ShaderDefVal: add an UInt option (#6881)

# Objective

- Fixes #6841 
- In some case, the number of maximum storage buffers is `u32::MAX` which doesn't fit in a `i32`

## Solution

- Add an option to have a `u32` in a `ShaderDefVal`

crates/bevy_pbr/src/render/light.rs

@@ -321,9 +321,9 @@ impl SpecializedMeshPipeline for ShadowPipeline {
 
         let mut bind_group_layout = vec![self.view_layout.clone()];
         let mut shader_defs = Vec::new();
-        shader_defs.push(ShaderDefVal::Int(
+        shader_defs.push(ShaderDefVal::UInt(
             "MAX_DIRECTIONAL_LIGHTS".to_string(),
-            MAX_DIRECTIONAL_LIGHTS as i32,
+            MAX_DIRECTIONAL_LIGHTS as u32,
         ));
 
         if layout.contains(Mesh::ATTRIBUTE_JOINT_INDEX)

crates/bevy_pbr/src/render/mesh.rs

@@ -590,9 +590,9 @@ impl SpecializedMeshPipeline for MeshPipeline {
             vertex_attributes.push(Mesh::ATTRIBUTE_NORMAL.at_shader_location(1));
         }
 
-        shader_defs.push(ShaderDefVal::Int(
+        shader_defs.push(ShaderDefVal::UInt(
             "MAX_DIRECTIONAL_LIGHTS".to_string(),
-            MAX_DIRECTIONAL_LIGHTS as i32,
+            MAX_DIRECTIONAL_LIGHTS as u32,
         ));
 
         if layout.contains(Mesh::ATTRIBUTE_UV_0) {

crates/bevy_render/src/render_resource/pipeline_cache.rs

@@ -123,6 +123,7 @@ struct ShaderCache {
 pub enum ShaderDefVal {
     Bool(String, bool),
     Int(String, i32),
+    UInt(String, u32),
 }
 
 impl From<&str> for ShaderDefVal {
@@ -137,6 +138,16 @@ impl From<String> for ShaderDefVal {
     }
 }
 
+impl ShaderDefVal {
+    pub fn value_as_string(&self) -> String {
+        match self {
+            ShaderDefVal::Bool(_, def) => def.to_string(),
+            ShaderDefVal::Int(_, def) => def.to_string(),
+            ShaderDefVal::UInt(_, def) => def.to_string(),
+        }
+    }
+}
+
 impl ShaderCache {
     fn get(
         &mut self,
@@ -176,9 +187,9 @@ impl ShaderCache {
                     shader_defs.push("SIXTEEN_BYTE_ALIGNMENT".into());
                 }
 
-                shader_defs.push(ShaderDefVal::Int(
+                shader_defs.push(ShaderDefVal::UInt(
                     String::from("AVAILABLE_STORAGE_BUFFER_BINDINGS"),
-                    render_device.limits().max_storage_buffers_per_shader_stage as i32,
+                    render_device.limits().max_storage_buffers_per_shader_stage,
                 ));
 
                 debug!(

crates/bevy_render/src/render_resource/shader.rs

@@ -425,7 +425,9 @@ impl ShaderProcessor {
 
         let shader_defs_unique =
             HashMap::<String, ShaderDefVal>::from_iter(shader_defs.iter().map(|v| match v {
-                ShaderDefVal::Bool(k, _) | ShaderDefVal::Int(k, _) => (k.clone(), v.clone()),
+                ShaderDefVal::Bool(k, _) | ShaderDefVal::Int(k, _) | ShaderDefVal::UInt(k, _) => {
+                    (k.clone(), v.clone())
+                }
             }));
         let mut scopes = vec![true];
         let mut final_string = String::new();
@@ -484,6 +486,16 @@ impl ShaderProcessor {
                         })?;
                         act_on(*def, val, op.as_str())?
                     }
+                    ShaderDefVal::UInt(name, def) => {
+                        let val = val.as_str().parse().map_err(|_| {
+                            ProcessShaderError::InvalidShaderDefComparisonValue {
+                                shader_def_name: name.clone(),
+                                value: val.as_str().to_string(),
+                                expected: "uint".to_string(),
+                            }
+                        })?;
+                        act_on(*def, val, op.as_str())?
+                    }
                 };
                 scopes.push(*scopes.last().unwrap() && new_scope);
             } else if self.else_regex.is_match(line) {
@@ -536,24 +548,18 @@ impl ShaderProcessor {
                     for capture in self.def_regex.captures_iter(line) {
                         let def = capture.get(1).unwrap();
                         if let Some(def) = shader_defs_unique.get(def.as_str()) {
-                            let def = match def {
-                                ShaderDefVal::Bool(_, def) => def.to_string(),
-                                ShaderDefVal::Int(_, def) => def.to_string(),
-                            };
-                            line_with_defs =
-                                self.def_regex.replace(&line_with_defs, def).to_string();
+                            line_with_defs = self
+                                .def_regex
+                                .replace(&line_with_defs, def.value_as_string())
+                                .to_string();
                         }
                     }
                     for capture in self.def_regex_delimited.captures_iter(line) {
                         let def = capture.get(1).unwrap();
                         if let Some(def) = shader_defs_unique.get(def.as_str()) {
-                            let def = match def {
-                                ShaderDefVal::Bool(_, def) => def.to_string(),
-                                ShaderDefVal::Int(_, def) => def.to_string(),
-                            };
                             line_with_defs = self
                                 .def_regex_delimited
-                                .replace(&line_with_defs, def)
+                                .replace(&line_with_defs, def.value_as_string())
                                 .to_string();
                         }
                     }