From c01878c174ad7548996a4ec78f67d96bf3836263 Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Sat, 9 Oct 2021 20:43:24 +0800
Subject: [PATCH] Import: fix transparency STEP export/import

App::Color::a in FreeCAD is actually interpreted as transparency
instead of alpha.
---
 src/Mod/Import/App/ExportOCAF.cpp  | 2 +-
 src/Mod/Import/App/ImportOCAF.cpp  | 2 +-
 src/Mod/Import/App/ImportOCAF2.cpp | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Mod/Import/App/ExportOCAF.cpp b/src/Mod/Import/App/ExportOCAF.cpp
index 9ba1a4d0ae..3a76769b42 100644
--- a/src/Mod/Import/App/ExportOCAF.cpp
+++ b/src/Mod/Import/App/ExportOCAF.cpp
@@ -104,7 +104,7 @@
 
 static inline Quantity_ColorRGBA convertColor(const App::Color &c)
 {
-    return Quantity_ColorRGBA(Quantity_Color(c.r, c.g, c.b, OCC_COLOR_SPACE), c.a);
+    return Quantity_ColorRGBA(Quantity_Color(c.r, c.g, c.b, OCC_COLOR_SPACE), 1.0 - c.a);
 }
 
 using namespace Import;
diff --git a/src/Mod/Import/App/ImportOCAF.cpp b/src/Mod/Import/App/ImportOCAF.cpp
index f92e7300b3..a6c392f0b7 100644
--- a/src/Mod/Import/App/ImportOCAF.cpp
+++ b/src/Mod/Import/App/ImportOCAF.cpp
@@ -122,7 +122,7 @@ static inline App::Color convertColor(const Quantity_ColorRGBA &c)
     return App::Color(static_cast<float>(r),
                       static_cast<float>(g),
                       static_cast<float>(b),
-                      static_cast<float>(c.Alpha()));
+                      1.0f - static_cast<float>(c.Alpha()));
 }
 
 #define OCAF_KEEP_PLACEMENT
diff --git a/src/Mod/Import/App/ImportOCAF2.cpp b/src/Mod/Import/App/ImportOCAF2.cpp
index 3b0d6ea49a..1c803be05c 100644
--- a/src/Mod/Import/App/ImportOCAF2.cpp
+++ b/src/Mod/Import/App/ImportOCAF2.cpp
@@ -92,12 +92,12 @@ static inline App::Color convertColor(const Quantity_ColorRGBA &c)
     return App::Color(static_cast<float>(r),
                       static_cast<float>(g),
                       static_cast<float>(b),
-                      static_cast<float>(c.Alpha()));
+                      1.0f - static_cast<float>(c.Alpha()));
 }
 
 static inline Quantity_ColorRGBA convertColor(const App::Color &c)
 {
-    return Quantity_ColorRGBA(Quantity_Color(c.r, c.g, c.b, OCC_COLOR_SPACE), c.a);
+    return Quantity_ColorRGBA(Quantity_Color(c.r, c.g, c.b, OCC_COLOR_SPACE), 1.0f - c.a);
 }
 
 static inline std::ostream& operator<<(std::ostream& os, const Quantity_ColorRGBA &c) {