Start to rig stuff for the aerodynamics test I wanted to make in the first place

src/bin/pumpkin.rs

@@ -32,6 +32,7 @@ where V: Into <Vec3>
 	))
 }
 
+// TODO: Use iota macro
 const KEY_LEFT: usize = 0;
 const KEY_RIGHT: usize = KEY_LEFT + 1;
 const KEY_UP: usize = KEY_RIGHT + 1;
@@ -60,41 +61,79 @@ impl ControllerState {
 	}
 }
 
+struct EulerAngles {
+	pub azimuth: f32,
+	pub altitude: f32,
+}
+
+impl Default for EulerAngles {
+	fn default () -> Self {
+		Self {
+			azimuth: 0.0,
+			altitude: 0.0,
+		}
+	}
+}
+
+impl EulerAngles {
+	pub fn to_vec3 (&self) -> Vec3 {
+		let alt = self.altitude * std::f32::consts::PI / 180.0;
+		let azi = self.azimuth * std::f32::consts::PI / 180.0;
+		
+		let z = alt.sin ();
+		let xy_len = alt.cos ();
+		
+		let x = xy_len * azi.sin ();
+		let y = xy_len * azi.cos ();
+		
+		(x, y, z).into ()
+	}
+}
+
 struct WorldState {
-	azimuth: f32,
+	camera: EulerAngles,
-	altitude: f32,
+	wind: EulerAngles,
 	spin_speed: i32,
 }
 
 impl WorldState {
 	pub fn new () -> Self {
 		Self {
-			azimuth: 0.0,
+			camera: Default::default (),
-			altitude: 0.0,
+			wind: Default::default (),
 			spin_speed: 0,
 		}
 	}
 	
-	pub fn step (&mut self, controller: &ControllerState) {
+	pub fn step (
+		&mut self, 
+		controller: &ControllerState,
+		user_control: &UserControl
+	) {
 		const SPIN_RAMP_TIME: i32 = 30;
 		
 		let spin_f = 4.0 * self.spin_speed as f32 / SPIN_RAMP_TIME as f32;
 		
+		let controlled_angle = match user_control {
+			UserControl::Camera => &mut self.camera,
+			UserControl::Wind => &mut self.wind,
+		};
+		
 		if controller.is_pressed (KEY_LEFT) {
 			self.spin_speed = std::cmp::min (self.spin_speed + 1, SPIN_RAMP_TIME);
-			self.azimuth += spin_f;
+			controlled_angle.azimuth += spin_f;
 		}
 		else if controller.is_pressed (KEY_RIGHT) {
 			self.spin_speed = std::cmp::min (self.spin_speed + 1, SPIN_RAMP_TIME);
-			self.azimuth -= spin_f;
+			controlled_angle.azimuth -= spin_f;
 		}
 		else if controller.is_pressed (KEY_UP) {
 			self.spin_speed = std::cmp::min (self.spin_speed + 1, SPIN_RAMP_TIME);
-			self.altitude = f32::min (90.0, self.altitude + spin_f);
+			controlled_angle.altitude = f32::min (90.0, controlled_angle.altitude + spin_f);
 		}
 		else if controller.is_pressed (KEY_DOWN) {
 			self.spin_speed = std::cmp::min (self.spin_speed + 1, SPIN_RAMP_TIME);
-			self.altitude = f32::max (-90.0, self.altitude - spin_f);
+			controlled_angle.altitude = f32::max (-90.0, controlled_angle.altitude - spin_f);
 		}
 		else {
 			self.spin_speed = 0;
@@ -145,11 +184,13 @@ where P: AsRef <std::path::Path>
 struct Arrow {
 	origin: Vec3,
 	direction: Vec3,
+	color: Vec3,
 }
 
 struct RenderableArrow {
 	model_mat: Mat4,
 	inv_model_mat: Mat4,
+	color: Vec3,
 }
 
 #[derive (Copy, Clone, PartialEq, Eq)]
@@ -233,6 +274,37 @@ impl From <StencilFunc> for u32 {
 	}
 }
 
