Cycles: Restructure kernel files organization

Since the kernel split work we're now having quite a few of new files, majority
of which are related on the kernel entry points. Keeping those files in the
root kernel folder will eventually make it really hard to follow which files are
actual implementation of Cycles kernel.

Those files are now moved to kernel/kernels/<device_type>. This way adding extra
entry points will be less noisy. It is also nice to have all device-specific
files grouped together.

Another change is in the way how split kernel invokes logic. Previously all the
logic was implemented directly in the .cl files, which makes it a bit tricky to
re-use the logic across other devices. Since we'll likely be looking into doing
same split work for CUDA devices eventually it makes sense to move logic from
.cl files to header files. Those files are stored in kernel/split. This does not
mean the header files will not give error messages when tried to be included
from other devices and their arguments will likely be changed, but having such
separation is a good start anyway.

There should be no functional changes.

Reviewers: juicyfruit, dingto

Differential Revision: https://developer.blender.org/D1314

1 files changed, 93 insertions, 0 deletions

diff --git a/intern/cycles/kernel/split/kernel_shader_eval.h b/intern/cycles/kernel/split/kernel_shader_eval.h
new file mode 100644
index 00000000000..0a8d77f52b0
--- /dev/null
+++ b/intern/cycles/kernel/split/kernel_shader_eval.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright 2011-2015 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "kernel_split_common.h"
+
+/*
+ * Note on kernel_shader_eval kernel
+ * This kernel is the 5th kernel in the ray tracing logic. This is
+ * the 4rd kernel in path iteration. This kernel sets up the ShaderData
+ * structure from the values computed by the previous kernels. It also identifies
+ * the rays of state RAY_TO_REGENERATE and enqueues them in QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS queue.
+ *
+ * The input and output of the kernel is as follows,
+ * rng_coop -------------------------------------------|--- kernel_shader_eval --|--- shader_data
+ * Ray_coop -------------------------------------------|                         |--- Queue_data (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS)
+ * PathState_coop -------------------------------------|                         |--- Queue_index (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS)
+ * Intersection_coop ----------------------------------|                         |
+ * Queue_data (QUEUE_ACTIVE_AND_REGENERATD_RAYS)-------|                         |
+ * Queue_index(QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS)---|                         |
+ * ray_state ------------------------------------------|                         |
+ * kg (globals + data) --------------------------------|                         |
+ * queuesize ------------------------------------------|                         |
+ *
+ * Note on Queues :
+ * This kernel reads from the QUEUE_ACTIVE_AND_REGENERATED_RAYS queue and processes
+ * only the rays of state RAY_ACTIVE;
+ * State of queues when this kernel is called,
+ * at entry,
+ * QUEUE_ACTIVE_AND_REGENERATED_RAYS will be filled with RAY_ACTIVE and RAY_REGENERATED rays
+ * QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be empty.
+ * at exit,
+ * QUEUE_ACTIVE_AND_REGENERATED_RAYS will be filled with RAY_ACTIVE and RAY_REGENERATED rays
+ * QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be filled with RAY_TO_REGENERATE rays
+ */
+
+ccl_device void kernel_shader_eval(
+	ccl_global char *globals,
+	ccl_constant KernelData *data,
+	ccl_global char *shader_data,               /* Output ShaderData structure to be filled */
+	ccl_global uint *rng_coop,                  /* Required for rbsdf calculation */
+	ccl_global Ray *Ray_coop,                   /* Required for setting up shader from ray */
+	ccl_global PathState *PathState_coop,       /* Required for all functions in this kernel */
+	Intersection *Intersection_coop, /* Required for setting up shader from ray */
+	ccl_global char *ray_state,                 /* Denotes the state of each ray */
+	ccl_global int *Queue_data,                 /* queue memory */
+	ccl_global int *Queue_index,                /* Tracks the number of elements in each queue */
+	int queuesize                               /* Size (capacity) of each queue */
+	)
+{
+	int ray_index = get_global_id(1) * get_global_size(0) + get_global_id(0);
+	/* Enqeueue RAY_TO_REGENERATE rays into QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS queue */
+	ccl_local unsigned int local_queue_atomics;
+	if(get_local_id(0) == 0 && get_local_id(1) == 0) {
+		local_queue_atomics = 0;
+	}
+	barrier(CLK_LOCAL_MEM_FENCE);
+
+	char enqueue_flag = (IS_STATE(ray_state, ray_index, RAY_TO_REGENERATE)) ? 1 : 0;
+
+	enqueue_ray_index_local(ray_index, QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS, enqueue_flag, queuesize, &local_queue_atomics, Queue_data, Queue_index);
+
+	ray_index = get_ray_index(ray_index, QUEUE_ACTIVE_AND_REGENERATED_RAYS, Queue_data, queuesize, 0);
+
+	if(ray_index == QUEUE_EMPTY_SLOT)
+		return;
+
+	/* Continue on with shader evaluation */
+	if(IS_STATE(ray_state, ray_index, RAY_ACTIVE)) {
+		KernelGlobals *kg = (KernelGlobals *)globals;
+		ShaderData *sd = (ShaderData *)shader_data;
+		Intersection *isect = &Intersection_coop[ray_index];
+		ccl_global uint *rng = &rng_coop[ray_index];
+		ccl_global PathState *state = &PathState_coop[ray_index];
+		Ray ray = Ray_coop[ray_index];
+
+		shader_setup_from_ray(kg, sd, isect, &ray, state->bounce, state->transparent_bounce);
+		float rbsdf = path_state_rng_1D_for_decision(kg, rng, state, PRNG_BSDF);
+		shader_eval_surface(kg, sd, rbsdf, state->flag, SHADER_CONTEXT_MAIN);
+	}
+}