Mesa (master): swr: fix polygonmode for front==back

[George Kyriazis]

Module: Mesa
Branch: master
Commit: 909f72e0a2178ede4497c352933c608e6e8dab00
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=909f72e0a2178ede4497c352933c608e6e8dab00

Author: George Kyriazis <george.kyriazis at intel.com>
Date:   Wed Apr 19 13:55:26 2017 -0500

swr: fix polygonmode for front==back

Rasterizer core only supports polygonmode front==back.  Add logic for
populating fillMode for the rasterizer only for that case correctly.
Provide enum conversion between mesa enums and core enums.

The core renders lines/points as tris. Previously, code would enable
stipple for polygonmode != FILL.  Modify stipple enable logic so that
this works correctly.

No regressions in vtk tests.
Fixes the following piglit tests:
	pointsprite
	gl-1.0-edgeflag-const

v2: remove cc stable, and remove "not implemented" assert
v3: modified commit message

Reviewed-by: Bruce Cherniak <bruce.cherniak at intel.com>

---

 src/gallium/drivers/swr/swr_state.cpp |  8 +++++++-
 src/gallium/drivers/swr/swr_state.h   | 20 ++++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/swr/swr_state.cpp b/src/gallium/drivers/swr/swr_state.cpp
index 56b13746d0..12b4e9d639 100644
--- a/src/gallium/drivers/swr/swr_state.cpp
+++ b/src/gallium/drivers/swr/swr_state.cpp
@@ -1153,6 +1153,10 @@ swr_update_derived(struct pipe_context *pipe,
          rastState->slopeScaledDepthBias = 0;
          rastState->depthBiasClamp = 0;
       }
+
+      /* translate polygon mode, at least for the front==back case */
+      rastState->fillMode = swr_convert_fill_mode(rasterizer->fill_front);
+
       struct pipe_surface *zb = fb->zsbuf;
       if (zb && swr_resource(zb->texture)->has_depth)
          rastState->depthFormat = swr_resource(zb->texture)->swr.format;
@@ -1423,7 +1427,9 @@ swr_update_derived(struct pipe_context *pipe,
    /* and points, since we rasterize them as triangles, too */
    /* Has to be before fragment shader, since it sets SWR_NEW_FS */
    if (p_draw_info) {
-      bool new_prim_is_poly = (u_reduced_prim(p_draw_info->mode) == PIPE_PRIM_TRIANGLES);
+      bool new_prim_is_poly =
+         (u_reduced_prim(p_draw_info->mode) == PIPE_PRIM_TRIANGLES) &&
+         (ctx->derived.rastState.fillMode == SWR_FILLMODE_SOLID);
       if (new_prim_is_poly != ctx->poly_stipple.prim_is_poly) {
          ctx->dirty |= SWR_NEW_FS;
          ctx->poly_stipple.prim_is_poly = new_prim_is_poly;
diff --git a/src/gallium/drivers/swr/swr_state.h b/src/gallium/drivers/swr/swr_state.h
index 9a8c4e1311..7940a960d9 100644
--- a/src/gallium/drivers/swr/swr_state.h
+++ b/src/gallium/drivers/swr/swr_state.h
@@ -376,4 +376,24 @@ swr_convert_prim_topology(const unsigned mode)
       return TOP_UNKNOWN;
    }
 };
+
+/*
+ * convert mesa PIPE_POLYGON_MODE_X to SWR enum SWR_FILLMODE
+ */
+static INLINE enum SWR_FILLMODE
+swr_convert_fill_mode(const unsigned mode)
+{
+   switch(mode) {
+   case PIPE_POLYGON_MODE_FILL:
+      return SWR_FILLMODE_SOLID;
+   case PIPE_POLYGON_MODE_LINE:
+      return SWR_FILLMODE_WIREFRAME;
+   case PIPE_POLYGON_MODE_POINT:
+      return SWR_FILLMODE_POINT;
+   default:
+      assert(0 && "Unknown fillmode");
+      return SWR_FILLMODE_SOLID; // at least do something sensible
+   }
+}
+
 #endif