Add non-flat depth mode.

src/computed.rs

@@ -4,6 +4,7 @@ use bevy::prelude::*;
 #[derive(Clone, Component, Default)]
 pub struct ComputedOutlineDepth {
     pub(crate) origin: Vec3,
+    pub(crate) flat: bool,
 }
 
 /// A component which specifies how the outline depth should be computed.
@@ -12,6 +13,8 @@ pub struct ComputedOutlineDepth {
 pub enum SetOutlineDepth {
     /// A flat plane facing the camera and intersecting the specified point in model-space.
     Flat { model_origin: Vec3 },
+    /// Real model-space.
+    Real,
 }
 
 /// A component which specifies that this outline lies at the same depth as its parent.
@@ -36,18 +39,20 @@ pub(crate) fn compute_outline_depth(
     for (mut computed, transform, changed_transform, set_depth, children) in root_query.iter_mut() {
         let mut changed = changed_transform;
         if changed {
-            let origin = if let Some((sd, sd_changed)) = set_depth {
+            let (origin, flat) = if let Some((sd, sd_changed)) = set_depth {
                 changed |= sd_changed;
                 match sd {
                     SetOutlineDepth::Flat {
                         model_origin: origin,
-                    } => *origin,
+                    } => (*origin, true),
+                    SetOutlineDepth::Real => (Vec3::NAN, false),
                 }
             } else {
-                Vec3::ZERO
+                (Vec3::ZERO, true)
             };
             let matrix = transform.compute_matrix();
             computed.origin = matrix.project_point3(origin);
+            computed.flat = flat;
         }
         if let Some((cs, changed_children)) = children {
             changed |= changed_children;

src/draw.rs

@@ -8,8 +8,8 @@ use bevy::render::view::ExtractedView;
 use crate::node::{OpaqueOutline, StencilOutline, TransparentOutline};
 use crate::pipeline::{OutlinePipeline, PassType, PipelineKey};
 use crate::uniforms::{
-    OutlineFragmentUniform, OutlineStencilUniform, OutlineVolumeUniform,
+    OutlineFragmentUniform, OutlineStencilFlags, OutlineStencilUniform, OutlineVolumeFlags,
-    SetOutlineStencilBindGroup, SetOutlineVolumeBindGroup,
+    OutlineVolumeUniform, SetOutlineStencilBindGroup, SetOutlineVolumeBindGroup,
 };
 use crate::view_uniforms::SetOutlineViewBindGroup;
 
@@ -30,7 +30,12 @@ pub(crate) fn queue_outline_stencil_mesh(
     mut pipelines: ResMut<SpecializedMeshPipelines<OutlinePipeline>>,
     mut pipeline_cache: ResMut<PipelineCache>,
     render_meshes: Res<RenderAssets<Mesh>>,
-    material_meshes: Query<(Entity, &Handle<Mesh>, &OutlineStencilUniform)>,
+    material_meshes: Query<(
+        Entity,
+        &Handle<Mesh>,
+        &OutlineStencilUniform,
+        &OutlineStencilFlags,
+    )>,
     mut views: Query<(&ExtractedView, &mut RenderPhase<StencilOutline>)>,
 ) {
     let draw_stencil = stencil_draw_functions
@@ -44,10 +49,11 @@ pub(crate) fn queue_outline_stencil_mesh(
 
     for (view, mut stencil_phase) in views.iter_mut() {
         let rangefinder = view.rangefinder3d();
-        for (entity, mesh_handle, stencil_uniform) in material_meshes.iter() {
+        for (entity, mesh_handle, stencil_uniform, stencil_flags) in material_meshes.iter() {
             if let Some(mesh) = render_meshes.get(mesh_handle) {
                 let key = base_key
                     .with_primitive_topology(mesh.primitive_topology)
+                    .with_flat_depth(stencil_flags.flat_depth)
                     .with_offset_zero(stencil_uniform.offset == 0.0);
                 let pipeline = pipelines
                     .specialize(&mut pipeline_cache, &stencil_pipeline, key, &mesh.layout)
@@ -87,6 +93,7 @@ pub(crate) fn queue_outline_volume_mesh(
         Entity,
         &Handle<Mesh>,
         &OutlineVolumeUniform,
+        &OutlineVolumeFlags,
         &OutlineFragmentUniform,
     )>,
     mut views: Query<(
@@ -108,7 +115,9 @@ pub(crate) fn queue_outline_volume_mesh(
 
     for (view, mut opaque_phase, mut transparent_phase) in views.iter_mut() {
         let rangefinder = view.rangefinder3d();
-        for (entity, mesh_handle, volume_uniform, fragment_uniform) in material_meshes.iter() {
+        for (entity, mesh_handle, volume_uniform, volume_flags, fragment_uniform) in
+            material_meshes.iter()
+        {
             if let Some(mesh) = render_meshes.get(mesh_handle) {
                 let transparent = fragment_uniform.colour[3] < 1.0;
                 let key = base_key
@@ -118,6 +127,7 @@ pub(crate) fn queue_outline_volume_mesh(
                     } else {
                         PassType::Opaque
                     })
+                    .with_flat_depth(volume_flags.flat_depth)
                     .with_offset_zero(volume_uniform.offset == 0.0);
                 let pipeline = pipelines
                     .specialize(&mut pipeline_cache, &outline_pipeline, key, &mesh.layout)

