-
Notifications
You must be signed in to change notification settings - Fork 1
/
pictureosc.cpp
186 lines (164 loc) · 4.71 KB
/
pictureosc.cpp
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
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
* File: pictureosc.cpp
*/
#include "userosc.h"
#if 1
#include "figure.h"
#else
#define VERTICES 6
#define WAVETABLES 1
static float figure_x[WAVETABLES][VERTICES] = {
{1.0, 0.5, 0.0, 0.5, 1.0, 0.5}
};
static float figure_y[WAVETABLES][VERTICES] = {
{0.0, 0.0, 0.5, 1.0, 0.5, 0.0}
};
#endif
#define BUFSIZE (VERTICES*4)
static q31_t wavetable[WAVETABLES][BUFSIZE];
typedef struct State {
float w0;
float phase;
float lfo, lfoz;
float shape;
float shape_start;
uint8_t table;
uint8_t interpolation;
uint8_t shape_type;
uint8_t flags;
} State;
static State s_state;
enum {
k_inter_lin = 0,
k_inter_cos,
k_nointer,
};
enum {
k_shape_flat = 0,
k_shape_square,
k_shape_triangle,
k_shape_sine
};
enum {
k_flags_none = 0,
k_flag_reset = 1<<0,
};
static void init_wavetable(q31_t *table, const int vertices, float *vx, float *vy) {
q31_t x, y;
for(int i = 0; i < vertices; i++) {
x = f32_to_q31(vx[i] - 1.0);
y = f32_to_q31(vy[i]);
table[i] = y;
table[i + vertices] = 0xffffffff - x;
table[i + 2 * vertices] = 0xffffffff - y;
table[i + 3 * vertices] = x;
}
}
void OSC_INIT(uint32_t platform, uint32_t api)
{
s_state.w0 = 0.f;
s_state.phase = 0.f;
s_state.lfo = s_state.lfoz = 0.f;
s_state.shape_start = 0.f;
s_state.interpolation = k_inter_lin;
s_state.shape_type = k_shape_flat;
s_state.flags = k_flags_none;
for (int i = 0; i < WAVETABLES; i++) {
init_wavetable(wavetable[i], VERTICES, figure_x[i], figure_y[i]);
}
}
void OSC_CYCLE(const user_osc_param_t * const params,
int32_t *yn,
const uint32_t frames)
{
const uint8_t flags = s_state.flags;
s_state.flags = k_flags_none;
const float note = (params->pitch >> 8) + (params->pitch & 0xFF)/256.0f;
const float w0 = s_state.w0 = osc_w0f_for_note((params->pitch)>>8, params->pitch & 0xFF);
float phase = (flags & k_flag_reset) ? 0.f : s_state.phase;
const float lfo = s_state.lfo = q31_to_f32(params->shape_lfo);
float lfoz = (flags & k_flag_reset) ? lfo : s_state.lfoz;
const float lfo_inc = (lfo - lfoz) / frames;
const int img = s_state.table;
q31_t * __restrict y = (q31_t *) yn;
const q31_t * y_e = y + frames;
for (; y != y_e; ) {
float pos = phase * BUFSIZE;
uint32_t idx = (uint32_t) pos;
const float frac = pos - idx;
const float m = q31_to_f32(wavetable[img][idx++]);
const float n = q31_to_f32(wavetable[img][(idx == BUFSIZE) ? 0 : idx]);
float sig;
switch(s_state.interpolation) {
case k_inter_cos:
sig = cosintf(frac, m, n);
break;
case k_nointer:
sig = m;
break;
default:
sig = linintf(frac, m, n);
}
float pwm = phase + s_state.shape_start;
pwm -= (uint32_t) pwm;
if (pwm < (s_state.shape + lfoz)) {
switch(s_state.shape_type) {
case k_shape_square:
sig = osc_bl2_sqrf(phase, osc_bl_sqr_idx(note));
break;
case k_shape_triangle:
if (pwm < 0.25) {
sig = pwm * 4;
} else if (pwm < 0.75) {
sig = -pwm * 4 + 2;
} else {
sig = pwm * 4 - 4;
}
break;
case k_shape_sine:
sig = osc_sinf(phase);
break;
default:
sig = 0.f;
}
}
*(y++) = f32_to_q31(sig);
phase += w0;
phase -= (uint32_t) phase;
lfoz += lfo_inc;
}
s_state.phase = phase;
s_state.lfoz = lfoz;
}
void OSC_NOTEON(const user_osc_param_t * const params)
{
s_state.flags |= k_flag_reset;
}
void OSC_NOTEOFF(const user_osc_param_t * const params)
{
}
void OSC_PARAM(uint16_t index, uint16_t value)
{
const float valf = param_val_to_f32(value);
switch (index) {
case k_user_osc_param_id1: /* shape type: flat, sqr, tri, sin */
s_state.shape_type = value;
break;
case k_user_osc_param_id2: /* shape phase of start: 3pi/4, 0, pi/4, pi/2 */
s_state.shape_start = 0.25 * (++value % 4);
break;
case k_user_osc_param_id3: /* interpolation method: linear, cos, none */
s_state.interpolation = value;
break;
case k_user_osc_param_id4:
case k_user_osc_param_id5:
case k_user_osc_param_id6:
case k_user_osc_param_shape:
s_state.shape = valf;
break;
case k_user_osc_param_shiftshape:
s_state.table = 0.99 * valf * WAVETABLES;
default:
break;
}
}