Add bind group and bind group layout builders

src/render.rs

@@ -1,7 +1,9 @@
+mod bind_group;
 mod context;
 mod texture;
 
 pub use self::{
+    bind_group::{BindGroupBuilder, BindGroupLayoutBuilder},
     context::Context,
     texture::{Texture, TextureBuilder},
 };

src/render/bind_group.rs

@@ -0,0 +1,96 @@
+use std::num::NonZeroU32;
+
+use super::Context;
+
+#[derive(Debug, Default)]
+pub struct BindGroupLayoutBuilder<'a> {
+    next_binding: u32,
+    entries: Vec<wgpu::BindGroupLayoutEntry>,
+    label: Option<&'a str>,
+}
+
+impl<'a> BindGroupLayoutBuilder<'a> {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    #[inline]
+    pub fn with_label(mut self, label: &'a str) -> Self {
+        self.label = Some(label);
+        self
+    }
+
+    #[inline]
+    pub fn with_entry(
+        mut self,
+        visibility: wgpu::ShaderStages,
+        ty: wgpu::BindingType,
+        count: Option<NonZeroU32>,
+    ) -> Self {
+        self.entries.push(wgpu::BindGroupLayoutEntry {
+            binding: self.next_binding,
+            visibility,
+            ty,
+            count,
+        });
+        self.next_binding += 1;
+        self
+    }
+
+    #[inline]
+    pub fn build(self, context: &Context) -> wgpu::BindGroupLayout {
+        context
+            .device
+            .create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+                label: self.label,
+                entries: &self.entries,
+            })
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct BindGroupBuilder<'a> {
+    next_binding: u32,
+    label: Option<&'a str>,
+    entries: Vec<wgpu::BindGroupEntry<'a>>,
+    layout: Option<&'a wgpu::BindGroupLayout>,
+}
+
+impl<'a> BindGroupBuilder<'a> {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    #[inline]
+    pub fn with_label(mut self, label: &'a str) -> Self {
+        self.label = Some(label);
+        self
+    }
+
+    #[inline]
+    pub fn with_entry(mut self, resource: wgpu::BindingResource<'a>) -> Self {
+        self.entries.push(wgpu::BindGroupEntry {
+            binding: self.next_binding,
+            resource,
+        });
+        self.next_binding += 1;
+        self
+    }
+
+    #[inline]
+    pub fn with_layout(mut self, layout: &'a wgpu::BindGroupLayout) -> Self {
+        self.layout = Some(layout);
+        self
+    }
+
+    #[inline]
+    pub fn build(self, context: &Context) -> wgpu::BindGroup {
+        context
+            .device
+            .create_bind_group(&wgpu::BindGroupDescriptor {
+                label: self.label,
+                layout: &self.layout.unwrap(),
+                entries: self.entries.as_slice(),
+            })
+    }
+}