Got the _good_ stencil shadows going

shaders/pumpkin-frag.glsl

@@ -10,16 +10,17 @@ varying lowp vec3 vary_color;
 varying lowp vec3 vary_normal;
 varying mediump vec2 vary_uv;
 varying lowp vec3 vary_object_space_light;
+varying lowp vec3 vary_object_space_sky;
 
 void main (void) {
 	lowp vec3 normal = normalize (vary_normal);
 	
 	lowp vec3 albedo = vary_color * max (uni_min_albedo, texture2D (uni_texture, vary_uv).rgb);
 	
-	lowp vec3 sky_color = pow (vec3 (42.0, 52.0, 109.0) / vec3 (255.0), vec3 (2.0));
+	lowp vec3 sky_color = pow (vec3 (89.0, 125.0, 206.0) / vec3 (255.0), vec3 (2.0));
 	
 	lowp float sun_factor = dot (normal, vary_object_space_light);
-	lowp float sky_factor = normal.z;
+	lowp float sky_factor = dot (normal, vary_object_space_sky);
 	
 	lowp vec3 sun = max (sun_factor, 0.0) * (vec3 (1.0) - sky_color);
 	lowp vec3 sky = (sky_factor * 0.5 + 0.5) * sky_color;

shaders/pumpkin-vert.glsl

@@ -4,6 +4,7 @@
 #line 0
 uniform highp mat4 uni_mvp;
 uniform lowp vec3 uni_albedo;
+uniform lowp vec3 uni_object_space_sky;
 uniform lowp vec3 uni_object_space_light;
 
 attribute highp vec4 attr_pos;
@@ -14,6 +15,7 @@ varying lowp vec3 vary_color;
 varying lowp vec3 vary_normal;
 varying mediump vec2 vary_uv;
 varying lowp vec3 vary_object_space_light;
+varying lowp vec3 vary_object_space_sky;
 
 void main (void) {
 	vary_uv = attr_uv;
@@ -21,6 +23,7 @@ void main (void) {
 	vary_normal = attr_normal;
 	vary_color = uni_albedo * uni_albedo;
 	vary_object_space_light = normalize (uni_object_space_light);
+	vary_object_space_sky = normalize (uni_object_space_sky);
 	
 	gl_Position = uni_mvp * attr_pos;
 }

shaders/shadow-frag.glsl

@@ -3,18 +3,6 @@
 #define highp
 #line 0
 
-uniform lowp float uni_dither_phase;
-
 void main (void) {
-	lowp float dither_phase = 0.0;
+	gl_FragColor = vec4 (0.0, 0.0, 0.0, 1.0);
-	dither_phase += 4.0 * mod (gl_FragCoord.y + 0.5, 4.0);
-	dither_phase += mod (gl_FragCoord.x + 0.5, 4.0);
-	dither_phase = mod (dither_phase, 16.0);
-	
-	lowp float dither = 1.0;
-	if (dither_phase == 0.0 || dither_phase == 10.0) {
-		dither = 0.0;
-	}
-	
-	gl_FragColor = vec4 (vec3 (20.0, 12.0, 28.0) / vec3 (255.0), dither);
 }

src/bin/pumpkin.rs

@@ -104,6 +104,7 @@ use iota::iota;
 iota! {
 	pub const MVP: u32 = iota;
 	        , OBJECT_SPACE_LIGHT
+	        , OBJECT_SPACE_SKY
 	        , ALBEDO
 	        , MIN_ALBEDO
 	        , MIN_BRIGHT
@@ -112,6 +113,14 @@ iota! {
 }
 }
 
+fn make_object_space_vec (inverse_model_mat: &Mat4, world_space_vec: &Vec3)
+-> Vec3
+{
+	let v = world_space_vec;
+	let v4 = *inverse_model_mat * Vec4::from ((v.x (), v.y (), v.z (), 0.0));
+	Vec3::from ((v4.x (), v4.y (), v4.z ()))
+}
+
 fn main () {
 	let sdl_context = sdl2::init ().unwrap ();
 	let video_subsystem = sdl_context.video ().unwrap ();
@@ -159,6 +168,7 @@ fn main () {
 		vec! [
 			(MVP, "mvp"),
 			(OBJECT_SPACE_LIGHT, "object_space_light"),
+			(OBJECT_SPACE_SKY, "object_space_sky"),
 			(ALBEDO, "albedo"),
 			(MIN_ALBEDO, "min_albedo"),
 			(MIN_BRIGHT, "min_bright"),
@@ -212,7 +222,7 @@ fn main () {
 	
 	let renderable_sky = RenderableModel::from_iqm (&sky_model);
 	
