🚧 still improving the pass system

src/bin/pumpkin.rs

@@ -152,7 +152,7 @@ struct RenderableArrow {
 	inv_model_mat: Mat4,
 }
 
-#[derive (Copy, Clone)]
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub enum FrontFace {
 	Cw,
 	Ccw,
@@ -171,7 +171,7 @@ impl From <FrontFace> for u32 {
 	}
 }
 
-#[derive (Copy, Clone)]
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub enum StencilOp {
 	Keep, 
 	Zero, 
@@ -202,7 +202,7 @@ impl From <StencilOp> for u32 {
 	}
 }
 
-#[derive (Copy, Clone)]
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub enum StencilFunc {
 	Never, 
 	Always, 
@@ -233,26 +233,30 @@ impl From <StencilFunc> for u32 {
 	}
 }
 
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub struct StencilOpState {
 	sfail: StencilOp,
 	dpfail: StencilOp,
 	dppass: StencilOp,
 }
 
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub struct StencilFuncState {
 	func: StencilFunc,
 	reference: i32,
 	mask: u32,
 }
 
+#[derive (Copy, Clone, PartialEq, Eq)]
 pub struct StencilState {
 	op: StencilOpState,
 	func: StencilFuncState,
 }
 
-// Anything that's None is "unknown"
+// These are POD where no extra data is needed
+// to safely use the flags / numbers
 
-pub struct GlState {
+pub struct IsoGlState {
 	flags: HashMap <u32, bool>,
 	front_face: Option <FrontFace>,
 	stencil: Option <StencilState>,
@@ -262,83 +266,174 @@ pub struct GlState {
 	stencil_mask: Option <u32>,
 }
 
+impl std::default::Default for IsoGlState {
+	fn default () -> Self {
+		Self {
+			flags: hashmap! {},
+			front_face: None,
+			stencil: None,
+			color_mask: None,
+			depth_mask: None,
+			stencil_mask: None,
+		}
+	}
+}
+
+// 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,
+		}
+	}
+}
+
+pub struct GlState {
+	iso: IsoGlState,
+	non_iso: NonIsoGlState,
+}
+
+impl std::default::Default for GlState {
+	fn default () -> Self {
+		Self {
+			iso: Default::default (),
+			non_iso: Default::default (),
+		}
+	}
+}
+
 pub struct Pass <'a> {
+	// 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>,
-	
-	// Anything that's None is "don't care"
-	
-	required_state: GlState,
 }
 
 impl Pass <'_> {
-	pub fn apply_slow (&self) {
-		let state = &self.required_state;
+	pub fn apply_diff (&self, old_state: &mut IsoGlState) {
+		let state = &self.iso;
+		
+		let mut flag_elision_count = 0;
 		
 		for (flag, value) in state.flags.iter () {
-			if *value {
-				glezz::enable (*flag);
+			let old_entry = old_state.flags.entry (*flag);
+			if match &old_entry {
+				hash_map::Entry::Vacant (_) => true,
+				hash_map::Entry::Occupied (o) => o.get () != value,
+			} {
+				if *value {
+					glezz::enable (*flag);
+				}
+				else {
+					glezz::disable (*flag);
+				}
+				
+				old_entry.or_insert (*value);
 			}
 			else {
-				glezz::disable (*flag);
+				flag_elision_count += 1;
 			}
 		}
+		if flag_elision_count > 0 {
+			//println! ("Elided {} flags", flag_elision_count);
+		}
 		
 		if let Some (v) = &state.front_face {
-			glezz::front_face ((*v).into ());
+			if old_state.front_face != state.front_face {
+				glezz::front_face ((*v).into ());
+				old_state.front_face = state.front_face;
+			}
+			else {
+				//println! ("Elided front_face ()");
+			}
 		}
 		
 		if let Some (v) = &state.stencil {
-			let func = &v.func;
-			let op = &v.op;
-			
-			unsafe {
-				gl::StencilFunc (
-					func.func.into (), 
-					func.reference.into (), 
-					func.mask.into ()
-				);
-				gl::StencilOp (
-					op.sfail.into (), 
-					op.dpfail.into (), 
-					op.dppass.into ()
-				);
+			if old_state.stencil != state.stencil {
+				let func = &v.func;
+				unsafe {
+					gl::StencilFunc (
+						func.func.into (), 
+						func.reference.into (), 
+						func.mask.into ()
+					);
+				}
+				
+				let op = &v.op;
+				unsafe {
+					gl::StencilOp (
+						op.sfail.into (), 
+						op.dpfail.into (), 
+						op.dppass.into ()
+					);
+				}
+			}
+			else {
+				//println! ("Elided stencil state");
 			}
 		}
 		
