| /******************************************************************************************* | |
| * | |
| *   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" | |
|  | |
| #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 | |
|  | |
| int main(void) | |
| { | |
|     // Initialization | |
|     //-------------------------------------------------------------------------------------- | |
|     const int screenWidth = 800; | |
|     const int screenHeight = 450; | |
| 
 | |
|     InitWindow(screenWidth, screenHeight, "raylib [audio] example - raw audio streaming"); | |
| 
 | |
|     InitAudioDevice();              // Initialize audio device | |
|  | |
|     SetAudioStreamBufferSizeDefault(MAX_SAMPLES_PER_UPDATE); | |
| 
 | |
|     // Init raw audio stream (sample rate: 22050, sample size: 16bit-short, channels: 1-mono) | |
|     AudioStream stream = LoadAudioStream(44100, 16, 1); | |
| 
 | |
|     // Buffer for the single cycle waveform we are synthesizing | |
|     short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES); | |
| 
 | |
|     // Frame buffer, describing the waveform when repeated over the course of a frame | |
|     short *writeBuf = (short *)malloc(sizeof(short)*MAX_SAMPLES_PER_UPDATE); | |
| 
 | |
|     PlayAudioStream(stream);        // Start processing stream buffer (no data loaded currently) | |
|  | |
|     // Position read in to determine next frequency | |
|     Vector2 mousePosition = { -100.0f, -100.0f }; | |
| 
 | |
|     // Cycles per second (hz) | |
|     float frequency = 440.0f; | |
| 
 | |
|     // Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency | |
|     float oldFrequency = 1.0f; | |
| 
 | |
|     // Cursor to read and copy the samples of the sine wave buffer | |
|     int readCursor = 0; | |
| 
 | |
|     // Computed size in samples of the sine wave | |
|     int waveLength = 1; | |
| 
 | |
|     Vector2 position = { 0, 0 }; | |
| 
 | |
|     SetTargetFPS(30);               // Set our game to run at 30 frames-per-second | |
|     //-------------------------------------------------------------------------------------- | |
|  | |
|     // Main game loop | |
|     while (!WindowShouldClose())    // Detect window close button or ESC key | |
|     { | |
|         // Update | |
|         //---------------------------------------------------------------------------------- | |
|  | |
|         // Sample mouse input. | |
|         mousePosition = GetMousePosition(); | |
| 
 | |
|         if (IsMouseButtonDown(MOUSE_BUTTON_LEFT)) | |
|         { | |
|             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 = (float)i; | |
|                 position.y = 250 + 50*data[i*MAX_SAMPLES/screenWidth]/32000.0f; | |
| 
 | |
|                 DrawPixelV(position, RED); | |
|             } | |
| 
 | |
|         EndDrawing(); | |
|         //---------------------------------------------------------------------------------- | |
|     } | |
| 
 | |
|     // De-Initialization | |
|     //-------------------------------------------------------------------------------------- | |
|     free(data);                 // Unload sine wave data | |
|     free(writeBuf);             // Unload write buffer | |
|  | |
|     UnloadAudioStream(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; | |
| }
 |