From ad2a55b2f3620864805b47470d6b436f0610dedf Mon Sep 17 00:00:00 2001
From: isk <isk@opencascade.com>
Date: Thu, 10 Dec 2015 14:18:38 +0300
Subject: [PATCH] 0026975: Visualization, TKOpenGl - handle triangle strips
 correctly within Ray-Tracing core

---
 src/OpenGl/OpenGl_View_Raytrace.cxx |  8 ++++----
 tests/bugs/vis/bug26975             | 27 +++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 tests/bugs/vis/bug26975

diff --git a/src/OpenGl/OpenGl_View_Raytrace.cxx b/src/OpenGl/OpenGl_View_Raytrace.cxx
index 45f9e79546..0839951abd 100644
--- a/src/OpenGl/OpenGl_View_Raytrace.cxx
+++ b/src/OpenGl/OpenGl_View_Raytrace.cxx
@@ -807,8 +807,8 @@ Standard_Boolean OpenGl_View::addRaytraceTriangleStripArray (OpenGl_TriangleSet&
   {
     for (Standard_Integer aVert = theOffset, aCW = 0; aVert < theOffset + theCount - 2; ++aVert, aCW = (aCW + 1) % 2)
     {
-      theSet.Elements.push_back (BVH_Vec4i (theIndices->Index (aVert + aCW ? 1 : 0),
-                                            theIndices->Index (aVert + aCW ? 0 : 1),
+      theSet.Elements.push_back (BVH_Vec4i (theIndices->Index (aVert + (aCW ? 1 : 0)),
+                                            theIndices->Index (aVert + (aCW ? 0 : 1)),
                                             theIndices->Index (aVert + 2),
                                             theMatID));
     }
@@ -817,8 +817,8 @@ Standard_Boolean OpenGl_View::addRaytraceTriangleStripArray (OpenGl_TriangleSet&
   {
     for (Standard_Integer aVert = theOffset, aCW = 0; aVert < theOffset + theCount - 2; ++aVert, aCW = (aCW + 1) % 2)
     {
-      theSet.Elements.push_back (BVH_Vec4i (aVert + aCW ? 1 : 0,
-                                            aVert + aCW ? 0 : 1,
+      theSet.Elements.push_back (BVH_Vec4i (aVert + (aCW ? 1 : 0),
+                                            aVert + (aCW ? 0 : 1),
                                             aVert + 2,
                                             theMatID));
     }
diff --git a/tests/bugs/vis/bug26975 b/tests/bugs/vis/bug26975
new file mode 100644
index 0000000000..11c3b0c3d1
--- /dev/null
+++ b/tests/bugs/vis/bug26975
@@ -0,0 +1,27 @@
+puts "============"
+puts "CR26975"
+puts "============"
+puts ""
+
+##########################################################################################
+puts "Visualization, TKOpenGl - handle triangle strips correctly within Ray-Tracing core"
+##########################################################################################
+
+pload MODELING VISUALIZATION
+vclear
+vinit View1
+vraytrace 0
+vdrawparray s trianglestrips v 0 0 0 n 0 0 1 v 0 2 0 n 0 0 1 v 2 0 0 n 0 0 1 v 2 2 0 n 0 0 1
+vfit
+
+vdump $imagedir/${casename}_rt_off.png
+
+vraytrace 1
+
+vdump $imagedir/${casename}_rt_on.png
+
+set color  [vreadpixel 250 250 rgb name]
+puts $color
+if { $color == "BLACK" } {
+    puts "ERROR: CR26975 is reproduced. Triangle strips incorrect within Ray-Tracing core."
+}