Port DNA (getting started) example to C++

crates/re_sdk/src/demo_util.rs

@@ -87,8 +87,8 @@ pub fn color_spiral(
         .map(move |i| {
             let angle = i as f32 * angular_step * TAU + angular_offset;
             glam::Vec3::new(
-                angle.sin() * radius,
                 angle.cos() * radius,
+                angle.sin() * radius,
                 i as f32 * z_step,
             )
         })

crates/re_types_builder/src/codegen/cpp/mod.rs

@@ -565,6 +565,31 @@ impl QuotedObject {
             ));
         };
 
+        // If we're a component with a single datatype field, add an implicit casting operator for convenience.
+        if obj.kind == ObjectKind::Component
+            && obj.fields.len() == 1
+            && matches!(obj.fields[0].typ, Type::Object { .. })
+        {
+            if let Type::Object(datatype_fqname) = &obj.fields[0].typ {
+                let data_type = quote_field_type(&mut hpp_includes, &obj.fields[0]);
+                let type_name = datatype_fqname.split('.').last().unwrap();
+                let field_name = format_ident!("{}", obj.fields[0].name);
+
+                methods.push(Method {
+                    docs: format!("Cast to the underlying {type_name} datatype").into(),
+                    declaration: MethodDeclaration {
+                        name_and_parameters: quote! { operator #data_type() const },
+                        is_static: false,
+                        return_type: quote! {},
+                    },
+                    definition_body: quote! {
+                        return #field_name;
+                    },
+                    inline: true,
+                });
+            }
+        }
+
         // Arrow serialization methods.
         // TODO(andreas): These are just utilities for to_data_cell. How do we hide them best from the public header?
         methods.push(arrow_data_type_method(

examples/cpp/CMakeLists.txt

@@ -1,6 +1,8 @@
 add_subdirectory(clock)
 add_subdirectory(minimal)
+add_subdirectory(dna)
 
 add_custom_target(examples)
 add_dependencies(examples example_minimal)
 add_dependencies(examples example_clock)
+add_dependencies(examples example_dna)

examples/cpp/clock/README.md

@@ -2,6 +2,8 @@
 title: Clock
 python: https://github.com/rerun-io/rerun/tree/latest/examples/python/clock/main.py
 rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/clock/src/main.rs
+# TODO(#3962): Update Link
+cpp: https://github.com/rerun-io/rerun/tree/main/examples/cpp/clock/main.cpp
 thumbnail: https://static.rerun.io/clock/ae4b8970edba8480431cb71e57b8cddd9e1769c7/480w.png
 ---
 

examples/cpp/dna/CMakeLists.txt

@@ -0,0 +1,27 @@
+cmake_minimum_required(VERSION 3.16)
+
+# If you use the example outside of the Rerun SDK you need to specify
+# where the rerun_c build is to be found by setting the `RERUN_CPP_URL` variable.
+# This can be done by passing `-DRERUN_CPP_URL=<path to rerun_sdk_cpp zip>` to cmake.
+if(DEFINED RERUN_REPOSITORY)
+    add_executable(example_dna main.cpp)
+    set_default_warning_settings(example_dna)
+else()
+    project(example_dna LANGUAGES CXX)
+
+    add_executable(example_dna main.cpp)
+
+    # Set the path to the rerun_c build.
+    set(RERUN_CPP_URL CACHE STRING "URL to the rerun_cpp zip.")
+
+    # Download the rerun_sdk
+    include(FetchContent)
+    FetchContent_Declare(rerun_sdk DOWNLOAD_EXTRACT_TIMESTAMP YES URL ${RERUN_CPP_URL})
+    FetchContent_MakeAvailable(rerun_sdk)
+
+    # Rerun requires at least C++17, but you can use an evern newer version.
+    set_property(TARGET example_dna PROPERTY CXX_STANDARD 17)
+endif()
+
+# Link against rerun_sdk.
+target_link_libraries(example_dna PRIVATE rerun_sdk)

examples/cpp/dna/README.md

@@ -0,0 +1,30 @@
+---
+title: Helix
+python: https://github.com/rerun-io/rerun/tree/latest/examples/python/dna/main.py
+rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/dna/src/main.rs
+# TODO(#3962): Update Link
+cpp: https://github.com/rerun-io/rerun/tree/main/examples/cpp/dna/main.cpp
+tags: [3d, api-example]
+description: "Simple example of logging point and line primitives to draw a 3D helix."
+thumbnail: https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/480w.png
+thumbnail_dimensions: [480, 285]
+demo: true
+---
+
+<picture>
+  <source media="(max-width: 480px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/480w.png">
+  <source media="(max-width: 768px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/768w.png">
+  <source media="(max-width: 1024px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/1024w.png">
+  <source media="(max-width: 1200px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/1200w.png">
+  <img src="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/full.png" alt="">
+</picture>
+
+Simple example of logging point and line primitives to draw a 3D helix.
+
+
+To build it from a checkout of the repository (requires a Rust toolchain):
+```bash
+cmake .
+cmake --build . --target example_dna
+./examples/cpp/dna/dna
+```