+#[derive (Copy, Clone, PartialEq, Eq)]
+pub enum DepthFunc {
+	Never, 
+	Always, 
+	Less, 
+	LessEqual, 
+	Equal, 
+	Greater, 
+	GreaterEqual,
+	NotEqual,
+}
+
+impl From <DepthFunc> for u32 {
+	fn from (v: DepthFunc) -> Self {
+		use DepthFunc::*;
+		{
+		use gl::*;
+		match v {
+			Never => NEVER,
+			Always => ALWAYS,
+			Less => LESS,
+			LessEqual => LEQUAL,
+			Equal => EQUAL,
+			Greater => GREATER,
+			GreaterEqual => GEQUAL,
+			NotEqual => NOTEQUAL,
+		}
+		}
+	}
+}
+
 #[derive (Copy, Clone, PartialEq, Eq)]
 pub struct StencilOpState {
 	sfail: StencilOp,
@@ -257,9 +329,12 @@ pub struct StencilState {
 // to safely use the flags / numbers
 
 pub struct IsoGlState {
+	shader_id: Option <u32>,
+	
 	flags: HashMap <u32, bool>,
 	front_face: Option <FrontFace>,
 	stencil: Option <StencilState>,
+	depth_func: Option <DepthFunc>,
 	
 	color_mask: Option <(u8, u8, u8, u8)>,
 	depth_mask: Option <u8>,
@@ -269,9 +344,11 @@ pub struct IsoGlState {
 impl std::default::Default for IsoGlState {
 	fn default () -> Self {
 		Self {
+			shader_id: None,
 			flags: hashmap! {},
 			front_face: None,
 			stencil: None,
+			depth_func: None,
 			color_mask: None,
 			depth_mask: None,
 			stencil_mask: None,
@@ -282,13 +359,11 @@ impl std::default::Default for IsoGlState {
 // These are POD IDs or hashes of non-POD data
 
 pub struct NonIsoGlState {
-	shader_id: Option <u32>,
 }
 
 impl std::default::Default for NonIsoGlState {
 	fn default () -> Self {
 		Self {
-			shader_id: None,
 		}
 	}
 }
@@ -307,17 +382,13 @@ impl std::default::Default for GlState {
 	}
 }
 
-pub struct Pass <'a> {
+pub struct Pass {
 	// In the context of a Pass, "None" means "Don't care"
 	
 	iso: IsoGlState,
-	
-	// Non-iso state must have its sources here
-	
-	shader: Option <&'a ShaderClosure>,
 }
 
-impl Pass <'_> {
+impl Pass {
 	pub fn apply_diff (&self, old_state: &mut IsoGlState) {
 		let state = &self.iso;
 		
@@ -381,6 +452,16 @@ impl Pass <'_> {
 			}
 		}
 		
+		if let Some (v) = &state.depth_func {
+			if old_state.depth_func != state.depth_func {
+				glezz::depth_func ((*v).into ());
+				old_state.depth_func = state.depth_func;
+			}
+			else {
+				//println! ("Elided depth_func ()");
+			}
+		}
+		
 		if let Some ((r, g, b, a)) = &state.color_mask {
 			if old_state.color_mask != state.color_mask {
 				glezz::color_mask (*r, *g, *b, *a);
@@ -425,15 +506,20 @@ impl Pass <'_> {
 		callback ();
 	}
 	
-	pub fn with_shader <F> (&self, gl_state: &mut GlState, callback: F) 
+	pub fn with_shader <F, S> (
-	where F: Fn (BorrowedShaderVars)
+		&self, 
+		gl_state: &mut GlState, 
+		shader_component: &S, 
+		callback: F
+	) 
+	where F: Fn (BorrowedShaderVars), S: ShaderLookup
 	{
-		if let Some (s) = self.shader {
+		if let Some (s) = self.iso.shader_id {
 			self.apply_diff (&mut gl_state.iso);
-			s.with (gl_state.non_iso.shader_id, |shader_vars| {
+			shader_component.lookup (s).with (gl_state.iso.shader_id, |shader_vars| {
 				callback (shader_vars);
 			});
-			gl_state.non_iso.shader_id = Some (s.get_id ());
+			gl_state.iso.shader_id = Some (s);
 		}
 		else {
 			panic! ("Called with_shader on a pass with no shader");
@@ -441,9 +527,15 @@ impl Pass <'_> {
 	}
 }
 
