Cycles: Refactor Progress system to provide better estimates

The Progress system in Cycles had two limitations so far:
 - It just counted tiles, but ignored their size. For example, when rendering a 600x500 image with 512x512 tiles, the right 88x500 tile would count for 50% of the progress, although it only covers 15% of the image.
 - Scene update time was incorrectly counted as rendering time - therefore, the remaining time started very long and gradually decreased.

This patch fixes both problems:
First of all, the Progress now has a function to ignore time spans, and that is used to ignore scene update time.
The larger change is the tile size: Instead of counting samples per tile, so that the final value is num_samples*num_tiles, the code now counts every sample for every pixel, so that the final value is num_samples*num_pixels.

Along with that, some unused variables were removed from the Progress and Session classes.

Reviewers: brecht, sergey, #cycles

Subscribers: brecht, candreacchio, sergey

Differential Revision: https://developer.blender.org/D2214

1 files changed, 5 insertions, 1 deletions

diff --git a/intern/cycles/render/tile.h b/intern/cycles/render/tile.h
index af1b1ed8b0f..5d92ebac355 100644
--- a/intern/cycles/render/tile.h
+++ b/intern/cycles/render/tile.h
@@ -64,6 +64,10 @@ public:
 		int resolution_divider;
 		int num_tiles;
 		int num_rendered_tiles;
+
+		/* Total samples over all pixels: Generally num_samples*num_pixels,
+		 * but can be higher due to the initial resolution division for previews. */
+		uint64_t total_pixel_samples;
 		/* This vector contains a list of tiles for every logical device in the session.
 		 * In each list, the tiles are sorted according to the tile order setting. */
 		vector<list<Tile> > tiles;
@@ -91,7 +95,7 @@ public:
 	/* Number to samples in the rendering range. */
 	int range_num_samples;
 
-	/* get number of actual samples to render. */
+	/* Get number of actual samples to render. */
 	int get_num_effective_samples();
 protected: