mandelbrot

#include <Arduino.h>
#include <gfx.hpp>
#include <st7789.hpp>
#include <htcw_button.hpp>
#include <tft_io.hpp>
//#include <FixedPoints.h>
#define LCD_WIDTH 135
#define LCD_HEIGHT 240
#define LCD_HOST VSPI
#define PIN_NUM_MISO -1
#define PIN_NUM_MOSI 19
#define PIN_NUM_CLK 18
#define PIN_NUM_CS 5
#define PIN_NUM_DC 16
#define PIN_NUM_RST 23
#define PIN_NUM_BCKL 4
using namespace arduino;
using namespace gfx;
using namespace std;
using bus_t = tft_spi_ex<LCD_HOST, PIN_NUM_CS, PIN_NUM_MOSI, PIN_NUM_MISO, PIN_NUM_CLK, SPI_MODE0>;
using display_t = st7789<LCD_WIDTH, LCD_HEIGHT, PIN_NUM_DC, PIN_NUM_RST, PIN_NUM_BCKL, bus_t, 0, true, 400, 200>;
using color_t = color<typename display_t::pixel_type>;
using fix_t =float;//SFixed<12,19>;
using button_1_t = button<35,10,true>;
using button_2_t = button<0,10,true>;
using rgb_t = rgb_pixel<24>;

static display_t dsp;

button_1_t button_1;
button_2_t button_2;

const int16_t
  res_bits        = 12,   // Fractional resolution
  pixelWidth  = dsp.dimensions().width,  // TFT dimensions
  pixelHeight = dsp.dimensions().height,
  iterations  = 20;  // Fractal iteration limit or 'dwell'
fix_t
  centerReal(-0.6), // Image center point in complex plane
  centerImag(0.0),
  rangeReal(3.0), // Image coverage in complex plane
  rangeImag(3.0),
  incRange(.95);

void setup() {
    Serial.begin(115200);
    draw::filled_rectangle(dsp,dsp.bounds(),color_t::black);
}
void loop() {
  int64_t       n, a, b, a2, b2, posReal, posImag;
  uint32_t      startTime,elapsedTime;


  int32_t
    startReal   = (int64_t)((centerReal - rangeReal * 0.5)   * (float)(1 << res_bits)),
    startImag   = (int64_t)((centerImag + rangeImag * 0.5)   * (float)(1 << res_bits)),
    incReal     = (int64_t)((rangeReal / (float)pixelWidth)  * (float)(1 << res_bits)),
    incImag     = (int64_t)((rangeImag / (float)pixelHeight) * (float)(1 << res_bits));

  startTime = millis();
  posImag = startImag;
  auto bt = draw::batch(dsp,dsp.bounds());
  for (int y = 0; y < dsp.dimensions().height; y++) {
    posReal = startReal;
    for (int x = 0; x < dsp.dimensions().width; x++) {
      a = posReal;
      b = posImag;
      for (n = iterations; n > 0 ; n--) {
        a2 = (a * a) >> res_bits;
        b2 = (b * b) >> res_bits;
        if ((a2 + b2) >= (4 << res_bits))
          break;
        b  = posImag + ((a * b) >> (res_bits - 1));
        a  = posReal + a2 - b2;
      }
      display_t::pixel_type px;
      px.native_value =  (n * 29)<<8 | (n * 67);
        bt.write(px);

      posReal += incReal;
    }
    posImag -= incImag;
  }
  bt.commit();
  elapsedTime = millis()-startTime;
  Serial.print("Took "); Serial.print(elapsedTime); Serial.println(" ms");

  rangeReal *= incRange;
  rangeImag *= incRange;
}