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/*
* 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.
*/
CCL_NAMESPACE_BEGIN
/* This kernel takes care of rays that hit the background (sceneintersect
* kernel), and for the rays of state RAY_UPDATE_BUFFER it updates the ray's
* accumulated radiance in the output buffer. This kernel also takes care of
* rays that have been determined to-be-regenerated.
*
* We will empty QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS queue in this kernel.
*
* Typically all rays that are in state RAY_HIT_BACKGROUND, RAY_UPDATE_BUFFER
* will be eventually set to RAY_TO_REGENERATE state in this kernel.
* Finally all rays of ray_state RAY_TO_REGENERATE will be regenerated and put
* in queue QUEUE_ACTIVE_AND_REGENERATED_RAYS.
*
* State of queues when this kernel is called:
* At entry,
* - QUEUE_ACTIVE_AND_REGENERATED_RAYS will be filled with RAY_ACTIVE rays.
* - QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be filled with
* RAY_UPDATE_BUFFER, RAY_HIT_BACKGROUND, RAY_TO_REGENERATE rays.
* 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 empty.
*/
ccl_device void kernel_buffer_update(KernelGlobals *kg,
ccl_local_param unsigned int *local_queue_atomics)
{
if(ccl_local_id(0) == 0 && ccl_local_id(1) == 0) {
*local_queue_atomics = 0;
}
ccl_barrier(CCL_LOCAL_MEM_FENCE);
int ray_index = ccl_global_id(1) * ccl_global_size(0) + ccl_global_id(0);
if(ray_index == 0) {
/* We will empty this queue in this kernel. */
kernel_split_params.queue_index[QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS] = 0;
}
char enqueue_flag = 0;
ray_index = get_ray_index(kg, ray_index,
QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS,
kernel_split_state.queue_data,
kernel_split_params.queue_size,
1);
#ifdef __COMPUTE_DEVICE_GPU__
/* If we are executing on a GPU device, we exit all threads that are not
* required.
*
* If we are executing on a CPU device, then we need to keep all threads
* active since we have barrier() calls later in the kernel. CPU devices,
* expect all threads to execute barrier statement.
*/
if(ray_index == QUEUE_EMPTY_SLOT) {
return;
}
#endif
#ifndef __COMPUTE_DEVICE_GPU__
if(ray_index != QUEUE_EMPTY_SLOT) {
#endif
int stride = kernel_split_params.stride;
ccl_global char *ray_state = kernel_split_state.ray_state;
ccl_global PathState *state = &kernel_split_state.path_state[ray_index];
PathRadiance *L = &kernel_split_state.path_radiance[ray_index];
ccl_global Ray *ray = &kernel_split_state.ray[ray_index];
ccl_global float3 *throughput = &kernel_split_state.throughput[ray_index];
if(IS_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER)) {
uint work_index = kernel_split_state.work_array[ray_index];
uint sample = get_work_sample(kg, work_index, ray_index) + kernel_split_params.start_sample;
uint tile_x, tile_y, pixel_x, pixel_y;
get_work_pixel_tile_position(kg, &pixel_x, &pixel_y, &tile_x, &tile_y, work_index, ray_index);
ccl_global float *buffer = kernel_split_params.buffer;
buffer += (kernel_split_params.offset + pixel_x + pixel_y*stride) * kernel_data.film.pass_stride;
/* accumulate result in output buffer */
kernel_write_result(kg, buffer, sample, L);
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_TO_REGENERATE);
}
if(IS_STATE(ray_state, ray_index, RAY_TO_REGENERATE)) {
/* We have completed current work; So get next work */
uint work_index;
int valid_work = get_next_work(kg, &work_index, ray_index);
if(!valid_work) {
/* If work is invalid, this means no more work is available and the thread may exit */
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_INACTIVE);
}
if(IS_STATE(ray_state, ray_index, RAY_TO_REGENERATE)) {
kernel_split_state.work_array[ray_index] = work_index;
/* Get the sample associated with the current work */
uint sample = get_work_sample(kg, work_index, ray_index) + kernel_split_params.start_sample;
/* Get pixel and tile position associated with current work */
uint tile_x, tile_y, pixel_x, pixel_y;
get_work_pixel_tile_position(kg, &pixel_x, &pixel_y, &tile_x, &tile_y, work_index, ray_index);
/* Remap rng_state according to the current work */
ccl_global uint *rng_state = kernel_split_params.rng_state;
rng_state += kernel_split_params.offset + pixel_x + pixel_y*stride;
/* Remap buffer according to the current work */
ccl_global float *buffer = kernel_split_params.buffer;
buffer += (kernel_split_params.offset + pixel_x + pixel_y*stride) * kernel_data.film.pass_stride;
/* Initialize random numbers and ray. */
uint rng_hash;
kernel_path_trace_setup(kg, rng_state, sample, pixel_x, pixel_y, &rng_hash, ray);
if(ray->t != 0.0f) {
/* Initialize throughput, path radiance, Ray, PathState;
* These rays proceed with path-iteration.
*/
*throughput = make_float3(1.0f, 1.0f, 1.0f);
path_radiance_init(L, kernel_data.film.use_light_pass);
path_state_init(kg, &kernel_split_state.sd_DL_shadow[ray_index], state, rng_hash, sample, ray);
#ifdef __SUBSURFACE__
kernel_path_subsurface_init_indirect(&kernel_split_state.ss_rays[ray_index]);
#endif
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_REGENERATED);
enqueue_flag = 1;
}
else {
/* These rays do not participate in path-iteration. */
float4 L_rad = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
/* Accumulate result in output buffer. */
kernel_write_pass_float4(buffer, sample, L_rad);
ASSIGN_RAY_STATE(ray_state, ray_index, RAY_TO_REGENERATE);
}
}
}
#ifndef __COMPUTE_DEVICE_GPU__
}
#endif
/* Enqueue RAY_REGENERATED rays into QUEUE_ACTIVE_AND_REGENERATED_RAYS;
* These rays will be made active during next SceneIntersectkernel.
*/
enqueue_ray_index_local(ray_index,
QUEUE_ACTIVE_AND_REGENERATED_RAYS,
enqueue_flag,
kernel_split_params.queue_size,
local_queue_atomics,
kernel_split_state.queue_data,
kernel_split_params.queue_index);
}
CCL_NAMESPACE_END
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