blinky-esp/main/leds.cpp

static const char *TAG = "leds";
#include <esp_log.h>

#include "leds.hpp"
#include "utils.hpp"


static inline uint8_t mix(int l, int r, Fixed x) {
    return ((l << shift) + (x * (r - l))) >> shift;
}

Color Gradient::at(Fixed x) const {
    int i_left = (x * n_colors) >> shift;
    int i_right = i_left < n_colors - 1 ? i_left + 1 : 0;
    Fixed ratio = (x * n_colors) - (i_left << shift);
    //ESP_LOGI(TAG, "at(%d) = %d between %d and %d", x, ratio, i_left, i_right);
    Color cl = colors[i_left];
    Color cr = colors[i_right];
    Color color = {
            mix(cl.r, cr.r, ratio),
            mix(cl.g, cr.g, ratio),
            mix(cl.b, cr.b, ratio)
        };
    /*ESP_LOGI(TAG, "(%d, %d, %d) %f (%d, %d, %d) -> (%d, %d, %d)",
        cl.r, cl.g, cl.b,
        ratio / (float)factor,
        cr.r, cr.g, cr.b,
        color.r, color.g, color.b
    );*/
    return color;
}


void Pattern::step(Color pixels[], int len, int64_t &last_us, Fixed &offset) const {
    int64_t now_us = time_us();
    int64_t duration_us = last_us == 0 ? 0 : now_us - last_us;
    last_us = now_us;
    //ESP_LOGI(TAG, "duration %d", duration_us);

    int offset_delta = (duration_us << shift) / (cycle_time_ms * 1000);
    if (reverse) offset -= offset_delta; else offset += offset_delta;
    Fixed off = march ?
            (((int)offset * cycle_length) & ~((1 << shift) - 1)) / cycle_length :
            offset;
    //ESP_LOGI(TAG, "cycle time %d, delta %d, offset %d, off %d", cycle_time_ms, offset_delta, offset, off);
    for (int i = 0; i < len; ++i) {
        pixels[i] = gradient.at(off + ((i << shift) / cycle_length));
    }
}


LEDStrip::LEDStrip(int _length) :
            length(_length), pattern(NULL),
            pixels(new Color[_length]),
            last_us(0), offset(0)
        {}

void LEDStrip::step() {
    if (pattern) pattern->step(pixels, length, last_us, offset);
}

static std::string termcolor(Color c) {
    return "\x1b[48;2;" +
            std::to_string((int)c.r) + ";" +
            std::to_string((int)c.g) + ";" +
            std::to_string((int)c.b) + "m";
}

void TerminalLEDs::show() const {
    std::string line;
    for (int i = 0; i < length; i++) {
        line += termcolor(pixels[i]) + " ";
    }
    line += "\x1b[0m";
    ESP_LOGI(TAG, "%s", line.c_str());
}