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/*******************************************************************************************
*
* raylib [audio] example - Raw audio streaming
*
* This example has been created using raylib 1.6 (www.raylib.com)
* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
* Example created by Ramon Santamaria (@raysan5) and reviewed by James Hofmann (@triplefox)
*
* Copyright (c) 2015-2019 Ramon Santamaria (@raysan5) and James Hofmann (@triplefox)
*
********************************************************************************************/
#include "raylib.h"
#if defined(PLATFORM_WEB)
#include <emscripten/emscripten.h>
#endif
#include <stdlib.h> // Required for: malloc(), free()
#include <math.h> // Required for: sinf()
#include <string.h> // Required for: memcpy()
#define MAX_SAMPLES 512
#define MAX_SAMPLES_PER_UPDATE 4096
//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;
AudioStream stream = { 0 };
short *data;
short *writeBuf;
Vector2 mousePosition = { -100.0f, -100.0f };
float frequency = 440.0f;
float oldFrequency = 1.0f;
int readCursor = 0;
int waveLength = 1;
Vector2 position = { 0, 0 };
//----------------------------------------------------------------------------------
// Module Functions Declaration
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void); // Update and Draw one frame
//----------------------------------------------------------------------------------
// Program Main Entry Point
//----------------------------------------------------------------------------------
int main(void)
{
// Initialization
//--------------------------------------------------------------------------------------
InitWindow(screenWidth, screenHeight, "raylib [audio] example - raw audio streaming");
InitAudioDevice(); // Initialize audio device
// Init raw audio stream (sample rate: 22050, sample size: 16bit-short, channels: 1-mono)
stream = InitAudioStream(22050, 16, 1);
// Buffer for the single cycle waveform we are synthesizing
data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
// Frame buffer, describing the waveform when repeated over the course of a frame
writeBuf = (short *)malloc(sizeof(short)*MAX_SAMPLES_PER_UPDATE);
PlayAudioStream(stream); // Start processing stream buffer (no data loaded currently)
#if defined(PLATFORM_WEB)
emscripten_set_main_loop(UpdateDrawFrame, 60, 1);
#else
SetTargetFPS(30); // Set our game to run at 30 frames-per-second
//--------------------------------------------------------------------------------------
// Main game loop
while (!WindowShouldClose()) // Detect window close button or ESC key
{
UpdateDrawFrame();
}
#endif
// De-Initialization
//--------------------------------------------------------------------------------------
free(data); // Unload sine wave data
free(writeBuf); // Unload write buffer
CloseAudioStream(stream); // Close raw audio stream and delete buffers from RAM
CloseAudioDevice(); // Close audio device (music streaming is automatically stopped)
CloseWindow(); // Close window and OpenGL context
//--------------------------------------------------------------------------------------
return 0;
}
//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void)
{
// Update
//----------------------------------------------------------------------------------
mousePosition = GetMousePosition();
if (IsMouseButtonDown(MOUSE_LEFT_BUTTON))
{
float fp = (float)(mousePosition.y);
frequency = 40.0f + (float)(fp);
}
// Rewrite the sine wave.
// Compute two cycles to allow the buffer padding, simplifying any modulation, resampling, etc.
if (frequency != oldFrequency)
{
// Compute wavelength. Limit size in both directions.
int oldWavelength = waveLength;
waveLength = (int)(22050/frequency);
if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
if (waveLength < 1) waveLength = 1;
// Write sine wave.
for (int i = 0; i < waveLength*2; i++)
{
data[i] = (short)(sinf(((2*PI*(float)i/waveLength)))*32000);
}
// Scale read cursor's position to minimize transition artifacts
readCursor = (int)(readCursor * ((float)waveLength / (float)oldWavelength));
oldFrequency = frequency;
}
// Refill audio stream if required
if (IsAudioStreamProcessed(stream))
{
// Synthesize a buffer that is exactly the requested size
int writeCursor = 0;
while (writeCursor < MAX_SAMPLES_PER_UPDATE)
{
// Start by trying to write the whole chunk at once
int writeLength = MAX_SAMPLES_PER_UPDATE-writeCursor;
// Limit to the maximum readable size
int readLength = waveLength-readCursor;
if (writeLength > readLength) writeLength = readLength;
// Write the slice
memcpy(writeBuf + writeCursor, data + readCursor, writeLength*sizeof(short));
// Update cursors and loop audio
readCursor = (readCursor + writeLength) % waveLength;
writeCursor += writeLength;
}
// Copy finished frame to audio stream
UpdateAudioStream(stream, writeBuf, MAX_SAMPLES_PER_UPDATE);
}
//----------------------------------------------------------------------------------
// Draw
//----------------------------------------------------------------------------------
BeginDrawing();
ClearBackground(RAYWHITE);
DrawText(TextFormat("sine frequency: %i",(int)frequency), GetScreenWidth() - 220, 10, 20, RED);
DrawText("click mouse button to change frequency", 10, 10, 20, DARKGRAY);
// Draw the current buffer state proportionate to the screen
for (int i = 0; i < screenWidth; i++)
{
position.x = i;
position.y = 250 + 50*data[i*MAX_SAMPLES/screenWidth]/32000;
DrawPixelV(position, RED);
}
EndDrawing();
//----------------------------------------------------------------------------------
}
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