0027832: Visualization - Scaled zbuffer trihedron

Code cleanup and test case modified.

src/Graphic3d/Graphic3d_TransformPers.hxx

@@ -409,6 +409,17 @@ void Graphic3d_TransformPers::Apply (const Handle(Graphic3d_Camera)& theCamera,
     }
 
     NCollection_Mat4<Standard_Real> aWorldView = theCamera->OrientationMatrix();
+    
+    //Adjust the camera axial scale for trihedron behaviour 
+    gp_XYZ anAxialScale = theCamera->AxialScale();
+    Standard_Real anAxialX = anAxialScale.X();
+    Standard_Real anAxialY = anAxialScale.Y();
+    Standard_Real anAxialZ = anAxialScale.Z();
+    if (anAxialX > 0.0 && anAxialY > 0.0 && anAxialZ > 0.0)
+    {
+      Graphic3d_TransformUtils::Scale (aWorldView, 1.0 / anAxialX, 1.0 / anAxialY, 1.0 / anAxialZ);
+    }
+    
     Graphic3d_TransformUtils::Translate (aWorldView, aCenter.X(), aCenter.Y(), aCenter.Z());
     Graphic3d_TransformUtils::Scale     (aWorldView, aScale,      aScale,      aScale);
     theWorldView.ConvertFrom (aWorldView);

tests/v3d/trihedron/bug27832

@@ -0,0 +1,46 @@
+puts "========"
+puts "0027832: Visualization - Scaled zbuffer trihedron"
+puts "========"
+puts ""
+
+pload MODELING VISUALIZATION
+vinit
+box b 10 10 10
+vdisplay b
+vfit
+vsetdispmode 1
+vzbufftrihedron -on
+#draw initial picture of box without visual scale
+vdump $imagedir/${casename}_unscaled.png
+
+#draw picture of box after visual scale
+#and zoomed out
+vscale 1 3 10
+vzoom 0.99
+
+set color_1 [vreadpixel 55 360 -rgb -name]
+set color_2 [vreadpixel 50 350 -rgb -name]
+set color_3 [vreadpixel 55 355 -rgb -name]
+
+if {$color_1 != "RED3"} {
+  puts "ERROR: trihedron does not maintain position"
+  puts "       additional investigation is needed"
+  puts "       expected color is: RED3"
+  puts "       current color is:  $color_1"
+}
+
+if {$color_2 != "BLUE3"} {
+  puts "ERROR: trihedron does not maintain position"
+  puts "       additional investigation is needed"
+  puts "       expected color is: BLUE3"
+  puts "       current color is:  $color_2"
+}
+
+if {$color_3 != "GREEN3"} {
+  puts "ERROR: trihedron does not maintain position"
+  puts "       additional investigation is needed"
+  puts "       expected color is: GREEN3"
+  puts "       current color is:  $color_3"
+}
+
+vdump $imagedir/${casename}_scaled.png