307 lines
11 KiB
C++
307 lines
11 KiB
C++
#pragma once
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#include "FastLED.h"
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#include "fl/namespace.h"
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#include "fl/str.h"
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#include "fx/fx1d.h"
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namespace fl {
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/// @file TwinkleFox.hpp
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/// @brief Twinkling "holiday" lights that fade in and out.
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/// @example TwinkleFox.ino
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// TwinkleFOX: Twinkling 'holiday' lights that fade in and out.
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// Colors are chosen from a palette; a few palettes are provided.
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//
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// This December 2015 implementation improves on the December 2014 version
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// in several ways:
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// - smoother fading, compatible with any colors and any palettes
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// - easier control of twinkle speed and twinkle density
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// - supports an optional 'background color'
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// - takes even less RAM: zero RAM overhead per pixel
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// - illustrates a couple of interesting techniques (uh oh...)
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//
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// The idea behind this (new) implementation is that there's one
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// basic, repeating pattern that each pixel follows like a waveform:
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// The brightness rises from 0..255 and then falls back down to 0.
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// The brightness at any given point in time can be determined as
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// as a function of time, for example:
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// brightness = sine( time ); // a sine wave of brightness over time
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//
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// So the way this implementation works is that every pixel follows
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// the exact same wave function over time. In this particular case,
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// I chose a sawtooth triangle wave (triwave8) rather than a sine wave,
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// but the idea is the same: brightness = triwave8( time ).
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//
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// The triangle wave function is a piecewise linear function that looks like:
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//
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// / \\
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// / \\
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// / \\
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// / \\
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//
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// Of course, if all the pixels used the exact same wave form, and
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// if they all used the exact same 'clock' for their 'time base', all
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// the pixels would brighten and dim at once -- which does not look
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// like twinkling at all.
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//
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// So to achieve random-looking twinkling, each pixel is given a
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// slightly different 'clock' signal. Some of the clocks run faster,
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// some run slower, and each 'clock' also has a random offset from zero.
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// The net result is that the 'clocks' for all the pixels are always out
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// of sync from each other, producing a nice random distribution
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// of twinkles.
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//
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// The 'clock speed adjustment' and 'time offset' for each pixel
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// are generated randomly. One (normal) approach to implementing that
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// would be to randomly generate the clock parameters for each pixel
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// at startup, and store them in some arrays. However, that consumes
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// a great deal of precious RAM, and it turns out to be totally
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// unnessary! If the random number generate is 'seeded' with the
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// same starting value every time, it will generate the same sequence
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// of values every time. So the clock adjustment parameters for each
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// pixel are 'stored' in a pseudo-random number generator! The PRNG
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// is reset, and then the first numbers out of it are the clock
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// adjustment parameters for the first pixel, the second numbers out
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// of it are the parameters for the second pixel, and so on.
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// In this way, we can 'store' a stable sequence of thousands of
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// random clock adjustment parameters in literally two bytes of RAM.
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//
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// There's a little bit of fixed-point math involved in applying the
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// clock speed adjustments, which are expressed in eighths. Each pixel's
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// clock speed ranges from 8/8ths of the system clock (i.e. 1x) to
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// 23/8ths of the system clock (i.e. nearly 3x).
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//
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// On a basic Arduino Uno or Leonardo, this code can twinkle 300+ pixels
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// smoothly at over 50 updates per seond.
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//
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// -Mark Kriegsman, December 2015
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// Adapted for FastLED 3.x in August 2023 by Marlin Unruh
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// TwinkleFox effect parameters
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// Overall twinkle speed.
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// 0 (VERY slow) to 8 (VERY fast).
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// 4, 5, and 6 are recommended, default is 4.
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#define TWINKLE_SPEED 4
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// Overall twinkle density.
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// 0 (NONE lit) to 8 (ALL lit at once).
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// Default is 5.
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#define TWINKLE_DENSITY 5
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// How often to change color palettes.
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#define SECONDS_PER_PALETTE 30
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// If AUTO_SELECT_BACKGROUND_COLOR is set to 1,
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// then for any palette where the first two entries
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// are the same, a dimmed version of that color will
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// automatically be used as the background color.
