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Generate most of ParamPtr with a macro

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This commit is contained in:
Robbert van der Helm 2022-03-03 14:28:52 +01:00
parent b5a471747f
commit fa01d3bfeb
2 changed files with 55 additions and 163 deletions
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216
src/param/internals.rs
View file

@ -3,7 +3,6 @@
use std::collections::HashMap;
use std::pin::Pin;
use super::range::Range;
use super::Param;
/// Re-export for use in the [Params] proc-macro.
@ -51,7 +50,8 @@ pub trait Params {
fn deserialize_fields(&self, serialized: &HashMap<String, String>);
}
/// Internal pointers to parameters. This is an implementation detail used by the wrappers.
/// Internal pointers to parameters. This is an implementation detail used by the wrappers for type
/// erasure.
#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
pub enum ParamPtr {
FloatParam(*mut super::FloatParam),
@ -82,136 +82,60 @@ where
F: Fn(&T) -> R;
}
/// Generate a [ParamPtr] function that forwards the function call to the underlying `Param`. We
/// can't have an `.as_param()` function since the return type would differ depending on the
/// underlying parameter type, so instead we need to type erase all of the functions individually.
macro_rules! param_ptr_forward(
(pub unsafe fn $method:ident(&self $(, $arg_name:ident: $arg_ty:ty)*) $(-> $ret:ty)?) => {
/// Calls the corresponding method on the underlying [Param] object.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this [ParamPtr] was created for
/// is still alive.
pub unsafe fn $method(&self $(, $arg_name: $arg_ty)*) $(-> $ret)? {
match &self {
ParamPtr::FloatParam(p) => (**p).$method($($arg_name),*),
ParamPtr::IntParam(p) => (**p).$method($($arg_name),*),
ParamPtr::BoolParam(p) => (**p).$method($($arg_name),*),
ParamPtr::EnumParam(p) => (**p).$method($($arg_name),*),
}
}
};
// XXX: Is there a way to combine these two? Hygienic macros don't let you call `&self` without
// it being defined in the macro.
(pub unsafe fn $method:ident(&mut self $(, $arg_name:ident: $arg_ty:ty)*) $(-> $ret:ty)?) => {
/// Calls the corresponding method on the underlying [Param] object.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this [ParamPtr] was created for
/// is still alive.
pub unsafe fn $method(&mut self $(, $arg_name: $arg_ty)*) $(-> $ret)? {
match &self {
ParamPtr::FloatParam(p) => (**p).$method($($arg_name),*),
ParamPtr::IntParam(p) => (**p).$method($($arg_name),*),
ParamPtr::BoolParam(p) => (**p).$method($($arg_name),*),
ParamPtr::EnumParam(p) => (**p).$method($($arg_name),*),
}
}
};
);
impl ParamPtr {
/// Get the number of steps for this paramter, if it is stepped.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn step_count(&self) -> Option<i32> {
match self {
ParamPtr::FloatParam(_) => None,
ParamPtr::IntParam(p) => match (**p).range {
Range::Linear { min, max } => Some(max - min),
Range::Skewed { min, max, .. } => Some(max - min),
Range::SymmetricalSkewed { min, max, .. } => Some(max - min),
},
ParamPtr::BoolParam(_) => Some(1),
ParamPtr::EnumParam(p) => Some((**p).len() as i32 - 1),
}
}
param_ptr_forward!(pub unsafe fn name(&self) -> &'static str);
param_ptr_forward!(pub unsafe fn step_count(&self) -> Option<usize>);
param_ptr_forward!(pub unsafe fn unit(&self) -> &'static str);
param_ptr_forward!(pub unsafe fn update_smoother(&self, sample_rate: f32, reset: bool));
param_ptr_forward!(pub unsafe fn initialize_block_smoother(&mut self, max_block_size: usize));
param_ptr_forward!(pub unsafe fn set_from_string(&mut self, string: &str) -> bool);
param_ptr_forward!(pub unsafe fn normalized_value(&self) -> f32);
param_ptr_forward!(pub unsafe fn set_normalized_value(&self, normalized: f32));
param_ptr_forward!(pub unsafe fn normalized_value_to_string(&self, normalized: f32, include_unit: bool) -> String);
param_ptr_forward!(pub unsafe fn string_to_normalized_value(&self, string: &str) -> Option<f32>);
/// Get the human readable name for this parameter.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn name(&self) -> &'static str {
match &self {
ParamPtr::FloatParam(p) => (**p).name,
ParamPtr::IntParam(p) => (**p).name,
ParamPtr::BoolParam(p) => (**p).name,
ParamPtr::EnumParam(p) => (**p).inner.name,
}
}
/// Get the unit label for this parameter.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn unit(&self) -> &'static str {
match &self {
ParamPtr::FloatParam(p) => (**p).unit,
ParamPtr::IntParam(p) => (**p).unit,
ParamPtr::BoolParam(_) => "",
ParamPtr::EnumParam(_) => "",
}
}
/// Update the smoother state to point to the current value. Also used when initializing and
