Pokitto Community Team / ByteBeat3

Implementation of Bytebeat algorithm on Pokitto. Bytebeat is generated music which is made by algorithm using usually one line function. The music is created as 8-bit samples. The simplest Bytebeat function is " t & (t>>8)" which combines two sawtooth waves: one higher frequency tone (t) and the other lower frequency (t<<8) tone. Read more in: http://countercomplex.blogspot.fi/2011/10/algorithmic-symphonies-from-one-line-of.html

Dependencies:   PokittoLib

ByteBeat3 - mathematical beats

Implementation of Bytebeat algorithm on Pokitto. Bytebeat is generated music which is made by algorithm using usually one line function. The music is created as 8-bit samples.

The simplest Bytebeat function is " t & (t>>8)" which combines two sawtooth waves: one higher frequency tone (t) and the other lower frequency (t<<8) tone.

Read more in: http://countercomplex.blogspot.fi/2011/10/algorithmic-symphonies-from-one-line-of.html

main.cpp@1:ca29888d96a9, 2018-03-30 (annotated)

Committer:
Haviital
Date:
Fri Mar 30 20:25:48 2018 +0000
Revision:
1:ca29888d96a9
Parent:
0:89ca7e98cd78 
Improved comments

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Haviital 0:89ca7e98cd78 1 #include "Pokitto.h"
Haviital 0:89ca7e98cd78 2
Haviital 0:89ca7e98cd78 3 Pokitto::Core mygame;
Haviital 0:89ca7e98cd78 4
Haviital 1:ca29888d96a9 5 // Fills an audio buffer with the samples generated by the Bytebeat function
Haviital 0:89ca7e98cd78 6 void generateBuffer(uint32_t bufferIndex, uint32_t nextT) {
Haviital 0:89ca7e98cd78 7
Haviital 0:89ca7e98cd78 8 uint32_t index= 0;
Haviital 0:89ca7e98cd78 9 for(uint32_t t=nextT; t<nextT+BUFFER_SIZE; t++,index++)
Haviital 0:89ca7e98cd78 10 //buffers[nextBufferIndexToFill][index] = t & (t>>8);
Haviital 0:89ca7e98cd78 11 buffers[bufferIndex][index] = ((t<<1)^((t<<1)+(t>>7)&t>>12))|t>>(4-(1^7&(t>>19)))|t>>7;
Haviital 0:89ca7e98cd78 12 //buffers[bufferIndex][index] = (t*9&t>>4|t*5&t>>7|t*3&t/1024)-1;
Haviital 0:89ca7e98cd78 13 }
Haviital 0:89ca7e98cd78 14
Haviital 0:89ca7e98cd78 15
Haviital 0:89ca7e98cd78 16 int main () {
Haviital 0:89ca7e98cd78 17 mygame.begin();
Haviital 1:ca29888d96a9 18 mygame.display.persistence = true; // Do not clear screen
Haviital 0:89ca7e98cd78 19 mygame.display.paletteptr[2] = COLOR_YELLOW;
Haviital 0:89ca7e98cd78 20
Haviital 1:ca29888d96a9 21 // The audio engine uses 4 buffers. Generate all 4 buffers ahead.
Haviital 0:89ca7e98cd78 22 uint32_t nextT = 0;
Haviital 0:89ca7e98cd78 23 generateBuffer(0, nextT); nextT += BUFFER_SIZE;
Haviital 0:89ca7e98cd78 24 generateBuffer(1, nextT); nextT += BUFFER_SIZE;
Haviital 0:89ca7e98cd78 25 generateBuffer(2, nextT); nextT += BUFFER_SIZE;
Haviital 0:89ca7e98cd78 26 generateBuffer(3, nextT); nextT += BUFFER_SIZE;
Haviital 0:89ca7e98cd78 27
Haviital 1:ca29888d96a9 28 // Set global audio variables
Haviital 0:89ca7e98cd78 29 currentBuffer = 0;
Haviital 0:89ca7e98cd78 30 currentPtr = buffers[currentBuffer];
Haviital 0:89ca7e98cd78 31 endPtr = currentPtr + BUFFER_SIZE;
Haviital 0:89ca7e98cd78 32
Haviital 1:ca29888d96a9 33 // Init audio stream.
Haviital 0:89ca7e98cd78 34 pokPlayStream(); // activate stream
Haviital 0:89ca7e98cd78 35 mygame.sound.ampEnable(true);
Haviital 0:89ca7e98cd78 36 mygame.sound.playMusicStream();
Haviital 0:89ca7e98cd78 37
Haviital 1:ca29888d96a9 38 // Print to the screen once.
Haviital 0:89ca7e98cd78 39 mygame.display.set_cursor(0,0);
Haviital 0:89ca7e98cd78 40 mygame.display.println("ByteBeat function:");
Haviital 0:89ca7e98cd78 41 mygame.display.println("");
Haviital 0:89ca7e98cd78 42 mygame.display.color = 2;
Haviital 0:89ca7e98cd78 43 mygame.display.println("((t<<1)^((t<<1)+(t>>7)");
Haviital 0:89ca7e98cd78 44 mygame.display.println("&t>>12))|t>>(4-(1^7&");
Haviital 0:89ca7e98cd78 45 mygame.display.println("(t>>19)))|t>>7");
Haviital 0:89ca7e98cd78 46
Haviital 0:89ca7e98cd78 47 uint32_t nextBufferIndexToFill = 0;
Haviital 0:89ca7e98cd78 48 while (mygame.isRunning()) {
Haviital 0:89ca7e98cd78 49 if (mygame.update()) {
Haviital 0:89ca7e98cd78 50
Haviital 1:ca29888d96a9 51 // Fill the next buffer if it is not used currently
Haviital 0:89ca7e98cd78 52 if((uint32_t)currentBuffer != nextBufferIndexToFill) {
Haviital 0:89ca7e98cd78 53
Haviital 1:ca29888d96a9 54 // Generate buffer
Haviital 0:89ca7e98cd78 55 generateBuffer(nextBufferIndexToFill, nextT);
Haviital 0:89ca7e98cd78 56
Haviital 0:89ca7e98cd78 57 if(++nextBufferIndexToFill > 3)
Haviital 0:89ca7e98cd78 58 nextBufferIndexToFill = 0;
Haviital 0:89ca7e98cd78 59 nextT += BUFFER_SIZE;
Haviital 0:89ca7e98cd78 60 }
Haviital 0:89ca7e98cd78 61 }
Haviital 0:89ca7e98cd78 62 }
Haviital 0:89ca7e98cd78 63 }