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3719602c PC |
1 | /* Copyright (C) 2010-2020 The RetroArch team |
2 | * | |
3 | * --------------------------------------------------------------------------------------- | |
4 | * The following license statement only applies to this file (tremolo.c). | |
5 | * --------------------------------------------------------------------------------------- | |
6 | * | |
7 | * Permission is hereby granted, free of charge, | |
8 | * to any person obtaining a copy of this software and associated documentation files (the "Software"), | |
9 | * to deal in the Software without restriction, including without limitation the rights to | |
10 | * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
11 | * and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, | |
16 | * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
19 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
21 | */ | |
22 | ||
23 | #include <math.h> | |
24 | #include <stdlib.h> | |
25 | #include <string.h> | |
26 | ||
27 | #include <retro_miscellaneous.h> | |
28 | #include <libretro_dspfilter.h> | |
29 | #include <string/stdstring.h> | |
30 | ||
31 | #define sqr(a) ((a) * (a)) | |
32 | ||
33 | struct tremolo_core | |
34 | { | |
35 | float *wavetable; | |
36 | float freq; | |
37 | float depth; | |
38 | int index; | |
39 | int maxindex; | |
40 | }; | |
41 | ||
42 | struct tremolo | |
43 | { | |
44 | struct tremolo_core left, right; | |
45 | }; | |
46 | ||
47 | static void tremolo_free(void *data) | |
48 | { | |
49 | struct tremolo *tre = (struct tremolo*)data; | |
50 | free(tre->left.wavetable); | |
51 | free(tre->right.wavetable); | |
52 | free(data); | |
53 | } | |
54 | ||
55 | static void tremolocore_init(struct tremolo_core *core,float depth,int samplerate,float freq) | |
56 | { | |
57 | double env; | |
58 | unsigned i; | |
59 | const double offset = 1. - depth / 2.; | |
60 | core->index = 0; | |
61 | core->maxindex = samplerate / freq; | |
62 | core->wavetable = malloc(core->maxindex * sizeof(float)); | |
63 | memset(core->wavetable, 0, core->maxindex * sizeof(float)); | |
64 | for (i = 0; i < core->maxindex; i++) | |
65 | { | |
66 | env = freq * i / samplerate; | |
67 | env = sin((M_PI*2) * fmod(env + 0.25, 1.0)); | |
68 | core->wavetable[i] = env * (1 - fabs(offset)) + offset; | |
69 | } | |
70 | } | |
71 | ||
72 | float tremolocore_core(struct tremolo_core *core,float in) | |
73 | { | |
74 | core->index = core->index % core->maxindex; | |
75 | return in * core->wavetable[core->index++]; | |
76 | } | |
77 | ||
78 | static void tremolo_process(void *data, struct dspfilter_output *output, | |
79 | const struct dspfilter_input *input) | |
80 | { | |
81 | unsigned i; | |
82 | float *out; | |
83 | struct tremolo *tre = (struct tremolo*)data; | |
84 | ||
85 | output->samples = input->samples; | |
86 | output->frames = input->frames; | |
87 | out = output->samples; | |
88 | ||
89 | for (i = 0; i < input->frames; i++, out += 2) | |
90 | { | |
91 | float in[2] = { out[0], out[1] }; | |
92 | out[0] = tremolocore_core(&tre->left, in[0]); | |
93 | out[1] = tremolocore_core(&tre->right, in[1]); | |
94 | } | |
95 | } | |
96 | ||
97 | static void *tremolo_init(const struct dspfilter_info *info, | |
98 | const struct dspfilter_config *config, void *userdata) | |
99 | { | |
100 | float freq, depth; | |
101 | struct tremolo *tre = (struct tremolo*)calloc(1, sizeof(*tre)); | |
102 | if (!tre) | |
103 | return NULL; | |
104 | ||
105 | config->get_float(userdata, "freq", &freq,4.0f); | |
106 | config->get_float(userdata, "depth", &depth, 0.9f); | |
107 | tremolocore_init(&tre->left,depth,info->input_rate,freq); | |
108 | tremolocore_init(&tre->right,depth,info->input_rate,freq); | |
109 | return tre; | |
110 | } | |
111 | ||
112 | static const struct dspfilter_implementation tremolo_plug = { | |
113 | tremolo_init, | |
114 | tremolo_process, | |
115 | tremolo_free, | |
116 | ||
117 | DSPFILTER_API_VERSION, | |
118 | "Tremolo", | |
119 | "tremolo", | |
120 | }; | |
121 | ||
122 | #ifdef HAVE_FILTERS_BUILTIN | |
123 | #define dspfilter_get_implementation tremolo_dspfilter_get_implementation | |
124 | #endif | |
125 | ||
126 | const struct dspfilter_implementation *dspfilter_get_implementation(dspfilter_simd_mask_t mask) | |
127 | { | |
128 | return &tremolo_plug; | |
129 | } | |
130 | ||
131 | #undef dspfilter_get_implementation |