-	let (renderable_pitch, pitch_colors) = {
+	let (renderable_pitch, pitch_colors, grass_index) = {
 		let data = load_small_file ("pitch.iqm", 1024 * 1024);
 		let model = Model::from_slice (&data);
 		
@@ -238,8 +248,12 @@ fn main () {
 			("Grass", (52.0, 101.0, 36.0)),
 		].into_iter ());
 		
+		let mut grass_index = None;
 		let colors: Vec <_> = (0..model.meshes.len ()).map (|i| {
 			let name = str::from_utf8 (model.get_mesh_name (i)).unwrap ();
+			if name == "Grass" {
+				grass_index = Some (i);
+			}
 			
 			match color_lookup.get (name) {
 				Some (t) => color_from_255 (*t),
@@ -247,7 +261,7 @@ fn main () {
 			}
 		}).collect ();
 		
-		(RenderableModel::from_iqm (&model), colors)
+		(RenderableModel::from_iqm (&model), colors, grass_index.unwrap ())
 	};
 	
 	glezz::enable_vertex_attrib_array (attrs ["pos"]);
@@ -306,16 +320,17 @@ fn main () {
 		let sky_mvp_mat = view_mat * Mat4::from_scale ((16.0, 16.0, 16.0).into ());
 		
 		let light = Vec3::from ((2.0, 0.0, 5.0)).normalize ();
+		//let light = Vec3::from ((0.0, 0.0, 0.0)).normalize ();
 		
 		let orange = color_from_255 ((210.0, 125.0, 44.0));
 		let green = color_from_255 ((52.0, 101.0, 36.0));
 		let white = color_from_255 ((255.0, 255.0, 255.0));
-		let off_white = color_from_255 ((222.0, 238.0, 214.0));
+		let _off_white = color_from_255 ((222.0, 238.0, 214.0));
 		let black = color_from_255 ((0.0, 0.0, 0.0));
-		let off_black = color_from_255 ((20.0, 12.0, 28.0));
+		let _off_black = color_from_255 ((20.0, 12.0, 28.0));
 		
 		glezz::clear_color (1.0f32, 0.0f32, 1.0f32, 1.0f32);
-		glezz::clear (gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT);
+		glezz::clear (gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT | gl::STENCIL_BUFFER_BIT);
 		glezz::enable (gl::CULL_FACE);
 		
 		let pumpkin_model_mat = 
@@ -330,18 +345,22 @@ fn main () {
 			use uniforms::*;
 			
 			shader_program.use_program ();
+			glezz::disable (gl::STENCIL_TEST);
 			glezz::front_face (gl::CW);
-			glezz::disable (gl::BLEND);
-			
-			glezz::uniform_3fv (unis [&MIN_BRIGHT], &black);
-			glezz::uniform_3fv (unis [&MIN_ALBEDO], &white);
 			
 			let mvp = view_mat * pumpkin_model_mat;
 			glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
 			
-			let object_space_light = pumpkin_model_mat.inverse () * Vec4::from ((light.x (), light.y (), light.z (), 0.0));
+			let inverse_pumpkin = pumpkin_model_mat.inverse ();
-			let object_space_light = Vec3::from ((object_space_light.x (), object_space_light.y (), object_space_light.z ()));
+			
+			let object_space_light = make_object_space_vec (&inverse_pumpkin, &light);
+			
+			let object_space_sky = make_object_space_vec (&inverse_pumpkin, &Vec3::from ((0.0, 0.0, 1.0)));
+			
+			glezz::uniform_3fv (unis [&MIN_BRIGHT], &black);
+			glezz::uniform_3fv (unis [&MIN_ALBEDO], &white);
 			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], &orange);
@@ -354,9 +373,10 @@ fn main () {
 			let mvp = view_mat * world_model_mat;
 			glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
 			
