feat(engine): add offset options to renderer::Command::DrawMesh

1 files changed, 35 insertions, 4 deletions

diff --git a/engine/src/renderer.rs b/engine/src/renderer.rs
index 52764db..b52e6b9 100644
--- a/engine/src/renderer.rs
+++ b/engine/src/renderer.rs
@@ -191,10 +191,40 @@ pub enum Command
         mesh: Mesh,
         usage: MeshUsage,
     },
-    DrawMesh(ObjectId),
+    DrawMesh(ObjectId, DrawMeshOptions),
     UpdateDrawProperties(DrawProperties, DrawPropertiesUpdateFlags),
 }
 
+builder! {
+    #[builder(name = DrawMeshOptionsBuilder, derives = (Debug, Default, Clone))]
+    #[derive(Debug, Default, Clone)]
+    #[non_exhaustive]
+    pub struct DrawMeshOptions {
+        pub element_offset: u32,
+        pub vertex_offset: u32,
+
+        #[builder(skip_generate_fn)]
+        pub element_cnt: Option<u32>,
+    }
+}
+
+impl DrawMeshOptions
+{
+    pub fn builder() -> DrawMeshOptionsBuilder
+    {
+        DrawMeshOptionsBuilder::default()
+    }
+}
+
+impl DrawMeshOptionsBuilder
+{
+    pub fn element_cnt(mut self, element_cnt: u32) -> Self
+    {
+        self.element_cnt = Some(element_cnt);
+        self
+    }
+}
+
 bitflags! {
     #[derive(Debug)]
     pub struct BufferClearMask: u8 {
@@ -531,9 +561,10 @@ pub fn add_main_render_passes(
                     });
                 }
 
-                render_pass
-                    .commands
-                    .push(Command::DrawMesh(ObjectId::Asset(mesh_asset.id())));
+                render_pass.commands.push(Command::DrawMesh(
+                    ObjectId::Asset(mesh_asset.id()),
+                    DrawMeshOptions::default(),
+                ));
 
                 if let Some(draw_flags) = draw_flags.as_deref()
                     && draw_flags.polygon_mode_config != PolygonModeConfig::default()