Update chunk rendering, improve chunk loading

- On world_init, LOAD_CHUNK amount of chunks are preloaded
- Chunks are loaded around the player's current chunk, in a square
  shape. The size of the shape is controlled by CHUNK_DISTANCE
- Allow chunks struct to be independent of a position. We load a chunk
  TO a position in the world chunk grid (x, y). This allows us to "wrap"
  chunks, so we have an endless world, but we are really just wrapping
  around

1 files changed, 28 insertions, 9 deletions

diff --git a/src/world.c b/src/world.c
index 72a0c21..41fdd17 100644
--- a/src/world.c
+++ b/src/world.c
@@ -1,29 +1,48 @@
 #include "world.h"
+#include "cglm/io.h"
+#include "chunk.h"
 #include <stdlib.h>
 #include <string.h>
 
+// LOAD_DISTANCE determines how many chunks are loaded on world creation
+#define LOAD_DISTANCE 4
+
 int world_init(int32_t seed, struct world** world) {
     srand(seed);
     struct world* wld = malloc(sizeof(struct world));
     memset(wld, 0, sizeof(struct world));
     wld->seed = seed;
     //TODO: Improve loading here
-    for (int i = 0; i < 2; i++) {
-        for (int j = 0; j < 2; j++) {
+    for (int i = 0; i < LOAD_DISTANCE; i++) {
+        for (int j = 0; j < LOAD_DISTANCE; j++) {
             struct chunk* chunk;
-            vec2 coords = { i, j };
-            chunk_gen(wld, coords, &chunk);
-            wld->chunks[i][j] = chunk;
-
+            int coords[2] = { i, j };
+            world_get_chunk(wld, coords, &chunk);
         }
     }
     *world = wld;
     return 0;
 }
 
-int world_get_chunk(struct world* world, vec2 coord, struct chunk** chunk) {
+int world_get_chunk(struct world* world, int coord[2], struct chunk** chunk) {
+    int w = ((abs(coord[0]) / WORLD_WIDTH) + 1) * WORLD_WIDTH;
+    int l = ((abs(coord[1]) / WORLD_LENGTH) + 1) * WORLD_LENGTH;
+    int x = (coord[0] + w) % WORLD_WIDTH;
+    int y = (coord[1] + l) % WORLD_LENGTH;
+    vec2 new_coord = { x, y };
+    struct chunk* c = world->chunks[x][y];
+    if (c != NULL) {
+        *chunk = c;
+    } else {
+        chunk_gen(world, new_coord, chunk);
+        world->chunks[x][y] = *chunk;
+    }
+    return 0;
+}
+
+void world_get_chunk_real_coord(struct world* world, vec2 coord, int out[2]) {
     int x = (int)coord[0] % WORLD_WIDTH;
     int y = (int)coord[1] % WORLD_LENGTH;
-    *chunk = world->chunks[x][y];
-    return 0;
+    out[0] = x;
+    out[1] = y;
 }