More things. So many things.

src/gen.c

@@ -1,6 +1,7 @@
 #include "include/gen.h"
 #include "include/geom.h"
 
+#include <stddef.h>
 #include <stdlib.h>
 #include <time.h>
 
@@ -33,9 +34,91 @@ void gen_asth() {
     }
 }
 
+size_t* min_idx(int* a, size_t n, size_t* out_n) {
+    if (!a || n == 0) return NULL;
+
+    int min_val = a[0];
+    for (size_t i = 1; i < n; i++) {
+        if (a[i] < min_val) min_val = a[i];
+    }
+
+    size_t o = 0;
+    for (size_t i = 0; i < n; i++) {
+        if (a[i] == min_val) o++;
+    }
+
+    size_t* idxs = malloc(o * sizeof(size_t));
+    if (!idxs) {
+        *out_n = 0;
+        return NULL;
+    }
+
+    size_t k = 0;
+    for (size_t i = 0; i < n; i++) {
+        if (a[i] == min_val) idxs[k++] = i;
+    }
+
+    *out_n = o;
+    return idxs;
+}
+
 void gen_lith() {
     srand(time(NULL));
 
+    Pt centers[NPLATES]; // The centers of each plate to be generated.
+
+    // Generate random plate centers.
+    for (int i = 0; i < NPLATES; i++) {
+        Pt p = (Pt){rand() % WORLD_SZ, rand() % WORLD_SZ};
+        centers[i] = p;
+    }
+
+    Pt* plareas[NPLATES];
+    int plareas_count[NPLATES];
+
+    for (int i = 0; i < NPLATES; i++) {
+        plareas[i] = (Pt*)malloc(
+            WORLD_SZ * WORLD_SZ * sizeof(Pt)
+        );                    // Points in the plate area.
+        plareas_count[i] = 0; // Number of points added to the plate area.
+    }
+
+    for (int y = 0; y < WORLD_SZ; y++) {
+        for (int x = 0; x < WORLD_SZ; x++) {
+            Pt pt = (Pt){x, y};
+            int distances[NPLATES]; // Distances from each plate to the current
+                                    // point.
+            for (int i = 0; i < NPLATES; i++) {
+                distances[i] = pt_cmp(&pt, &centers[i]);
+            }
+
+            size_t n;
+            size_t* idxs = min_idx(
+                distances, NPLATES, &n
+            ); // The index(es) of the closest plate(s) in the centers array.
+
+            for (int i = 0; i < n; i++) {
+                plareas[idxs[i]][plareas_count[idxs[i]]++] = pt;
+            }
+        }
+    }
+
+    Pt* plhulls[NPLATES];          // The convex hulls of each plate.
+    size_t plhulls_count[NPLATES]; // The number of points in each hull.
+
+    for (int i = 0; i < NPLATES; i++) {
+        size_t count;
+        plhulls[i] = cvx_hull(plareas[i], plareas_count[i], &count);
+        plhulls_count[i] = count;
+    }
+
+    Plate pls[NPLATES];
+
+    for (int i = 0; i < NPLATES; i++) {
+        Tri* tris = malloc(plhulls_count[i] / 3 + 2);
+        tris[0] = (Tri){plhulls[i][0], plhulls[i][1], plhulls[i][2]};
+    }
+
     Tri* tri1 = tri_init((Pt){0, 0}, (Pt){0, 7}, (Pt){7, 0});
     Tri* tri2 = tri_init((Pt){7, 0}, (Pt){0, 7}, (Pt){7, 7});