+   if (c->has_flat_shading)
       brw_clip_tri_flat_shade(c);
    
    brw_clip_init_clipmask(c);
diff --git a/src/mesa/drivers/dri/i965/brw_clip_util.c b/src/mesa/drivers/dri/i965/brw_clip_util.c
index 37b77341648..9d77d1e1b46 100644
--- a/src/mesa/drivers/dri/i965/brw_clip_util.c
+++ b/src/mesa/drivers/dri/i965/brw_clip_util.c
@@ -290,49 +290,21 @@ struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c )
 }
 
 
-/* If flatshading, distribute color from provoking vertex prior to
+/* Distribute flatshaded attributes from provoking vertex prior to
  * clipping.
  */
-void brw_clip_copy_colors( struct brw_clip_compile *c,
+void brw_clip_copy_flatshaded_attributes( struct brw_clip_compile *c,
 			   GLuint to, GLuint from )
 {
    struct brw_compile *p = &c->func;
 
-   if (brw_clip_have_varying(c, VARYING_SLOT_COL0))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL0)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL0)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_COL1))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL1)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_COL1)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_BFC0))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC0)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC0)));
-
-   if (brw_clip_have_varying(c, VARYING_SLOT_BFC1))
-      brw_MOV(p, 
-	      byte_offset(c->reg.vertex[to],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC1)),
-	      byte_offset(c->reg.vertex[from],
-                          brw_varying_to_offset(&c->vue_map,
-                                                VARYING_SLOT_BFC1)));
+   for (int i = 0; i < c->vue_map.num_slots; i++) {
+      if (c->key.interpolation_mode.mode[i] == INTERP_QUALIFIER_FLAT) {
+         brw_MOV(p,
+                 byte_offset(c->reg.vertex[to], brw_vue_slot_to_offset(i)),
+                 byte_offset(c->reg.vertex[from], brw_vue_slot_to_offset(i)));
+      }
+   }
 }