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Diffstat (limited to 'backends/lua.md')
| -rw-r--r-- | backends/lua.md | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/backends/lua.md b/backends/lua.md index 91e8fe2..970e8e2 100644 --- a/backends/lua.md +++ b/backends/lua.md @@ -5,15 +5,32 @@ events using the Lua programming language. Every instance has it's own interpreter state which can be loaded with custom handler scripts. -To process incoming channel events, the MIDIMonster calls corresponding Lua functions with -the value (as a Lua `number` type) as parameter. To send output on a channel, the Lua environment -provides the function `output(channel-name, value)`. +To process incoming channel events, the MIDIMonster calls corresponding Lua functions (if they exist) +with the value (as a Lua `number` type) as parameter. + +The following functions are provided within the Lua interpreter for interaction with the MIDIMonster + +| Function | Usage example | Description | +|-------------------------------|-------------------------------|---------------------------------------| +| `output(string, number)` | `output("foo", 0.75)` | Output a value event to a channel | +| `interval(function, number)` | `interval(update, 100)` | Register a function to be called periodically. Intervals are milliseconds (rounded to the nearest 10 ms) | +| `input_value(string)` | `input_value("foo")` | Get the last input value on a channel | +| `output_value(string)` | `output_value("bar") | Get the last output value on a channel | + Example script: ``` function bar(value) output("foo", value / 2) end + +step = 0 +function toggle() + output("bar", step * 1.0) + step = (step + 1) % 2; +end + +interval(toggle, 1000) ``` Input values range between 0.0 and 1.0, output values are clamped to the same range. @@ -41,9 +58,12 @@ lua1.foo > lua2.bar #### Known bugs / problems -Using `output` as an input channel name to a Lua instance does not work, as the interpreter has -`output` globally assigned to the event output function. Using `output` as an output channel name -via `output("output", value)` works as intended. +Using any of the interface functions (`output`, `interval`, `input\_value`, `output\_value`) as an +input channel name to a Lua instance will not call any handler functions. +Using these names as arguments to the output and value interface functions works as intended. + +Output values will not trigger corresponding input event handlers unless the channel is mapped +back in the MIDIMonster configuration. The path to the Lua source files is relative to the current working directory. This may lead to problems when copying configuration between installations. |