+void vg_start(void)
+{
+ glGenVertexArrays( 1, &world.tile_vao );
+ glGenBuffers( 1, &world.tile_vbo );
+
+ float quad_mesh[] =
+ {
+ 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f,
+ 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f
+ };
+
+ glBindVertexArray( world.tile_vao );
+ glBindBuffer( GL_ARRAY_BUFFER, world.tile_vbo );
+ glBufferData
+ (
+ GL_ARRAY_BUFFER,
+ sizeof( quad_mesh ),
+ quad_mesh,
+ GL_STATIC_DRAW
+ );
+
+ glVertexAttribPointer( 0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0 );
+ glEnableVertexAttribArray( 0 );
+
+ VG_CHECK_GL();
+}
+
+void vg_free(void)
+{
+ glDeleteVertexArrays( 1, &world.tile_vao );
+ glDeleteBuffers( 1, &world.tile_vbo );
+}
+
+void vg_update(void)
+{
+ float ratio = (float)vg_window_y / (float)vg_window_x;
+ float const size = 7.5f;
+
+ m3x3_projection( m_projection, -size, size, size*ratio, -size*ratio );
+ m3x3_identity( m_view );
+ m3x3_mul( m_projection, m_view, vg_pv );
+ vg_projection_update();
+}