1 files changed, 81 insertions, 3 deletions

diff --git a/src/rendering/src/rendering.c b/src/rendering/src/rendering.c
index 9f13998..26805c8 100644
--- a/src/rendering/src/rendering.c
+++ b/src/rendering/src/rendering.c
@@ -196,7 +196,7 @@ ShaderBuffer* shaderbuffer_cat(ShaderBuffer* dst, ShaderBuffer *restrict src) {
   // Verify the size
   const usize sz_src = src->size_elem * src->count;
   const usize sz_dst = dst->size_elem * dst->count;
-  if (sz_src + sz_dst >= dst->size) {
+  if (dst->data == NULL || sz_dst + sz_src >= dst->size) {
     const usize sz_new = (1 + ((sz_src + sz_dst) / 4096)) * 4096;
     // Resize dst size
     dst->data = realloc(dst->data, sz_new);
@@ -253,7 +253,6 @@ i32 renderbatch_add(RenderBatch* renderbatch, RenderObject* obj) {
 
       // Copy meta data
       renderbatch->renderobj.buffer[i].components = obj->buffer[i].components;
-      renderbatch->renderobj.buffer[i].buffertype = obj->buffer[i].buffertype;
       renderbatch->renderobj.buffer[i].size_elem = obj->buffer[i].size_elem;
 
       renderbatch->renderobj.buffer[i].data = malloc(newsz);
@@ -290,7 +289,86 @@ i32 renderbatch_add(RenderBatch* renderbatch, RenderObject* obj) {
 }
 
 i32 renderbatch_add_ext(RenderBatch* renderbatch, RenderObject* obj, Transform* t) {
-  return -1;
+  // Check if its a valid renderbatch
+  if (renderbatch == NULL) {
+    ERROR("renderbatch was null!");
+    return -1;
+  }
+
+  // Check whether we have initialized models & instance memory
+  if (renderbatch->models == NULL) {
+    const usize sz = 8 * sizeof(RenderObject*);
+    renderbatch->models = calloc(8, sizeof(RenderObject*));
+    renderbatch->msize = sz;
+    renderbatch->mcount = 0;
+  }
+
+  if (renderbatch->instances == NULL) {
+    // Allocate enough for 4 times the models
+    const usize modelbufsz = renderbatch->msize / sizeof(RenderObject*);
+    const usize sz = 4 * modelbufsz * sizeof(BatchModelInstance);
+    renderbatch->instances = calloc(4 * modelbufsz, sizeof(BatchModelInstance));
+    renderbatch->inst_size = sz;
+    renderbatch->inst_count = 0;
+  }
+
+  // The index of the model
+  isize model_idx = -1;
+
+  // Find the model, to check if it already exists
+  for (usize i = 0; i < renderbatch->mcount; i++) {
+    // Compare the model pointers
+    if (obj == renderbatch->models[i]) {
+      model_idx = (isize)i;
+      break;
+    }
+  }
+
+  // Model doesn't exist, add it
+  if (-1 == model_idx) {
+    // Check if there's room enough
+    if ((1 + renderbatch->mcount) * sizeof(RenderObject*) > renderbatch->msize) {
+      // Realloc if necessary
+      const usize sz = renderbatch->msize * 2;
+      renderbatch->models = realloc(renderbatch->models, sz);
+      renderbatch->msize = sz;
+    }
+
+    // If this is the first model, we want to copy the renderobj, and
+    // shaderbuffer parameters.
+    if (renderbatch->mcount == 0) {
+      // Shader, VAO, modelviewprojection, and texture, are set when the shaderobj
+      // is actually created with RenderObject_new later.
+      // The number of buffers should be the same.
+      renderbatch->renderobj.buffer_len = obj->buffer_len;
+      if (renderbatch->renderobj.buffer == NULL) {
+        renderbatch->renderobj.buffer = calloc(obj->buffer_len, sizeof(ShaderBuffer));
+      } else {
+        ERROR("RenderObj buffer is already initialized!");
+        return -1;
+      }
+
+      // Copy each buffers parameters
+      for (usize i = 0; i < renderbatch->renderobj.buffer_len; i++) {
+        renderbatch->renderobj.buffer[i].buffername = 0;
+        renderbatch->renderobj.buffer[i].buffertype = obj->buffer[i].buffertype;
+        // Size and count should be zero
+
+        renderbatch->renderobj.buffer[i].components = obj->buffer[i].components;
+        renderbatch->renderobj.buffer[i].size_elem = obj->buffer[i].size_elem;
+        // Data should also be null
+      }
+    }
+
+    // Concatenate the buffers
+    for (usize i = 0; i < renderbatch->renderobj.buffer_len; i++) {
+      shaderbuffer_cat(&renderbatch->renderobj.buffer[i], &obj->buffer[i]);
+    }
+  }
+
+  renderbatch->models[renderbatch->mcount++] = obj;
+
+  return (i32)renderbatch->mcount - 1;
 }
 
 // renderbatch_refresh: Copy all models in the renderbatch to the batchs' model.