feat(engine): add using element buffers

1 files changed, 24 insertions, 5 deletions

diff --git a/engine/src/opengl/vertex_array.rs b/engine/src/opengl/vertex_array.rs
index ba2ded2..6b6065c 100644
--- a/engine/src/opengl/vertex_array.rs
+++ b/engine/src/opengl/vertex_array.rs
@@ -1,6 +1,6 @@
 use std::mem::size_of;
 
-use crate::opengl::buffer::Buffer;
+use crate::opengl::buffer::{ArrayKind as ArrayBufferKind, Buffer};
 use crate::opengl::currently_bound::CurrentlyBound;
 use crate::vertex::{Attribute, AttributeComponentType, Vertex};
 
@@ -26,11 +26,11 @@ impl VertexArray
     }
 
     /// Draws the currently bound vertex array.
-    pub fn draw(
+    pub fn draw_arrays(
         _currently_bound: &CurrentlyBound<Self>,
         primitive_kind: PrimitiveKind,
         start_index: u32,
-        index_cnt: u32,
+        cnt: u32,
     )
     {
         unsafe {
@@ -38,14 +38,33 @@ impl VertexArray
             gl::DrawArrays(
                 primitive_kind.into_gl(),
                 start_index as gl::types::GLint,
-                index_cnt as gl::types::GLsizei,
+                cnt as gl::types::GLsizei,
+            );
+        }
+    }
+
+    /// Draws the currently bound vertex array.
+    pub fn draw_elements(
+        _currently_bound: &CurrentlyBound<Self>,
+        primitive_kind: PrimitiveKind,
+        offset: u32,
+        cnt: u32,
+    )
+    {
+        unsafe {
+            #[allow(clippy::cast_possible_wrap)]
+            gl::DrawElements(
+                primitive_kind.into_gl(),
+                cnt as gl::types::GLsizei,
+                gl::UNSIGNED_INT,
+                (offset as gl::types::GLint) as *const _,
             );
         }
     }
 
     pub fn configure_attrs(
         _currently_bound: &CurrentlyBound<Self>,
-        _vert_buf_curr_bound: &CurrentlyBound<Buffer<Vertex>>,
+        _vert_buf_curr_bound: &CurrentlyBound<Buffer<Vertex, ArrayBufferKind>>,
     )
     {
         let mut offset = 0;