/// restoring a plugin so everything is in sync. In that case the smoother should completely
/// reset to the current value.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn update_smoother(&self, sample_rate: f32, reset: bool) {
match &self {
ParamPtr::FloatParam(p) => (**p).update_smoother(sample_rate, reset),
ParamPtr::IntParam(p) => (**p).update_smoother(sample_rate, reset),
ParamPtr::BoolParam(p) => (**p).update_smoother(sample_rate, reset),
ParamPtr::EnumParam(p) => (**p).update_smoother(sample_rate, reset),
}
}
/// Allocate memory for block-based smoothing. The [crate::Plugin::initialize_block_smoothers()]
/// method will do this for every smoother.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn initialize_block_smoother(&mut self, max_block_size: usize) {
match &self {
ParamPtr::FloatParam(p) => (**p).initialize_block_smoother(max_block_size),
ParamPtr::IntParam(p) => (**p).initialize_block_smoother(max_block_size),
ParamPtr::BoolParam(p) => (**p).initialize_block_smoother(max_block_size),
ParamPtr::EnumParam(p) => (**p).initialize_block_smoother(max_block_size),
}
}
/// Set this parameter based on a string. Returns whether the updating succeeded. That can fail
/// if the string cannot be parsed.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn set_from_string(&mut self, string: &str) -> bool {
match &self {
ParamPtr::FloatParam(p) => (**p).set_from_string(string),
ParamPtr::IntParam(p) => (**p).set_from_string(string),
ParamPtr::BoolParam(p) => (**p).set_from_string(string),
ParamPtr::EnumParam(p) => (**p).set_from_string(string),
}
}
/// Get the normalized `[0, 1]` value for this parameter.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn normalized_value(&self) -> f32 {
match &self {
ParamPtr::FloatParam(p) => (**p).normalized_value(),
ParamPtr::IntParam(p) => (**p).normalized_value(),
ParamPtr::BoolParam(p) => (**p).normalized_value(),
ParamPtr::EnumParam(p) => (**p).normalized_value(),
}
}
/// Set this parameter based on a normalized value.
///
/// This does **not** update the smoother.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn set_normalized_value(&self, normalized: f32) {
match &self {
ParamPtr::FloatParam(p) => (**p).set_normalized_value(normalized),
ParamPtr::IntParam(p) => (**p).set_normalized_value(normalized),
ParamPtr::BoolParam(p) => (**p).set_normalized_value(normalized),
ParamPtr::EnumParam(p) => (**p).set_normalized_value(normalized),
}
}
// These functions involve casts since the plugin formats only do floating point types, so we
// can't generate them with the macro:
/// Get the normalized value for a plain, unnormalized value, as a float. Used as part of the
/// wrappers.
@ -244,38 +168,6 @@ impl ParamPtr {
ParamPtr::EnumParam(p) => (**p).preview_plain(normalized) as f32,
}
}
/// Get the string representation for a normalized value. Used as part of the wrappers. Most
/// plugin formats already have support for units, in which case it shouldn't be part of this
/// string or some DAWs may show duplicate units.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn normalized_value_to_string(&self, normalized: f32, include_unit: bool) -> String {
match &self {
ParamPtr::FloatParam(p) => (**p).normalized_value_to_string(normalized, include_unit),
ParamPtr::IntParam(p) => (**p).normalized_value_to_string(normalized, include_unit),
ParamPtr::BoolParam(p) => (**p).normalized_value_to_string(normalized, include_unit),
ParamPtr::EnumParam(p) => (**p).normalized_value_to_string(normalized, include_unit),
}
}
/// Get the string representation for a normalized value. Used as part of the wrappers.
///
/// # Safety
///
/// Calling this function is only safe as long as the object this `ParamPtr` was created for is
/// still alive.
pub unsafe fn string_to_normalized_value(&self, string: &str) -> Option<f32> {
match &self {
ParamPtr::FloatParam(p) => (**p).string_to_normalized_value(string),
ParamPtr::IntParam(p) => (**p).string_to_normalized_value(string),
ParamPtr::BoolParam(p) => (**p).string_to_normalized_value(string),
ParamPtr::EnumParam(p) => (**p).string_to_normalized_value(string),
}
}
}
impl<'a, T> PersistentField<'a, T> for std::sync::RwLock<T>

2
src/wrapper/vst3/wrapper.rs
View file

@ -336,7 +336,7 @@ impl<P: Vst3Plugin> IEditController for Wrapper<P> {
u16strlcpy(&mut info.units, param_ptr.unit());
// TODO: The host assumes these steps are distirbuted linearly, so this may cause weird
// behavior with skewed integers
info.step_count = param_ptr.step_count().unwrap_or(0);
info.step_count = param_ptr.step_count().unwrap_or(0) as i32;
info.default_normalized_value = *default_value as f64;
info.unit_id = vst3_sys::vst::kRootUnitId;
info.flags = vst3_sys::vst::ParameterFlags::kCanAutomate as i32;