diff options
Diffstat (limited to 'src/libs/sig/ops_sin.c')
| -rw-r--r-- | src/libs/sig/ops_sin.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/src/libs/sig/ops_sin.c b/src/libs/sig/ops_sin.c index da5b371..4acc8e5 100644 --- a/src/libs/sig/ops_sin.c +++ b/src/libs/sig/ops_sin.c @@ -50,6 +50,15 @@ static float output_sqr(float rads) } +static float output_tri(float rads) +{ + /* This approximation comes from: + * https://calculushowto.com/triangle-wave-function/ + */ + return M_2_PI * asinf(fabsf(sinf(M_PI * rads))); +} + + static float output(void *context, unsigned ticks_ms, float (*output_fn)(float rads)) { ops_sin_ctxt_t *ctxt = context; @@ -87,6 +96,12 @@ static float ops_sqr_output(void *context, unsigned ticks_ms) } +static float ops_tri_output(void *context, unsigned ticks_ms) +{ + return output(context, ticks_ms, output_tri); +} + + sig_ops_t sig_ops_sin = { .size = ops_sin_size, .init = ops_sin_init, @@ -101,3 +116,11 @@ sig_ops_t sig_ops_sqr = { .destroy = ops_sin_destroy, .output = ops_sqr_output, }; + + +sig_ops_t sig_ops_tri = { + .size = ops_sin_size, + .init = ops_sin_init, + .destroy = ops_sin_destroy, + .output = ops_tri_output, +}; |