Implement spritebatch properly.

src/duskgl/display/mesh/meshgl.h

@@ -18,9 +18,10 @@ typedef enum {
 typedef struct {
   int32_t vertexCount;
   meshprimitivetypegl_t primitiveType;
+  const meshvertex_t *vertices;
   
   #ifdef DUSK_OPENGL_LEGACY
-    const meshvertex_t *vertices;
+    // Nothing needed
   #else
     GLuint vaoId;
     GLuint vboId;
@@ -43,6 +44,20 @@ errorret_t meshInitGL(
   const meshvertex_t *vertices
 );
 
+/**
+ * Flushes the vertices (stored in memory) to the GPU.
+ * 
+ * @param mesh Mesh to flush vertices for.
+ * @param vertOffset First vertice index to flush.
+ * @param vertCount Count of vertices to flush.
+ * @return Error state.
+ */
+errorret_t meshFlushGL(
+  meshgl_t *mesh,
+  const int32_t vertOffset,
+  const int32_t vertCount
+);
+
 /**
  * Draws a mesh using OpenGL.
  *