TFT_eSPI/examples/Smooth Graphics/Arc_meter_demo/Arc_meter_demo.ino

209 lines
7.0 KiB
C++

// This is a test sketch being developed for a new arc based meter widget
// The meter grahic is fully anti-aliased to avoid jaggy pixelated edges
// For this demo randomly sized meters are drawn, cycled and redrawn a random size.
// The meter is ramped up and down 0-100 and 100-0, then pauses before a new
// random sized meter is drawn
// If the radius is > 25 then the value is drawn in the middle
// The outer ring of the meter uses the drawSmoothCircle function (which draws
// a narrow full circle smooth arc)
// Uncomment to draw meter digits and label text
//#define DRAW_DIGITS
// If DRAW_DIGITS is defined the OpenFontRender library must be loaded since
// the sketch uses a scaleable TrueType font for the text and numerals.
// https://github.com/Bodmer/OpenFontRender
#define LOOP_DELAY 0 // This controls how frequently the meter is updated
// for test purposes this is set to 0
#include <SPI.h>
#include <TFT_eSPI.h> // Hardware-specific library
#ifdef DRAW_DIGITS
#include "NotoSans_Bold.h"
#include "OpenFontRender.h"
#define TTF_FONT NotoSans_Bold
#endif
TFT_eSPI tft = TFT_eSPI(); // Invoke custom library with default width and height
TFT_eSprite spr = TFT_eSprite(&tft); // Declare Sprite object "spr" with pointer to "tft" object
#ifdef DRAW_DIGITS
OpenFontRender ofr;
#endif
#define DARKER_GREY 0x18E3
uint32_t runTime = 0; // time for next update
int reading = 0; // Value to be displayed
int d = 0; // Variable used for the sinewave test waveform
bool range_error = 0;
int8_t ramp = 1;
bool initMeter = true;
void setup(void) {
Serial.begin(115200);
tft.begin();
tft.setRotation(1);
tft.fillScreen(TFT_NAVY);
//tft.setViewport(0, 0, 240, 320);
}
void loop() {
static uint16_t maxRadius = 0;
int8_t ramp = 1;
static uint8_t radius = 0;
static int16_t xpos = tft.width() / 2;
static int16_t ypos = tft.height() / 2;
bool newMeter = false;
if (maxRadius == 0) {
maxRadius = tft.width();
if (tft.height() < maxRadius) maxRadius = tft.height();
maxRadius = (0.6 * maxRadius) / 2;
radius = maxRadius;
}
// Choose a random meter radius for test purposes and draw for one range cycle
// Clear old meter first
tft.fillCircle(xpos, ypos, radius + 1, TFT_NAVY);
radius = random(20, maxRadius); // Random radius
initMeter = true;
#ifdef DRAW_DIGITS
// Loading a font takes a few milliseconds, so for test purposes it is done outside the test loop
if (ofr.loadFont(TTF_FONT, sizeof(TTF_FONT))) {
Serial.println("Render initialize error");
return;
}
#endif
initMeter = true;
reading = 0;
ramp = 1;
while (!newMeter) {
if (millis() - runTime >= LOOP_DELAY) {
runTime = millis();
reading += ramp;
ringMeter(xpos, ypos, radius, reading, "Watts"); // Draw analogue meter
if (reading > 99) ramp = -1;
if (reading <= 0) ramp = 1;
if (reading > 99) delay(1000);
if (reading <= 0) {
delay(1000);
newMeter = true;
}
}
}
#ifdef DRAW_DIGITS
ofr.unloadFont(); // Recover space used by font metrics etc
#endif
}
// #########################################################################
// Draw the meter on the screen, returns x coord of righthand side
// #########################################################################
// x,y is centre of meter, r the radius, val a number in range 0-100
// units is the meter scale label
void ringMeter(int x, int y, int r, int val, const char *units)
{
static uint16_t last_angle = 30;
if (initMeter) {
initMeter = false;
last_angle = 30;
tft.fillCircle(x, y, r, DARKER_GREY);
tft.drawSmoothCircle(x, y, r, TFT_SILVER, DARKER_GREY);
uint16_t tmp = r - 3;
tft.drawArc(x, y, tmp, tmp - tmp / 5, last_angle, 330, TFT_BLACK, DARKER_GREY);
}
r -= 3;
// Range here is 0-100 so value is scaled to an angle 30-330
int val_angle = map(val, 0, 100, 30, 330);
if (last_angle != val_angle) {
// Could load the required font here
//if (ofr.loadFont(TTF_FONT, sizeof(TTF_FONT))) {
// Serial.println("Render initialize error");
// return;
//}
#ifdef DRAW_DIGITS
ofr.setDrawer(spr); // Link renderer to sprite (font will be rendered in sprite spr)
// Add value in centre if radius is a reasonable size
if ( r >= 25 ) {
// This code gets the font dimensions in pixels to determine the required the sprite size
ofr.setFontSize((6 * r) / 4);
ofr.setFontColor(TFT_WHITE, DARKER_GREY);
// The OpenFontRender library only has simple print functions...
// Digit jiggle for chaging values often happens with proportional fonts because
// digit glyph width varies ( 1 narrower that 4 for example). This code prints up to
// 3 digits with even spacing.
// A few experiemntal fudge factors are used here to position the
// digits in the sprite...
// Create a sprite to draw the digits into
uint8_t w = ofr.getTextWidth("444");
uint8_t h = ofr.getTextHeight("4") + 4;
spr.createSprite(w, h + 2);
spr.fillSprite(DARKER_GREY); // (TFT_BLUE); // (DARKER_GREY);
char str_buf[8]; // Buffed for string
itoa (val, str_buf, 10); // Convert value to string (null terminated)
uint8_t ptr = 0; // Pointer to a digit character
uint8_t dx = 4; // x offfset for cursor position
if (val < 100) dx = ofr.getTextWidth("4") / 2; // Adjust cursor x for 2 digits
if (val < 10) dx = ofr.getTextWidth("4"); // Adjust cursor x for 1 digit
while ((uint8_t)str_buf[ptr] != 0) ptr++; // Count the characters
while (ptr) {
ofr.setCursor(w - dx - w / 20, -h / 2.5); // Offset cursor position in sprtie
ofr.rprintf(str_buf + ptr - 1); // Draw a character
str_buf[ptr - 1] = 0; // Replace character with a null
dx += 1 + w / 3; // Adjust cursor for next character
ptr--; // Decrement character pointer
}
spr.pushSprite(x - w / 2, y - h / 2); // Push sprite containing the val number
spr.deleteSprite(); // Recover used memory
// Make the TFT the print destination, print the units label direct to the TFT
ofr.setDrawer(tft);
ofr.setFontColor(TFT_GOLD, DARKER_GREY);
ofr.setFontSize(r / 2.0);
ofr.setCursor(x, y + (r * 0.4));
ofr.cprintf("Watts");
}
#endif
//ofr.unloadFont(); // Recover space used by font metrics etc
// Allocate a value to the arc thickness dependant of radius
uint8_t thickness = r / 5;
if ( r < 25 ) thickness = r / 3;
// Update the arc, only the zone between last_angle and new val_angle is updated
if (val_angle > last_angle) {
tft.drawArc(x, y, r, r - thickness, last_angle, val_angle, TFT_SKYBLUE, TFT_BLACK); // TFT_SKYBLUE random(0x10000)
}
else {
tft.drawArc(x, y, r, r - thickness, val_angle, last_angle, TFT_BLACK, DARKER_GREY);
}
last_angle = val_angle; // Store meter arc position for next redraw
}
}