environment basic stuff untested

environment.c

@@ -0,0 +1,102 @@
+#include "c-colours/colours.h"
+#include "datastructures/datatypes.h"
+#include "vect.h"
+
+#define ROOM_WIDTH 2000
+
+enum {
+    E_ROOM_WIDTH = 2000,
+    E_ROOM_RES = 30,
+    E_ROOM_TILES = E_ROOM_WIDTH / E_ROOM_RES,
+};
+
+struct environment {
+    int level;
+    Vect position;
+    ArrayList ceil;
+    ArrayList floor;
+    ArrayList bg1;
+    ArrayList bg2;
+    ArrayList colours;
+};
+
+double linear_interpolate(double a0, double a1, double w) {
+    return (1.0f - w) * a0 + w * a1;
+}
+
+double perlin(Vect coordinate) {
+    Vect a = coordinate;
+    Vect b = coordinate;
+    a.x = (int)a.x;
+    a.y = (int)a.y;
+    b.x = a.x + 1;
+    b.y = a.y + 1;
+
+    double sx = coordinate.x - a.x;
+    double sy = coordinate.y - a.y;
+
+    Vect d = b;
+    d.y = a.y;
+
+    double n0 = vect_dot(a, coordinate);
+    double n1 = vect_dot(d, coordinate);
+
+    double ix0 = linear_interpolate(n0, n1, sx);
+
+    Vect c;
+    c.x = a.x;
+    c.y = b.y;
+
+    n0 = vect_dot(c, coordinate);
+    n1 = vect_dot(b, coordinate);
+    double ix1 = linear_interpolate(n0, n1, sy);
+
+    return linear_interpolate(ix0, ix1, sy);
+}
+
+ArrayList get_colours(int seed) {
+    struct colour base = get_random_color(seed);
+    struct colour *adj = get_adjacent(base, 20, 4);
+    ArrayList l = new_arlst_wfree(4, free);
+
+    for (int i = 0; i < 4; i++) {
+        arlst_add(&l, adj + i);
+    }
+
+    return l;
+}
+
+
+struct environment get_scene_at(Vect coordinate, int seed) {
+    // basic cache for the last room generated
+    static Vect last_room;
+    static struct environment e;
+    Vect room_coord;
+    room_coord.x = (int)coordinate.x - (int)coordinate.x % ROOM_WIDTH;
+    room_coord.y = 0;
+    if (room_coord.x == last_room.x) {
+        return e;
+    }
+    last_room = room_coord;
+
+    e.floor = new_arlst_wfree(E_ROOM_TILES, free);
+    e.ceil = new_arlst_wfree(E_ROOM_TILES, free);
+    e.bg1 = new_arlst_wfree(E_ROOM_TILES, free);
+    e.bg2 = new_arlst_wfree(E_ROOM_TILES, free);
+    e.colours = get_colours(seed);
+
+    Vect bit;
+    bit.y = 100 * seed;
+
+    for (int i = 0; i < E_ROOM_TILES; i += E_ROOM_RES) {
+        bit.x = room_coord.x + i;
+        double *z = malloc(sizeof(double));
+        *z = perlin(bit);
+        arlst_add(&e.floor, z);
+        arlst_add(&e.ceil, z + 90);
+        arlst_add(&e.bg1, z + 20);
+        arlst_add(&e.bg2, z + 70);
+    }
+
+    return e;
+}