Add World and multi-chunk rendering

- More than 1 chunk can now be rendered with the help of the world
  struct
- Block coords are now in world space, not local space
- Engine init code cleaned up for cleaner world/chunk handling

7 files changed, 87 insertions, 21 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 34e23b2..f86a139 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -7,4 +7,5 @@ add_executable(junkcraft
     window.c
     engine.c
     chunk.c
+    world.c
 )
diff --git a/src/chunk.c b/src/chunk.c
index 77c2301..982882d 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -17,10 +17,28 @@
 
 void _chunk_plains_gen(struct chunk* chunk);
 
-int chunk_gen(struct world* world, struct chunk *chunk) {
-    // struct chunk neighbor = {0};
+int chunk_gen(struct world* world, vec2 coord, struct chunk **chunk) {
+    *chunk = malloc(sizeof(struct chunk));
+    memcpy((*chunk)->coord,coord, sizeof(vec2));
+    // struct chunk* neighbor_top = { 0 };
+    // struct chunk* neighbor_bottom = { 0 };
+    // struct chunk* neighbor_left = { 0 };
+    // struct chunk* neighbor_right = { 0 };
+    // vec2 top = { 0, 1 };
+    // vec2 bottom = { 0, -1 };
+    // vec2 left = { -1, 0 };
+    // vec2 right = { 1, 0 };
+    // glm_vec2_add(top, coord, top);
+    // glm_vec2_add(bottom, coord, bottom);
+    // glm_vec2_add(left, coord, left);
+    // glm_vec2_add(right, coord, right);
+    // world_get_chunk(world, top, &neighbor_top);
+    // world_get_chunk(world, bottom, &neighbor_bottom);
+    // world_get_chunk(world, left, &neighbor_left);
+    // world_get_chunk(world, right, &neighbor_right);
+
     // world_get_chunk(world, chunk->coord, &neighbor);
-    _chunk_plains_gen(chunk);
+    _chunk_plains_gen(*chunk);
     // switch (chunk->biome) {
     //     case JUNK_BIOME_PLAINS:
     //         _
@@ -95,13 +113,11 @@ void _chunk_plains_gen(struct chunk* chunk) {
             int z_final = (z1 + z2) / 2;
             for (int h = 0; h < z_final; h++) {
                 struct block* blk = malloc(sizeof(struct block));
-                vec3 pos = {x, h, -y - 1};
+                // Adjust block coordinates with global chunk coordinates
+                vec3 pos = {x + (CHUNK_WIDTH * chunk->coord[0]), h, -y - 1 - (CHUNK_LENGTH * chunk->coord[1])};
                 block_init(pos, blk);
                 chunk->blocks[x][y][h] = blk;
             }
         }
     }
-    fprintf(stderr, "POI Coords\n");
-    glm_vec3_print(poi1, stderr);
-    glm_vec3_print(poi2, stderr);
 }
diff --git a/src/chunk.h b/src/chunk.h
index 87c33fa..4d06f5f 100644
--- a/src/chunk.h
+++ b/src/chunk.h
@@ -1,21 +1,27 @@
 #pragma once
 #include "block.h"
 #include "world.h"
-#include "junk/vector.h"
 #include <stdint.h>
-enum biome {
-    JUNK_BIOME_PLAINS,
-};
 #define CHUNK_WIDTH 16
 #define CHUNK_LENGTH 16
 #define CHUNK_HEIGHT 128
 
+enum biome {
+    JUNK_BIOME_PLAINS,
+};
+
+
+//NOTE: Forward declare world here. There is a circular dependency between 
+// chunk and world, and the order in which compiler sees them causes issues.
+// World.c compiles -> includes world.h -> first line is include chunk.h -> struct world
+// is used here, which messes it up. Forward declare to avoid errors
+struct world;
 struct chunk {
     struct block* blocks[CHUNK_WIDTH][CHUNK_LENGTH][CHUNK_HEIGHT];
     enum biome biome;
     vec2 coord;
 };
 
