Display two not textured triangles in 3D with camera with horizontal rotation

Thanks to `glium/examples/teapot` which was loading an OBJ and not having any rotation for the camera.

src/support/mod.rs

@@ -0,0 +1,132 @@
+#![allow(dead_code)]
+use glium::glutin::event::{Event, StartCause};
+use glium::glutin::event_loop::{ControlFlow, EventLoop};
+use glium::vertex::VertexBufferAny;
+use glium::{self, Display};
+use std::time::{Duration, Instant};
+
+pub mod camera;
+
+pub enum Action {
+    Stop,
+    Continue,
+}
+
+pub fn start_loop<F>(event_loop: EventLoop<()>, mut callback: F) -> !
+where
+    F: 'static + FnMut(&Vec<Event<'_, ()>>) -> Action,
+{
+    let mut events_buffer = Vec::new();
+    let mut next_frame_time = Instant::now();
+    event_loop.run(move |event, _, control_flow| {
+        let run_callback = match event.to_static() {
+            Some(Event::NewEvents(cause)) => match cause {
+                StartCause::ResumeTimeReached { .. } | StartCause::Init => true,
+                _ => false,
+            },
+            Some(event) => {
+                events_buffer.push(event);
+                false
+            }
+            None => {
+                // Ignore this event.
+                false
+            }
+        };
+
+        let action = if run_callback {
+            let action = callback(&events_buffer);
+            next_frame_time = Instant::now() + Duration::from_nanos(16666667);
+            // TODO: Add back the old accumulator loop in some way
+
+            events_buffer.clear();
+            action
+        } else {
+            Action::Continue
+        };
+
+        match action {
+            Action::Continue => {
+                *control_flow = ControlFlow::WaitUntil(next_frame_time);
+            }
+            Action::Stop => *control_flow = ControlFlow::Exit,
+        }
+    })
+}
+
+/// Returns a vertex buffer that should be rendered as `TrianglesList`.
+pub fn load_ground(display: &Display) -> VertexBufferAny {
+    #[derive(Copy, Clone)]
+    struct Vertex {
+        position: [f32; 3],
+        normal: [f32; 3],
+        texture: [f32; 2],
+    }
+
+    implement_vertex!(Vertex, position, normal, texture);
+
+    let mut vertex_data = Vec::new();
+
+    vertex_data.push(Vertex {
+        position: [0.0, 0.0, 0.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    vertex_data.push(Vertex {
+        position: [1.0, 0.0, 0.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    vertex_data.push(Vertex {
+        position: [0.0, 0.0, 1.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    vertex_data.push(Vertex {
+        position: [1.0, 0.0, 0.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    vertex_data.push(Vertex {
+        position: [0.0, 0.0, 1.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    vertex_data.push(Vertex {
+        position: [1.0, 0.0, 1.0],
+        normal: [0.0, 0.0, 1.0],
+        texture: [0.0, 0.0],
+    });
+
+    /*for object in data.objects.iter() {
+        for polygon in object.groups.iter().flat_map(|g| g.polys.iter()) {
+            match polygon {
+                obj::SimplePolygon(indices) => {
+                    for v in indices.iter() {
+                        let position = data.position[v.0];
+                        let texture = v.1.map(|index| data.texture[index]);
+                        let normal = v.2.map(|index| data.normal[index]);
+
+                        let texture = texture.unwrap_or([0.0, 0.0]);
+                        let normal = normal.unwrap_or([0.0, 0.0, 0.0]);
+
+                        vertex_data.push(Vertex {
+                            position,
+                            normal,
+                            texture,
+                        })
+                    }
+                }
+            }
+        }
+    }*/
+
+    glium::vertex::VertexBuffer::new(display, &vertex_data)
+        .unwrap()
+        .into()
+}