Merge pull request #9350 from Pokechu22/sw-viewport

Software: Invert backface test when viewport is positive

Source/Core/VideoBackends/Software/Clipper.cpp

@@ -488,6 +488,11 @@ bool CullTest(const OutputVertexData* v0, const OutputVertexData* v1, const Outp
   float normalZDir = (x0 * w2 - x2 * w0) * y1 + (x2 * y0 - x0 * y2) * w1 + (y2 * w0 - y0 * w2) * x1;
 
   backface = normalZDir <= 0.0f;
+  // Jimmie Johnson's Anything with an Engine has a positive viewport, while other games have a
+  // negative viewport.  The positive viewport does not require vertices to be vertically mirrored,
+  // but the backface test does need to be inverted for things to be drawn.
+  if (xfmem.viewport.ht > 0)
+    backface = !backface;
 
   // TODO: Are these tests / the definition of backface above backwards?
   if ((bpmem.genMode.cullmode == CullMode::Back || bpmem.genMode.cullmode == CullMode::All) &&