+pub trait ShaderLookup {
+	fn lookup <'a> (&'a self, id: u32) -> &'a ShaderClosure;
+}
+
 struct GameGraphics {
-	shader_diffuse: ShaderClosure,
+	passes: Vec <Pass>,
-	shader_shadow: ShaderClosure,
+	
+	shaders: Vec <ShaderClosure>,
+	shader_lookup: HashMap <u32, usize>,
 	
 	mesh_pumpkin: RenderableModel,
 	mesh_sky: RenderableModel,
@@ -456,6 +548,12 @@ struct GameGraphics {
 	grass_index: usize,
 }
 
+impl ShaderLookup for GameGraphics {
+	fn lookup <'a> (&'a self, id: u32) -> &'a ShaderClosure {
+		&self.shaders [self.shader_lookup [&id]]
+	}
+}
+
 impl GameGraphics {
 	pub fn new () -> Self {
 		let uniform_names = {
@@ -480,10 +578,21 @@ impl GameGraphics {
 			]
 		};
 		
-		let shader_diffuse = ShaderClosure::new (shader_from_files ("shaders/pumpkin-vert.glsl", "shaders/pumpkin-frag.glsl"), &uniform_names, &attr_names);
+		let shaders: Vec <_> = [
-		let shader_shadow = ShaderClosure::new (shader_from_files ("shaders/shadow-vert.glsl", "shaders/shadow-frag.glsl"), &uniform_names, &attr_names);
+			("shaders/pumpkin-vert.glsl", "shaders/pumpkin-frag.glsl"),
+			("shaders/shadow-vert.glsl", "shaders/shadow-frag.glsl"),
+		].iter ()
+		.map (|(v, f)| {
+			ShaderClosure::new (shader_from_files (v, f), &uniform_names, &attr_names)
+		})
+		.collect ();
 		
-		shader_diffuse.with (None, |shader_vars| {
+		let shader_lookup = HashMap::from_iter (shaders.iter ().enumerate ()
+		.map (|(i, s)| {
+			(s.get_id (), i)
+		}));
+		
+		shaders [0].with (None, |shader_vars| {
 			let attrs = shader_vars.attrs;
 			use renderable_model::attributes::*;
 			glezz::enable_vertex_attrib_array (attrs [POS]);
@@ -538,9 +647,183 @@ impl GameGraphics {
 			(colors, grass_index.unwrap ())
 		};
 		
