feat(lambda-rs): Add support for textures

crates/lambda-rs-platform/src/wgpu/bind.rs

@@ -97,6 +97,35 @@ mod tests {
     );
     assert_eq!(Visibility::All.to_wgpu(), wgpu::ShaderStages::all());
   }
+
+  #[test]
+  fn sampled_texture_2d_layout_entry_is_correct() {
+    let builder = BindGroupLayoutBuilder::new()
+      .with_sampled_texture_2d(1, Visibility::Fragment)
+      .with_sampler(2, Visibility::Fragment);
+    assert_eq!(builder.entries.len(), 2);
+    match builder.entries[0].ty {
+      wgpu::BindingType::Texture {
+        sample_type,
+        view_dimension,
+        multisampled,
+      } => {
+        assert_eq!(view_dimension, wgpu::TextureViewDimension::D2);
+        assert_eq!(multisampled, false);
+        match sample_type {
+          wgpu::TextureSampleType::Float { filterable } => assert!(filterable),
+          _ => panic!("expected float sample type"),
+        }
+      }
+      _ => panic!("expected texture binding type"),
+    }
+    match builder.entries[1].ty {
+      wgpu::BindingType::Sampler(kind) => {
+        assert_eq!(kind, wgpu::SamplerBindingType::Filtering);
+      }
+      _ => panic!("expected sampler binding type"),
+    }
+  }
 }
 
 /// Builder for creating a `wgpu::BindGroupLayout`.
@@ -155,6 +184,56 @@ impl BindGroupLayoutBuilder {
     return self;
   }
 
+  /// Declare a sampled texture binding (2D) at the provided index.
+  pub fn with_sampled_texture_2d(
+    mut self,
+    binding: u32,
+    visibility: Visibility,
+  ) -> Self {
+    self.entries.push(wgpu::BindGroupLayoutEntry {
+      binding,
+      visibility: visibility.to_wgpu(),
+      ty: wgpu::BindingType::Texture {
+        sample_type: wgpu::TextureSampleType::Float { filterable: true },
+        view_dimension: wgpu::TextureViewDimension::D2,
+        multisampled: false,
+      },
+      count: None,
+    });
+    return self;
+  }
+
+  /// Declare a sampled texture binding with an explicit view dimension.
+  pub fn with_sampled_texture_dim(
+    mut self,
+    binding: u32,
+    visibility: Visibility,
+    view_dimension: crate::wgpu::texture::ViewDimension,
+  ) -> Self {
+    self.entries.push(wgpu::BindGroupLayoutEntry {
+      binding,
+      visibility: visibility.to_wgpu(),
+      ty: wgpu::BindingType::Texture {
+        sample_type: wgpu::TextureSampleType::Float { filterable: true },
+        view_dimension: view_dimension.to_wgpu(),
+        multisampled: false,
+      },
+      count: None,
+    });
+    return self;
+  }
+
+  /// Declare a filtering sampler binding at the provided index.
+  pub fn with_sampler(mut self, binding: u32, visibility: Visibility) -> Self {
+    self.entries.push(wgpu::BindGroupLayoutEntry {
+      binding,
+      visibility: visibility.to_wgpu(),
+      ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
+      count: None,
+    });
+    return self;
+  }
+
   /// Build the layout using the provided device.
   pub fn build(self, gpu: &Gpu) -> BindGroupLayout {
     let raw =
@@ -220,6 +299,32 @@ impl<'a> BindGroupBuilder<'a> {
     return self;
   }
 
+  /// Bind a texture view at a binding index.
+  pub fn with_texture(
+    mut self,
+    binding: u32,
+    texture: &'a crate::wgpu::texture::Texture,
+  ) -> Self {
+    self.entries.push(wgpu::BindGroupEntry {
+      binding,
+      resource: wgpu::BindingResource::TextureView(texture.view()),
+    });
+    return self;
+  }
+
+  /// Bind a sampler at a binding index.
+  pub fn with_sampler(
+    mut self,
+    binding: u32,
+    sampler: &'a crate::wgpu::texture::Sampler,
+  ) -> Self {
+    self.entries.push(wgpu::BindGroupEntry {
+      binding,
+      resource: wgpu::BindingResource::Sampler(sampler.raw()),
+    });
+    return self;
+  }
+
   /// Build the bind group with the accumulated entries.
   pub fn build(self, gpu: &Gpu) -> BindGroup {
     let layout = self

crates/lambda-rs-platform/src/wgpu/mod.rs

@@ -1,13 +1,11 @@
 //! Cross‑platform GPU abstraction built on top of `wgpu`.
 //!
 //! This module exposes a small, opinionated wrapper around core `wgpu` types
-//! to make engine code concise while keeping configuration explicit. The
-//! builders here (for the instance, surface, and device/queue) provide sane
-//! defaults and narrow the surface area used by Lambda, without hiding
-//! important handles when you need to drop down to raw `wgpu`.
-
-// keep this module focused on exports and submodules
+//! organized into focused submodules (instance, surface, gpu, pipeline, etc.).
+//! Higher layers import these modules rather than raw `wgpu` to keep Lambda’s
+//! API compact and stable.
 
