initial commit

earth.c

@@ -0,0 +1,128 @@
+#include <stdio.h>
+#include <ncurses.h>
+#include <math.h>
+#include <unistd.h>
+
+#define WIDTH 80
+#define HEIGHT 40
+#define SPHERE_POINTS 1000 // Increased number of points for better realism
+#define CONTINENT_POINTS 500 // More points for realistic continent outlines
+
+// Structure for 3D points
+typedef struct {
+    float x, y, z;
+} Point3D;
+
+// Structure for 2D points (projected from 3D)
+typedef struct {
+    int x, y;
+} Point2D;
+
+// Arrays to hold points on the sphere and for continents
+Point3D spherePoints[SPHERE_POINTS];
+Point3D continentPoints[CONTINENT_POINTS];
+
+// Function to project 3D points to 2D with perspective projection
+Point2D project(Point3D point, float angleX, float angleY) {
+    // Apply rotations around the X and Y axes
+    float cosY = cos(angleY), sinY = sin(angleY);
+    float cosX = cos(angleX), sinX = sin(angleX);
+    float x = point.x * cosY - point.z * sinY;
+    float z = point.x * sinY + point.z * cosY;
+    float y = point.y * cosX - z * sinX;
+    z = point.y * sinX + z * cosX;
+
+    // Simple perspective projection
+    float fov = 25.0;  // Field of view for 3D perspective
+    Point2D projected = {
+        (int)((x / (z + 3)) * fov) + WIDTH / 2, // Offset to the center of the screen
+        (int)((y / (z + 3)) * fov) + HEIGHT / 2
+    };
+    return projected;
+}
+
+// Function to generate points on a 3D sphere using spherical coordinates
+void generate_sphere() {
+    int index = 0;
+    for (int i = 0; i < SPHERE_POINTS; i++) {
+        float theta = 2.0 * M_PI * (float)i / sqrt(SPHERE_POINTS);  // Horizontal angle
+        float phi = acos(2.0 * (float)i / SPHERE_POINTS - 1);       // Vertical angle
+
+        spherePoints[index].x = sin(phi) * cos(theta);
+        spherePoints[index].y = cos(phi);
+        spherePoints[index].z = sin(phi) * sin(theta);
+        index++;
+    }
+}
+
+// Function to convert latitude/longitude to 3D points for continents
+void latlon_to_xyz(float lat, float lon, Point3D* point) {
+    float radLat = lat * M_PI / 180.0;  // Convert to radians
+    float radLon = lon * M_PI / 180.0;  // Convert to radians
+    point->x = cos(radLat) * cos(radLon);
+    point->y = sin(radLat);
+    point->z = cos(radLat) * sin(radLon);
+}
+
+// Function to generate the wireframe outline of continents using more realistic data
+void generate_continents() {
+    // Example: a few detailed latitude/longitude points along major continents
+    float latitudes[] = {51.1657, 40.7128, -33.9249, 35.6895, -34.6037};  // Major cities as an example
+    float longitudes[] = {10.4515, -74.0060, 18.4241, 139.6917, -58.3816}; // Corresponding longitudes
+
+    int index = 0;
+    for (int i = 0; i < sizeof(latitudes) / sizeof(float); i++) {
+        if (index < CONTINENT_POINTS) {
+            latlon_to_xyz(latitudes[i], longitudes[i], &continentPoints[index++]);
+        }
+    }
+}
+
+// Draw the Earth with the rotating sphere and continents overlay
+void draw_earth(float angleX, float angleY) {
+    clear();
+
+    // Draw the wireframe for the sphere
+    for (int i = 0; i < SPHERE_POINTS; i++) {
+        Point2D projected = project(spherePoints[i], angleX, angleY);
+        if (projected.x >= 0 && projected.x < WIDTH && projected.y >= 0 && projected.y < HEIGHT) {
+            mvprintw(projected.y, projected.x, "o"); // Draw points for the sphere
+        }
+    }
+
+    // Draw the wireframe for the continents
+    for (int i = 0; i < CONTINENT_POINTS; i++) {
+        Point2D projected = project(continentPoints[i], angleX, angleY);
+        if (projected.x >= 0 && projected.x < WIDTH && projected.y >= 0 && projected.y < HEIGHT) {
+            mvprintw(projected.y, projected.x, "x"); // Draw points for the continents
+        }
+    }
+
+    refresh();
+}
+
+int main() {
+    initscr();            // Start ncurses
+    curs_set(0);          // Hide cursor
+    timeout(0);           // Non-blocking input
+    noecho();             // Disable character echo
+
+    // Generate sphere points and continent wireframe
+    generate_sphere();
+    generate_continents();
+
+    float angleX = 0, angleY = 0;
+    while (1) {
+        draw_earth(angleX, angleY); // Draw the rotating Earth
+        angleX += 0.01;            // Rotate around X axis
+        angleY += 0.02;            // Rotate around Y axis
+        usleep(50000);             // Delay for animation speed
+
+        int ch = getch();          // Check for user input
+        if (ch == 'q') break;      // Quit if 'q' is pressed
+    }
+
+    endwin();  // End ncurses
+    return 0;
+}
+