Cycles; Make baking a feature-specific option

This means render devices now might skip building baking kernels in cases when
only actual render-related functionality is used.

For now it's only implemented for OpenCL split kernel device and mainly needed
to work around some compiler-specific bugs which crashes on building the kernel.

Using OpenCL for baking might still crash the driver, but at least there is now
higher probability of that GPU will be usable to render the scene.

Real fix should actually be done in the driver side.

intern/cycles/blender/blender_session.cpp

@@ -543,6 +543,11 @@ void BlenderSession::bake(BL::Object b_object, const string& pass_type, const in
 	size_t object_index = OBJECT_NONE;
 	int tri_offset = 0;
 
+	/* Set baking flag in advance, so kernel loading can check if we need
+	 * any baking capabilities.
+	 */
+	scene->bake_manager->set_baking(true);
+
 	/* ensure kernels are loaded before we do any scene updates */
 	session->load_kernels();
 
@@ -572,7 +577,6 @@ void BlenderSession::bake(BL::Object b_object, const string& pass_type, const in
 	BufferParams buffer_params = BlenderSync::get_buffer_params(b_render, b_v3d, b_rv3d, scene->camera, width, height);
 
 	scene->bake_manager->set_shader_limit((size_t)b_engine.tile_x(), (size_t)b_engine.tile_y());
-	scene->bake_manager->set_baking(true);
 
 	/* set number of samples */
 	session->tile_manager.set_samples(session_params.samples);

intern/cycles/device/device.h

@@ -97,6 +97,9 @@ public:
 	bool use_object_motion;
 	bool use_camera_motion;
 
+	/* Denotes whether baking functionality is needed. */
+	bool use_baking;
+
 	DeviceRequestedFeatures()
 	{
 		/* TODO(sergey): Find more meaningful defaults. */
@@ -107,6 +110,7 @@ public:
 		use_hair = false;
 		use_object_motion = false;
 		use_camera_motion = false;
+		use_baking = false;
 	}
 
 	bool modified(const DeviceRequestedFeatures& requested_features)
@@ -114,7 +118,11 @@ public:
 		return !(experimental == requested_features.experimental &&
 		         max_closure == requested_features.max_closure &&
 		         max_nodes_group == requested_features.max_nodes_group &&
-		         nodes_features == requested_features.nodes_features);
+		         nodes_features == requested_features.nodes_features &&
+		         use_hair == requested_features.use_hair &&
+		         use_object_motion == requested_features.use_object_motion &&
+		         use_camera_motion == requested_features.use_camera_motion &&
+		         use_baking == requested_features.use_baking);
 	}
 };
 

intern/cycles/device/device_opencl.cpp

@@ -1560,6 +1560,9 @@ protected:
 		if(!requested_features.use_camera_motion) {
 			build_options += " -D__NO_CAMERA_MOTION__";
 		}
+		if(!requested_features.use_baking) {
+			build_options += " -D__NO_BAKING__";
+		}
 		return build_options;
 	}
 

intern/cycles/render/session.cpp

@@ -637,6 +637,9 @@ DeviceRequestedFeatures Session::get_requested_device_features()
 		requested_features.use_camera_motion |= mesh->use_motion_blur;
 	}
 
+	BakeManager *bake_manager = scene->bake_manager;
+	requested_features.use_baking = bake_manager->get_baking();
+
 	return requested_features;
 }