@@ 45,17 45,19 @@ proc clear*(c: var DebugCtx) =
     c.mesh.set_len(0)
 
 proc draw*(c: DebugCtx, mvp: var Mat4f) =
-    gl_use_program(c.prog)
-    let p = gl_map_named_buffer(c.buffer, GL_WRITE_ONLY)
-    copy_mem(p, c.mesh[0].unsafeAddr, Vec3f.sizeof * len(c.mesh))
-    discard gl_unmap_named_buffer(c.buffer)
+    if len(c.mesh) > 0:
+        gl_use_program(c.prog)
 
-    gl_bind_vertex_array(c.buffer_vao)
-    gl_bind_buffer(GL_ARRAY_BUFFER, c.buffer)
-    gl_uniform_matrix4fv(gl_get_uniform_location(c.prog, "MVP"), 1, false, mvp.caddr)
-    gl_point_size(5)
-    gl_draw_arrays(GL_LINES, 0, (len(c.mesh)).GLsizei)
-    gl_draw_arrays(GL_POINTS, 0, (len(c.mesh)).GLsizei)
+        let p = gl_map_named_buffer(c.buffer, GL_WRITE_ONLY)
+        copy_mem(p, c.mesh[0].unsafeAddr, Vec3f.sizeof * len(c.mesh))
+        discard gl_unmap_named_buffer(c.buffer)
+
+        gl_bind_vertex_array(c.buffer_vao)
+        gl_bind_buffer(GL_ARRAY_BUFFER, c.buffer)
+        gl_uniform_matrix4fv(gl_get_uniform_location(c.prog, "MVP"), 1, false, mvp.caddr)
+        gl_point_size(5)
+        gl_draw_arrays(GL_LINES, 0, (len(c.mesh)).GLsizei)
+        gl_draw_arrays(GL_POINTS, 0, (len(c.mesh)).GLsizei)
 
 proc edge*(c: var DebugCtx, vs: varargs[Vec3f]) =
     for (a, b) in zip(vs, vs[1..^1]):


@@ 63,7 65,7 @@ proc edge*(c: var DebugCtx, vs: varargs[Vec3f]) =
         c.mesh.add(b)
 
 proc sphere*(c: var DebugCtx, pos: Vec3f, radius: float32, np: uint = 8, nm: uint = 16) =
-    for j in 0..< np:
+    for j in 0 ..< np:
         let pp = PI * (j).float / np.float
         let p = PI * (j + 1).float / np.float
         let

@@ 287,6 287,8 @@ if is_main_module:
 
     var c = DefaultOpenglWindowConfig
     c.title = "game"
+    c.version = glv45
+
     var w = new_window(c)
     w.cursor_position_cb = cursor_pos_callback
     w.cursor_mode = cm_disabled


@@ 294,6 296,8 @@ if is_main_module:
     glfw.make_context_current(w)
     var debug = init_debug()
 
+    echo "Version: ", cast[cstring](gl_get_string(GL_VERSION))
+
     ###
 
     let prog = make_program((GL_VERTEX_SHADER, """

@@ 0,0 1,53 @@
+import unittest
+import glm
+import game
+import options
+import glfw
+import opengl
+import debug_draw
+
+let unit_sphere = (vec3f(0, 0, 0), vec3f(1, 1, 1)).Ellipse
+
+proc display_scene(triangle: array[3, Vec3f]) =
+    glfw.initialize()
+    load_extensions()
+
+    let width = 800
+    let height = 600
+
+
+    let proj: Mat4[float32] = perspective[float32](Pi / 4, width.float32 / height.float32, 0.1, 100)
+
+    var c = DefaultOpenglWindowConfig
+    c.title = "game"
+    var w = new_window(c)
+
+    glfw.make_context_current(w)
+
+    var debug = init_debug()
+
+    while true:
+        let cam_pos = vec3f(sin(glfw.get_time()) * 5, 2, cos(glfw.get_time()) * 5)
+        let view: Mat4[float32] = look_at(cam_pos, vec3f(0, 0, 0), vec3f(0, 1, 0))
+        var mvp = proj * view
+
+        gl_clear(GL_COLOR_BUFFER_BIT)
+        debug.sphere(unit_sphere.pos, unit_sphere.radius.x)
+        debug.edge(triangle[0], triangle[1], triangle[2], triangle[0])
+        debug.draw(mvp)
+
+        w.swap_buffers
+        poll_events()
+        if w.should_close == true or w.is_key_down(keyEscape):
+            break
+
+display_scene([vec3f(2, 2, 2), vec3f(2, 0, 2), vec3f(2, 2, 0)])
+
+suite "collision":
+    test "no collision":
+        require not check_collision(unit_sphere, vec3f(0, 0, 0), ([vec3f(2, 2, 2), vec3f(2, 0, 2), vec3f(2, 2, 0)]).Triangle).is_some()
+        require not check_collision(unit_sphere, vec3f(0, 0, 0), ([vec3f(2, 2, 2), vec3f(2, 0, 2), vec3f(2, 2, 0)]).Triangle).is_some()
+
+    test "collisions while still":
+        require check_collision(unit_sphere, vec3f(0, 0, 0), ([vec3f(0, 0, 0), vec3f(2, 0, 2), vec3f(2, 2, 0)]).Triangle).is_some()
+        require check_collision(unit_sphere, vec3f(0, 0, 0), ([vec3f(2, 2, 2), vec3f(2, 0, 2), vec3f(2, 2, 0)]).Triangle).is_some()