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1 | | -// Extracted from ReaPack's and ReaImGui's source code (LGPL v3) |
2 | | - |
3 | | -/* Usage example: |
4 | | -static int HelloWorld(int foo, int bar) { return foo * bar; } |
5 | | -
|
6 | | -extern "C" REAPER_PLUGIN_DLL_EXPORT int REAPER_PLUGIN_ENTRYPOINT( |
7 | | - REAPER_PLUGIN_HINSTANCE instance, reaper_plugin_info_t *rec) |
8 | | -{ |
9 | | - // ... |
10 | | - // API_HelloWorld and APIdef_HelloWorld must also be registered as usual |
11 | | - plugin_register("APIvararg_HelloWorld", |
12 | | - reinterpret_cast<void *>(&InvokeReaScriptAPI<&HelloWorld>)); |
13 | | - // ... |
14 | | -} |
15 | | -*/ |
16 | | - |
17 | | -#include <tuple> |
18 | | - |
19 | | -template<typename T> |
20 | | -struct ReaScriptAPI; |
21 | | - |
22 | | -template<typename R, typename... Args> |
23 | | -struct ReaScriptAPI<R(*)(Args...)> |
24 | | -{ |
25 | | - static const void *applyVarArg(R(*fn)(Args...), void **argv, const int argc) |
26 | | - { |
27 | | - if(static_cast<size_t>(argc) < sizeof...(Args)) |
28 | | - return nullptr; |
29 | | - |
30 | | - const auto &args { makeTuple(argv, std::index_sequence_for<Args...>{}) }; |
31 | | - |
32 | | - if constexpr (std::is_void_v<R>) { |
33 | | - std::apply(fn, args); |
34 | | - return nullptr; |
35 | | - } |
36 | | - else if constexpr (std::is_floating_point_v<R>) { |
37 | | - const auto value { std::apply(fn, args) }; |
38 | | - void *storage { argv[argc - 1] }; |
39 | | - *static_cast<double *>(storage) = value; |
40 | | - return storage; |
41 | | - } |
42 | | - else { |
43 | | - // cast numbers to have the same size as a pointer to avoid warnings |
44 | | - using IntPtrR = std::conditional_t<std::is_pointer_v<R>, R, uintptr_t>; |
45 | | - const auto value { static_cast<IntPtrR>(std::apply(fn, args)) }; |
46 | | - return reinterpret_cast<const void *>(value); |
47 | | - } |
48 | | - } |
49 | | - |
50 | | -private: |
51 | | - template<size_t I> |
52 | | - using NthType = typename std::tuple_element<I, std::tuple<Args...>>::type; |
53 | | - |
54 | | - template<size_t... I> |
55 | | - static auto makeTuple(void **argv, std::index_sequence<I...>) |
56 | | - { |
57 | | - // C++17 is amazing |
58 | | - return std::make_tuple( |
59 | | - std::is_floating_point_v<NthType<I>> ? |
60 | | - *reinterpret_cast<NthType<I>*>(argv[I]) : |
61 | | - (NthType<I>)reinterpret_cast<uintptr_t>(argv[I]) |
62 | | - ... |
63 | | - ); |
64 | | - } |
65 | | - |
66 | | -}; |
67 | | - |
68 | | -template<auto fn> |
69 | | -const void *InvokeReaScriptAPI(void **argv, int argc) |
70 | | -{ |
71 | | - return ReaScriptAPI<decltype(fn)>::applyVarArg(fn, argv, argc); |
72 | | -} |
| 1 | +// Extracted from ReaPack's and ReaImGui's source code (LGPL v3) |
| 2 | + |
| 3 | +/* Usage example: |
| 4 | +static int HelloWorld(int foo, int bar) { return foo * bar; } |
| 5 | +
|
| 6 | +extern "C" REAPER_PLUGIN_DLL_EXPORT int REAPER_PLUGIN_ENTRYPOINT( |
| 7 | + REAPER_PLUGIN_HINSTANCE instance, reaper_plugin_info_t *rec) |
| 8 | +{ |
| 9 | + // ... |
| 10 | + // API_HelloWorld and APIdef_HelloWorld must also be registered as usual |
| 11 | + plugin_register("APIvararg_HelloWorld", |
| 12 | + reinterpret_cast<void *>(&InvokeReaScriptAPI<&HelloWorld>)); |
| 13 | + // ... |
| 14 | +} |
| 15 | +*/ |
| 16 | + |
| 17 | +#include <tuple> |
| 18 | + |
| 19 | +template<typename T> |
| 20 | +struct ReaScriptAPI; |
| 21 | + |
| 22 | +template<typename R, typename... Args> |
| 23 | +struct ReaScriptAPI<R(*)(Args...)> |
| 24 | +{ |
| 25 | + static const void *applyVarArg(R(*fn)(Args...), void **argv, const int argc) |
| 26 | + { |
| 27 | + if(static_cast<size_t>(argc) < sizeof...(Args)) |
| 28 | + return nullptr; |
| 29 | + |
| 30 | + const auto &args { makeTuple(argv, std::index_sequence_for<Args...>{}) }; |
| 31 | + |
| 32 | + if constexpr (std::is_void_v<R>) { |
| 33 | + std::apply(fn, args); |
| 34 | + return nullptr; |
| 35 | + } |
| 36 | + else if constexpr (std::is_floating_point_v<R>) { |
| 37 | + const auto value { std::apply(fn, args) }; |
| 38 | + void *storage { argv[argc - 1] }; |
| 39 | + *static_cast<double *>(storage) = value; |
| 40 | + return storage; |
| 41 | + } |
| 42 | + else { |
| 43 | + // cast numbers to have the same size as a pointer to avoid warnings |
| 44 | + using IntPtrR = std::conditional_t<std::is_pointer_v<R>, R, uintptr_t>; |
| 45 | + const auto value { static_cast<IntPtrR>(std::apply(fn, args)) }; |
| 46 | + return reinterpret_cast<const void *>(value); |
| 47 | + } |
| 48 | + } |
| 49 | + |
| 50 | +private: |
| 51 | + template<size_t I> |
| 52 | + using NthType = typename std::tuple_element<I, std::tuple<Args...>>::type; |
| 53 | + |
| 54 | + template<size_t... I> |
| 55 | + static auto makeTuple(void **argv, std::index_sequence<I...>) |
| 56 | + { |
| 57 | + // C++17 is amazing |
| 58 | + return std::make_tuple( |
| 59 | + std::is_floating_point_v<NthType<I>> ? |
| 60 | + *reinterpret_cast<NthType<I>*>(argv[I]) : |
| 61 | + (NthType<I>)reinterpret_cast<uintptr_t>(argv[I]) |
| 62 | + ... |
| 63 | + ); |
| 64 | + } |
| 65 | + |
| 66 | +}; |
| 67 | + |
| 68 | +template<auto fn> |
| 69 | +const void *InvokeReaScriptAPI(void **argv, int argc) |
| 70 | +{ |
| 71 | + return ReaScriptAPI<decltype(fn)>::applyVarArg(fn, argv, argc); |
| 72 | +} |
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