Compositor: Add support for canvas compositingtemp-compositor-canvas

This patch adds functionality for operations that require pixels
translation or resizing on "Full Frame" mode, allowing to adjust
their canvas within the output canvas. It fixes current cropping
issues in translate, scale, rotate and transform nodes by adjusting
their canvas to the result, instead of the input canvas.
Only the scale node canvas is limited to the scene output
resolution size for performance reasons as there are many
operations that require their whole input to be rendered.

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

1 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/compositor/intern/COM_SharedOperationBuffers.cc b/source/blender/compositor/intern/COM_SharedOperationBuffers.cc
index 7e0486b0f54..55153bd4f0a 100644
--- a/source/blender/compositor/intern/COM_SharedOperationBuffers.cc
+++ b/source/blender/compositor/intern/COM_SharedOperationBuffers.cc
@@ -76,9 +76,17 @@ void SharedOperationBuffers::register_read(NodeOperation *read_op)
 /**
  * Get registered areas given operation needs to render.
  */
-blender::Span<rcti> SharedOperationBuffers::get_areas_to_render(NodeOperation *op)
+Vector<rcti> SharedOperationBuffers::get_areas_to_render(NodeOperation *op,
+                                                         const int offset_x,
+                                                         const int offset_y)
 {
-  return get_buffer_data(op).render_areas.as_span();
+  Span<rcti> render_areas = get_buffer_data(op).render_areas.as_span();
+  Vector<rcti> dst_areas;
+  for (rcti dst : render_areas) {
+    BLI_rcti_translate(&dst, offset_x, offset_y);
+    dst_areas.append(std::move(dst));
+  }
+  return dst_areas;
 }
 
 /**