acid-drop

- Hacking the planet from a LilyGo T-Deck using custom firmware
git clone git://git.acid.vegas/acid-drop.git
Draw_Smooth_Circles.ino (2710B)
      1 // Example for drawSmoothCircle function. Which draws anti-aliased circles
      2 // The circle periphery has a "thickness" of ~3 pixles to minimise the
      3 // "braiding" effect present in narrow anti-aliased lines.
      4 
      5 // For thicker or thinner circle outlines use the drawArc function.
      6 
      7 #include <TFT_eSPI.h>       // Include the graphics library
      8 TFT_eSPI tft = TFT_eSPI();  // Create object "tft"
      9 
     10 // -------------------------------------------------------------------------
     11 // Setup
     12 // -------------------------------------------------------------------------
     13 void setup(void) {
     14   Serial.begin(115200);
     15   tft.init();
     16   tft.fillScreen(TFT_BLACK);
     17 }
     18 
     19 // -------------------------------------------------------------------------
     20 // Main loop
     21 // -------------------------------------------------------------------------
     22 void loop()
     23 {
     24   static uint32_t radius = 2;
     25   static uint32_t index = 0;
     26 
     27   uint16_t fg_color = rainbow(index);
     28   uint16_t bg_color = TFT_BLACK;       // This is the background colour used for smoothing (anti-aliasing)
     29 
     30   uint16_t x = tft.width() / 2; // Position of centre of arc
     31   uint16_t y = tft.height() / 2;
     32 
     33   tft.drawSmoothCircle(x, y, radius, fg_color, bg_color);
     34 
     35   radius += 11;
     36   index += 5;
     37   index = index%192;
     38 
     39   if (radius > tft.height()/2) {
     40     delay (1000);
     41     radius = 2;
     42   }
     43 }
     44 
     45 
     46 // -------------------------------------------------------------------------
     47 // Return a 16 bit rainbow colour
     48 // -------------------------------------------------------------------------
     49 unsigned int rainbow(byte value)
     50 {
     51   // If 'value' is in the range 0-159 it is converted to a spectrum colour
     52   // from 0 = red through to 127 = blue to 159 = violet
     53   // Extending the range to 0-191 adds a further violet to red band
     54  
     55   value = value%192;
     56   
     57   byte red   = 0; // Red is the top 5 bits of a 16 bit colour value
     58   byte green = 0; // Green is the middle 6 bits, but only top 5 bits used here
     59   byte blue  = 0; // Blue is the bottom 5 bits
     60 
     61   byte sector = value >> 5;
     62   byte amplit = value & 0x1F;
     63 
     64   switch (sector)
     65   {
     66     case 0:
     67       red   = 0x1F;
     68       green = amplit; // Green ramps up
     69       blue  = 0;
     70       break;
     71     case 1:
     72       red   = 0x1F - amplit; // Red ramps down
     73       green = 0x1F;
     74       blue  = 0;
     75       break;
     76     case 2:
     77       red   = 0;
     78       green = 0x1F;
     79       blue  = amplit; // Blue ramps up
     80       break;
     81     case 3:
     82       red   = 0;
     83       green = 0x1F - amplit; // Green ramps down
     84       blue  = 0x1F;
     85       break;
     86     case 4:
     87       red   = amplit; // Red ramps up
     88       green = 0;
     89       blue  = 0x1F;
     90       break;
     91     case 5:
     92       red   = 0x1F;
     93       green = 0;
     94       blue  = 0x1F - amplit; // Blue ramps down
     95       break;
     96   }
     97   return red << 11 | green << 6 | blue;
     98 }