From 2f9bccc348d6ab3d71fb9f126de108a4ae6e97ce Mon Sep 17 00:00:00 2001
From: Brett <brettmaster1@gmail.com>
Date: Mon, 8 Jan 2024 21:29:39 -0500
Subject: [PATCH] way of accessing and binding shared references. normal vbo
 now returns a shared_ptr which can be used in place of a vbo_t

---
 include/blt/gfx/model.h |  9 +++++++--
 src/blt/gfx/model.cpp   | 19 +++++++++++++++----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/include/blt/gfx/model.h b/include/blt/gfx/model.h
index 7036f99..79383bb 100644
--- a/include/blt/gfx/model.h
+++ b/include/blt/gfx/model.h
@@ -85,9 +85,10 @@ namespace blt::gfx
      */
     class static_dynamic_array
     {
+        public:
+            using vbo_type = std::shared_ptr<vbo_t_owner>;
         private:
             static constexpr size_t DATA_SIZE = 8;
-            using vbo_type = std::shared_ptr<vbo_t_owner>;
             using array_t = std::array<vbo_type, DATA_SIZE>;
             std::variant<array_t, vbo_type*> data_;
             size_t size_ = DATA_SIZE;
@@ -130,6 +131,8 @@ namespace blt::gfx
             static_dynamic_array VBOs;
             HASHSET<GLuint> used_attributes;
             vbo_t element;
+            
+            void handle_vbo(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset);
         public:
             vertex_array();
             
@@ -150,8 +153,10 @@ namespace blt::gfx
              * @param stride how many bytes this data takes (for the entire per-vertex data structure) 0 will assume packed data
              *               This is in effect how many bytes until the next block of data
              * @param offset offset into the data structure to where the data is stored
+             * @return a shared pointer to the stored vbo. used for chaining VAOs with multiple shared VBOs
              */
-            void bindVBO(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset);
+            static_dynamic_array::vbo_type bindVBO(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset);
+            void bindVBO(const static_dynamic_array::vbo_type& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset);
             
             inline void bindElement(const vbo_t& vbo)
             {
diff --git a/src/blt/gfx/model.cpp b/src/blt/gfx/model.cpp
index 89eacff..c695b32 100644
--- a/src/blt/gfx/model.cpp
+++ b/src/blt/gfx/model.cpp
@@ -130,7 +130,21 @@ namespace blt::gfx
         glDeleteVertexArrays(1, &vaoID);
     }
     
-    void vertex_array::bindVBO(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset)
+    static_dynamic_array::vbo_type vertex_array::bindVBO(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride,
+                                                         long offset)
+    {
+        handle_vbo(vbo, attribute_number, coordinate_size, type, stride, offset);
+        VBOs[attribute_number] = std::make_shared<vbo_t_owner>(vbo);
+        return VBOs[attribute_number];
+    }
+    
+    void vertex_array::bindVBO(const static_dynamic_array::vbo_type& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset)
+    {
+        handle_vbo(vbo->vbo, attribute_number, coordinate_size, type, stride, offset);
+        VBOs[attribute_number] = vbo;
+    }
+    
+    void vertex_array::handle_vbo(const vbo_t& vbo, int attribute_number, int coordinate_size, GLenum type, int stride, long offset)
     {
         used_attributes.insert(attribute_number);
         bind();
@@ -138,9 +152,6 @@ namespace blt::gfx
         
         glVertexAttribPointer(attribute_number, coordinate_size, type, GL_FALSE, stride < 0 ? 0 : stride, (void*) offset);
         glEnableVertexAttribArray(attribute_number);
-        
-        VBOs[attribute_number] = std::make_shared<vbo_t_owner>(vbo);
-        
         unbind();
     }
 }
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