1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
/*
Copyright 2018 Google Inc. All Rights Reserved.
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 "dsp/shoe_box_room.h"
#include "base/constants_and_types.h"
namespace vraudio {
void ComputeReflections(const WorldPosition& relative_listener_position,
const WorldPosition& room_dimensions,
const float* reflection_coefficients,
std::vector<Reflection>* reflections) {
DCHECK(reflection_coefficients);
DCHECK(reflections);
DCHECK_EQ(reflections->size(), kNumRoomSurfaces);
const WorldPosition kOrigin(0.0f, 0.0f, 0.0f);
if (!IsPositionInAabb(relative_listener_position, kOrigin, room_dimensions)) {
// Listener is outside the room, skip computation.
std::fill(reflections->begin(), reflections->end(), Reflection());
return;
}
// Calculate the distance of the listener to each wall.
// Since all the sources are 'attached' to the listener in the computation
// of reflections, the distance travelled is arbitrary. So, we add 1.0f to
// the computed distance in order to avoid delay time approaching 0 and the
// magnitude approaching +inf.
const WorldPosition offsets = 0.5f * room_dimensions;
const float distances_travelled[kNumRoomSurfaces] = {
offsets[0] + relative_listener_position[0] + 1.0f,
offsets[0] - relative_listener_position[0] + 1.0f,
offsets[1] + relative_listener_position[1] + 1.0f,
offsets[1] - relative_listener_position[1] + 1.0f,
offsets[2] + relative_listener_position[2] + 1.0f,
offsets[2] - relative_listener_position[2] + 1.0f};
for (size_t i = 0; i < kNumRoomSurfaces; ++i) {
// Convert distances to time delays in seconds.
(*reflections)[i].delay_time_seconds =
distances_travelled[i] / kSpeedOfSound;
// Division by distance is performed here as we don't want this applied more
// than once.
(*reflections)[i].magnitude =
reflection_coefficients[i] / distances_travelled[i];
}
}
} // namespace vraudio
|
