strichmaennchen git · main

#include "time.h"
#include <math.h>
#include <stdlib.h>

float fmodf(float x, float y);
float cosf(float x);
float sinf(float x);
float fmaxf(float x, float y);

#define M_PI 3.14159265358979323846





float Time_delta(Uint64* prev_ticks) {
    Uint64 now = SDL_GetTicks();
    float dt = (now - *prev_ticks) / 1000.0f;
    *prev_ticks = now;
    return dt;
}

Time* Time_init(float timeScale) {
    Time* t = malloc(sizeof(Time));
    if (!t) return NULL;
    //t->hours = 12.0f;
    t->hours = 13.0f;
    t->minutes = 0.0f;
    t->seconds = 0.0f;
    t->timeScale = timeScale;

    t->dayStart = 7.0f;  // 07:00
    t->dayEnd   = 21.0f; // 21:00

    Time_computeSunPosition(t);

    return t;
}

void Time_update(Time* t, float deltaSeconds) {
    float scaled = deltaSeconds * t->timeScale;
    t->seconds += scaled;
    if (t->seconds >= 60.0f) {
        t->minutes += (int)(t->seconds / 60.0f);
        t->seconds = fmodf(t->seconds, 60.0f);
    }
    if (t->minutes >= 60.0f) {
        t->hours += (int)(t->minutes / 60.0f);
        t->minutes = fmodf(t->minutes, 60.0f);
    }
    if (t->hours >= 24.0f) t->hours -= 24.0f;

    Time_computeSunPosition(t);
}

float Time_getFractionOfDay(const Time* t) {
    return (t->hours + t->minutes/60.0f + t->seconds/3600.0f) / 24.0f;
}

void Time_computeSunPosition(Time* t) {
                                  //
    float hour = t->hours + t->minutes/60.0f + t->seconds/3600.0f;
    float dayFraction = (hour - t->dayStart) / (t->dayEnd - t->dayStart); // 0..1 during day
    float nightFraction = (hour < t->dayStart)
                            ? (hour + 24.0f - t->dayEnd) / (24.0f - (t->dayEnd - t->dayStart))
                            : (hour - t->dayEnd) / (24.0f - (t->dayEnd - t->dayStart));

    // Continuous sun angle
    float angle;
    if (hour >= t->dayStart && hour <= t->dayEnd) {
        angle = dayFraction * M_PI;              // day: sunrise → sunset
    } else {
        angle = nightFraction * M_PI + M_PI;     // night: continue the half-circle downward
    }

    // Sun points along X/Y plane
    t->sunDirection = (Vec3){ cosf(angle), sinf(angle), 0.0f };

    // Sun color: interpolate warm colors at sunrise/sunset
    float intensity = fmaxf(t->sunDirection.y, 0.0f);
    t->sunColor.x = 1.0f * intensity;
    t->sunColor.y = 0.95f * intensity;
    t->sunColor.z = 0.8f * intensity;

    // ambient color
    t->ambientColor.x = 0.1f  + 0.2f * intensity;
    t->ambientColor.y = 0.1f  + 0.2f * intensity;
    t->ambientColor.z = 0.15f + 0.2f * intensity;

    t->dayFactor = intensity;
}



void Time_destroy(Time* t) {
    free(t);
}