forked from bartvdbraak/blender
140 lines
4.9 KiB
C
140 lines
4.9 KiB
C
/*
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* Copyright 2011-2015 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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CCL_NAMESPACE_BEGIN
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/* This kernel takes care of direct lighting logic.
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* However, the "shadow ray cast" part of direct lighting is handled
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* in the next kernel.
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*
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* This kernels determines the rays for which a shadow_blocked() function
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* associated with direct lighting should be executed. Those rays for which
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* a shadow_blocked() function for direct-lighting must be executed, are
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* marked with flag RAY_SHADOW_RAY_CAST_DL and enqueued into the queue
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* QUEUE_SHADOW_RAY_CAST_DL_RAYS
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*
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* Note on Queues:
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* This kernel only reads from the QUEUE_ACTIVE_AND_REGENERATED_RAYS queue
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* and processes only the rays of state RAY_ACTIVE; If a ray needs to execute
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* the corresponding shadow_blocked part, after direct lighting, the ray is
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* marked with RAY_SHADOW_RAY_CAST_DL flag.
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*
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* State of queues when this kernel is called:
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* - State of queues QUEUE_ACTIVE_AND_REGENERATED_RAYS and
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* QUEUE_HITBG_BUFF_UPDATE_TOREGEN_RAYS will be same before and after this
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* kernel call.
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* - QUEUE_SHADOW_RAY_CAST_DL_RAYS queue will be filled with rays for which a
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* shadow_blocked function must be executed, after this kernel call
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* Before this kernel call the QUEUE_SHADOW_RAY_CAST_DL_RAYS will be empty.
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*/
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ccl_device void kernel_direct_lighting(KernelGlobals *kg,
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ccl_local_param unsigned int *local_queue_atomics)
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{
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if(ccl_local_id(0) == 0 && ccl_local_id(1) == 0) {
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*local_queue_atomics = 0;
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}
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ccl_barrier(CCL_LOCAL_MEM_FENCE);
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char enqueue_flag = 0;
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int ray_index = ccl_global_id(1) * ccl_global_size(0) + ccl_global_id(0);
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ray_index = get_ray_index(kg, ray_index,
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QUEUE_ACTIVE_AND_REGENERATED_RAYS,
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kernel_split_state.queue_data,
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kernel_split_params.queue_size,
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0);
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#ifdef __COMPUTE_DEVICE_GPU__
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/* If we are executing on a GPU device, we exit all threads that are not
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* required.
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*
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* If we are executing on a CPU device, then we need to keep all threads
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* active since we have barrier() calls later in the kernel. CPU devices,
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* expect all threads to execute barrier statement.
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*/
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if(ray_index == QUEUE_EMPTY_SLOT) {
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return;
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}
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#endif
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#ifndef __COMPUTE_DEVICE_GPU__
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if(ray_index != QUEUE_EMPTY_SLOT) {
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#endif
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if(IS_STATE(kernel_split_state.ray_state, ray_index, RAY_ACTIVE)) {
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ccl_global PathState *state = &kernel_split_state.path_state[ray_index];
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ShaderData *sd = &kernel_split_state.sd[ray_index];
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/* direct lighting */
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#ifdef __EMISSION__
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if((kernel_data.integrator.use_direct_light &&
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(sd->flag & SD_BSDF_HAS_EVAL)))
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{
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/* Sample illumination from lights to find path contribution. */
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ccl_global RNG* rng = &kernel_split_state.rng[ray_index];
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float light_t = path_state_rng_1D(kg, rng, state, PRNG_LIGHT);
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float light_u, light_v;
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path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
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float terminate = path_state_rng_light_termination(kg, rng, state);
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LightSample ls;
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if(light_sample(kg,
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light_t, light_u, light_v,
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sd->time,
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sd->P,
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state->bounce,
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&ls)) {
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Ray light_ray;
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#ifdef __OBJECT_MOTION__
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light_ray.time = sd->time;
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#endif
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BsdfEval L_light;
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bool is_lamp;
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if(direct_emission(kg, sd, &kernel_split_state.sd_DL_shadow[ray_index], &ls, state, &light_ray, &L_light, &is_lamp, terminate)) {
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/* Write intermediate data to global memory to access from
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* the next kernel.
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*/
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kernel_split_state.light_ray[ray_index] = light_ray;
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kernel_split_state.bsdf_eval[ray_index] = L_light;
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kernel_split_state.is_lamp[ray_index] = is_lamp;
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/* Mark ray state for next shadow kernel. */
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ADD_RAY_FLAG(kernel_split_state.ray_state, ray_index, RAY_SHADOW_RAY_CAST_DL);
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enqueue_flag = 1;
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}
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}
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}
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#endif /* __EMISSION__ */
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}
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#ifndef __COMPUTE_DEVICE_GPU__
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}
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#endif
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#ifdef __EMISSION__
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/* Enqueue RAY_SHADOW_RAY_CAST_DL rays. */
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enqueue_ray_index_local(ray_index,
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QUEUE_SHADOW_RAY_CAST_DL_RAYS,
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enqueue_flag,
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kernel_split_params.queue_size,
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local_queue_atomics,
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kernel_split_state.queue_data,
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kernel_split_params.queue_index);
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#endif
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}
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CCL_NAMESPACE_END
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