genesys: Add a way to debug image pipelines

backend/genesys_image_pipeline.cc

@@ -44,6 +44,7 @@
 #define DEBUG_DECLARE_ONLY
 
 #include "genesys_image_pipeline.h"
+#include "genesys_low.h"
 #include <numeric>
 
 ImagePipelineNode::~ImagePipelineNode() {}
@@ -560,6 +561,36 @@ void ImagePipelineNodeExtract::get_next_row_data(std::uint8_t* out_data)
     current_line_++;
 }
 
+ImagePipelineNodeDebug::ImagePipelineNodeDebug(ImagePipelineNode& source,
+                                               const std::string& path) :
+    source_(source),
+    path_{path},
+    buffer_{source_.get_row_bytes()}
+{}
+
+ImagePipelineNodeDebug::~ImagePipelineNodeDebug()
+{
+    catch_all_exceptions(__func__, [&]()
+    {
+        if (buffer_.empty())
+            return;
+
+        auto format = get_format();
+        buffer_.linearize();
+        sanei_genesys_write_pnm_file(path_.c_str(), buffer_.get_front_row_ptr(),
+                                     get_pixel_format_depth(format),
+                                     get_pixel_channels(format),
+                                     get_width(), buffer_.height());
+    });
+}
+
+void ImagePipelineNodeDebug::get_next_row_data(std::uint8_t* out_data)
+{
+    buffer_.push_back();
+    source_.get_next_row_data(out_data);
+    std::memcpy(buffer_.get_back_row_ptr(), out_data, get_row_bytes());
+}
+
 std::size_t ImagePipelineStack::get_input_width() const
 {
     ensure_node_exists();
@@ -615,6 +646,16 @@ void ImagePipelineStack::ensure_node_exists() const
     }
 }
 
+void ImagePipelineStack::clear()
+{
+    // we need to destroy the nodes back to front, so that the destructors still have valid
+    // references to sources
+    for (auto it = nodes_.rbegin(); it != nodes_.rend(); ++it) {
+        it->reset();
+    }
+    nodes_.clear();
+}
+
 std::vector<std::uint8_t> ImagePipelineStack::get_all_data()
 {
     auto row_bytes = get_output_row_bytes();

backend/genesys_image_pipeline.h

@@ -402,6 +402,24 @@ private:
     std::vector<uint8_t> cached_line_;
 };
 
+class ImagePipelineNodeDebug : public ImagePipelineNode
+{
+public:
+    ImagePipelineNodeDebug(ImagePipelineNode& source, const std::string& path);
+    ~ImagePipelineNodeDebug() override;
+
+    std::size_t get_width() const override { return source_.get_width(); }
+    std::size_t get_height() const override { return source_.get_height(); }
+    PixelFormat get_format() const override { return source_.get_format(); }
+
+    void get_next_row_data(std::uint8_t* out_data) override;
+
+private:
+    ImagePipelineNode& source_;
+    std::string path_;
+    RowBuffer buffer_;
+};
+
 class ImagePipelineStack
 {
 public:
@@ -417,10 +435,7 @@ public:
     PixelFormat get_output_format() const;
     std::size_t get_output_row_bytes() const;
 
-    void clear()
-    {
-        nodes_.clear();
-    }
+    void clear();
 
     template<class Node, class... Args>
     void push_first_node(Args&&... args)