firmware/src/graphics/BRC.cpp

#include "BRC.h"
#include "GPSStatus.h"
#include "gps/GeoCoord.h"
#include "graphics/Screen.h"

using namespace meshtastic;

const int32_t BRC_LATI = (40.786958 * 1e7);
const int32_t BRC_LONI = (-119.202994 * 1e7);
const double BRC_LATF = 40.786958;
const double BRC_LONF = -119.202994;
const double BRC_NOON = 1.5;
const double RAD_TO_HOUR = (6.0 / 3.14159);
const double METER_TO_FEET = 3.28084;
const double FEET_TO_METER = 1.0 / METER_TO_FEET;

// Pre-calculated street data for performance
struct StreetInfo {
    float center;
    float width;
    const char *name;
};

/*
# python code to generate the StreetInfo

esp_center = 2500
street_info = [
  # name, width, preceeding block depth
  ('Esp', 40, 60), # block size is fake
  ('A',   30, 400),
  ('B',   30, 250),
  ('C',   30, 250),
  ('D',   30, 250),
  ('E',   40, 250),
  ('F',   30, 450), # E-F block is exra deep
  ('G',   30, 250),
  ('H',   30, 250),
  ('I',   30, 250),
  ('J',   30, 150),
  ('K',   50, 150),
]

street_center = esp_center - street_info[0][1] //2 - street_info[0][2]
last_center = esp_center
for (name, street_width, block_width) in street_info:
    offset = (street_width + block_width) // 2
    street_center += street_width //2 + block_width

    dia = street_center * 2
    dist = street_center - last_center

    print(f"{{{street_center}, {offset}, \"{name}\"}},\t// +{dist}ft\tdia: {dia:,}ft")

    last_center = street_center
    street_center += street_width //2

street_center += 50 # extra buffer after the edge of k to include walk-in camping parking
print(f"{{{street_center}, 0, nullptr}},\t// +{street_center-last_center}ft")
*/

static const StreetInfo streets[] = {
    {2500, 50, "Esp"},  // +0ft	dia: 5,000ft
    {2935, 215, "A"},   // +435ft	dia: 5,870ft
    {3215, 140, "B"},   // +280ft	dia: 6,430ft
    {3495, 140, "C"},   // +280ft	dia: 6,990ft
    {3775, 140, "D"},   // +280ft	dia: 7,550ft
    {4060, 145, "E"},   // +285ft	dia: 8,120ft
    {4545, 240, "F"},   // +485ft	dia: 9,090ft
    {4825, 140, "G"},   // +280ft	dia: 9,650ft
    {5105, 140, "H"},   // +280ft	dia: 10,210ft
    {5385, 140, "I"},   // +280ft	dia: 10,770ft
    {5565, 90, "J"},    // +180ft	dia: 11,130ft
    {5755, 100, "K"},   // +190ft	dia: 11,510ft
    {5830, 0, nullptr}, // +75ft
};

BRCAddress::BRCAddress(int32_t lat, int32_t lon)
{
    bearing = GeoCoord::bearing(BRC_LATF, BRC_LONF, DegD(lat), DegD(lon)) * RAD_TO_HOUR;
    bearing += 12.0 - BRC_NOON;
    while (bearing > 12.0) {
        bearing -= 12.0;
    }

    // In imperial units because that is how golden spike data is provided.
    distance = GeoCoord::latLongToMeter(BRC_LATF, BRC_LONF, DegD(lat), DegD(lon)) * METER_TO_FEET;
};

int BRCAddress::radial(char *buf, size_t len)
{
    uint8_t hour = (uint8_t)(bearing);
    uint8_t minute = (uint8_t)((bearing - hour) * 60.0);
    hour %= 12;
    if (hour == 0) {
        hour = 12;
    }
    return snprintf(buf, len, "%d:%02d", hour, minute);
};

int BRCAddress::annular(char *buf, size_t len, bool noUnit)
{
    const char *unit = "m";
    float unitMultiplier = FEET_TO_METER;
    if (config.display.units == meshtastic_Config_DisplayConfig_DisplayUnits_IMPERIAL) {
        unitMultiplier = 1.0;
        unit = "ft";
    }
    if (noUnit)
        unit = "";

    if (bearing > 1.75 && bearing < 10.25) {
        const char *street = nullptr;
        float dist = 0;
        // Find the appropriate street based on distance
        for (const auto &s : streets) {
            if (distance > s.center - s.width) {
                street = s.name;
                dist = distance - s.center;
            } else {
                break;
            }
        }
        if (street) {
            return snprintf(buf, len, "%s %d%s", street, int(dist * unitMultiplier), unit);
        }
    }

    return snprintf(buf, len, "%d%s", int(distance * unitMultiplier), unit);
};

int BRCAddress::full(char *buf, size_t len)
{
    auto l = radial(buf, len - 4);
    buf += l;
    *(buf++) = ' ';
    *(buf++) = '&';
    *(buf++) = ' ';
    buf += annular(buf, len - l - 4, false);
    buf[l] = 0; // always null terminated
    return l;
};

int BRCAddress::compact(char *buf, size_t len)
{
    auto l = radial(buf, len - 2);
    buf += l;
    *(buf++) = '&';
    buf += annular(buf, len - l - 2, true);
    buf[l] = 0; // always null terminated
    return l;
};