+		let passes = vec! [
+			// Clear everything
+			Pass {
+				iso: IsoGlState {
+					shader_id: None,
+					flags: hashmap! {},
+					front_face: None,
+					stencil: None,
+					depth_func: None,
+					color_mask: Some ((1, 1, 1, 1)),
+					depth_mask: Some (1),
+					stencil_mask: Some (255),
+				},
+			},
+			// Draw world
+			Pass {
+				iso: IsoGlState {
+					shader_id: Some (shaders [0].get_id ()),
+					flags: hashmap! {
+						gl::CULL_FACE => true,
+						gl::DEPTH_TEST => true,
+						gl::TEXTURE_2D => true,
+						gl::STENCIL_TEST => false,
+					},
+					front_face: Some (FrontFace::Cw),
+					stencil: Some (StencilState {
+						func: StencilFuncState {
+							func: StencilFunc::Always,
+							reference: 0,
+							mask: 0,
+						},
+						op: StencilOpState {
+							sfail: StencilOp::Keep,
+							dpfail: StencilOp::Keep,
+							dppass: StencilOp::Keep,
+						},
+					}),
+					depth_func: Some (DepthFunc::Less),
+					color_mask: Some ((1, 1, 1, 1)),
+					depth_mask: Some (1),
+					stencil_mask: Some (0),
+				},
+			},
+			// Write shadows into stencil buffer
+			Pass {
+				iso: IsoGlState {
+					shader_id: Some (shaders [1].get_id ()),
+					flags: hashmap! {
+						gl::CULL_FACE => true,
+						gl::DEPTH_TEST => true,
+						gl::STENCIL_TEST => true,
+					},
+					front_face: Some (FrontFace::Ccw),
+					stencil: Some (StencilState {
+						func: StencilFuncState {
+							func: StencilFunc::Always,
+							reference: 1,
+							mask: 1,
+						},
+						op: StencilOpState {
+							sfail: StencilOp::Keep,
+							dpfail: StencilOp::Keep,
+							dppass: StencilOp::Replace,
+						},
+					}),
+					depth_func: Some (DepthFunc::Less),
+					color_mask: Some ((0, 0, 0, 0)),
+					depth_mask: Some (0),
+					stencil_mask: Some (255),
+				},
+			},
+			// Draw lit ground
+			Pass {
+				iso: IsoGlState {
+					shader_id: Some (shaders [0].get_id ()),
+					flags: hashmap! {
+						gl::CULL_FACE => true,
+						gl::DEPTH_TEST => true,
+						gl::TEXTURE_2D => true,
+						gl::STENCIL_TEST => true,
+					},
+					front_face: Some (FrontFace::Cw),
+					stencil: Some (StencilState {
+						func: StencilFuncState {
+							func: StencilFunc::NotEqual,
+							reference: 0,
+							mask: 1,
+						},
+						op: StencilOpState {
+							sfail: StencilOp::Keep,
+							dpfail: StencilOp::Keep,
+							dppass: StencilOp::Keep,
+						},
+					}),
+					depth_func: Some (DepthFunc::Less),
+					color_mask: Some ((1, 1, 1, 1)),
+					depth_mask: Some (1),
+					stencil_mask: Some (0),
+				},
+			},
+			// Draw unlit ground
+			Pass {
+				iso: IsoGlState {
+					shader_id: Some (shaders [0].get_id ()),
+					flags: hashmap! {
+						gl::CULL_FACE => true,
+						gl::DEPTH_TEST => true,
+						gl::TEXTURE_2D => true,
+						gl::STENCIL_TEST => true,
+					},
+					front_face: Some (FrontFace::Cw),
+					stencil: Some (StencilState {
+						func: StencilFuncState {
+							func: StencilFunc::Equal,
+							reference: 0,
+							mask: 1,
+						},
+						op: StencilOpState {
+							sfail: StencilOp::Keep,
+							dpfail: StencilOp::Keep,
+							dppass: StencilOp::Keep,
+						},
+					}),
+					depth_func: Some (DepthFunc::Less),
+					color_mask: Some ((1, 1, 1, 1)),
+					depth_mask: Some (1),
+					stencil_mask: Some (0),
+				},
+			},
+			// Clear depth
+			Pass {
+				iso: IsoGlState {
+					shader_id: None,
+					flags: hashmap! {},
+					front_face: None,
+					stencil: None,
+					depth_func: None,
+					color_mask: None,
+					depth_mask: Some (1),
+					stencil_mask: None,
+				},
+			},
+			// Draw arrows
+			Pass {
+				iso: IsoGlState {
+					shader_id: Some (shaders [0].get_id ()),
+					flags: hashmap! {
+						gl::CULL_FACE => true,
+						gl::DEPTH_TEST => true,
+						gl::TEXTURE_2D => true,
+						gl::STENCIL_TEST => false,
+					},
+					front_face: Some (FrontFace::Cw),
+					stencil: Some (StencilState {
+						func: StencilFuncState {
+							func: StencilFunc::Always,
+							reference: 0,
+							mask: 0,
+						},
+						op: StencilOpState {
+							sfail: StencilOp::Keep,
+							dpfail: StencilOp::Keep,
+							dppass: StencilOp::Keep,
+						},
+					}),
+					depth_func: Some (DepthFunc::Less),
+					color_mask: Some ((1, 1, 1, 1)),
+					depth_mask: Some (1),
+					stencil_mask: Some (0),
+				},
+			},
+		];
+		
 		Self {
-			shader_diffuse,
+			passes,
-			shader_shadow,
+			shaders,
+			shader_lookup,
 			
 			mesh_pumpkin,
 			mesh_sky,
@@ -574,8 +857,8 @@ impl GameGraphics {
 			green,
 		];
 		
