Compound oscillation demo for ESP32

CompoundOscillation.ino

// Compound oscillation demo for ESP32
// Loosely coded by tobozo (c+) apr 2022 -
// Inspired by this GIF
//   - https://twitter.com/bayraitt/status/1514499189975134210

#include <ESP32-Chimera-Core.h> // https://github.com/tobozo/ESP32-Chimera-Core

static LGFX &tft(M5.Lcd);
static LGFX_Sprite* spriteLines   = new LGFX_Sprite( &tft );
static LGFX_Sprite* spriteMix     = new LGFX_Sprite( &tft );

static constexpr const int gridSize = 6;
static constexpr const int gridMargin = 10;
static constexpr const uint32_t bgcolor = 0x4d4845U;
static constexpr const uint32_t hgcolor = 0xffffffU;
static constexpr const uint32_t fgcolor = 0x888888U;

static float angle = 0;
static int sqWidth;
static int sqSize;
static int offsetX = gridMargin;
static int offsetY = gridMargin;
static int spritePosX, spritePosY;


uint8_t blend(float a, float b, float bias=0.5f)
{
  return  sqrtf( ((1 - bias) * (a*a)) + ( bias * (b*b ) ) );
}

void drawGrid( float angle_offset = 0 )
{
  int xlist[gridSize], ylist[gridSize];
  for( int i=1; i<=gridSize; i++ ) {
    int pos = (i*sqWidth)+sqSize;

    int xp = roundf(cosf( (angle * (float)i + angle_offset) ) * sqSize);
    int yp = roundf(sinf( (angle * (float)i + angle_offset) ) * sqSize);

    xlist[i-1] = xp+pos;
    ylist[i-1] = yp+pos;

    uint16_t c = map( i, 0, gridSize, 0, 255 );
    spriteLines->setColor(tft.color332( c, 255-c, 128 ));

    spriteLines->drawPixel( offsetX + xp + pos, offsetY + yp + sqSize );
    spriteLines->drawPixel( offsetX + xp + sqSize, offsetY + yp + pos );
  }

  for( int v = 1; v <= gridSize; v++ ) {
    int cv = map( v, 0, gridSize, 0, 255 );
    for( int h = 1; h <= gridSize; h++ ) {
      int ch = map( h, 0, gridSize, 0, 255 );
      int c = blend(cv, ch);
      spriteLines->setColor(tft.color332( c, 255-c, 128 ));
      spriteLines->drawPixel( offsetX + xlist[h-1], offsetY + ylist[v-1] );
    }
  }
}

void drawBullet( int x, int y )
{
  spriteLines->pushSprite( spriteMix, 4-x, 4-y );
  spriteMix->fillCircle( 4, 4, 2, TFT_WHITE );
  spriteMix->pushSprite(spritePosX+x-4, spritePosY+y-4);
}

void drawBullets( float angle_offset = 0 )
{
  int xlist[gridSize], ylist[gridSize];
  for( int i=1; i<=gridSize; i++ ) {
    int pos = (i*sqWidth)+sqSize;

    int xp = roundf(cosf( (angle * (float)i + angle_offset) ) * sqSize);
    int yp = roundf(sinf( (angle * (float)i + angle_offset) ) * sqSize);

    xlist[i-1] = xp+pos;
    ylist[i-1] = yp+pos;

    drawBullet( offsetX + xp + pos, offsetY + yp + sqSize );
    drawBullet( offsetX + xp + sqSize, offsetY + yp + pos );
  }

  for( int v = 0; v < gridSize; v++ ) {
    for( int h = 0; h < gridSize; h++ ) {
      drawBullet( offsetX + xlist[h], offsetY + ylist[v] );
    }
  }
}

void setupSprites()
{
  uint16_t squareSize = min(tft.width(),tft.height());
  sqWidth = (squareSize-gridMargin ) / (gridSize+1);
  sqSize = (sqWidth/2)-4;

  spriteLines->setColorDepth( 8 );
  if( ! spriteLines->createSprite( squareSize, squareSize ) ) {
    Serial.println("Can't create spriteLines, halting");
    while(1) delay(1);
  }
  spriteLines->fillSprite(bgcolor);

  spriteMix->setColorDepth( 8 );
  if( ! spriteMix->createSprite( 9, 9 ) ) {
    Serial.println("Can't create spriteMix, halting");
    while(1) delay(1);
  }
  spriteMix->fillSprite(bgcolor);

  spritePosX = (tft.width()  - spriteLines->width() ) >> 1;
  spritePosY = (tft.height() - spriteLines->height()) >> 1;
}

void setup()
{
  M5.begin();
  tft.fillScreen(tft.color16to8(tft.color24to16(bgcolor)));
  setupSprites();

  // fill the grid, only needs one pass
  // also animate bullets
  for( float a=0; a<2*PI*gridSize; a +=.01f ) {
    angle = fmodf( a, 2*PI );
    drawGrid();
    drawBullets();
  }
}

void loop()
{
  drawBullets();
  angle = fmodf( angle, 2*PI );
  angle += .01f;
}