/* * 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_background_buffer_update kernel. * This is the fourth kernel in the ray tracing logic, and the third * of the path iteration kernels. 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. * * The input and output are as follows, * * rng_coop ---------------------------------------------|--- kernel_background_buffer_update --|--- PathRadiance_coop * throughput_coop --------------------------------------| |--- L_transparent_coop * per_sample_output_buffers ----------------------------| |--- per_sample_output_buffers * Ray_coop ---------------------------------------------| |--- ray_state * PathState_coop ---------------------------------------| |--- Queue_data (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) * L_transparent_coop -----------------------------------| |--- Queue_data (QUEUE_ACTIVE_AND_REGENERATED_RAYS) * ray_state --------------------------------------------| |--- Queue_index (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) * Queue_data (QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS) ----| |--- Queue_index (QUEUE_ACTIVE_AND_REGENERATED_RAYS) * Queue_index (QUEUE_ACTIVE_AND_REGENERATED_RAYS) ------| |--- work_array * parallel_samples -------------------------------------| |--- PathState_coop * end_sample -------------------------------------------| |--- throughput_coop * kg (globals + data) ----------------------------------| |--- rng_coop * rng_state --------------------------------------------| |--- Ray * PathRadiance_coop ------------------------------------| | * sw ---------------------------------------------------| | * sh ---------------------------------------------------| | * sx ---------------------------------------------------| | * sy ---------------------------------------------------| | * stride -----------------------------------------------| | * work_array -------------------------------------------| |--- work_array * queuesize --------------------------------------------| | * start_sample -----------------------------------------| |--- work_pool_wgs * work_pool_wgs ----------------------------------------| | * num_samples ------------------------------------------| | * * note on shader_data : shader_data argument is neither an input nor an output for this kernel. It is just filled and consumed here itself. * Note on Queues : * This kernel fetches rays from QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS queue. * * 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 char kernel_background_buffer_update( ccl_global char *globals, ccl_constant KernelData *data, ccl_global char *shader_data, ccl_global float *per_sample_output_buffers, ccl_global uint *rng_state, ccl_global uint *rng_coop, /* Required for buffer Update */ ccl_global float3 *throughput_coop, /* Required for background hit processing */ PathRadiance *PathRadiance_coop, /* Required for background hit processing and buffer Update */ ccl_global Ray *Ray_coop, /* Required for background hit processing */ ccl_global PathState *PathState_coop, /* Required for background hit processing */ ccl_global float *L_transparent_coop, /* Required for background hit processing and buffer Update */ ccl_global char *ray_state, /* Stores information on the current state of a ray */ int sw, int sh, int sx, int sy, int stride, int rng_state_offset_x, int rng_state_offset_y, int rng_state_stride, ccl_global unsigned int *work_array, /* Denotes work of each ray */ int end_sample, int start_sample, #ifdef __WORK_STEALING__ ccl_global unsigned int *work_pool_wgs, unsigned int num_samples, #endif #ifdef __KERNEL_DEBUG__ DebugData *debugdata_coop, #endif int parallel_samples, /* Number of samples to be processed in parallel */ int ray_index) { char enqueue_flag = 0; /* Load kernel globals structure and ShaderData strucuture */ KernelGlobals *kg = (KernelGlobals *)globals; ShaderData *sd = (ShaderData *)shader_data; #ifdef __KERNEL_DEBUG__ DebugData *debug_data = &debugdata_coop[ray_index]; #endif ccl_global PathState *state = &PathState_coop[ray_index]; PathRadiance *L = L = &PathRadiance_coop[ray_index]; ccl_global Ray *ray = &Ray_coop[ray_index]; ccl_global float3 *throughput = &throughput_coop[ray_index]; ccl_global float *L_transparent = &L_transparent_coop[ray_index]; ccl_global uint *rng = &rng_coop[ray_index]; #ifdef __WORK_STEALING__ unsigned int my_work; ccl_global float *initial_per_sample_output_buffers; ccl_global uint *initial_rng; #endif unsigned int sample; unsigned int tile_x; unsigned int tile_y; unsigned