-		let longitude = state.azimuth.to_radians ();
+		let longitude = state.camera.azimuth.to_radians ();
-		let latitude = (state.altitude - 90.0).to_radians ();
+		let latitude = (state.camera.altitude - 90.0).to_radians ();
 		
 		let proj_mat = Mat4::perspective_rh_gl (30.0f32.to_radians (), 1280.0 / 720.0, 0.5, 500.0);
 		
@@ -598,122 +881,9 @@ impl GameGraphics {
 		
 		//println! ("Started frame");
 		
-		let passes = vec! [
+		let mut passes = self.passes.iter ();
-			// Clear everything
-			Pass {
-				shader: None,
-				iso: IsoGlState {
-					flags: hashmap! {},
-					front_face: None,
-					stencil: None,
-					color_mask: Some ((1, 1, 1, 1)),
-					depth_mask: Some (1),
-					stencil_mask: Some (255),
-				},
-			},
-			// Draw world
-			Pass {
-				shader: Some (&self.shader_diffuse),
-				iso: IsoGlState {
-					flags: hashmap! {
-						gl::CULL_FACE => true,
-						gl::DEPTH_TEST => true,
-						gl::TEXTURE_2D => true,
-						gl::STENCIL_TEST => false,
-					},
-					front_face: Some (FrontFace::Cw),
-					stencil: None,
-					color_mask: Some ((1, 1, 1, 1)),
-					depth_mask: Some (1),
-					stencil_mask: Some (0),
-				},
-			},
-			// Write shadows into stencil buffer
-			Pass {
-				shader: Some (&self.shader_shadow),
-				iso: IsoGlState {
-					flags: hashmap! {
-						gl::CULL_FACE => true,
-						gl::DEPTH_TEST => true,
-						gl::STENCIL_TEST => true,
-					},
-					front_face: Some (FrontFace::Ccw),
-					stencil: Some (StencilState {
-						func: StencilFuncState {
-							func: StencilFunc::Always,
-							reference: 1,
-							mask: 1,
-						},
-						op: StencilOpState {
-							sfail: StencilOp::Keep,
-							dpfail: StencilOp::Keep,
-							dppass: StencilOp::Replace,
-						},
-					}),
-					color_mask: Some ((0, 0, 0, 0)),
-					depth_mask: Some (0),
-					stencil_mask: Some (255),
-				},
-			},
-			// Draw lit ground
-			Pass {
-				shader: Some (&self.shader_diffuse),
-				iso: IsoGlState {
-					flags: hashmap! {
-						gl::CULL_FACE => true,
-						gl::DEPTH_TEST => true,
-						gl::TEXTURE_2D => true,
-						gl::STENCIL_TEST => true,
-					},
-					front_face: Some (FrontFace::Cw),
-					stencil: Some (StencilState {
-						func: StencilFuncState {
-							func: StencilFunc::NotEqual,
-							reference: 0,
-							mask: 1,
-						},
-						op: StencilOpState {
-							sfail: StencilOp::Keep,
-							dpfail: StencilOp::Keep,
-							dppass: StencilOp::Keep,
-						},
-					}),
-					color_mask: Some ((1, 1, 1, 1)),
-					depth_mask: Some (1),
-					stencil_mask: Some (0),
-				},
-			},
-			// Draw unlit ground
-			Pass {
-				shader: Some (&self.shader_diffuse),
-				iso: IsoGlState {
-					flags: hashmap! {
-						gl::CULL_FACE => true,
-						gl::DEPTH_TEST => true,
-						gl::TEXTURE_2D => true,
-						gl::STENCIL_TEST => true,
-					},
-					front_face: Some (FrontFace::Cw),
-					stencil: Some (StencilState {
-						func: StencilFuncState {
-							func: StencilFunc::Equal,
-							reference: 0,
-							mask: 1,
-						},
-						op: StencilOpState {
-							sfail: StencilOp::Keep,
-							dpfail: StencilOp::Keep,
-							dppass: StencilOp::Keep,
-						},
-					}),
-					color_mask: Some ((1, 1, 1, 1)),
-					depth_mask: Some (1),
-					stencil_mask: Some (0),
-				},
-			},
-		];
 		
