1 /*
2  * Copyright 2011-2015 Blender Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 CCL_NAMESPACE_BEGIN
18 
19 /* Shadow ray cast for direct visible light. */
kernel_shadow_blocked_dl(KernelGlobals * kg)20 ccl_device void kernel_shadow_blocked_dl(KernelGlobals *kg)
21 {
22   unsigned int dl_queue_length = kernel_split_params.queue_index[QUEUE_SHADOW_RAY_CAST_DL_RAYS];
23   ccl_barrier(CCL_LOCAL_MEM_FENCE);
24 
25   int ray_index = QUEUE_EMPTY_SLOT;
26   int thread_index = ccl_global_id(1) * ccl_global_size(0) + ccl_global_id(0);
27   if (thread_index < dl_queue_length) {
28     ray_index = get_ray_index(kg,
29                               thread_index,
30                               QUEUE_SHADOW_RAY_CAST_DL_RAYS,
31                               kernel_split_state.queue_data,
32                               kernel_split_params.queue_size,
33                               1);
34   }
35 
36 #ifdef __BRANCHED_PATH__
37   /* TODO(mai): move this somewhere else? */
38   if (thread_index == 0) {
39     /* Clear QUEUE_INACTIVE_RAYS before next kernel. */
40     kernel_split_params.queue_index[QUEUE_INACTIVE_RAYS] = 0;
41   }
42 #endif /* __BRANCHED_PATH__ */
43 
44   if (ray_index == QUEUE_EMPTY_SLOT)
45     return;
46 
47   ccl_global PathState *state = &kernel_split_state.path_state[ray_index];
48   Ray ray = kernel_split_state.light_ray[ray_index];
49   PathRadiance *L = &kernel_split_state.path_radiance[ray_index];
50   ShaderData *sd = kernel_split_sd(sd, ray_index);
51   float3 throughput = kernel_split_state.throughput[ray_index];
52 
53   BsdfEval L_light = kernel_split_state.bsdf_eval[ray_index];
54   ShaderData *emission_sd = AS_SHADER_DATA(&kernel_split_state.sd_DL_shadow[ray_index]);
55   bool is_lamp = kernel_split_state.is_lamp[ray_index];
56 
57 #if defined(__BRANCHED_PATH__) || defined(__SHADOW_TRICKS__)
58   bool use_branched = false;
59   int all = 0;
60 
61   if (state->flag & PATH_RAY_SHADOW_CATCHER) {
62     use_branched = true;
63     all = 1;
64   }
65 #  if defined(__BRANCHED_PATH__)
66   else if (kernel_data.integrator.branched) {
67     use_branched = true;
68 
69     if (IS_FLAG(kernel_split_state.ray_state, ray_index, RAY_BRANCHED_INDIRECT)) {
70       all = (kernel_data.integrator.sample_all_lights_indirect);
71     }
72     else {
73       all = (kernel_data.integrator.sample_all_lights_direct);
74     }
75   }
76 #  endif /* __BRANCHED_PATH__ */
77 
78   if (use_branched) {
79     kernel_branched_path_surface_connect_light(
80         kg, sd, emission_sd, state, throughput, 1.0f, L, all);
81   }
82   else
83 #endif /* defined(__BRANCHED_PATH__) || defined(__SHADOW_TRICKS__)*/
84   {
85     /* trace shadow ray */
86     float3 shadow;
87 
88     if (!shadow_blocked(kg, sd, emission_sd, state, &ray, &shadow)) {
89       /* accumulate */
90       path_radiance_accum_light(kg, L, state, throughput, &L_light, shadow, 1.0f, is_lamp);
91     }
92     else {
93       path_radiance_accum_total_light(L, state, throughput, &L_light);
94     }
95   }
96 }
97 
98 CCL_NAMESPACE_END
99