created timeline block node

app/node/block/timeline/timeline.cpp

@@ -0,0 +1,37 @@
+#include "timeline.h"
+
+TimelineBlock::TimelineBlock() :
+  current_block_(nullptr)
+{
+}
+
+void TimelineBlock::Process(const rational &time)
+{
+  // Run default process function
+  Block::Process(time);
+
+    // This node represents the end of the timeline, so if the time is beyond its start, there's no image to display
+  if (time >= in()) {
+    texture_output_->set_value(0);
+    current_block_ = nullptr;
+    return;
+  }
+
+  // If we're here, we need to find the current clip to display
+  if (current_block_ == nullptr) {
+    current_block_ = this;
+  }
+
+  // If the time requested is an earlier Block, traverse earlier until we find it
+  while (time < current_block_->in()) {
+    current_block_ = current_block_->previous();
+  }
+
+  // If the time requested is in a later Block, traverse later
+  while (time > current_block_->out()) {
+    current_block_ = current_block_->next();
+  }
+
+  // At this point, we must have found the correct block so we use its texture output to produce the image
+  current_block_->texture_output()->get_value(time);
+}