-int chunk_gen(struct world* world, struct chunk* chunk);
+int chunk_gen(struct world* wld, vec2 coord, struct chunk** chunk);
 int chunk_gen_structures(void* neighbor_data, struct chunk* chunk);
 int chunk_gen_terrain(void* neighbor_data, struct chunk* chunk);
diff --git a/src/engine.c b/src/engine.c
index d8df9b3..08f4852 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -2,7 +2,11 @@
 #include "block.h"
 #include "chunk.h"
 #include "window.h"
+#include "world.h"
 #include <junk/vector.h>
+#include <time.h>
+
+void _engine_insert_chunk_ptrs(struct engine* engine, struct chunk* chunk);
 
 int engine_init(struct engine *engine) {
     // Setup the Window
@@ -27,9 +31,22 @@ int engine_init(struct engine *engine) {
     // Setup Objects to draw
     vector_init(&engine->objects);
     // Setup root chunk
-    struct chunk* chunk = malloc(sizeof(struct chunk));
-    chunk_gen(NULL, chunk);
-
+    struct world* world;
+    world_init(time(NULL), &world);
+    vec2 curr_chunk = { 0, 0 };
+    int chunk_distance = 2;
+    for (int i = 0; i < chunk_distance; i++) {
+        for (int j = 0; j  < chunk_distance; j++) {
+            struct chunk* chunk;
+            vec2 chunk_coord = { curr_chunk[0] + i, curr_chunk[1] + j };
+            world_get_chunk(world, chunk_coord, &chunk);
+            _engine_insert_chunk_ptrs(engine, chunk);
+        }
+    }
+    engine->game_loop = 1;
+    return 0;
+}
+void _engine_insert_chunk_ptrs(struct engine* engine, struct chunk* chunk) {
     int counter = 0;
     for (int i = 0; i < CHUNK_WIDTH; i++) {
         for (int j = 0; j < CHUNK_LENGTH; j++) {
@@ -44,9 +61,6 @@ int engine_init(struct engine *engine) {
             }
         }
     }
-
-    engine->game_loop = 1;
-    return 0;
 }
 
 void engine_draw(struct engine* engine) {
@@ -59,6 +73,7 @@ void engine_draw(struct engine* engine) {
             }
         }
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+        glClearColor(0.529f, 0.808f, 0.922f, 1.0f);
         glEnable(GL_DEPTH_TEST);
         //glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
         glUseProgram(engine->shader->program);
diff --git a/src/junkcraft.c b/src/junkcraft.c
index 6a12a40..4a1a96a 100644
--- a/src/junkcraft.c
+++ b/src/junkcraft.c
@@ -2,7 +2,6 @@
 #include <time.h>
 
 int main() {
-    srand(time(NULL));
     struct engine engine = { 0 };
     if (engine_init(&engine) != 0) {
         return -1;
diff --git a/src/world.c b/src/world.c
new file mode 100644
index 0000000..e81f100
--- /dev/null
+++ b/src/world.c
@@ -0,0 +1,28 @@
+#include "world.h"
+#include <stdlib.h>
+#include <string.h>
+
+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;
+    for (int i = 0; i < WORLD_WIDTH; i++) {
+        for (int j = 0; j < WORLD_LENGTH; j++) {
+            struct chunk* chunk;
+            vec2 coords = { i, j };
+            chunk_gen(wld, coords, &chunk);
+            wld->chunks[i][j] = chunk;
+
+        }
+    }
+    *world = wld;
+    return 0;
+}
+
+int world_get_chunk(struct world* world, vec2 coord, struct chunk** chunk) {
+    int x = (int)coord[0] % WORLD_WIDTH;
+    int y = (int)coord[1] % WORLD_LENGTH;
+    *chunk = world->chunks[x][y];
+    return 0;
+}
diff --git a/src/world.h b/src/world.h
index 5be1cf2..c65a1d0 100644
--- a/src/world.h
+++ b/src/world.h
@@ -3,11 +3,12 @@
 #include <stdint.h>
 #define WORLD_LENGTH 32
 #define WORLD_WIDTH 32
+
 struct world {
     struct chunk* chunks[WORLD_WIDTH][WORLD_LENGTH];
     int32_t seed;
 };
 
-int world_init(int32_t seed);
+int world_init(int32_t seed, struct world** world);
 int world_save(int32_t seed);
-int world_get_chunk(struct world* world, vec2 coord, struct chunk* chunk);
+int world_get_chunk(struct world* world, vec2 coord, struct chunk** chunk);