acid-drop

- Hacking the planet from a LilyGo T-Deck using custom firmware
git clone git://git.acid.vegas/acid-drop.git
Smooth_font_gradient.ino (4255B)
      1 /*
      2   This sketch is based on Font Demo 1. It introduces a method for rendering
      3   anti-aliased fonts on a graded background. This is achieved by telling the
      4   TFT_eSPI library the pixel color at each point on the screen. In this sketch
      5   a graded background is drawn, the color of each pixel can therefore be
      6   determined. The TFT does not need to support reading of the graphics memory.
      7   The sketch could be adapted so only part of the screen is gas a color gradient.
      8 
      9   The TFT_eSPI library must be given the name of the function in the sketch
     10   that will return the pixel color at a position x,y on the TFT. In this
     11   sketch that function is called gradientColor, so this line is included:
     12 
     13     tft.setCallback(gradientColor);
     14 
     15   TFT_eSPI will call this function during the rendering of the anti-aliased
     16   font to blend the edges of each character with the returned color.
     17 
     18   If the TFT supports reading the screen RAM then the returned value can be
     19   tft.readPixel(x,y) and anti-aliased text can the be drawn over any screen
     20   image. See "Smooth_font_over_image" example.
     21 */
     22 //  The fonts used are in the sketch data folder, press Ctrl+K to view.
     23 
     24 //  Upload the fonts and icons to SPIFFS (must set at least 1M for SPIFFS) using the
     25 //  "Tools"  "ESP8266 (or ESP32) Sketch Data Upload" menu option in the IDE.
     26 //  To add this option follow instructions here for the ESP8266:
     27 //  https://github.com/esp8266/arduino-esp8266fs-plugin
     28 //  or for the ESP32:
     29 //  https://github.com/me-no-dev/arduino-esp32fs-plugin
     30 
     31 //  Close the IDE and open again to see the new menu option.
     32 
     33 //  A processing sketch to create new fonts can be found in the Tools folder of TFT_eSPI
     34 //  https://github.com/Bodmer/TFT_eSPI/tree/master/Tools/Create_Smooth_Font/Create_font
     35 
     36 //  This sketch uses font files created from the Noto family of fonts:
     37 //  https://www.google.com/get/noto/
     38 
     39 #define AA_FONT_SMALL "NotoSansBold15"
     40 #define AA_FONT_LARGE "NotoSansBold36"
     41 
     42 // Font files are stored in SPIFFS, so load the library
     43 #include <FS.h>
     44 
     45 #include <SPI.h>
     46 #include <TFT_eSPI.h>       // Hardware-specific library
     47 
     48 TFT_eSPI tft = TFT_eSPI();
     49 
     50 #define TOP_COLOR    TFT_RED
     51 #define BOTTOM_COLOR TFT_BLACK
     52 
     53 #define GRADIENT_HEIGHT (9 + tft.fontHeight() * 5) // Gradient over 5 lines
     54 #define OUTSIDE_GRADIENT TFT_BLUE
     55 
     56 uint16_t gradientColor(uint16_t x, uint16_t y)
     57 {
     58   if (y > GRADIENT_HEIGHT) return OUTSIDE_GRADIENT;   // Outside gradient area
     59   uint8_t alpha = (255 * y) / GRADIENT_HEIGHT;        // alpha is a value in the range 0-255
     60   return tft.alphaBlend(alpha, BOTTOM_COLOR, TOP_COLOR);
     61 }
     62 
     63 void fillGradient() {
     64   uint16_t w = tft.width();
     65   for (uint16_t y = 0; y < tft.height(); ++y) {
     66     uint16_t color = gradientColor(0, y); // x not used here
     67     tft.drawFastHLine(0, y, w, color);
     68   }
     69 }
     70 
     71 void setup(void) {
     72   Serial.begin(115200);
     73 
     74   tft.begin();
     75 
     76   tft.setCallback(gradientColor); // Switch on color callback for anti-aliased fonts
     77   //tft.setCallback(nullptr);     // Switch off callback (off by default)
     78 
     79   tft.setRotation(1);
     80 
     81   if (!SPIFFS.begin()) {
     82     Serial.println("SPIFFS initialisation failed!");
     83     while (1) yield(); // Stay here twiddling thumbs waiting
     84   }
     85   Serial.println("\r\nSPIFFS available!");
     86 
     87   // ESP32 will crash if any of the fonts are missing
     88   bool font_missing = false;
     89   if (SPIFFS.exists("/NotoSansBold15.vlw") == false) font_missing = true;
     90   if (SPIFFS.exists("/NotoSansBold36.vlw")    == false) font_missing = true;
     91 
     92   if (font_missing)
     93   {
     94     Serial.println("\r\nFont missing in SPIFFS, did you upload it?");
     95     while (1) yield();
     96   }
     97   else Serial.println("\r\nFonts found OK.");
     98 }
     99 
    100 
    101 void loop() {
    102 
    103   // Select a font size commensurate with screen size
    104   if (tft.width()>= 320)
    105     tft.loadFont(AA_FONT_LARGE);
    106   else
    107     tft.loadFont(AA_FONT_SMALL);
    108 
    109   fillGradient(); // Put here after selecting the font so fontHeight() is already set
    110 
    111   tft.setTextColor(TFT_WHITE); // Background color is ignored in gradient area
    112   tft.setCursor(0, 10); // Set cursor at top left of screen
    113 
    114   uint32_t t = millis();
    115   tft.println(" Ode to a small\n lump of green\n putty I found\n in my armpit\n one midsummer\n morning ");
    116   Serial.println(t = millis()-t);
    117 
    118   tft.unloadFont(); // Remove the font to recover memory used
    119 
    120   delay(2000);
    121 }