Add chunk_unloading on chunk Changes

If we change a chunk, unload all chunks. This removes block GPU data
(vbo, ebo, vao). We anyways redraw so we don't lose anything

5 files changed, 61 insertions, 13 deletions

diff --git a/src/block.c b/src/block.c
index 2197b2a..56db3f4 100644
--- a/src/block.c
+++ b/src/block.c
@@ -22,6 +22,12 @@ int block_init(vec3 pos, struct block* blk) {
     // Store buffer data into struct
     // Initialize vbo and ebo for block
     memcpy(blk->coords, pos, sizeof(vec3));
+    block_load_gpu(blk);
+    block_update(blk);
+    return 0;
+}
+
+void block_load_gpu(struct block* blk) {
     // ========== Constants of a block ================
     // Local world coordinates
     float vertices[] = {
@@ -122,8 +128,6 @@ int block_init(vec3 pos, struct block* blk) {
     //call is create_vbo. Since VAO is already bound, it gets bound to the OLD
     //VAO!! Always clear before use. 
     glBindVertexArray(0);
-    block_update(blk);
-    return 0;
 }
 
 void block_update(struct block* blk) {
@@ -172,3 +176,12 @@ void block_debug(struct block *blk) {
     glm_mat4_print(blk->model, stderr);
 
 }
+
+void block_unload(struct block *blk) {
+    // Clear VBO data
+    glDeleteBuffers(1, &blk->_vbo);
+    // Clear EBO data
+    glDeleteBuffers(1, &blk->_ebo);
+    // Clear VAO
+    glDeleteVertexArrays(1, &blk->_vao);
+}
diff --git a/src/block.h b/src/block.h
index b19265d..f55f784 100644
--- a/src/block.h
+++ b/src/block.h
@@ -24,3 +24,13 @@ int block_init(vec3 pos, struct block* blk);
 int block_draw(struct block* blk, struct shader* shader);
 void block_debug(struct block* blk);
 void block_update(struct block* blk);
+
+/**
+ * Remove GPU related data of a block. This is usually called by chunk_unload
+ *
+ */
+void block_unload(struct block* blk);
+/**
+ * Load GPU data of a block
+ */
+void block_load_gpu(struct block* blk);
diff --git a/src/chunk.c b/src/chunk.c
index 4d15486..4918d22 100644
--- a/src/chunk.c
+++ b/src/chunk.c
@@ -114,6 +114,7 @@ void _chunk_plains_gen(struct chunk* chunk) {
             }
         }
     }
+    chunk->loaded = 1;
 }
 
 
@@ -125,16 +126,25 @@ void chunk_load(struct chunk *chunk, int coord[2]) {
             for (int z = 0; z < CHUNK_LENGTH; z++) {
                 struct block* blk = chunk->blocks[x][z][y];
                 if (blk != NULL) {
-                // Translate to world coordinates
-                // First do block updates, set the position of the block in local 
-                // chunk coordinates
-                 block_update(blk);
-                 // Then translate them to world coordinates
-                 glm_translate(blk->model, translation);
+                    // If chunk is unloaded, send block data to GPU
+                    if (chunk->loaded == 0) {
+                        // Add GPU data
+                        block_load_gpu(blk);
+                    }
+                    // Translate to world coordinates
+                    // First do block updates, set the position of the block in local 
+                    // chunk coordinates
+                    block_update(blk);
+                    // Then translate them to world coordinates
+                    glm_translate(blk->model, translation);
                 }
             }
         }
     }
+    if (chunk->loaded == 0) {
+        //We've reloaded all data - flip bit again
+        chunk->loaded = 1;
+    }
 }
 
 void chunk_draw(struct chunk* chunk, struct shader* shader) {
@@ -154,4 +164,17 @@ void chunk_draw(struct chunk* chunk, struct shader* shader) {
 }
 
 void chunk_unload(struct chunk* chunk) {
+    for (int i = 0; i < CHUNK_WIDTH; i++) {
+        for (int j = 0; j < CHUNK_LENGTH; j++) {
+            for (int k = 0; k < CHUNK_HEIGHT; k++) {
+                struct block* blk = chunk->blocks[i][j][k];
+                if (blk == NULL) {
+                    continue;
+                }
+                block_unload(blk);
+            }
+        }
+    }
+    chunk->loaded = 0;
+
 }
diff --git a/src/chunk.h b/src/chunk.h
index ac24a2d..0122cf9 100644
--- a/src/chunk.h
+++ b/src/chunk.h
@@ -20,6 +20,7 @@ struct chunk {
     struct block* blocks[CHUNK_WIDTH][CHUNK_LENGTH][CHUNK_HEIGHT];
     enum biome biome;
     vec2 coord;
+    int loaded;
 };
 
 /**
@@ -38,7 +39,7 @@ int chunk_gen(struct world* wld, vec2 coord, struct chunk** chunk);
  */
 void chunk_load(struct chunk* chunk, int coord[2]);
 /**
- * Unload a chunk. Delete GPU data, not the chunk data itself
+ * Unload a chunk. Delete block GPU and memory data, not the chunk data itself
  *
  * @param chunk Chunk to load
  */
diff --git a/src/engine.c b/src/engine.c
index 2d509f3..b840a2f 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -63,9 +63,7 @@ void engine_update(struct engine* engine) {
                 engine->curr_chunk[1],
                 curr_chunk[0],
                 curr_chunk[1]);
-        // Update the curr_chunk
-        memcpy(engine->curr_chunk, curr_chunk, sizeof(vec2));
-        // Load chunks of CHUNK_DISTANCE around curr_chunk
+        // Unload existing chunks
         for (int i = -CHUNK_DISTANCE; i <= CHUNK_DISTANCE; i++) {
             for (int j = -CHUNK_DISTANCE; j  <= CHUNK_DISTANCE; j++) {
                 struct chunk* chunk;
@@ -75,9 +73,12 @@ void engine_update(struct engine* engine) {
                 int real_coord[2] = { i + CHUNK_DISTANCE, j + CHUNK_DISTANCE };
                 // engine->loaded_chunks[real_coord[0]][real_coord[1]] = chunk;
                 // Load chunk
-                chunk_load(chunk, chunk_coord);
+                chunk_unload(chunk);
             }
         }
+        // Update the curr_chunk
+        memcpy(engine->curr_chunk, curr_chunk, sizeof(vec2));
+        // Load chunks of CHUNK_DISTANCE around curr_chunk
     }
 }