+// Keep this module focused on exports and submodules only.
 pub mod bind;
 pub mod buffer;
 pub mod command;
@@ -16,4 +14,5 @@ pub mod instance;
 pub mod pipeline;
 pub mod render_pass;
 pub mod surface;
+pub mod texture;
 pub mod vertex;

crates/lambda-rs-platform/src/wgpu/pipeline.rs

@@ -8,6 +8,7 @@ use crate::wgpu::{
   bind,
   gpu::Gpu,
   surface::SurfaceFormat,
+  texture::DepthFormat,
   vertex::ColorFormat,
 };
 
@@ -210,6 +211,7 @@ pub struct RenderPipelineBuilder<'a> {
   vertex_buffers: Vec<(u64, Vec<VertexAttributeDesc>)>,
   cull_mode: CullingMode,
   color_target_format: Option<wgpu::TextureFormat>,
+  depth_stencil: Option<wgpu::DepthStencilState>,
 }
 
 impl<'a> RenderPipelineBuilder<'a> {
@@ -221,6 +223,7 @@ impl<'a> RenderPipelineBuilder<'a> {
       vertex_buffers: Vec::new(),
       cull_mode: CullingMode::Back,
       color_target_format: None,
+      depth_stencil: None,
     };
   }
 
@@ -258,6 +261,20 @@ impl<'a> RenderPipelineBuilder<'a> {
     return self;
   }
 
+  /// Enable depth testing/writes using the provided depth format and default compare/write settings.
+  ///
+  /// Defaults: compare Less, depth writes enabled, no stencil.
+  pub fn with_depth_stencil(mut self, format: DepthFormat) -> Self {
+    self.depth_stencil = Some(wgpu::DepthStencilState {
+      format: format.to_wgpu(),
+      depth_write_enabled: true,
+      depth_compare: wgpu::CompareFunction::Less,
+      stencil: wgpu::StencilState::default(),
+      bias: wgpu::DepthBiasState::default(),
+    });
+    return self;
+  }
+
   /// Build the render pipeline from provided shader modules.
   pub fn build(
     self,
@@ -333,7 +350,7 @@ impl<'a> RenderPipelineBuilder<'a> {
           layout: layout_ref,
           vertex: vertex_state,
           primitive: primitive_state,
-          depth_stencil: None,
+          depth_stencil: self.depth_stencil,
           multisample: wgpu::MultisampleState::default(),
           fragment,
           multiview: None,

crates/lambda-rs-platform/src/wgpu/render_pass.rs

@@ -54,6 +54,31 @@ impl Default for ColorOperations {
   }
 }
 
+/// Depth load operation for a depth attachment.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum DepthLoadOp {
+  /// Load the existing contents of the depth attachment.
+  Load,
+  /// Clear the depth attachment to the provided value in [0,1].
+  Clear(f32),
+}
+
+/// Depth operations (load/store) for the depth attachment.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct DepthOperations {
+  pub load: DepthLoadOp,
+  pub store: StoreOp,
+}
+
+impl Default for DepthOperations {
+  fn default() -> Self {
+    return Self {
+      load: DepthLoadOp::Clear(1.0),
+      store: StoreOp::Store,
+    };
+  }
+}
+
 /// Configuration for beginning a render pass.
 #[derive(Clone, Debug, Default)]
 pub struct RenderPassConfig {
@@ -255,13 +280,17 @@ impl RenderPassBuilder {
     return self;
   }
 
+  // Depth attachment is supplied at build time by the caller.
+
   /// Build (begin) the render pass on the provided encoder using the provided
   /// color attachments list. The attachments list MUST outlive the returned
   /// render pass value.
   pub fn build<'view>(
     &'view self,
     encoder: &'view mut command::CommandEncoder,
     attachments: &'view mut RenderColorAttachments<'view>,
+    depth_view: Option<crate::wgpu::surface::TextureViewRef<'view>>,
+    depth_ops: Option<DepthOperations>,
   ) -> RenderPass<'view> {
     let operations = match self.config.color_operations.load {
       ColorLoadOp::Load => wgpu::Operations {
@@ -288,10 +317,35 @@ impl RenderPassBuilder {
     // Apply operations to all provided attachments.
     attachments.set_operations_for_all(operations);
 
+    // Optional depth attachment
+    let depth_stencil_attachment = depth_view.map(|v| {
+      let dop = depth_ops.unwrap_or_default();
+      wgpu::RenderPassDepthStencilAttachment {
+        view: v.raw,
+        depth_ops: Some(match dop.load {
+          DepthLoadOp::Load => wgpu::Operations {
+            load: wgpu::LoadOp::Load,
+            store: match dop.store {
+              StoreOp::Store => wgpu::StoreOp::Store,
+              StoreOp::Discard => wgpu::StoreOp::Discard,
+            },
+          },
+          DepthLoadOp::Clear(value) => wgpu::Operations {
+            load: wgpu::LoadOp::Clear(value as f32),
+            store: match dop.store {
+              StoreOp::Store => wgpu::StoreOp::Store,
+              StoreOp::Discard => wgpu::StoreOp::Discard,
+            },
+          },
+        }),
+        stencil_ops: None,
+      }
+    });
+
     let desc: wgpu::RenderPassDescriptor<'view> = wgpu::RenderPassDescriptor {
       label: self.config.label.as_deref(),
       color_attachments: attachments.as_slice(),
-      depth_stencil_attachment: None,
+      depth_stencil_attachment,
       timestamp_writes: None,
       occlusion_query_set: None,
     };