blinky-esp/main/screen_leds.cpp

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

#include "screen_leds.hpp"


static inline void fill(uint16_t *buffer, uint16_t value, int w, int h, int p = -1) {
    if (p <= 0) p = w;
    uint16_t *line = buffer;
    while (--h >= 0) {
        uint16_t *pixel = line;
        for (int _w = w; _w > 0; --_w) {
            *pixel = value;
            ++pixel;
        }
        line += p;
    }
}

static inline void box(uint16_t *buffer, uint16_t value, int x, int y, int w, int h, int p = -1) {
    if (p <= 0) p = w;
    fill(buffer + x + (y * p), value, w, h, p);
}

static inline uint16_t rgb16(int r, int g, int b) {
    return ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((uint8_t)b >> 3);
}

static inline uint16_t color_to_565(Color c) {
    return rgb16(c.r, c.g, c.b);
}

ScreenLEDs::ScreenLEDs(int length) : LEDStrip(length), display(135, 240) {}

void ScreenLEDs::length_changing(int length) {
    fill(display.get_buffer(), COLOR_BLACK, display.get_width(), display.get_height());
}

void ScreenLEDs::show() {
    const int width = display.get_width();
    const int height = display.get_height();
    const int pitch = display.get_pitch();
    auto buffer = display.get_buffer();

    const size_t size = ((width + height) * 2) / (length + 4);

    int lx = 0, ly = 0;
    int dx = 0, dy = size;
    for (size_t l = 0; l < length; ++l) {
        if (ly + dy > height) {
            ly -= dy;
            dx = size;
            dy = 0;
            lx += dx;
        } else if (ly < 0) {
            ly -= dy;
            dx = -size;
            dy = 0;
            lx += dx;
        } else if (lx + dx > width) {
            lx -= dx;
            dx = 0;
            dy = -size;
            ly += dy;
        } else if (lx < 0) {
            lx -= dx;
            dx = 0;
            dy = size;
            ly += dy;
        }

        box(buffer, color_to_565(pixels[l]), lx, ly, size, size, pitch);

        lx += dx;
        ly += dy;
    }

    display.refresh();
}