122 lines
4.2 KiB
C++
122 lines
4.2 KiB
C++
/*
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This sketch is based on Font Demo 1. It introduces a method for rendering
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anti-aliased fonts on a graded background. This is acheived by telling the
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TFT_eSPI library the pixel color at each point on the screen. In this sketch
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a graded background is drawn, the color of each pixel can therefore be
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determined. The TFT does not need to support reading of the graphics memory.
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The sketch could be adapted so only part of the screen is gas a color gradient.
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The TFT_eSPI library must be given the name of the function in the sketch
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that will return the pixel xolor at a position x,y on the TFT. In this
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sketch that function is called gradientColor, so this line is included:
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tft.setCallback(gradientColor);
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TFT_eSPI will call this function during the rendering of the anti-aliased
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font to blend the edges of each character with the returned color.
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If the TFT supports reading the screen RAM then the returned value can be
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tft.readPixel(x,y) and anti-aliased text can the be drawn over any screen
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image. See "Smooth_font_over_image" example.
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*/
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// The fonts used are in the sketch data folder, press Ctrl+K to view.
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// Upload the fonts and icons to SPIFFS (must set at least 1M for SPIFFS) using the
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// "Tools" "ESP8266 (or ESP32) Sketch Data Upload" menu option in the IDE.
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// To add this option follow instructions here for the ESP8266:
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// https://github.com/esp8266/arduino-esp8266fs-plugin
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// or for the ESP32:
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// https://github.com/me-no-dev/arduino-esp32fs-plugin
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// Close the IDE and open again to see the new menu option.
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// A processing sketch to create new fonts can be found in the Tools folder of TFT_eSPI
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// https://github.com/Bodmer/TFT_eSPI/tree/master/Tools/Create_Smooth_Font/Create_font
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// This sketch uses font files created from the Noto family of fonts:
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// https://www.google.com/get/noto/
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#define AA_FONT_SMALL "NotoSansBold15"
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#define AA_FONT_LARGE "NotoSansBold36"
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// Font files are stored in SPIFFS, so load the library
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#include <FS.h>
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#include <SPI.h>
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#include <TFT_eSPI.h> // Hardware-specific library
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TFT_eSPI tft = TFT_eSPI();
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#define TOP_COLOR TFT_RED
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#define BOTTOM_COLOR TFT_BLACK
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#define GRADIENT_HEIGHT (9 + tft.fontHeight() * 5) // Gradient over 5 lines
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#define OUTSIDE_GRADIENT TFT_BLUE
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uint16_t gradientColor(uint16_t x, uint16_t y)
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{
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if (y > GRADIENT_HEIGHT) return OUTSIDE_GRADIENT; // Outside gradient area
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uint8_t alpha = (255 * y) / GRADIENT_HEIGHT; // alpha is a value in the range 0-255
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return tft.alphaBlend(alpha, BOTTOM_COLOR, TOP_COLOR);
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}
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void fillGradient() {
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uint16_t w = tft.width();
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for (uint16_t y = 0; y < tft.height(); ++y) {
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uint16_t color = gradientColor(0, y); // x not used here
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tft.drawFastHLine(0, y, w, color);
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}
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}
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void setup(void) {
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Serial.begin(115200);
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tft.begin();
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tft.setCallback(gradientColor); // Switch on color callback for anti-aliased fonts
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//tft.setCallback(nullptr); // Switch off callback (off by default)
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tft.setRotation(1);
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if (!SPIFFS.begin()) {
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Serial.println("SPIFFS initialisation failed!");
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while (1) yield(); // Stay here twiddling thumbs waiting
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}
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Serial.println("\r\nSPIFFS available!");
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// ESP32 will crash if any of the fonts are missing
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bool font_missing = false;
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if (SPIFFS.exists("/NotoSansBold15.vlw") == false) font_missing = true;
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if (SPIFFS.exists("/NotoSansBold36.vlw") == false) font_missing = true;
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if (font_missing)
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{
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Serial.println("\r\nFont missing in SPIFFS, did you upload it?");
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while (1) yield();
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}
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else Serial.println("\r\nFonts found OK.");
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}
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void loop() {
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// Select a font size comensurate with screen size
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if (tft.width()>= 320)
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tft.loadFont(AA_FONT_LARGE);
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else
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tft.loadFont(AA_FONT_SMALL);
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fillGradient(); // Put here after selecting the font so fontHeight() is already set
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tft.setTextColor(TFT_WHITE); // Background color is ignored in gradient area
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tft.setCursor(0, 10); // Set cursor at top left of screen
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uint32_t t = millis();
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tft.println(" Ode to a small\n lump of green\n putty I found\n in my armpit\n one midsummer\n morning ");
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Serial.println(t = millis()-t);
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tft.unloadFont(); // Remove the font to recover memory used
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delay(2000);
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}
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