libSDL2pp/examples/audio_sine.cc
Zakhar Koval e538ba15bf
Fix #134
2022-05-02 12:14:27 +03:00

64 lines
2.1 KiB
C++

/*
libSDL2pp - C++11 bindings/wrapper for SDL2
Copyright (C) 2013-2016 Dmitry Marakasov <amdmi3@amdmi3.ru>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include <cmath>
#include <iostream>
#include <SDL.h>
#include <SDL2pp/SDL.hh>
#include <SDL2pp/AudioDevice.hh>
#include <SDL2pp/AudioSpec.hh>
using namespace SDL2pp;
int main(int, char*[]) {
try {
SDL sdl(SDL_INIT_AUDIO);
// XXX: these should be constexpr and not captured in lambda
// below, but that fails on microsoft crapiler
int samplerate = 48000;
float frequency = 2093.00f; // C7 tone
int64_t nsample = 0;
// Setup audio device, and provide callback which plays sine wave with specified frequency
AudioSpec spec(samplerate, AUDIO_S16SYS, 1, 4096);
// Open audio device
AudioDevice dev(NullOpt, 0, spec, [&nsample, samplerate, frequency](Uint8* stream, int len) {
// fill provided buffer with sine wave
for (Uint8* ptr = stream; ptr < stream + len; ptr += 2)
*(Uint16*)ptr = (Uint16)(32766.0f * sin(nsample++ / (float)samplerate * frequency));
}
);
// Sound plays after this call
dev.Pause(false);
// Play for 1 second, after which everything is stopped and closed
SDL_Delay(1000);
} catch (std::exception& e) {
std::cerr << "Error: " << e.what() << std::endl;
return 1;
}
}