implemented alpha dis/re/assoc functions for offline pathway

app/render/colorservice.cpp

@@ -1,5 +1,7 @@
 #include "colorservice.h"
 
+#include <QFloat16>
+
 #include "common/define.h"
 
 ColorService::ColorService(const char* source_space, const char* dest_space)
@@ -12,10 +14,14 @@ ColorService::ColorService(const char* source_space, const char* dest_space)
 
 void ColorService::Init()
 {
-  // FIXME: Hardcoded values for testing purposes
-  OCIO::ConstConfigRcPtr config = OCIO::Config::CreateFromFile("/run/media/matt/Home/OpenColorIO/ocio.configs.0.7v4/nuke-default/config.ocio");
+  try {
+    // FIXME: Hardcoded values for testing purposes
+    OCIO::ConstConfigRcPtr config = OCIO::Config::CreateFromFile("/run/media/matt/Home/OpenColorIO/ocio.configs.0.7v4/nuke-default/config.ocio");
 
-  OCIO::SetCurrentConfig(config);
+    OCIO::SetCurrentConfig(config);
+  } catch (OCIO::Exception& exception) {
+    qWarning() << "OpenColorIO Error:" << exception.what();
+  }
 }
 
 ColorServicePtr ColorService::Create(const char *source_space, const char *dest_space)
@@ -30,7 +36,67 @@ void ColorService::ConvertFrame(FramePtr f)
   processor->apply(img);
 }
 
+void ColorService::DisassociateAlpha(FramePtr f)
+{
+  AssociateAlphaPixFmtFilter(kDisassociate, f);
+}
+
+void ColorService::AssociateAlpha(FramePtr f)
+{
+  AssociateAlphaPixFmtFilter(kAssociate, f);
+}
+
+void ColorService::ReassociateAlpha(FramePtr f)
+{
+  AssociateAlphaPixFmtFilter(kReassociate, f);
+}
+
 OpenColorIO::v1::ConstProcessorRcPtr ColorService::GetProcessor()
 {
   return processor;
 }
+
+void ColorService::AssociateAlphaPixFmtFilter(ColorService::AlphaAction action, FramePtr f)
+{
+  int pixel_count = f->width() * f->height() * kRGBAChannels;
+
+  switch (static_cast<olive::PixelFormat>(f->format())) {
+  case olive::PIX_FMT_INVALID:
+  case olive::PIX_FMT_COUNT:
+    qWarning() << "Alpha association functions received an invalid pixel format";
+    break;
+  case olive::PIX_FMT_RGBA8:
+  case olive::PIX_FMT_RGBA16:
+    qWarning() << "Alpha association functions only works on float-based pixel formats at this time";
+    break;
+  case olive::PIX_FMT_RGBA16F:
+  {
+    AssociateAlphaInternal<qfloat16>(action, reinterpret_cast<qfloat16*>(f->data()), pixel_count);
+    break;
+  }
+  case olive::PIX_FMT_RGBA32F:
+  {
+    AssociateAlphaInternal<float>(action, reinterpret_cast<float*>(f->data()), pixel_count);
+    break;
+  }
+  }
+}
+
+template<typename T>
+void ColorService::AssociateAlphaInternal(ColorService::AlphaAction action, T *data, int pix_count)
+{
+  for (int i=0;i<pix_count;i+=kRGBAChannels) {
+    T alpha = data[i+kRGBChannels];
+
+    // FIXME: Is qIsNull the correct approach here or should it literally be an != 0?
+    if (action == kAssociate || !qIsNull(alpha)) {
+      for (int j=0;j<kRGBChannels;j++) {
+        if (action == kDisassociate) {
+          data[i+j] /= alpha;
+        } else {
+          data[i+j] *= alpha;
+        }
+      }
+    }
+  }
+}

app/render/colorservice.h

@@ -22,10 +22,27 @@ public:
 
   void ConvertFrame(FramePtr f);
 
+  static void DisassociateAlpha(FramePtr f);
+
+  static void AssociateAlpha(FramePtr f);
+
+  static void ReassociateAlpha(FramePtr f);
+
   OCIO::ConstProcessorRcPtr GetProcessor();
 
 private:
   OCIO::ConstProcessorRcPtr processor;
+
+  enum AlphaAction {
+    kAssociate,
+    kDisassociate,
+    kReassociate
+  };
+
+  static void AssociateAlphaPixFmtFilter(AlphaAction action, FramePtr f);
+
+  template<typename T>
+  static void AssociateAlphaInternal(AlphaAction action, T* data, int pix_count);
 };
 
 #endif // COLORSERVICE_H