Mesa (master): r300g: follow pipe_rasterizer_state::light_twoside

[Marek Olšák]

Module: Mesa
Branch: master
Commit: d044ecbe7625af1118655bcc9dba7ed00342534f
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=d044ecbe7625af1118655bcc9dba7ed00342534f

Author: Marek Olšák <maraeo at gmail.com>
Date:   Sat May  8 22:50:49 2010 +0200

r300g: follow pipe_rasterizer_state::light_twoside

---

 src/gallium/drivers/r300/r300_context.h       |    2 ++
 src/gallium/drivers/r300/r300_state.c         |    6 +++++-
 src/gallium/drivers/r300/r300_state_derived.c |   24 ++++++++++++++++++++----
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/r300/r300_context.h b/src/gallium/drivers/r300/r300_context.h
index dd16565..4b401a7 100644
--- a/src/gallium/drivers/r300/r300_context.h
+++ b/src/gallium/drivers/r300/r300_context.h
@@ -442,6 +442,8 @@ struct r300_context {
     boolean stencil_ref_bf_fallback;
     /* Point sprites texcoord index,  1 bit per texcoord */
     int sprite_coord_enable;
+    /* Whether two-sided color selection is enabled (AKA light_twoside). */
+    boolean two_sided_color;
 
     /* upload managers */
     struct u_upload_mgr *upload_vb;
diff --git a/src/gallium/drivers/r300/r300_state.c b/src/gallium/drivers/r300/r300_state.c
index 1344415..3990997 100644
--- a/src/gallium/drivers/r300/r300_state.c
+++ b/src/gallium/drivers/r300/r300_state.c
@@ -870,6 +870,7 @@ static void r300_bind_rs_state(struct pipe_context* pipe, void* state)
     struct r300_context* r300 = r300_context(pipe);
     struct r300_rs_state* rs = (struct r300_rs_state*)state;
     int last_sprite_coord_enable = r300->sprite_coord_enable;
+    boolean last_two_sided_color = r300->two_sided_color;
 
     if (r300->draw) {
         draw_flush(r300->draw);
@@ -879,15 +880,18 @@ static void r300_bind_rs_state(struct pipe_context* pipe, void* state)
     if (rs) {
         r300->polygon_offset_enabled = rs->rs.offset_cw || rs->rs.offset_ccw;
         r300->sprite_coord_enable = rs->rs.sprite_coord_enable;
+        r300->two_sided_color = rs->rs.light_twoside;
     } else {
         r300->polygon_offset_enabled = FALSE;
         r300->sprite_coord_enable = 0;
+        r300->two_sided_color = FALSE;
     }
 
     UPDATE_STATE(state, r300->rs_state);
     r300->rs_state.size = 27 + (r300->polygon_offset_enabled ? 5 : 0);
 
-    if (last_sprite_coord_enable != r300->sprite_coord_enable) {
+    if (last_sprite_coord_enable != r300->sprite_coord_enable ||
+        last_two_sided_color != r300->two_sided_color) {
         r300->rs_block_state.dirty = TRUE;
     }
 }
diff --git a/src/gallium/drivers/r300/r300_state_derived.c b/src/gallium/drivers/r300/r300_state_derived.c
index 193a60c..c738899 100644
--- a/src/gallium/drivers/r300/r300_state_derived.c
+++ b/src/gallium/drivers/r300/r300_state_derived.c
@@ -355,10 +355,26 @@ static void r300_update_rs_block(struct r300_context *r300)
     /* Set up back-face colors. The rasterizer will do the color selection
      * automatically. */
     if (any_bcolor_used) {
-        for (i = 0; i < ATTR_COLOR_COUNT; i++) {
-            rs.vap_vsm_vtx_assm |= R300_INPUT_CNTL_COLOR;
-            rs.vap_out_vtx_fmt[0] |= R300_VAP_OUTPUT_VTX_FMT_0__COLOR_0_PRESENT << (2+i);
-            stream_loc_notcl[loc++] = 4 + i;
+        if (r300->two_sided_color) {
+            /* Rasterize as back-face colors. */
+            for (i = 0; i < ATTR_COLOR_COUNT; i++) {
+                rs.vap_vsm_vtx_assm |= R300_INPUT_CNTL_COLOR;
+                rs.vap_out_vtx_fmt[0] |= R300_VAP_OUTPUT_VTX_FMT_0__COLOR_0_PRESENT << (2+i);
+                stream_loc_notcl[loc++] = 4 + i;
+            }
+        } else {
+            /* Rasterize two fake texcoords to prevent from the two-sided color
+             * selection. */
+            /* XXX Consider recompiling the vertex shader to save 2 RS units. */
+            for (i = 0; i < 2; i++) {
+                rs.vap_vsm_vtx_assm |= (R300_INPUT_CNTL_TC0 << tex_count);
+                rs.vap_out_vtx_fmt[1] |= (4 << (3 * tex_count));
+                stream_loc_notcl[loc++] = 6 + tex_count;
+
+                /* Rasterize it. */
+                rX00_rs_tex(&rs, tex_count, tex_count, SWIZ_XYZW);
+                tex_count++;
+            }
         }
     }