render: rewrite PCF for spot lights to somehow fix PCSS directional lights

examples/shadows/src/main.rs

@@ -8,7 +8,7 @@ use lyra_engine::{
     math::{self, Quat, Transform, Vec3},
     render::{
         graph::{ShadowCasterSettings, ShadowFilteringMode},
-        light::{directional::DirectionalLight, PointLight},
+        light::{directional::DirectionalLight, PointLight, SpotLight},
     },
     scene::{
         CameraComponent, FreeFlyCamera, FreeFlyCameraPlugin, WorldTransform,
@@ -184,12 +184,15 @@ fn setup_scene_plugin(game: &mut Game) {
             },
             ShadowCasterSettings {
                 filtering_mode: ShadowFilteringMode::Pcss,
+                pcf_samples_num: 64,
+                pcss_blocker_search_samples: 36,
+                constant_depth_bias_scale: 5.0,
                 ..Default::default()
             },
             light_tran,
         ));
 
-        world.spawn((
+        /* world.spawn((
             cube_mesh.clone(),
             PointLight {
                 enabled: true,
@@ -207,31 +210,40 @@ fn setup_scene_plugin(game: &mut Game) {
                 Quat::IDENTITY,
                 Vec3::new(0.5, 0.5, 0.5),
             ),
-        ));
+        )); */
 
-        /* world.spawn((
+        let t = Transform::new(
-            //cube_mesh.clone(),
+            Vec3::new(4.0 - 1.43, -13.0, 0.0),
-            PointLight {
+            //Vec3::new(-5.0, 1.0, -0.28),
+            //Vec3::new(-10.0, 0.94, -0.28), 
+        
+            Quat::from_euler(math::EulerRot::XYZ, 0.0, math::Angle::Degrees(-45.0).to_radians(), 0.0),
+            Vec3::new(0.15, 0.15, 0.15),
+        );
+
+        world.spawn((
+            SpotLight {
                 enabled: true,
-                color: Vec3::new(0.278, 0.984, 0.0),
+                color: Vec3::new(1.0, 0.0, 0.0),
-                intensity: 2.0,
+                intensity: 3.0,
-                range: 9.0,
+                range: 4.5,
+                //cutoff: math::Angle::Degrees(45.0),
                 ..Default::default()
             },
-            Transform::from_xyz(-0.5, 2.0, -5.0),
+            /* ShadowCasterSettings {
-        )); */
+                filtering_mode: ShadowFilteringMode::Pcf,
+                ..Default::default()
+            }, */
+            WorldTransform::from(t),
+            t,
+            //cube_mesh.clone(),
+        ));
     }
 
     let mut camera = CameraComponent::new_3d();
-    //camera.transform.translation += math::Vec3::new(0.0, 2.0, 10.5);
+    camera.transform.translation = math::Vec3::new(-1.0, -10.0, -1.5);
-    /* camera.transform.translation = math::Vec3::new(-3.0, -8.0, -3.0);
     camera.transform.rotate_x(math::Angle::Degrees(-27.0));
-    camera.transform.rotate_y(math::Angle::Degrees(-55.0)); */
+    camera.transform.rotate_y(math::Angle::Degrees(-90.0));
-
-    camera.transform.translation = math::Vec3::new(15.0, -8.0, 1.0);
-    camera.transform.rotate_x(math::Angle::Degrees(-27.0));
-    //camera.transform.rotate_y(math::Angle::Degrees(-90.0));
-    camera.transform.rotate_y(math::Angle::Degrees(90.0));
 
     world.spawn((camera, FreeFlyCamera::default()));
 }

lyra-game/src/render/graph/passes/shadows.rs

@@ -20,7 +20,7 @@ use wgpu::util::DeviceExt;
 