examples/cpp/dna/main.cpp

@@ -29,7 +29,7 @@ int main() {
 
     std::vector<rerun::LineStrip3D> lines;
     for (size_t i = 0; i < points1.size(); ++i) {
-        lines.emplace_back(points1[i], points2[i]);
+        lines.emplace_back(rerun::LineStrip3D({points1[i].xyz, points2[i].xyz}));
     }
 
     rec.log(

examples/python/dna/README.md

@@ -1,6 +1,9 @@
 ---
 title: Helix
 python: https://github.com/rerun-io/rerun/tree/latest/examples/python/dna/main.py
+rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/dna/src/main.rs
+# TODO(#3962): Update Link
+cpp: https://github.com/rerun-io/rerun/tree/main/examples/cpp/dna/main.cpp
 tags: [3d, api-example]
 description: "Simple example of logging point and line primitives to draw a 3D helix."
 thumbnail: https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/480w.png

examples/rust/clock/README.md

@@ -2,6 +2,8 @@
 title: Clock
 python: https://github.com/rerun-io/rerun/tree/latest/examples/python/clock/main.py
 rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/clock/src/main.rs
+# TODO(#3962): Update Link
+cpp: https://github.com/rerun-io/rerun/tree/main/examples/cpp/clock/main.cpp
 thumbnail: https://static.rerun.io/clock/ae4b8970edba8480431cb71e57b8cddd9e1769c7/480w.png
 ---
 

examples/rust/dna/README.md

@@ -0,0 +1,26 @@
+---
+title: Helix
+python: https://github.com/rerun-io/rerun/tree/latest/examples/python/dna/main.py
+rust: https://github.com/rerun-io/rerun/tree/latest/examples/rust/dna/src/main.rs
+# TODO(#3962): Update Link
+cpp: https://github.com/rerun-io/rerun/tree/main/examples/cpp/dna/main.cpp
+tags: [3d, api-example]
+description: "Simple example of logging point and line primitives to draw a 3D helix."
+thumbnail: https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/480w.png
+thumbnail_dimensions: [480, 285]
+demo: true
+---
+
+<picture>
+  <source media="(max-width: 480px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/480w.png">
+  <source media="(max-width: 768px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/768w.png">
+  <source media="(max-width: 1024px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/1024w.png">
+  <source media="(max-width: 1200px)" srcset="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/1200w.png">
+  <img src="https://static.rerun.io/helix/f4c375546fa9d24f7cd3a1a715ebf75b2978817a/full.png" alt="">
+</picture>
+
+Simple example of logging point and line primitives to draw a 3D helix.
+
+```bash
+cargo run --release
+```

pixi.toml

@@ -48,6 +48,11 @@ py-test = { cmd = "python -m pytest -vv rerun_py/tests/unit", depends_on = [
   "py-build",
 ] }
 
+cpp-build-all = { depends_on = [
+  "cpp-build-tests",
+  "cpp-build-examples",
+  "cpp-build-doc-examples",
+] }
 cpp-prepare = "cmake -G Ninja -B build -S . -DCMAKE_BUILD_TYPE=Debug"
 cpp-build-tests = { cmd = "cmake --build build --config Debug --target rerun_sdk_tests", depends_on = [
   "cpp-prepare",

rerun_cpp/src/rerun.hpp

@@ -22,6 +22,7 @@ namespace rerun {
     using components::HalfSizes2D;
     using components::HalfSizes3D;
     using components::InstanceKey;
+    using components::LineStrip3D;
     using components::Material;
     using components::MediaType;
     using components::MeshProperties;

rerun_cpp/src/rerun/component_batch.hpp

@@ -34,9 +34,9 @@ namespace rerun {
         template <typename... Ts>
         struct NoAdapterFor : std::false_type {};
 
+        // `NoAdapterFor` always evaluates to false, but in a way that requires template instantiation.
         static_assert(
-            NoAdapterFor<TComponent, TInput>::value, // Always evaluate to false, but in a way that
-                                                     // requires template instantiation.
+            NoAdapterFor<TComponent, TInput>::value,
             "ComponentBatchAdapter is not implemented for this type. "
             "It is implemented for for single components as well as std::vector, std::array, and "
             "c-arrays of components. "