use config for viewer reassoc

Fixes #1661

app/config/config.cpp

@@ -100,6 +100,7 @@ void Config::SetDefaults()
   SetEntryInternal(QStringLiteral("ShowClipWhileDragging"), NodeValue::kBoolean, true);
   SetEntryInternal(QStringLiteral("StopPlaybackOnLastFrame"), NodeValue::kBoolean, false);
   SetEntryInternal(QStringLiteral("UseLegacyColorInInputTab"), NodeValue::kBoolean, false);
+  SetEntryInternal(QStringLiteral("ReassocLinToNonLin"), NodeValue::kBoolean, false);
 
   SetEntryInternal(QStringLiteral("AutoCacheDelay"), NodeValue::kInt, 1000);
 

app/render/renderprocessor.cpp

@@ -96,7 +96,9 @@ FramePtr RenderProcessor::GenerateFrame(TexturePtr texture, const rational& time
 
       if (output_color_transform) {
         // Yes color transform, blit color managed
-        render_ctx_->BlitColorManaged(output_color_transform, texture, Renderer::kAlphaNone, blit_tex.get(), true, matrix);
+        render_ctx_->BlitColorManaged(output_color_transform, texture,
+                                      Config::Current()[QStringLiteral("ReassocLinToNonLin")].toBool() ? Renderer::kAlphaAssociated : Renderer::kAlphaNone,
+                                      blit_tex.get(), true, matrix);
       } else {
         // No color transform, just blit
         ShaderJob job;

app/widget/viewer/viewerdisplay.cpp

@@ -391,7 +391,9 @@ void ViewerDisplayWidget::OnPaint()
         texture_to_draw = deinterlace_texture_;
       }
 
-      renderer()->BlitColorManaged(color_service(), texture_to_draw, Renderer::kAlphaNone, device_params, false,
+      renderer()->BlitColorManaged(color_service(), texture_to_draw,
+                                   Config::Current()[QStringLiteral("ReassocLinToNonLin")].toBool() ? Renderer::kAlphaAssociated : Renderer::kAlphaNone,
+                                   device_params, false,
                                    combined_matrix_flipped_, crop_matrix_);
     }
   }