 use crate::render::{
     graph::{Node, NodeDesc, NodeType, SlotAttribute, SlotValue},
-    light::{directional::DirectionalLight, LightType, PointLight},
+    light::{directional::DirectionalLight, LightType, PointLight, SpotLight},
     resource::{FragmentState, RenderPipeline, RenderPipelineDescriptor, Shader, VertexState},
     transform_buffer_storage::TransformBuffers,
     vertex::Vertex,
@@ -186,6 +186,7 @@ impl ShadowMapsPass {
         light_type: LightType,
         entity: Entity,
         light_pos: Transform,
+        light_half_outer_angle: Option<Angle>,
         are_settings_custom: bool,
         shadow_settings: ShadowCasterSettings,
     ) -> LightDepthMap {
@@ -265,7 +266,58 @@ impl ShadowMapsPass {
                 indices[0] = uniform_index;
                 (atlas_index, indices)
             }
-            LightType::Spotlight => todo!(),
+            LightType::Spotlight => {
+                let directional_size = SHADOW_SIZE * 4;
+                // directional lights require a single map, so allocate that in the atlas.
+                let atlas_index = atlas
+                    .pack(directional_size.x as _, directional_size.y as _)
+                    .expect("failed to pack new shadow map into texture atlas");
+                let atlas_frame = atlas.texture_frame(atlas_index).expect("Frame missing");
+
+                let aspect = SHADOW_SIZE.x as f32 / SHADOW_SIZE.y as f32;
+                let projection = glam::Mat4::perspective_rh(
+                    (light_half_outer_angle.unwrap() * 2.0).to_radians(),
+                    aspect,
+                    shadow_settings.near_plane,
+                    shadow_settings.far_plane,
+                );
+
+                // honestly no clue why this works, but I got it from here and the results are good
+                // https://github.com/asylum2010/Asylum_Tutorials/blob/423e5edfaee7b5ea450a450e65f2eabf641b2482/ShaderTutors/43_ShadowMapFiltering/main.cpp#L323
+                /* let frustum_size = Vec2::new(0.5 * projection.col(0).x, 0.5 * projection.col(1).y);
+                // maybe its better to make this a vec2 on the gpu?
+                let size_avg = (frustum_size.x + frustum_size.y) / 2.0;
+                let light_size_uv = 0.2 * size_avg; */
+
+                let light_trans = light_pos.translation;
+                let look_view = glam::Mat4::look_at_rh(
+                    light_trans,
+                    light_trans + glam::vec3(1.0, 0.0, 0.0),
+                    glam::vec3(0.0, -1.0, 0.0),
+                );
+
+                let light_proj = projection * look_view;
+
+                let u = LightShadowUniform {
+                    space_mat: light_proj,
+                    atlas_frame,
+                    near_plane: shadow_settings.near_plane,
+                    far_plane: shadow_settings.far_plane,
+                    light_size_uv: 0.0,
+                    _padding1: 0,
+                    light_pos: light_pos.translation,
+                    has_shadow_settings,
+                    pcf_samples_num: u.pcf_samples_num,
+                    pcss_blocker_search_samples: u.pcss_blocker_search_samples,
+                    constant_depth_bias: DEFAULT_CONSTANT_DEPTH_BIAS * shadow_settings.constant_depth_bias_scale,
+                    _padding2: 0,
+                };
+
+                let uniform_index = self.light_uniforms_buffer.insert(queue, &u);
+                let mut indices = [0; 6];
+                indices[0] = uniform_index;
+                (atlas_index, indices)
+            },
             LightType::Point => {
                 let aspect = SHADOW_SIZE.x as f32 / SHADOW_SIZE.y as f32;
                 let projection = glam::Mat4::perspective_rh(
@@ -626,6 +678,7 @@ impl Node for ShadowMapsPass {
                     LightType::Directional,
                     entity,
                     *pos,
+                    None,
                     custom_settings,
                     shadow_settings,
                 );
@@ -649,6 +702,31 @@ impl Node for ShadowMapsPass {
                     LightType::Point,
                     entity,
                     *pos,
+                    None,
+                    custom_settings,
+                    shadow_settings,
+                );
+                index_components_queue.push_back((entity, atlas_index));
+            }
+        }
+
+        for (entity, pos, shadow_settings, spot) in world.view_iter::<(
+            Entities,
+            &Transform,
+            Option<&ShadowCasterSettings>,
+            &SpotLight,
+        )>() {
+            if !self.depth_maps.contains_key(&entity) {
+                let (custom_settings, shadow_settings) = shadow_settings
+                    .map(|ss| (true, ss.clone()))
+                    .unwrap_or((false, settings));
+
+                let atlas_index = self.create_depth_map(
+                    &context.queue,
+                    LightType::Spotlight,
+                    entity,
+                    *pos,
+                    Some(spot.outer_cutoff),
                     custom_settings,
                     shadow_settings,
                 );
@@ -807,7 +885,23 @@ impl Node for ShadowMapsPass {
                         );
                     }
                 }
-                LightType::Spotlight => todo!(),
+                LightType::Spotlight => {
+                    pass.set_pipeline(&pipeline);
+
+                    let frame = atlas
+                        .texture_frame(light_depth_map.atlas_index)
+                        .expect("missing atlas frame for light");
+
+                    light_shadow_pass_impl(
+                        &mut pass,
+                        &self.uniforms_bg,
+                        &render_meshes,
+                        &mesh_buffers,
+                        &transforms,
+                        &frame,
+                        light_depth_map.uniform_index[0] as _,
+                    );
+                },
             }
         }
     }