-		passes [0].with (gl_state, || {
+		passes.next ().unwrap ().with (gl_state, || {
 			glezz::clear_color (1.0f32, 0.0f32, 1.0f32, 1.0f32);
 			glezz::clear (gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT | gl::STENCIL_BUFFER_BIT);
 		});
@@ -730,7 +900,8 @@ impl GameGraphics {
 		use uniforms::*;
 		
 		// Draw the world except the ground plane
-		passes [1].with_shader (gl_state, |shader_vars| {
+		passes.next ().unwrap ().with_shader (gl_state, self, 
+		|shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -759,19 +930,6 @@ impl GameGraphics {
 				i != self.grass_index
 			});
 			
-			glezz::uniform_3fv (unis [&ALBEDO], &magenta);
-			for arrow in arrows.iter () {
-				let mvp = view_mat * arrow.model_mat;
-				
-				glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
-				let object_space_light = make_object_space_vec (&arrow.inv_model_mat, &light);
-				let object_space_sky = make_object_space_vec (&arrow.inv_model_mat, &Vec3::from ((0.0, 0.0, 1.0)));
-				glezz::uniform_3fv (unis [&OBJECT_SPACE_LIGHT], &object_space_light);
-				glezz::uniform_3fv (unis [&OBJECT_SPACE_SKY], &object_space_sky);
-				
-				self.mesh_arrow.draw_all (attrs, |_| true);
-			}
-			
 			let draw_sky = true;
 			if draw_sky {
 				self.texture.bind ();
@@ -786,7 +944,8 @@ impl GameGraphics {
 		});
 		
 		// Draw shadows into stencil buffer
-		passes [2].with_shader (gl_state, |shader_vars| {
+		passes.next ().unwrap ().with_shader (gl_state, self, 
+		|shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -813,7 +972,8 @@ impl GameGraphics {
 		let object_space_light = make_object_space_vec (&inverse_pumpkin, &light);
 		
 		// Draw unlit ground
-		passes [3].with_shader (gl_state, |shader_vars| {
+		passes.next ().unwrap ().with_shader (gl_state, self, 
+		|shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -835,14 +995,49 @@ impl GameGraphics {
 		});
 		
 		// Draw lit ground
-		passes [4].with_shader (gl_state, |shader_vars| {
+		passes.next ().unwrap ().with_shader (gl_state, self, 
+		|shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
 			glezz::uniform_3fv (unis [&OBJECT_SPACE_LIGHT], &object_space_light);
 			self.mesh_pitch.draw (attrs, self.grass_index);
 		});
+		
+		// Clear depth
+		passes.next ().unwrap ().with (gl_state, || {
+			glezz::clear (gl::DEPTH_BUFFER_BIT);
+		});
+		
+		// Draw arrows
+		passes.next ().unwrap ().with_shader (gl_state, self,
+		|shader_vars| {
+			let unis = &shader_vars.unis;
+			
+			glezz::uniform_3fv (unis [&MIN_BRIGHT], &black);
+			glezz::uniform_3fv (unis [&MIN_ALBEDO], &white);
+			
+			for arrow in arrows.iter () {
+				let mvp = view_mat * arrow.model_mat;
+				
+				glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
+				let object_space_light = make_object_space_vec (&arrow.inv_model_mat, &light);
+				let object_space_sky = make_object_space_vec (&arrow.inv_model_mat, &Vec3::from ((0.0, 0.0, 1.0)));
+				glezz::uniform_3fv (unis [&OBJECT_SPACE_LIGHT], &object_space_light);
+				glezz::uniform_3fv (unis [&OBJECT_SPACE_SKY], &object_space_sky);
+				
+				glezz::uniform_3fv (unis [&ALBEDO], &arrow.color);
+				
+				self.mesh_arrow.draw_all (shader_vars.attrs, |_| true);
 			}
+		});
+	}
+}
+
+#[derive (Copy, Clone, PartialEq, Eq)]
+enum UserControl {
+	Camera,
+	Wind,
 }
 
 fn main () {
@@ -871,16 +1066,13 @@ fn main () {
 	let graphics = GameGraphics::new ();
 	let mut gl_state = Default::default ();
 	