+			for (i, color) in pitch_colors.iter ().enumerate ().take (renderable_pitch.num_meshes ())
 			{
-				for i in 0..renderable_pitch.num_meshes () {
+				glezz::uniform_3fv (unis [&ALBEDO], color);
-					glezz::uniform_3fv (unis [&ALBEDO], &pitch_colors [i]);
+				if i != grass_index {
 					renderable_pitch.draw (&attrs, i);
 				}
 			}
@@ -373,17 +393,16 @@ fn main () {
 				renderable_sky.draw (&attrs, 0);
 			}
 			
+			glezz::enable (gl::STENCIL_TEST);
+			unsafe {
+				gl::StencilFunc (gl::ALWAYS, 1, 1);
+				gl::StencilOp (gl::KEEP, gl::KEEP, gl::REPLACE);
+				
+				gl::ColorMask (0, 0, 0, 0);
+				gl::DepthMask (0);
+				gl::StencilMask (1);
+			}
 			shadow_shader.use_program ();
-			glezz::front_face (gl::CCW);
-			glezz::enable (gl::BLEND);
-			glezz::blend_func (gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
-			
-			glezz::uniform_1f (shadow_unis [&DITHER_PHASE], dither_phase as f32);
-			
-			glezz::uniform_3fv (shadow_unis [&MIN_BRIGHT], &black);
-			glezz::uniform_3fv (shadow_unis [&MIN_ALBEDO], &white);
-			
-			glezz::uniform_3fv (shadow_unis [&OBJECT_SPACE_LIGHT], &object_space_light);
 			
 			let view_mat = view_mat * shadow_mat;
 			
@@ -398,11 +417,47 @@ fn main () {
 			let mvp = view_mat * world_model_mat;
 			glezz::uniform_matrix_4fv (shadow_unis [&MVP], &mvp);
 			
-			{
 			for i in 0..renderable_pitch.num_meshes () {
+				if i != grass_index {
 					renderable_pitch.draw (&shadow_attrs, i);
 				}
 			}
+			
+			unsafe {
+				gl::ColorMask (255, 255, 255, 255);
+				gl::DepthMask (1);
+			}
+			shader_program.use_program ();
+			glezz::front_face (gl::CW);
+			
+			let inverse_pumpkin = pumpkin_model_mat.inverse ();
+			
+			let object_space_light = make_object_space_vec (&inverse_pumpkin, &light);
+			
+			let object_space_sky = make_object_space_vec (&inverse_pumpkin, &Vec3::from ((0.0, 0.0, 1.0)));
+			
+			glezz::uniform_3fv (unis [&MIN_BRIGHT], &black);
+			glezz::uniform_3fv (unis [&MIN_ALBEDO], &white);
+			glezz::uniform_3fv (unis [&OBJECT_SPACE_SKY], &object_space_sky);
+			
+			let mvp = view_mat * world_model_mat;
+			glezz::uniform_matrix_4fv (unis [&MVP], &mvp);
+			
+			glezz::uniform_3fv (unis [&ALBEDO], &pitch_colors [grass_index]);
+			
+			unsafe {
+				gl::StencilFunc (gl::NOTEQUAL, 0, 1);
+				gl::StencilOp (gl::KEEP, gl::KEEP, gl::KEEP);
+			}
+			glezz::uniform_3fv (unis [&OBJECT_SPACE_LIGHT], &Vec3::from ((0.0, 0.0, 0.0)));
+			renderable_pitch.draw (&attrs, grass_index);
+			
+			unsafe {
+				gl::StencilFunc (gl::EQUAL, 0, 1);
+				gl::StencilOp (gl::KEEP, gl::KEEP, gl::KEEP);
+			}
+			glezz::uniform_3fv (unis [&OBJECT_SPACE_LIGHT], &object_space_light);
+			renderable_pitch.draw (&attrs, grass_index);
 		}
 		
 		window.gl_swap_window ();