lyra-game/src/render/shaders/base.wgsl

@@ -190,7 +190,8 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
             let shadow = calc_shadow_point_light(in.world_position, in.world_normal, light_dir, light, atlas_dimensions);
             light_res += blinn_phong_point_light(in.world_position, in.world_normal, light, u_material, specular_color, shadow);
         } else if (light.light_ty == LIGHT_TY_SPOT) {
-            light_res += blinn_phong_spot_light(in.world_position, in.world_normal, light, u_material, specular_color);
+            let shadow = calc_shadow_spot_light(in.world_position, in.world_normal, light_dir, light, atlas_dimensions);
+            light_res += blinn_phong_spot_light(in.world_position, in.world_normal, light, u_material, specular_color, shadow);
         }
     }
 
@@ -482,11 +483,62 @@ fn pcf_point_light(tex_coords: vec3<f32>, test_depth: f32, shadow_us: array<Ligh
     return saturate(shadow);
 }
 
-/*fn pcf_point_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, samples_num: u32, uv_radius: f32) -> f32 {
+fn calc_shadow_spot_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_dir: vec3<f32>, light: Light, atlas_dimensions: vec2<i32>) -> f32 {
+    let map_data: LightShadowMapUniform = u_light_shadow[light.light_shadow_uniform_index[0]];
+    let frag_pos_light_space = map_data.light_space_matrix * vec4<f32>(world_pos, 1.0);
+
+    var proj_coords = frag_pos_light_space.xyz / frag_pos_light_space.w;
+    // for some reason the y component is flipped after transforming
+    proj_coords.y = -proj_coords.y;
+
+    // Remap xy to [0.0, 1.0]
+    let xy_remapped = proj_coords.xy * 0.5 + 0.5;
+    
+    // use a bias to avoid shadow acne
+    let current_depth = proj_coords.z - map_data.constant_depth_bias;
+
+    // get settings
+    let settings = get_shadow_settings(map_data);
+    let pcf_samples_num = settings.x;
+    let pcss_blocker_search_samples = settings.y;
+
     var shadow = 0.0;
-    for (var i = 0; i < i32(samples_num); i++) {
+    // hardware 2x2 PCF via camparison sampler
+    if pcf_samples_num == 2u {
+        let region_coords = to_atlas_frame_coords(map_data, xy_remapped, false);
+        shadow = textureSampleCompareLevel(t_shadow_maps_atlas, s_shadow_maps_atlas_compare, region_coords, current_depth);
+    }
+    // only PCF is supported for spot lights
+    else if pcf_samples_num > 0u {
+        let texel_size = 1.0 / f32(map_data.atlas_frame.width);
+        shadow = pcf_spot_light(xy_remapped, current_depth, map_data, i32(pcf_samples_num), texel_size);
+    }
+    // no filtering
+    else {
+        let region_coords = to_atlas_frame_coords(map_data, xy_remapped, false);
+        let closest_depth = textureSampleLevel(t_shadow_maps_atlas, s_shadow_maps_atlas, region_coords, 0.0);
+        shadow = select(1.0, 0.0, current_depth > closest_depth);
+    }
+
+    // dont cast shadows outside the light's far plane
+    if (proj_coords.z > 1.0) {
+        shadow = 1.0;
+    }
+
+    // dont cast shadows if the texture coords would go past the shadow maps
+    if (xy_remapped.x > 1.0 || xy_remapped.x < 0.0 || xy_remapped.y > 1.0 || xy_remapped.y < 0.0) {
+        shadow = 1.0;
+    }
+
+    return shadow;
+}
+
+/// Calculate the shadow coefficient using PCF of a directional light
+fn pcf_spot_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, samples_num: i32, uv_radius: f32) -> f32 {
+    var shadow = 0.0;
+    for (var i = 0; i < samples_num; i++) {
         let offset = tex_coords + u_pcf_poisson_disc[i] * uv_radius;
-        let new_coords = to_atlas_frame_coords(shadow_u, offset);
+        let new_coords = to_atlas_frame_coords(shadow_u, offset, false);
         
