Compositor: Add support for canvas compositing

This commit adds functionality for operations that require pixel
translation or resizing on "Full Frame" mode, allowing to adjust
their canvas. It fixes most cropping issues in translate, scale,
rotate and transform nodes by adjusting their canvas to the result,
instead of the input canvas.

Operations output buffer is still always on (0,0) position for
easier image algorithm implementation, even when the
canvas is not.

Current limitations (will be addressed on bcon2):
- Displayed translation in Viewer node is limited to 6000px.
- When scaling up the canvas size is limited to the
 scene resolution size x 1.5 . From that point it crops.

If none of these limitations are hit, the Viewer node displays
the full input with any translation.

Differential Revision: https://developer.blender.org/D12466

1 files changed, 4 insertions, 2 deletions

diff --git a/source/blender/compositor/intern/COM_FullFrameExecutionModel.h b/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
index f75d4f1afdc..66dfb8f052c 100644
--- a/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
+++ b/source/blender/compositor/intern/COM_FullFrameExecutionModel.h
@@ -61,8 +61,10 @@ class FullFrameExecutionModel : public ExecutionModel {
   void determine_areas_to_render_and_reads();
   void render_operations();
   void render_output_dependencies(NodeOperation *output_op);
-  Vector<MemoryBuffer *> get_input_buffers(NodeOperation *op);
-  MemoryBuffer *create_operation_buffer(NodeOperation *op);
+  Vector<MemoryBuffer *> get_input_buffers(NodeOperation *op,
+                                           const int output_x,
+                                           const int output_y);
+  MemoryBuffer *create_operation_buffer(NodeOperation *op, const int output_x, const int output_y);
   void render_operation(NodeOperation *op);
 
   void operation_finished(NodeOperation *operation);