+	let mut user_control = UserControl::Camera;
+	let mut graphics_frames = 0;
+	
 	let mut event_pump = sdl_context.event_pump ().unwrap ();
 	'running: loop {
 		let frames_to_do = time_step.step ();
 		
-		let controller = ControllerState::from_sdl_keyboard (&event_pump.keyboard_state ());
-		
-		for _ in 0..frames_to_do {
-			state.step (&controller);
-		}
-		
 		let _mouse = event_pump.mouse_state ();
 		
 		for event in event_pump.poll_iter() {
@@ -889,27 +1081,55 @@ fn main () {
 				Event::KeyDown { keycode: Some (Keycode::Escape), .. } => {
 					break 'running
 				},
+				Event::KeyDown { keycode: Some (Keycode::C), .. } => {
+					user_control = UserControl::Camera;
+				},
+				Event::KeyDown { keycode: Some (Keycode::W), .. } => {
+					user_control = UserControl::Wind;
+				},
 				_ => (),
 			}
 		}
 		
+		let controller = ControllerState::from_sdl_keyboard (&event_pump.keyboard_state ());
+		
+		for _ in 0..frames_to_do {
+			state.step (&controller, &user_control);
+		}
+		
+		let gravity = (0.0, 0.0, -1.0).into ();
+		let wind = state.wind.to_vec3 () * -1.0;
+		let origin: Vec3 = (0.0, 0.0, 1.35).into ();
+		
+		let control_flash = if graphics_frames % 16 >= 8 {
+			(1.0, 1.0, 1.0).into ()
+		}
+		else {
+			(1.0, 0.0, 0.0).into ()
+		};
+		
 		let arrows = vec![
 			Arrow {
-				origin: (0.0, 0.0, 1.0).into (),
+				origin: (0.0, 0.0, 1.35).into (),
-				direction: (0.0, 0.0, 1.0).into (),
+				direction: gravity,
+				color: (1.0, 0.5, 0.5).into (),
 			},
 			Arrow {
-				origin: (1.0, 0.0, 1.0).into (),
+				origin: origin + wind * -2.0,
-				direction: (1.0, 0.0, 0.0).into (),
+				direction: wind,
+				color: if user_control == UserControl::Wind {
+					control_flash
+				}
+				else {
+					(1.0, 0.5, 1.0).into ()
 				},
-			Arrow {
-				origin: (0.0, 1.0, 1.0).into (),
-				direction: (0.0, 1.0, 0.0).into (),
 			},
 		];
 		
 		let renderable_arrows: Vec <_> = arrows.iter ().map (|arrow| {
-			let d = arrow.direction;
+			let dir_len = arrow.direction.length ();
+			
+			let d = arrow.direction / dir_len;
 			
 			let up: Vec3 = if d.z () > 0.5 {
 				(-1.0, 0.0, 0.0)
@@ -932,9 +1152,11 @@ fn main () {
 			dir_mat.set_y_axis ((up.x (), up.y (), up.z (), 0.0).into ());
 			dir_mat.set_z_axis ((d.x (), d.y (), d.z (), 0.0).into ());
 			
+			let s = dir_len * 0.0625;
+			
 			let model_mat =
 			Mat4::from_translation (arrow.origin) *
-			Mat4::from_scale ((0.125, 0.125, 0.125).into ()) *
+			Mat4::from_scale ((s, s, s).into ()) *
 			dir_mat;
 			
 			let inv_model_mat = model_mat.inverse ();
@@ -942,6 +1164,7 @@ fn main () {
 			RenderableArrow {
 				model_mat,
 				inv_model_mat,
+				color: arrow.color,
 			}
 		}).collect ();
 		
@@ -950,6 +1173,7 @@ fn main () {
 		graphics.draw (&state, &mut gl_state, &renderable_arrows);
 		
 		window.gl_swap_window ();
+		graphics_frames += 1;
 		
 		std::thread::sleep (Duration::from_millis (15));
 	}

src/glezz.rs

@@ -97,6 +97,12 @@ pub fn stencil_mask (v: u32) {
 	}
 }
 
+pub fn depth_func (v: u32) {
+	unsafe {
+		gl::DepthFunc (v);
+	}
+}
+
 // More abstract things below here