Icons.cpp

#include "Icons.h"

//====================================================================================
// This is the function to draw the icon stored as an array in program memory (FLASH)
//====================================================================================

// To speed up rendering we use a 64 pixel buffer
#define BUFF_SIZE 64

// Draw array "icon" of defined width and height at coordinate x,y
// Maximum icon size is 255x255 pixels to avoid integer overflow

void Icons::draw(TFT_HX8357 tft, const unsigned short* icon, int16_t x, int16_t y, int8_t width, int8_t height) {

  uint16_t  pix_buffer[BUFF_SIZE];   // Pixel buffer (16 bits per pixel)

  // Set up a window the right size to stream pixels into
  tft.setWindow(x, y, x + width - 1, y + height - 1);

  // Work out the number whole buffers to send
  uint16_t nb = ((uint16_t)height * width) / BUFF_SIZE;

  // Fill and send "nb" buffers to TFT
  for (int i = 0; i < nb; i++) {
    for (int j = 0; j < BUFF_SIZE; j++) {
      pix_buffer[j] = pgm_read_word(&icon[i * BUFF_SIZE + j]);
    }
    tft.pushColors(pix_buffer, BUFF_SIZE);
  }

  // Work out number of pixels not yet sent
  uint16_t np = ((uint16_t)height * width) % BUFF_SIZE;

  // Send any partial buffer left over
  if (np) {
    for (int i = 0; i < np; i++) pix_buffer[i] = pgm_read_word(&icon[nb * BUFF_SIZE + i]);
    tft.pushColors(pix_buffer, np);
  }
}