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Fix off-by-1 error in VST3 parameter range

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Running the VST3 SDK Validator [1] for the midi_inverter plugin shows
one failing test:

    [Scan Parameters]
    Info:  ===Scan Parameters ====================================
    Info:  This component exports 2080 parameter(s)
    Info:     Parameter 000 (id=2147481569): [title="MIDI Ch. 1 CC 0"] [unit=""] [type = F, default = 0.000000, unit = 0]
    Info:     Parameter 001 (id=2147481570): [title="MIDI Ch. 1 CC 1"] [unit=""] [type = F, default = 0.000000, unit = 0]
    Info:     Parameter 002 (id=2147481571): [title="MIDI Ch. 1 CC 2"] [unit=""] [type = F, default = 0.000000, unit = 0]

[...]

    Info:     Parameter 2077 (id=2147483646): [title="MIDI Ch. 16 CC 127"] [unit=""] [type = F, default = 0.000000, unit = 0]
    Info:     Parameter 2078 (id=2147483647): [title="MIDI Ch. 16 Channel Pressure"] [unit=""] [type = F, default = 0.000000, unit = 0]
    ERROR: =>Parameter 2079 (id=-2147483648): Invalid Id!!!
    [XXXXXXX Failed]

The relevant part of the test code [2] looks like this:

    int32 paramId = paramInfo.id;
    if (paramId < 0)
    {
        // Error
    }

This shows that the parameter ID must be INT32_MAX = (1 << 31) - 1 at
most. As far as I see, even Steinberg's own documentation [3] gets
this wrong.

[1]: 55d7ed3c6a/samples/vst-hosting/validator
[2]: 55d7ed3c6a/source/vst/testsuite/general/scanparameters.cpp (L100)
[3]: https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Parameters+Automation/Index.html
This commit is contained in:
Simon Leiner 2022-09-28 23:20:18 +02:00 committed by Robbert van der Helm
parent fae7050113
commit 958767acf2
1 changed files with 2 additions and 2 deletions
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4
src/wrapper/vst3/util.rs
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@ -16,8 +16,8 @@ pub const VST3_MIDI_NUM_PARAMS: u32 = VST3_MIDI_CCS * VST3_MIDI_CHANNELS;
/// plugin's parameters overlap with this range. The mapping to a parameter index is
/// `VST3_MIDI_PARAMS_START + (cc_idx + (channel * VST3_MIDI_CCS))`.
pub const VST3_MIDI_PARAMS_START: u32 = VST3_MIDI_PARAMS_END - VST3_MIDI_NUM_PARAMS;
/// The (exlucive) end of the MIDI CC parameter range. Anything above this is reserved by the host.
pub const VST3_MIDI_PARAMS_END: u32 = (1 << 31) + 1;
/// The (exclusive) end of the MIDI CC parameter range. Anything above this is reserved by the host.
pub const VST3_MIDI_PARAMS_END: u32 = 1 << 31;
/// Early exit out of a VST3 function when one of the passed pointers is null
macro_rules! check_null_ptr {