From 4138305491a4fcc7f287d283babc33d8acf5715a Mon Sep 17 00:00:00 2001
From: Robert Swain <robert.swain@gmail.com>
Date: Wed, 30 Jun 2021 01:56:45 +0200
Subject: [PATCH] wgsl PBR fixes (#12)

bevy_pbr2: Fix light uniforms
---
 pipelined/bevy_pbr2/src/render/light.rs |  3 ++-
 pipelined/bevy_pbr2/src/render/mod.rs   |  1 -
 pipelined/bevy_pbr2/src/render/pbr.wgsl | 20 +++++++++++---------
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/pipelined/bevy_pbr2/src/render/light.rs b/pipelined/bevy_pbr2/src/render/light.rs
index d9d785504b883..e9d678d4f9ac8 100644
--- a/pipelined/bevy_pbr2/src/render/light.rs
+++ b/pipelined/bevy_pbr2/src/render/light.rs
@@ -43,9 +43,10 @@ pub struct GpuLight {
 #[repr(C)]
 #[derive(Copy, Clone, Debug, AsStd140)]
 pub struct GpuLights {
+    // TODO: this comes first to work around a WGSL alignment issue. We need to solve this issue before releasing the renderer rework
+    lights: [GpuLight; MAX_OMNI_LIGHTS],
     ambient_color: Vec4,
     len: u32,
-    lights: [GpuLight; MAX_OMNI_LIGHTS],
 }
 
 // NOTE: this must be kept in sync MAX_OMNI_LIGHTS in pbr.frag
diff --git a/pipelined/bevy_pbr2/src/render/mod.rs b/pipelined/bevy_pbr2/src/render/mod.rs
index 9b7229981dc11..86066d94bed6b 100644
--- a/pipelined/bevy_pbr2/src/render/mod.rs
+++ b/pipelined/bevy_pbr2/src/render/mod.rs
@@ -42,7 +42,6 @@ impl FromWorld for PbrShaders {
         let render_device = world.get_resource::<RenderDevice>().unwrap();
         let shader = Shader::from_wgsl(include_str!("pbr.wgsl"));
         let shader_module = render_device.create_shader_module(&shader);
-        println!("{}", GpuLights::std140_size_static());
 
         // TODO: move this into ViewMeta?
         let view_layout = render_device.create_bind_group_layout(&BindGroupLayoutDescriptor {
diff --git a/pipelined/bevy_pbr2/src/render/pbr.wgsl b/pipelined/bevy_pbr2/src/render/pbr.wgsl
index 9eb3e9bf971c8..ac76008202837 100644
--- a/pipelined/bevy_pbr2/src/render/pbr.wgsl
+++ b/pipelined/bevy_pbr2/src/render/pbr.wgsl
@@ -22,9 +22,10 @@ struct Vertex {
 };
 
 struct VertexOutput {
-    [[builtin(position)]] world_position: vec4<f32>;
-    [[location(0)]] world_normal: vec3<f32>;
-    [[location(1)]] uv: vec2<f32>;
+    [[builtin(position)]] clip_position: vec4<f32>;
+    [[location(0)]] world_position: vec4<f32>;
+    [[location(1)]] world_normal: vec3<f32>;
+    [[location(2)]] uv: vec2<f32>;
 };
 
 [[stage(vertex)]]
@@ -33,7 +34,8 @@ fn vertex(vertex: Vertex) -> VertexOutput {
 
     var out: VertexOutput;
     out.uv = vertex.uv;
-    out.world_position = view.view_proj * world_position;
+    out.world_position = world_position;
+    out.clip_position = view.view_proj * world_position;
     // FIXME: The inverse transpose of the model matrix should be used to correctly handle scaling
     // of normals
     out.world_normal = mat3x3<f32>(mesh.transform.x.xyz, mesh.transform.y.xyz, mesh.transform.z.xyz) * vertex.normal;
@@ -95,11 +97,11 @@ struct OmniLight {
 
 [[block]]
 struct Lights {
-    ambient_color: vec4<f32>;
-    num_lights: u32;
     // NOTE: this array size must be kept in sync with the constants defined bevy_pbr2/src/render/light.rs
     // TODO: this can be removed if we move to storage buffers for light arrays
     omni_lights: array<OmniLight, 10>;
+    ambient_color: vec4<f32>;
+    num_lights: u32;
 };
 
 let FLAGS_BASE_COLOR_TEXTURE_BIT: u32         = 1u;
@@ -359,9 +361,9 @@ fn fetch_shadow(light_id: i32, homogeneous_coords: vec4<f32>) -> f32 {
 
 struct FragmentInput {
     [[builtin(front_facing)]] is_front: bool;
-    [[builtin(position)]] world_position: vec4<f32>;
-    [[location(0)]] world_normal: vec3<f32>;
-    [[location(1)]] uv: vec2<f32>;
+    [[location(0)]] world_position: vec4<f32>;
+    [[location(1)]] world_normal: vec3<f32>;
+    [[location(2)]] uv: vec2<f32>;
 };
 
 [[stage(fragment)]]