src/outline.wgsl

@@ -60,12 +60,19 @@ fn vertex(vertex: VertexInput) -> @builtin(position) vec4<f32> {
     let model = mesh.model;
 #endif
     let clip_pos = view.view_proj * (model * vec4<f32>(vertex.position, 1.0));
+#ifdef FLAT_DEPTH
     let ndc_pos = clip_pos.xy / clip_pos.w;
+    let out_zw = vec2<f32>(model_origin_z(vstage.origin, view.view_proj), 1.0);
+#else
+    let ndc_pos = clip_pos.xy;
+    let out_zw = clip_pos.zw;
+#endif
 #ifdef OFFSET_ZERO
-    let ndc_delta = vec2<f32>(0.0, 0.0);
+    let out_xy = ndc_pos;
 #else
     let clip_norm = mat4to3(view.view_proj) * (mat4to3(model) * vertex.normal);
-    let ndc_delta = vstage.offset * normalize(clip_norm.xy) * view_uniform.scale;
+    let ndc_delta = vstage.offset * normalize(clip_norm.xy) * view_uniform.scale * out_zw.y;
+    let out_xy = ndc_pos + ndc_delta;
 #endif
-    return vec4<f32>(ndc_pos + ndc_delta, model_origin_z(vstage.origin, view.view_proj), 1.0);
+    return vec4<f32>(out_xy, out_zw);
 }

src/pipeline.rs

@@ -49,7 +49,8 @@ impl PipelineKey {
         msaa_samples_minus_one, set_msaa_samples_minus_one: 5, 0;
         primitive_topology_int, set_primitive_topology_int: 8, 6;
         pass_type_int, set_pass_type_int: 10, 9;
-        pub offset_zero, set_offset_zero: 11;
+        pub flat_depth, set_flat_depth: 11;
+        pub offset_zero, set_offset_zero: 12;
     }
 
     pub(crate) fn new() -> Self {
@@ -99,6 +100,11 @@ impl PipelineKey {
         self.set_offset_zero(offset_zero);
         self
     }
+
+    pub(crate) fn with_flat_depth(mut self, flat_depth: bool) -> Self {
+        self.set_flat_depth(flat_depth);
+        self
+    }
 }
 
 #[derive(Resource)]
@@ -207,6 +213,15 @@ impl SpecializedMeshPipeline for OutlinePipeline {
             },
         );
         bind_layouts.push(self.outline_view_bind_group_layout.clone());
+        let cull_mode;
+        if key.flat_depth() {
+            vertex_defs.push("FLAT_DEPTH".to_string());
+            cull_mode = Some(Face::Back);
+        } else if key.pass_type() == PassType::Stencil {
+            cull_mode = Some(Face::Back);
+        } else {
+            cull_mode = Some(Face::Front);
+        }
         if key.offset_zero() {
             vertex_defs.push("OFFSET_ZERO".to_string());
         } else {
@@ -255,7 +270,7 @@ impl SpecializedMeshPipeline for OutlinePipeline {
             layout: Some(bind_layouts),
             primitive: PrimitiveState {
                 front_face: FrontFace::Ccw,
-                cull_mode: Some(Face::Back),
+                cull_mode,
                 unclipped_depth: false,
                 polygon_mode: PolygonMode::Fill,
                 conservative: false,

src/uniforms.rs

@@ -15,19 +15,19 @@ use bevy::{
 
 use crate::{pipeline::OutlinePipeline, ComputedOutlineDepth, OutlineStencil, OutlineVolume};
 
-macro_rules! outline_vertex_uniform {
+#[derive(Clone, Component, ShaderType)]
-    ($x:ident) => {
+pub(crate) struct OutlineStencilUniform {
-        #[derive(Clone, Component, ShaderType)]
-        pub(crate) struct $x {
     #[align(16)]
     pub origin: Vec3,
     pub offset: f32,
-        }
-    };
 }
 
-outline_vertex_uniform!(OutlineStencilUniform);
+#[derive(Clone, Component, ShaderType)]
-outline_vertex_uniform!(OutlineVolumeUniform);
+pub(crate) struct OutlineVolumeUniform {
+    #[align(16)]
+    pub origin: Vec3,
+    pub offset: f32,
+}
 
 #[derive(Clone, Component, ShaderType)]
 pub(crate) struct OutlineFragmentUniform {
@@ -35,6 +35,16 @@ pub(crate) struct OutlineFragmentUniform {
     pub colour: Vec4,
 }
 
+#[derive(Component)]
+pub(crate) struct OutlineStencilFlags {
+    pub flat_depth: bool,
+}
+
+#[derive(Component)]
+pub(crate) struct OutlineVolumeFlags {
+    pub flat_depth: bool,
+}
+
 #[derive(Resource)]
 pub(crate) struct OutlineStencilBindGroup {
     pub bind_group: BindGroup,
@@ -50,9 +60,14 @@ pub(crate) fn extract_outline_stencil_uniforms(
     query: Extract<Query<(Entity, &OutlineStencil, &ComputedOutlineDepth)>>,
 ) {
     for (entity, stencil, computed) in query.iter() {
-        commands.get_or_spawn(entity).insert(OutlineStencilUniform {
+        commands
+            .get_or_spawn(entity)
+            .insert(OutlineStencilUniform {
                 origin: computed.origin,
                 offset: stencil.offset,
+            })
+            .insert(OutlineStencilFlags {
+                flat_depth: computed.flat,
             });
     }
 }
@@ -73,6 +88,9 @@ pub(crate) fn extract_outline_volume_uniforms(
             })
             .insert(OutlineFragmentUniform {
                 colour: outline.colour.as_linear_rgba_f32().into(),
+            })
+            .insert(OutlineVolumeFlags {
+                flat_depth: computed.flat,
             });
     }
 }