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

9 files changed, 47 insertions, 8 deletions

diff --git a/intern/cycles/device/device.h b/intern/cycles/device/device.h
index b9bdffa2618..988ad10607d 100644
--- a/intern/cycles/device/device.h
+++ b/intern/cycles/device/device.h
@@ -220,6 +220,7 @@ public:
 	DeviceInfo info;
 	virtual const string& error_message() { return error_msg; }
 	bool have_error() { return !error_message().empty(); }
+	virtual bool show_samples() const { return false; }
 
 	/* statistics */
 	Stats &stats;
diff --git a/intern/cycles/device/device_cpu.cpp b/intern/cycles/device/device_cpu.cpp
index aed86d8d853..c8e001ec2fd 100644
--- a/intern/cycles/device/device_cpu.cpp
+++ b/intern/cycles/device/device_cpu.cpp
@@ -112,6 +112,11 @@ public:
 		task_pool.stop();
 	}
 
+	virtual bool show_samples() const
+	{
+		return (TaskScheduler::num_threads() == 1);
+	}
+
 	void mem_alloc(device_memory& mem, MemoryType /*type*/)
 	{
 		mem.device_pointer = mem.data_pointer;
@@ -275,7 +280,7 @@ public:
 
 				tile.sample = sample + 1;
 
-				task.update_progress(&tile);
+				task.update_progress(&tile, tile.w*tile.h);
 			}
 
 			task.release_tile(tile);
diff --git a/intern/cycles/device/device_cuda.cpp b/intern/cycles/device/device_cuda.cpp
index fbb97f78e70..233f94be1bf 100644
--- a/intern/cycles/device/device_cuda.cpp
+++ b/intern/cycles/device/device_cuda.cpp
@@ -115,6 +115,12 @@ public:
 		return path_exists(cubins_path);
 	}
 
+	virtual bool show_samples() const
+	{
+		/* The CUDADevice only processes one tile at a time, so showing samples is fine. */
+		return true;
+	}
+
 /*#ifdef NDEBUG
 #define cuda_abort()
 #else
@@ -1267,7 +1273,7 @@ public:
 
 					tile.sample = sample + 1;
 
-					task->update_progress(&tile);
+					task->update_progress(&tile, tile.w*tile.h);
 				}
 
 				task->release_tile(tile);
diff --git a/intern/cycles/device/device_multi.cpp b/intern/cycles/device/device_multi.cpp
index 48fd159d508..31b800640d3 100644
--- a/intern/cycles/device/device_multi.cpp
+++ b/intern/cycles/device/device_multi.cpp
@@ -89,6 +89,14 @@ public:
 		return error_msg;
 	}
 
+	virtual bool show_samples() const
+	{
+		if(devices.size() > 1) {
+			return false;
+		}
+		return devices.front().device->show_samples();
+	}
+
 	bool load_kernels(const DeviceRequestedFeatures& requested_features)
 	{
 		foreach(SubDevice& sub, devices)
diff --git a/intern/cycles/device/device_network.cpp b/intern/cycles/device/device_network.cpp
index 3eb5ad2d2db..53eef6cf199 100644
--- a/intern/cycles/device/device_network.cpp
+++ b/intern/cycles/device/device_network.cpp
@@ -51,6 +51,11 @@ public:
 
 	thread_mutex rpc_lock;
 
+	virtual bool show_samples() const
+	{
+		return false;
+	}
+
 	NetworkDevice(DeviceInfo& info, Stats &stats, const char *address)
 	: Device(info, stats, true), socket(io_service)
 	{
diff --git a/intern/cycles/device/device_task.cpp b/intern/cycles/device/device_task.cpp
index 1f1128a28f8..48d18035c13 100644
--- a/intern/cycles/device/device_task.cpp
+++ b/intern/cycles/device/device_task.cpp
@@ -19,6 +19,8 @@
 
 #include "device_task.h"
 
+#include "buffers.h"
+
 #include "util_algorithm.h"
 #include "util_time.h"
 
@@ -99,14 +101,18 @@ void DeviceTask::split(list<DeviceTask>& tasks, int num, int max_size)
 	}
 }
 
-void DeviceTask::update_progress(RenderTile *rtile)
+void DeviceTask::update_progress(RenderTile *rtile, int pixel_samples)
 {
 	if((type != PATH_TRACE) &&
 	   (type != SHADER))
 		return;
 
-	if(update_progress_sample)
-		update_progress_sample();
+	if(update_progress_sample) {
+		if(pixel_samples == -1) {
+			pixel_samples = shader_w;
+		}
+		update_progress_sample(pixel_samples, rtile? rtile->sample : 0);
+	}
 
 	if(update_tile_sample) {
 		double current_time = time_dt();
diff --git a/intern/cycles/device/device_task.h b/intern/cycles/device/device_task.h
index 8423e83bdfd..8bd54c3d2b0 100644
--- a/intern/cycles/device/device_task.h
+++ b/intern/cycles/device/device_task.h
@@ -56,10 +56,10 @@ public:
 	int get_subtask_count(int num, int max_size = 0);
 	void split(list<DeviceTask>& tasks, int num, int max_size = 0);
 
-	void update_progress(RenderTile *rtile);
+	void update_progress(RenderTile *rtile, int pixel_samples = -1);
 
 	function<bool(Device *device, RenderTile&)> acquire_tile;
-	function<void(void)> update_progress_sample;
+	function<void(long, int)> update_progress_sample;
 	function<void(RenderTile&)> update_tile_sample;
 	function<void(RenderTile&)> release_tile;
 	function<bool(void)> get_cancel;
diff --git a/intern/cycles/device/opencl/opencl_mega.cpp b/intern/cycles/device/opencl/opencl_mega.cpp
index 369c086df57..6ea7619e022 100644
--- a/intern/cycles/device/opencl/opencl_mega.cpp
+++ b/intern/cycles/device/opencl/opencl_mega.cpp
@@ -39,6 +39,10 @@ public:
 	{
 	}
 
+	virtual bool show_samples() const {
+		return true;
+	}
+
 	virtual void load_kernels(const DeviceRequestedFeatures& /*requested_features*/,
 	                          vector<OpenCLProgram*> &programs)
 	{
@@ -120,7 +124,7 @@ public:
 
 					tile.sample = sample + 1;
 
-					task->update_progress(&tile);
+					task->update_progress(&tile, tile.w*tile.h);
 				}
 
 				/* Complete kernel execution before release tile */
diff --git a/intern/cycles/device/opencl/opencl_split.cpp b/intern/cycles/device/opencl/opencl_split.cpp
index 239e73a40fd..3c3c2150128 100644
--- a/intern/cycles/device/opencl/opencl_split.cpp
+++ b/intern/cycles/device/opencl/opencl_split.cpp
@@ -247,6 +247,10 @@ public:
 		}
 	}
 
+	virtual bool show_samples() const {
+		return false;
+	}
+
 	/* Split kernel utility functions. */
 	size_t get_tex_size(const char *tex_name)
 	{