1/*******************************************************************************************
2*
3* raylib [audio] example - Raw audio streaming
4*
5* This example has been created using raylib 1.6 (www.raylib.com)
6* raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
7*
8* Example created by Ramon Santamaria (@raysan5) and reviewed by James Hofmann (@triplefox)
9*
10* Copyright (c) 2015-2019 Ramon Santamaria (@raysan5) and James Hofmann (@triplefox)
11*
12********************************************************************************************/
13
14#include "raylib.h"
15
16#include <stdlib.h> // Required for: malloc(), free()
17#include <math.h> // Required for: sinf()
18#include <string.h> // Required for: memcpy()
19
20#define MAX_SAMPLES 512
21#define MAX_SAMPLES_PER_UPDATE 4096
22
23int main(void)
24{
25 // Initialization
26 //--------------------------------------------------------------------------------------
27 const int screenWidth = 800;
28 const int screenHeight = 450;
29
30 InitWindow(screenWidth, screenHeight, "raylib [audio] example - raw audio streaming");
31
32 InitAudioDevice(); // Initialize audio device
33
34 // Init raw audio stream (sample rate: 22050, sample size: 16bit-short, channels: 1-mono)
35 AudioStream stream = InitAudioStream(22050, 16, 1);
36
37 // Buffer for the single cycle waveform we are synthesizing
38 short *data = (short *)malloc(sizeof(short)*MAX_SAMPLES);
39
40 // Frame buffer, describing the waveform when repeated over the course of a frame
41 short *writeBuf = (short *)malloc(sizeof(short)*MAX_SAMPLES_PER_UPDATE);
42
43 PlayAudioStream(stream); // Start processing stream buffer (no data loaded currently)
44
45 // Position read in to determine next frequency
46 Vector2 mousePosition = { -100.0f, -100.0f };
47
48 // Cycles per second (hz)
49 float frequency = 440.0f;
50
51 // Previous value, used to test if sine needs to be rewritten, and to smoothly modulate frequency
52 float oldFrequency = 1.0f;
53
54 // Cursor to read and copy the samples of the sine wave buffer
55 int readCursor = 0;
56
57 // Computed size in samples of the sine wave
58 int waveLength = 1;
59
60 Vector2 position = { 0, 0 };
61
62 SetTargetFPS(30); // Set our game to run at 30 frames-per-second
63 //--------------------------------------------------------------------------------------
64
65 // Main game loop
66 while (!WindowShouldClose()) // Detect window close button or ESC key
67 {
68 // Update
69 //----------------------------------------------------------------------------------
70
71 // Sample mouse input.
72 mousePosition = GetMousePosition();
73
74 if (IsMouseButtonDown(MOUSE_LEFT_BUTTON))
75 {
76 float fp = (float)(mousePosition.y);
77 frequency = 40.0f + (float)(fp);
78 }
79
80 // Rewrite the sine wave.
81 // Compute two cycles to allow the buffer padding, simplifying any modulation, resampling, etc.
82 if (frequency != oldFrequency)
83 {
84 // Compute wavelength. Limit size in both directions.
85 int oldWavelength = waveLength;
86 waveLength = (int)(22050/frequency);
87 if (waveLength > MAX_SAMPLES/2) waveLength = MAX_SAMPLES/2;
88 if (waveLength < 1) waveLength = 1;
89
90 // Write sine wave.
91 for (int i = 0; i < waveLength*2; i++)
92 {
93 data[i] = (short)(sinf(((2*PI*(float)i/waveLength)))*32000);
94 }
95
96 // Scale read cursor's position to minimize transition artifacts
97 readCursor = (int)(readCursor * ((float)waveLength / (float)oldWavelength));
98 oldFrequency = frequency;
99 }
100
101 // Refill audio stream if required
102 if (IsAudioStreamProcessed(stream))
103 {
104 // Synthesize a buffer that is exactly the requested size
105 int writeCursor = 0;
106
107 while (writeCursor < MAX_SAMPLES_PER_UPDATE)
108 {
109 // Start by trying to write the whole chunk at once
110 int writeLength = MAX_SAMPLES_PER_UPDATE-writeCursor;
111
112 // Limit to the maximum readable size
113 int readLength = waveLength-readCursor;
114
115 if (writeLength > readLength) writeLength = readLength;
116
117 // Write the slice
118 memcpy(writeBuf + writeCursor, data + readCursor, writeLength*sizeof(short));
119
120 // Update cursors and loop audio
121 readCursor = (readCursor + writeLength) % waveLength;
122
123 writeCursor += writeLength;
124 }
125
126 // Copy finished frame to audio stream
127 UpdateAudioStream(stream, writeBuf, MAX_SAMPLES_PER_UPDATE);
128 }
129 //----------------------------------------------------------------------------------
130
131 // Draw
132 //----------------------------------------------------------------------------------
133 BeginDrawing();
134
135 ClearBackground(RAYWHITE);
136
137 DrawText(FormatText("sine frequency: %i",(int)frequency), GetScreenWidth() - 220, 10, 20, RED);
138 DrawText("click mouse button to change frequency", 10, 10, 20, DARKGRAY);
139
140 // Draw the current buffer state proportionate to the screen
141 for (int i = 0; i < screenWidth; i++)
142 {
143 position.x = i;
144 position.y = 250 + 50*data[i*MAX_SAMPLES/screenWidth]/32000;
145
146 DrawPixelV(position, RED);
147 }
148
149 EndDrawing();
150 //----------------------------------------------------------------------------------
151 }
152
153 // De-Initialization
154 //--------------------------------------------------------------------------------------
155 free(data); // Unload sine wave data
156 free(writeBuf); // Unload write buffer
157
158 CloseAudioStream(stream); // Close raw audio stream and delete buffers from RAM
159 CloseAudioDevice(); // Close audio device (music streaming is automatically stopped)
160
161 CloseWindow(); // Close window and OpenGL context
162 //--------------------------------------------------------------------------------------
163
164 return 0;
165}
166