Use BufferSubData instead of MapBuffer

src/gl/mod.rs

@@ -668,6 +668,12 @@ impl Buffer {
         }
     }
 
+    pub fn re_set_data(&self, target: BufferTarget, data: &[u8]) {
+        unsafe {
+            gl::BufferSubData(target, 0, data.len() as isize, data.as_ptr() as *const _);
+        }
+    }
+
     /// Maps the memory in the buffer on the gpu to memory which the program
     /// can access. The access flag will specify how the program plans to use the
     /// returned data. It'll unmap itself once the returned value is dropped.

src/main.rs

@@ -211,6 +211,9 @@ fn handle_window_event(window: &glutin::Window,
         }
         Event::KeyboardInput(glutin::ElementState::Pressed, key, virt) => {
             println!("Key: {:?} {:?}", key, virt);
+            if virt == Some(VirtualKeyCode::H) {
+                game.server.world.flag_dirty_all();
+            }
         }
 
         _ => (),

src/render/mod.rs

@@ -365,8 +365,7 @@ impl Renderer {
             info.buffer_size = data.len();
             info.buffer.set_data(gl::ARRAY_BUFFER, data, gl::DYNAMIC_DRAW);
         } else {
-            let mut target = info.buffer.map(gl::ARRAY_BUFFER, gl::WRITE_ONLY, data.len());
-            target.write_all(data).unwrap();
+            info.buffer.re_set_data(gl::ARRAY_BUFFER, data);
         }
 
         self.chunk_shader.position.vertex_pointer(3, gl::FLOAT, false, 40, 0);

src/render/ui.rs

@@ -169,8 +169,7 @@ impl UIState {
                 self.prev_size = self.data.len();
                 self.buffer.set_data(gl::ARRAY_BUFFER, &self.data, gl::STREAM_DRAW);
             } else {
-                let mut target = self.buffer.map(gl::ARRAY_BUFFER, gl::WRITE_ONLY, self.data.len());
-                target.write_all(&self.data[..]).unwrap();
+                self.buffer.re_set_data(gl::ARRAY_BUFFER, &self.data);
             }
             gl::draw_elements(gl::TRIANGLES, self.count, self.index_type, 0);
         }