         shadow += textureSampleCompare(t_shadow_maps_atlas, s_shadow_maps_atlas_compare, new_coords, test_depth);
     }
@@ -494,7 +546,7 @@ fn pcf_point_light(tex_coords: vec3<f32>, test_depth: f32, shadow_us: array<Ligh
 
     // clamp shadow to [0; 1]
     return saturate(shadow);
-}*/
+}
 
 fn debug_grid(in: VertexOutput) -> vec4<f32> {
     let tile_index_float: vec2<f32> = in.clip_position.xy / 16.0;
@@ -574,7 +626,7 @@ fn blinn_phong_point_light(world_pos: vec3<f32>, world_norm: vec3<f32>, point_li
     return (shadow * (ambient_color + diffuse_color + specular_color)) * point_light.intensity;
 }
 
-fn blinn_phong_spot_light(world_pos: vec3<f32>, world_norm: vec3<f32>, spot_light: Light, material: Material, specular_factor: vec3<f32>) -> vec3<f32> {
+fn blinn_phong_spot_light(world_pos: vec3<f32>, world_norm: vec3<f32>, spot_light: Light, material: Material, specular_factor: vec3<f32>, shadow: f32) -> vec3<f32> {
     let light_color = spot_light.color;
     let light_pos = spot_light.position;
     let camera_view_pos = u_camera.position;
@@ -609,13 +661,13 @@ fn blinn_phong_spot_light(world_pos: vec3<f32>, world_norm: vec3<f32>, spot_ligh
     let distance = length(light_pos - world_pos);
     let attenuation = calc_attenuation(spot_light, distance);
 
-    ambient_color *= attenuation * spot_light.intensity * cone;
+    ambient_color *= attenuation * cone;
-    diffuse_color *= attenuation * spot_light.intensity * cone;
+    diffuse_color *= attenuation * cone;
-    specular_color *= attenuation * spot_light.intensity * cone;
+    specular_color *= attenuation * cone;
     //// end of spot light attenuation ////
 
-
+    //return /*ambient_color +*/ diffuse_color + specular_color;
-    return /*ambient_color +*/ diffuse_color + specular_color;
+    return (shadow * (diffuse_color + specular_color)) * spot_light.intensity;
 }
 
 fn calc_attenuation(light: Light, distance: f32) -> f32 {

lyra-math/src/angle.rs

@@ -10,7 +10,7 @@ pub fn radians_to_degrees(radians: f32) -> f32 {
     radians * 180.0 / PI
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Copy, Debug)]
 pub enum Angle {
     Degrees(f32),
     Radians(f32),
@@ -68,4 +68,18 @@ impl std::ops::SubAssign for Angle {
             Angle::Radians(r) => *r -= rhs.to_radians(),
         }
     }
+}
+
+impl std::ops::Mul<f32> for Angle {
+    type Output = Angle;
+
+    fn mul(self, rhs: f32) -> Self::Output {
+        Angle::Radians(self.to_radians() * rhs)
+    }
+}
+
+impl std::ops::MulAssign<f32> for Angle {
+    fn mul_assign(&mut self, rhs: f32) {
+        *self = *self * rhs;
+    }
 }