 		if let Some ((r, g, b, a)) = &state.color_mask {
-			unsafe {
-				gl::ColorMask (*r, *g, *b, *a);
+			if old_state.color_mask != state.color_mask {
+				glezz::color_mask (*r, *g, *b, *a);
+				old_state.color_mask = state.color_mask;
+			}
+			else {
+				//println! ("Elided color_mask ()");
 			}
 		}
 		
 		if let Some (v) = &state.depth_mask {
-			unsafe {
-				gl::DepthMask (*v);
+			if old_state.depth_mask != state.depth_mask {
+				glezz::depth_mask (*v);
+				old_state.depth_mask = state.depth_mask;
+			}
+			else {
+				//println! ("Elided depth_mask ()");
 			}
 		}
 		
 		if let Some (v) = &state.stencil_mask {
-			unsafe {
-				gl::StencilMask (*v);
+			if old_state.stencil_mask != state.stencil_mask {
+				glezz::stencil_mask (*v);
+				old_state.stencil_mask = state.stencil_mask;
+			}
+			else {
+				//println! ("Elided stencil_mask ()");
 			}
 		}
 	}
 	
-	pub fn with <F> (&self, callback: F)
+	pub fn apply_slow (&self) {
+		let mut iso = IsoGlState::default ();
+		
+		self.apply_diff (&mut iso);
+	}
+	
+	pub fn with <F> (&self, gl_state: &mut GlState, callback: F)
 	where F: Fn ()
 	{
-		self.apply_slow ();
+		self.apply_diff (&mut gl_state.iso);
 		callback ();
 	}
 	
-	pub fn with_shader <F> (&self, callback: F) 
+	pub fn with_shader <F> (&self, gl_state: &mut GlState, callback: F) 
 	where F: Fn (BorrowedShaderVars)
 	{
 		if let Some (s) = self.shader {
-			s.with (|shader_vars| {
-				self.apply_slow ();
+			self.apply_diff (&mut gl_state.iso);
+			s.with (gl_state.non_iso.shader_id, |shader_vars| {
 				callback (shader_vars);
 			});
+			gl_state.non_iso.shader_id = Some (s.get_id ());
 		}
 		else {
 			panic! ("Called with_shader on a pass with no shader");
@@ -388,7 +483,7 @@ impl GameGraphics {
 		let shader_diffuse = ShaderClosure::new (shader_from_files ("shaders/pumpkin-vert.glsl", "shaders/pumpkin-frag.glsl"), &uniform_names, &attr_names);
 		let shader_shadow = ShaderClosure::new (shader_from_files ("shaders/shadow-vert.glsl", "shaders/shadow-frag.glsl"), &uniform_names, &attr_names);
 		
-		shader_diffuse.with (|shader_vars| {
+		shader_diffuse.with (None, |shader_vars| {
 			let attrs = shader_vars.attrs;
 			use renderable_model::attributes::*;
 			glezz::enable_vertex_attrib_array (attrs [POS]);
@@ -462,6 +557,7 @@ impl GameGraphics {
 	pub fn draw (
 		&self,
 		state: &WorldState,
+		gl_state: &mut GlState,
 		arrows: &[RenderableArrow]
 	) 
 	{
@@ -500,11 +596,13 @@ impl GameGraphics {
 		
 		let light = Vec3::from ((0.25, -0.125, 1.0)).normalize ();
 		
