From: Jason Ekstrand <jason.ekstrand@intel.com>
Date: Fri, 28 Apr 2017 14:12:24 +0000 (-0700)
Subject: spirv: Flip the tessellation winding order
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fc91cbe20ba580930bac06632e7a6d4ed39bc3ab;p=mesa.git

spirv: Flip the tessellation winding order

It's not SPIR-V that's backwards from GLSL, it's Vulkan that's backwards
from GL.  Let's make NIR consistent with the source language and do the
flipping inside the Vulkan driver instead.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
---

diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
index 91577402a2c..ee2a2979aaf 100644
--- a/src/amd/vulkan/radv_pipeline.c
+++ b/src/amd/vulkan/radv_pipeline.c
@@ -262,6 +262,7 @@ radv_tess_pipeline_compile(struct radv_pipeline *pipeline,
 	if (tcs_nir == NULL)
 		return;
 
+	tes_nir->info.tess.ccw = !tes_nir->info.tess.ccw;
 	nir_lower_tes_patch_vertices(tes_nir,
 				     tcs_nir->info.tess.tcs_vertices_out);
 
diff --git a/src/compiler/spirv/spirv_to_nir.c b/src/compiler/spirv/spirv_to_nir.c
index 86536856b6f..6ce9d1ada34 100644
--- a/src/compiler/spirv/spirv_to_nir.c
+++ b/src/compiler/spirv/spirv_to_nir.c
@@ -2951,17 +2951,12 @@ vtn_handle_execution_mode(struct vtn_builder *b, struct vtn_value *entry_point,
    case SpvExecutionModeVertexOrderCw:
       assert(b->shader->stage == MESA_SHADER_TESS_CTRL ||
              b->shader->stage == MESA_SHADER_TESS_EVAL);
-      /* Vulkan's notion of CCW seems to match the hardware backends,
-       * but be the opposite of OpenGL.  Currently NIR follows GL semantics,
-       * so we set it backwards here.
-       */
-      b->shader->info.tess.ccw = true;
+      b->shader->info.tess.ccw = false;
       break;
    case SpvExecutionModeVertexOrderCcw:
       assert(b->shader->stage == MESA_SHADER_TESS_CTRL ||
              b->shader->stage == MESA_SHADER_TESS_EVAL);
-      /* Backwards; see above */
-      b->shader->info.tess.ccw = false;
+      b->shader->info.tess.ccw = true;
       break;
    case SpvExecutionModePointMode:
       assert(b->shader->stage == MESA_SHADER_TESS_CTRL ||
diff --git a/src/intel/vulkan/genX_pipeline.c b/src/intel/vulkan/genX_pipeline.c
index 6dfa49b8737..844c11803c2 100644
--- a/src/intel/vulkan/genX_pipeline.c
+++ b/src/intel/vulkan/genX_pipeline.c
@@ -1217,7 +1217,18 @@ emit_3dstate_hs_te_ds(struct anv_pipeline *pipeline)
 
    anv_batch_emit(&pipeline->batch, GENX(3DSTATE_TE), te) {
       te.Partitioning = tes_prog_data->partitioning;
-      te.OutputTopology = tes_prog_data->output_topology;
+
+      /* Vulkan has its winding order backwards from GL so TRI_CCW becomes
+       * TRI_CW and vice versa.
+       */
+      if (tes_prog_data->output_topology == OUTPUT_TRI_CCW) {
+         te.OutputTopology = OUTPUT_TRI_CW;
+      } else if (tes_prog_data->output_topology == OUTPUT_TRI_CW) {
+         te.OutputTopology = OUTPUT_TRI_CCW;
+      } else {
+         te.OutputTopology = tes_prog_data->output_topology;
+      }
+
       te.TEDomain = tes_prog_data->domain;
       te.TEEnable = true;
       te.MaximumTessellationFactorOdd = 63.0;