nodes: further optimized merge node to passthrough RGB blend textures

app/render/job/generatejob.h

@@ -27,23 +27,29 @@ namespace olive {
 
 class GenerateJob : public AcceleratedJob {
 public:
+  enum AlphaChannelSetting {
+    kAlphaAuto,
+    kAlphaForceOn,
+    kAlphaForceOff
+  };
+
   GenerateJob()
   {
-    alpha_channel_required_ = false;
+    alpha_channel_required_ = kAlphaAuto;
   }
 
-  bool GetAlphaChannelRequired() const
+  AlphaChannelSetting GetAlphaChannelRequired() const
   {
     return alpha_channel_required_;
   }
 
-  void SetAlphaChannelRequired(bool e)
+  void SetAlphaChannelRequired(AlphaChannelSetting e)
   {
     alpha_channel_required_ = e;
   }
 
 private:
-  bool alpha_channel_required_;
+  AlphaChannelSetting alpha_channel_required_;
 
 };
 

app/render/renderprocessor.cpp

@@ -456,22 +456,7 @@ QVariant RenderProcessor::ProcessShader(const Node *node, const TimeRange &range
 
   VideoParams tex_params = ticket_->property("vparam").value<VideoParams>();
 
-  bool input_textures_have_alpha = false;
-  for (auto it=job.GetValues().cbegin(); it!=job.GetValues().cend(); it++) {
-    if (it.value().type() == NodeValue::kTexture) {
-      TexturePtr tex = it.value().data().value<TexturePtr>();
-      if (tex && tex->channel_count() == VideoParams::kRGBAChannelCount) {
-        input_textures_have_alpha = true;
-        break;
-      }
-    }
-  }
-
-  if (input_textures_have_alpha || job.GetAlphaChannelRequired()) {
-    tex_params.set_channel_count(VideoParams::kRGBAChannelCount);
-  } else {
-    tex_params.set_channel_count(VideoParams::kRGBChannelCount);
-  }
+  tex_params.set_channel_count(GetChannelCountFromJob(job));
 
   TexturePtr destination = render_ctx_->CreateTexture(tex_params);
 
@@ -521,12 +506,7 @@ QVariant RenderProcessor::ProcessFrameGeneration(const Node *node, const Generat
   FramePtr frame = Frame::Create();
 
   VideoParams frame_params = ticket_->property("vparam").value<VideoParams>();
-  if (job.GetAlphaChannelRequired()) {
-    frame_params.set_channel_count(VideoParams::kRGBAChannelCount);
-  } else {
-    frame_params.set_channel_count(VideoParams::kRGBChannelCount);
-  }
-
+  frame_params.set_channel_count(GetChannelCountFromJob(job));
   frame->set_video_params(frame_params);
   frame->allocate();
 

app/render/texture.cpp

@@ -28,12 +28,16 @@ const Texture::Interpolation Texture::kDefaultInterpolation = Texture::kMipmappe
 
 Texture::~Texture()
 {
-  renderer_->DestroyNativeTexture(id_);
+  if (renderer_) {
+    renderer_->DestroyNativeTexture(id_);
+  }
 }
 
 void Texture::Upload(void *data, int linesize)
 {
-  renderer_->UploadToTexture(this, data, linesize);
+  if (renderer_) {
+    renderer_->UploadToTexture(this, data, linesize);
+  }
 }
 
 }

app/render/texture.h

@@ -45,6 +45,19 @@ public:
 
   static const Interpolation kDefaultInterpolation;
 
+  /**
+   * @brief Construct a dummy texture with no renderer backend
+   */
+  Texture(const VideoParams& param) :
+    renderer_(nullptr),
+    params_(param),
+    type_(k2D)
+  {
+  }
+
+  /**
+   * @brief Construct a real texture linked to a renderer backend
+   */
   Texture(Renderer* renderer, const QVariant& native, const VideoParams& param, Type type) :
     renderer_(renderer),
     params_(param),
@@ -67,6 +80,11 @@ public:
 
   void Upload(void* data, int linesize);
 
+  bool IsDummy() const
+  {
+    return !renderer_;
+  }
+
   int width() const
   {
     return params_.effective_width();