this seems to be causing glitches

This reverts commit 3a713dd1ed.

Revert "this seems to be causing glitches"

This reverts commit ffda7fd4552dc11b6240332195e603e012d740b0.

Revert "vao changes"

This reverts commit 60e38616bd.

openglgeometrybank.h

@@ -164,7 +164,8 @@ public:
     static
     void
         reset() {
-            m_activebuffer = 0; }
+            m_activebuffer = 0;
+            m_activestreams = stream::none; }
 
 private:
 // types:
@@ -198,6 +199,7 @@ private:
 
 // members:
     static GLuint m_activebuffer; // buffer bound currently on the opengl end, if any
+    static unsigned int m_activestreams;
     GLuint m_buffer { NULL }; // id of the buffer holding data on the opengl end
 	GLuint m_vao = 0;
     std::size_t m_buffercapacity{ 0 }; // total capacity of the last established buffer
@@ -205,6 +207,48 @@ private:
 
 };
 
+// opengl display list based variant of the geometry bank
+
+class opengl_dlgeometrybank : public geometry_bank {
+
+public:
+// constructors:
+    opengl_dlgeometrybank() = default;
+// destructor:
+    ~opengl_dlgeometrybank() {
+        for( auto &chunkrecord : m_chunkrecords ) {
+            ::glDeleteLists( chunkrecord.list, 1 ); } }
+
+private:
+// types:
+    struct chunk_record {
+        GLuint list { 0 }; // display list associated with the chunk
+        unsigned int streams { 0 }; // stream combination used to generate the display list
+    };
+
+    typedef std::vector<chunk_record> chunkrecord_sequence;
+
+// methods:
+    // create() subclass details
+    void
+        create_( geometry_handle const &Geometry );
+    // replace() subclass details
+    void
+        replace_( geometry_handle const &Geometry );
+    // draw() subclass details
+    void
+        draw_( geometry_handle const &Geometry, unsigned int const Streams );
+    // release () subclass details
+    void
+        release_();
+    void
+        delete_list( geometry_handle const &Geometry );
+
+// members:
+    chunkrecord_sequence m_chunkrecords; // helper data for all stored geometry chunks, in matching order
+
+};
+
 // geometry bank manager, holds collection of geometry banks
 
 typedef geometry_handle geometrybank_handle;