int pixel_x; unsigned int pixel_y; unsigned int my_sample_tile; #ifdef __WORK_STEALING__ my_work = work_array[ray_index]; sample = get_my_sample(my_work, sw, sh, parallel_samples, ray_index) + start_sample; get_pixel_tile_position(&pixel_x, &pixel_y, &tile_x, &tile_y, my_work, sw, sh, sx, sy, parallel_samples, ray_index); my_sample_tile = 0; initial_per_sample_output_buffers = per_sample_output_buffers; initial_rng = rng_state; #else /* __WORK_STEALING__ */ sample = work_array[ray_index]; int tile_index = ray_index / parallel_samples; /* buffer and rng_state's stride is "stride". Find x and y using ray_index */ tile_x = tile_index % sw; tile_y = tile_index / sw; my_sample_tile = ray_index - (tile_index * parallel_samples); #endif /* __WORK_STEALING__ */ rng_state += (rng_state_offset_x + tile_x) + (rng_state_offset_y + tile_y) * rng_state_stride; per_sample_output_buffers += (((tile_x + (tile_y * stride)) * parallel_samples) + my_sample_tile) * kernel_data.film.pass_stride; if(IS_STATE(ray_state, ray_index, RAY_HIT_BACKGROUND)) { /* eval background shader if nothing hit */ if(kernel_data.background.transparent && (state->flag & PATH_RAY_CAMERA)) { *L_transparent = (*L_transparent) + average((*throughput)); #ifdef __PASSES__ if(!(kernel_data.film.pass_flag & PASS_BACKGROUND)) #endif ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER); } if(IS_STATE(ray_state, ray_index, RAY_HIT_BACKGROUND)) { #ifdef __BACKGROUND__ /* sample background shader */ float3 L_background = indirect_background(kg, state, ray, sd); path_radiance_accum_background(L, (*throughput), L_background, state->bounce); #endif ASSIGN_RAY_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER); } } if(IS_STATE(ray_state, ray_index, RAY_UPDATE_BUFFER)) { float3 L_sum = path_radiance_clamp_and_sum(kg, L); kernel_write_light_passes(kg, per_sample_output_buffers, L, sample); #ifdef __KERNEL_DEBUG__ kernel_write_debug_passes(kg, per_sample_output_buffers, state, debug_data, sample); #endif float4 L_rad = make_float4(L_sum.x, L_sum.y, L_sum.z, 1.0f - (*L_transparent)); /* accumulate result in output buffer */ kernel_write_pass_float4(per_sample_output_buffers, sample, L_rad); path_rng_end(kg, rng_state, *rng); ASSIGN_RAY_STATE(ray_state, ray_index, RAY_TO_REGENERATE); } if(IS_STATE(ray_state, ray_index, RAY_TO_REGENERATE)) { #ifdef __WORK_STEALING__ /* We have completed current work; So get next work */ int valid_work = get_next_work(work_pool_wgs, &my_work, sw, sh, num_samples, parallel_samples, 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); } #else /* __WORK_STEALING__ */ if((sample + parallel_samples) >= end_sample) { ASSIGN_RAY_STATE(ray_state, ray_index, RAY_INACTIVE); } #endif /* __WORK_STEALING__ */ if(IS_STATE(ray_state, ray_index, RAY_TO_REGENERATE)) { #ifdef __WORK_STEALING__ work_array[ray_index] = my_work; /* Get the sample associated with the current work */ sample = get_my_sample(my_work, sw, sh, parallel_samples, ray_index) + start_sample; /* Get pixel and tile position associated with current work */ get_pixel_tile_position(&pixel_x, &pixel_y, &tile_x, &tile_y, my_work, sw, sh, sx, sy, parallel_samples, ray_index); my_sample_tile = 0; /* Remap rng_state according to the current work */ rng_state = initial_rng + ((rng_state_offset_x + tile_x) + (rng_state_offset_y + tile_y) * rng_state_stride); /* Remap per_sample_output_buffers according to the current work */ per_sample_output_buffers = initial_per_sample_output_buffers + (((tile_x + (tile_y * stride)) * parallel_samples) + my_sample_tile) * kernel_data.film.pass_stride; #else /* __WORK_STEALING__ */ work_array[ray_index] = sample + parallel_samples; sample = work_array[ray_index]; /* Get ray position from ray index */ pixel_x = sx + ((ray_index / parallel_samples) % sw); pixel_y = sy + ((ray_index / parallel_samples) / sw); #endif /* __WORK_STEALING__ */ /* Initialize random numbers and ray. */ kernel_path_trace_setup(kg, rng_state, sample, pixel_x, pixel_y, rng, ray); if(ray->t != 0.0f) { /* Initialize throughput, L_transparent, Ray, PathState; * These rays proceed with path-iteration. */ *throughput = make_float3(1.0f, 1.0f, 1.0f); *L_transparent = 0.0f; path_radiance_init(L, kernel_data.film.use_light_pass); path_state_init(kg, state, rng, sample, ray); #ifdef __KERNEL_DEBUG__ debug_data_init(debug_data); #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(per_sample_output_buffers, sample, L_rad); path_rng_end(kg, rng_state, *rng); ASSIGN_RAY_STATE(ray_state, ray_index, RAY_TO_REGENERATE); } } } return enqueue_flag; }