Add invert green channel option to texture tool.

Source/Engine/Tools/TextureTool/TextureTool.DirectXTex.cpp

@@ -625,7 +625,7 @@ bool TextureTool::ImportTextureDirectXTex(ImageType type, const StringView& path
     }
 
     bool keepAsIs = false;
-    if (!options.FlipY && options.Compress && type == ImageType::DDS && mipLevels == sourceMipLevels && DirectX::IsCompressed(sourceDxgiFormat) && !DirectX::IsSRGB(sourceDxgiFormat))
+    if (!options.FlipY && !options.InvertGreenChannel && options.Compress && type == ImageType::DDS && mipLevels == sourceMipLevels && DirectX::IsCompressed(sourceDxgiFormat) && !DirectX::IsSRGB(sourceDxgiFormat))
     {
         // Keep image in the current compressed format (artist choice) so we don't have to run the slow mipmap generation
         keepAsIs = true;
@@ -700,6 +700,35 @@ bool TextureTool::ImportTextureDirectXTex(ImageType type, const StringView& path
         SET_CURRENT_IMG(tmpImg);
     }
 
+    if (!keepAsIs && options.InvertGreenChannel)
+    {
+        auto& timage = GET_TMP_IMG();
+
+        result = TransformImage(currentImage->GetImages(), currentImage->GetImageCount(), currentImage->GetMetadata(),
+            [&](DirectX::XMVECTOR* outPixels, const DirectX::XMVECTOR* inPixels, size_t w, size_t y)
+            {
+                static const DirectX::XMVECTORU32 s_selecty = { { { DirectX::XM_SELECT_0, DirectX::XM_SELECT_1, DirectX::XM_SELECT_0, DirectX::XM_SELECT_0 } } };
+
+                UNREFERENCED_PARAMETER(y);
+
+                for (size_t j = 0; j < w; ++j)
+                {
+                    const DirectX::XMVECTOR value = inPixels[j];
+
+                    const DirectX::XMVECTOR inverty = DirectX::XMVectorSubtract(DirectX::g_XMOne, value);
+
+                    outPixels[j] = DirectX::XMVectorSelect(value, inverty, s_selecty);
+                }
+            }, timage);
+        if (FAILED(result))
+        {
+            errorMsg = String::Format(TEXT("Cannot invert green channel in texture, error: {0:x}"), static_cast<uint32>(result));
+            return true;
+        }
+        // Use converted image
+        SET_CURRENT_IMG(timage);
+    }
+
     // Generate mip maps chain
     if (!keepAsIs && useMipLevels && options.GenerateMipMaps)
     {

Source/Engine/Tools/TextureTool/TextureTool.cpp

@@ -26,7 +26,7 @@ namespace
 
 String TextureTool::Options::ToString() const
 {
-    return String::Format(TEXT("Type: {}, IsAtlas: {}, NeverStream: {}, IndependentChannels: {}, sRGB: {}, GenerateMipMaps: {}, FlipY: {}, Scale: {}, MaxSize: {}, Resize: {}, PreserveAlphaCoverage: {}, PreserveAlphaCoverageReference: {}, SizeX: {}, SizeY: {}"),
+    return String::Format(TEXT("Type: {}, IsAtlas: {}, NeverStream: {}, IndependentChannels: {}, sRGB: {}, GenerateMipMaps: {}, FlipY: {}, InvertGreen: {} Scale: {}, MaxSize: {}, Resize: {}, PreserveAlphaCoverage: {}, PreserveAlphaCoverageReference: {}, SizeX: {}, SizeY: {}"),
                           ScriptingEnum::ToString(Type),
                           IsAtlas,
                           NeverStream,
@@ -34,6 +34,7 @@ String TextureTool::Options::ToString() const
                           sRGB,
                           GenerateMipMaps,
                           FlipY,
+                          InvertGreenChannel,
                           Scale,
                           MaxSize,
                           MaxSize,
@@ -71,6 +72,9 @@ void TextureTool::Options::Serialize(SerializeStream& stream, const void* otherO
     stream.JKEY("FlipY");
     stream.Bool(FlipY);
 
+    stream.JKEY("InvertGreenChannel");
+    stream.Bool(InvertGreenChannel);
+
     stream.JKEY("Resize");
     stream.Bool(Resize);
 
@@ -128,6 +132,7 @@ void TextureTool::Options::Deserialize(DeserializeStream& stream, ISerializeModi
     sRGB = JsonTools::GetBool(stream, "sRGB", sRGB);
     GenerateMipMaps = JsonTools::GetBool(stream, "GenerateMipMaps", GenerateMipMaps);
     FlipY = JsonTools::GetBool(stream, "FlipY", FlipY);
+    InvertGreenChannel = JsonTools::GetBool(stream, "InvertGreenChannel", InvertGreenChannel);
     Resize = JsonTools::GetBool(stream, "Resize", Resize);
     PreserveAlphaCoverage = JsonTools::GetBool(stream, "PreserveAlphaCoverage", PreserveAlphaCoverage);
     PreserveAlphaCoverageReference = JsonTools::GetFloat(stream, "PreserveAlphaCoverageReference", PreserveAlphaCoverageReference);

Source/Engine/Tools/TextureTool/TextureTool.h

@@ -57,6 +57,10 @@ API_CLASS(Namespace="FlaxEngine.Tools", Static) class FLAXENGINE_API TextureTool
         API_FIELD(Attributes="EditorOrder(70)")
         bool FlipY = false;
 
+        // True if to invert the green channel on a normal map. Good for OpenGL to DirectX conversion.
+        API_FIELD(Attributes = "EditorOrder(71)")
+        bool InvertGreenChannel = false;
+
         // Texture size scale. Allows increasing or decreasing the imported texture resolution. Default is 1.
         API_FIELD(Attributes="EditorOrder(80), Limit(0.0001f, 1000.0f, 0.01f)")
         float Scale = 1.0f;