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#define AUTO_SELECT_BACKGROUND_COLOR 0
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// If COOL_LIKE_INCANDESCENT is set to 1, colors will
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// fade out slighted 'reddened', similar to how
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// incandescent bulbs change color as they get dim down.
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#define COOL_LIKE_INCANDESCENT 1
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FASTLED_SMART_PTR(TwinkleFox);
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class TwinkleFox : public Fx1d {
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public:
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CRGBPalette16 targetPalette;
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CRGBPalette16 currentPalette;
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TwinkleFox(uint16_t num_leds)
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: Fx1d(num_leds), backgroundColor(CRGB::Black),
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twinkleSpeed(TWINKLE_SPEED), twinkleDensity(TWINKLE_DENSITY),
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coolLikeIncandescent(COOL_LIKE_INCANDESCENT),
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autoSelectBackgroundColor(AUTO_SELECT_BACKGROUND_COLOR) {
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chooseNextColorPalette(targetPalette);
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}
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void draw(DrawContext context) override {
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EVERY_N_MILLISECONDS(10) {
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nblendPaletteTowardPalette(currentPalette, targetPalette, 12);
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}
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drawTwinkleFox(context.leds);
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}
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void chooseNextColorPalette(CRGBPalette16 &pal);
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fl::string fxName() const override { return "TwinkleFox"; }
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private:
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CRGB backgroundColor;
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uint8_t twinkleSpeed;
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uint8_t twinkleDensity;
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bool coolLikeIncandescent;
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bool autoSelectBackgroundColor;
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void drawTwinkleFox(CRGB *leds) {
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// "PRNG16" is the pseudorandom number generator
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// It MUST be reset to the same starting value each time
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// this function is called, so that the sequence of 'random'
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// numbers that it generates is (paradoxically) stable.
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uint16_t PRNG16 = 11337;
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fl::u32 clock32 = millis();
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CRGB bg = backgroundColor;
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if (autoSelectBackgroundColor &&
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currentPalette[0] == currentPalette[1]) {
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bg = currentPalette[0];
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uint8_t bglight = bg.getAverageLight();
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if (bglight > 64) {
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bg.nscale8_video(16);
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} else if (bglight > 16) {
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bg.nscale8_video(64);
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} else {
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bg.nscale8_video(86);
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}
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}
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uint8_t backgroundBrightness = bg.getAverageLight();
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for (uint16_t i = 0; i < mNumLeds; i++) {
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PRNG16 = (uint16_t)(PRNG16 * 2053) + 1384;
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uint16_t myclockoffset16 = PRNG16;
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PRNG16 = (uint16_t)(PRNG16 * 2053) + 1384;
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uint8_t myspeedmultiplierQ5_3 =
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((((PRNG16 & 0xFF) >> 4) + (PRNG16 & 0x0F)) & 0x0F) + 0x08;
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fl::u32 myclock30 =
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(fl::u32)((clock32 * myspeedmultiplierQ5_3) >> 3) +
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myclockoffset16;
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uint8_t myunique8 = PRNG16 >> 8;
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CRGB c = computeOneTwinkle(myclock30, myunique8);
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uint8_t cbright = c.getAverageLight();
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int16_t deltabright = cbright - backgroundBrightness;
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if (deltabright >= 32 || (!bg)) {
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leds[i] = c;
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} else if (deltabright > 0) {
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leds[i] = blend(bg, c, deltabright * 8);
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} else {
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leds[i] = bg;
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}
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}
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}
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CRGB computeOneTwinkle(fl::u32 ms, uint8_t salt) {
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uint16_t ticks = ms >> (8 - twinkleSpeed);
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uint8_t fastcycle8 = ticks;
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uint16_t slowcycle16 = (ticks >> 8) + salt;
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slowcycle16 += sin8(slowcycle16);
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slowcycle16 = (slowcycle16 * 2053) + 1384;
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uint8_t slowcycle8 = (slowcycle16 & 0xFF) + (slowcycle16 >> 8);
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uint8_t bright = 0;
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if (((slowcycle8 & 0x0E) / 2) < twinkleDensity) {
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bright = attackDecayWave8(fastcycle8);
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}
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uint8_t hue = slowcycle8 - salt;
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CRGB c;
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if (bright > 0) {
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c = ColorFromPalette(currentPalette, hue, bright, NOBLEND);
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if (coolLikeIncandescent) {
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coolLikeIncandescentFunction(c, fastcycle8);
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}
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} else {
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c = CRGB::Black;
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}
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return c;
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}
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uint8_t attackDecayWave8(uint8_t i) {
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if (i < 86) {
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return i * 3;
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} else {
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i -= 86;
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return 255 - (i + (i / 2));
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}
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}
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void coolLikeIncandescentFunction(CRGB &c, uint8_t phase) {
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if (phase < 128)
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return;
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uint8_t cooling = (phase - 128) >> 4;
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c.g = qsub8(c.g, cooling);
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c.b = qsub8(c.b, cooling * 2);
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}
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};
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// Color palettes
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// Color palette definitions
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// A mostly red palette with green accents and white trim.
