Simplify audiofilter construction through better default parameters

Author: jepler

shared-bindings/audiofilters/Filter.c

@@ -71,8 +71,8 @@
 static mp_obj_t audiofilters_filter_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
     enum { ARG_filter, ARG_mix, ARG_buffer_size, ARG_sample_rate, ARG_bits_per_sample, ARG_samples_signed, ARG_channel_count, };
     static const mp_arg_t allowed_args[] = {
-        { MP_QSTR_filter, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_OBJ_NULL} },
-        { MP_QSTR_mix, MP_ARG_OBJ | MP_ARG_KW_ONLY,  {.u_obj = MP_OBJ_NULL} },
+        { MP_QSTR_filter, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE} },
+        { MP_QSTR_mix, MP_ARG_OBJ | MP_ARG_KW_ONLY,  {.u_obj = MP_ROM_INT(1)} },
         { MP_QSTR_buffer_size, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 512} },
         { MP_QSTR_sample_rate, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 8000} },
         { MP_QSTR_bits_per_sample, MP_ARG_INT | MP_ARG_KW_ONLY, {.u_int = 16} },

shared-module/audiofilters/Filter.c

@@ -48,15 +48,8 @@ void common_hal_audiofilters_filter_construct(audiofilters_filter_obj_t *self,
 
     // The below section sets up the effect's starting values.
 
-    if (filter == MP_OBJ_NULL) {
-        filter = mp_const_none;
-    }
     common_hal_audiofilters_filter_set_filter(self, filter);
 
-    // If we did not receive a BlockInput we need to create a default float value
-    if (mix == MP_OBJ_NULL) {
-        mix = mp_obj_new_float(1.0);
-    }
     synthio_block_assign_slot(mix, &self->mix, MP_QSTR_mix);
 }