+		//println! ("Started frame");
+		
 		let passes = vec! [
 			// Clear everything
 			Pass {
 				shader: None,
-				required_state: GlState {
+				iso: IsoGlState {
 					flags: hashmap! {},
 					front_face: None,
 					stencil: None,
@@ -516,7 +614,7 @@ impl GameGraphics {
 			// Draw world
 			Pass {
 				shader: Some (&self.shader_diffuse),
-				required_state: GlState {
+				iso: IsoGlState {
 					flags: hashmap! {
 						gl::CULL_FACE => true,
 						gl::DEPTH_TEST => true,
@@ -533,7 +631,7 @@ impl GameGraphics {
 			// Write shadows into stencil buffer
 			Pass {
 				shader: Some (&self.shader_shadow),
-				required_state: GlState {
+				iso: IsoGlState {
 					flags: hashmap! {
 						gl::CULL_FACE => true,
 						gl::DEPTH_TEST => true,
@@ -560,7 +658,7 @@ impl GameGraphics {
 			// Draw lit ground
 			Pass {
 				shader: Some (&self.shader_diffuse),
-				required_state: GlState {
+				iso: IsoGlState {
 					flags: hashmap! {
 						gl::CULL_FACE => true,
 						gl::DEPTH_TEST => true,
@@ -588,7 +686,7 @@ impl GameGraphics {
 			// Draw unlit ground
 			Pass {
 				shader: Some (&self.shader_diffuse),
-				required_state: GlState {
+				iso: IsoGlState {
 					flags: hashmap! {
 						gl::CULL_FACE => true,
 						gl::DEPTH_TEST => true,
@@ -615,7 +713,7 @@ impl GameGraphics {
 			},
 		];
 		
-		passes [0].with (|| {
+		passes [0].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);
 		});
@@ -632,7 +730,7 @@ impl GameGraphics {
 		use uniforms::*;
 		
 		// Draw the world except the ground plane
-		passes [1].with_shader (|shader_vars| {
+		passes [1].with_shader (gl_state, |shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -688,7 +786,7 @@ impl GameGraphics {
 		});
 		
 		// Draw shadows into stencil buffer
-		passes [2].with_shader (|shader_vars| {
+		passes [2].with_shader (gl_state, |shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -715,7 +813,7 @@ impl GameGraphics {
 		let object_space_light = make_object_space_vec (&inverse_pumpkin, &light);
 		
 		// Draw unlit ground
-		passes [3].with_shader (|shader_vars| {
+		passes [3].with_shader (gl_state, |shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -737,7 +835,7 @@ impl GameGraphics {
 		});
 		
 		// Draw lit ground
-		passes [4].with_shader (|shader_vars| {
+		passes [4].with_shader (gl_state, |shader_vars| {
 			let unis = shader_vars.unis;
 			let attrs = shader_vars.attrs;
 			
@@ -771,6 +869,7 @@ fn main () {
 	let mut state = WorldState::new ();
 	
 	let graphics = GameGraphics::new ();
+	let mut gl_state = Default::default ();
 	
 	let mut event_pump = sdl_context.event_pump ().unwrap ();
 	'running: loop {
@@ -848,7 +947,7 @@ fn main () {
 		
 		window.gl_make_current (&gl_ctx).unwrap ();
 		
-		graphics.draw (&state, &renderable_arrows);
+		graphics.draw (&state, &mut gl_state, &renderable_arrows);
 		
 		window.gl_swap_window ();
 		

src/glezz.rs

@@ -79,6 +79,24 @@ pub fn uniform_matrix_4fv (uni: i32, m: &Mat4) {
 	}
 }
 
+pub fn color_mask (r: u8, g: u8, b: u8, a: u8) {
+	unsafe {
+		gl::ColorMask (r, g, b, a);
+	}
+}
+
+pub fn depth_mask (v: u8) {
+	unsafe {
+		gl::DepthMask (v);
+	}
+}
+
+pub fn stencil_mask (v: u32) {
+	unsafe {
+		gl::StencilMask (v);
+	}
+}
+
 // More abstract things below here
 
 

src/shader.rs

@@ -119,6 +119,10 @@ impl ShaderProgram {
 		}
 	}
 	
+	pub fn get_id (&self) -> u32 {
+		self.id
+	}
+	
 	// 'use' is a keyword
 	
 	pub fn use_program (&self) {

src/shader_closure.rs

@@ -67,10 +67,19 @@ impl ShaderClosure {
 		}
 	}
 	
-	pub fn with <F> (&self, callback: F)
+	pub fn get_id (&self) -> u32 {
+		self.program.get_id ()
+	}
+	
+	pub fn with <F> (&self, previous_id: Option <u32>, callback: F)
 	where F: Fn (BorrowedShaderVars)
 	{
-		self.program.use_program ();
+		if previous_id != Some (self.get_id ()) {
+			self.program.use_program ();
+		}
+		else {
+			//println! ("Elided use_program ()");
+		}
 		
 		callback (BorrowedShaderVars {
 			unis: &self.uniforms,