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// "CRGB::Gray" is used as white to keep the brightness more uniform.
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const TProgmemRGBPalette16 RedGreenWhite_p FL_PROGMEM = {
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CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red,
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CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Gray, CRGB::Gray,
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CRGB::Green, CRGB::Green, CRGB::Green, CRGB::Green};
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const TProgmemRGBPalette16 Holly_p FL_PROGMEM = {
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0x00580c, 0x00580c, 0x00580c, 0x00580c, 0x00580c, 0x00580c,
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0x00580c, 0x00580c, 0x00580c, 0x00580c, 0x00580c, 0x00580c,
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0x00580c, 0x00580c, 0x00580c, 0xB00402};
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const TProgmemRGBPalette16 RedWhite_p FL_PROGMEM = {
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CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Gray, CRGB::Gray,
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CRGB::Gray, CRGB::Gray, CRGB::Red, CRGB::Red, CRGB::Red, CRGB::Red,
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CRGB::Gray, CRGB::Gray, CRGB::Gray, CRGB::Gray};
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const TProgmemRGBPalette16 BlueWhite_p FL_PROGMEM = {
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CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue,
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CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue, CRGB::Blue,
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CRGB::Blue, CRGB::Gray, CRGB::Gray, CRGB::Gray};
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const TProgmemRGBPalette16 FairyLight_p = {
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB(CRGB::FairyLight).nscale8_constexpr(uint8_t(128)).as_uint32_t(),
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CRGB(CRGB::FairyLight).nscale8_constexpr(uint8_t(128)).as_uint32_t(),
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB(CRGB::FairyLight).nscale8_constexpr(64).as_uint32_t(),
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CRGB(CRGB::FairyLight).nscale8_constexpr(64).as_uint32_t(),
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight,
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CRGB::FairyLight};
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const TProgmemRGBPalette16 Snow_p FL_PROGMEM = {
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0x304048, 0x304048, 0x304048, 0x304048, 0x304048, 0x304048,
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0x304048, 0x304048, 0x304048, 0x304048, 0x304048, 0x304048,
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0x304048, 0x304048, 0x304048, 0xE0F0FF};
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const TProgmemRGBPalette16 RetroC9_p FL_PROGMEM = {
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0xB80400, 0x902C02, 0xB80400, 0x902C02, 0x902C02, 0xB80400,
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0x902C02, 0xB80400, 0x046002, 0x046002, 0x046002, 0x046002,
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0x070758, 0x070758, 0x070758, 0x606820};
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const TProgmemRGBPalette16 Ice_p FL_PROGMEM = {
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0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040,
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0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040, 0x0C1040,
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0x182080, 0x182080, 0x182080, 0x5080C0};
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// Add or remove palette names from this list to control which color
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// palettes are used, and in what order.
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const TProgmemRGBPalette16 *ActivePaletteList[] = {
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&RetroC9_p, &BlueWhite_p, &RainbowColors_p, &FairyLight_p,
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&RedGreenWhite_p, &PartyColors_p, &RedWhite_p, &Snow_p,
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&Holly_p, &Ice_p};
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void TwinkleFox::chooseNextColorPalette(CRGBPalette16 &pal) {
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const uint8_t numberOfPalettes =
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sizeof(ActivePaletteList) / sizeof(ActivePaletteList[0]);
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static uint8_t whichPalette = -1;
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whichPalette = addmod8(whichPalette, 1, numberOfPalettes);
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pal = *(ActivePaletteList[whichPalette]);
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}
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} // namespace fl
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