Extract preview sample pass request helper

docs/modernization/tasks.md

@@ -1958,6 +1958,34 @@ ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_composito
 cmake --build --preset windows-msvc-default --config Debug --target PanoPainter
 ```
 
+### STR-044 - Extract Preview Sample Pass Request Construction
+
+Status: Ready
+Score: no score movement
+Debt: `DEBT-0036`
+Scope: `src/node_stroke_preview.cpp`, `tests/paint_renderer/compositor_tests.cpp`
+
+Goal:
+
+Move the remaining `execute_stroke_preview_sample_pass()` request construction
+into a retained helper so the executor wrapper keeps only request dispatch and
+dirty-bounds return handling.
+
+Done Checks:
+
+- `execute_stroke_preview_sample_pass()` no longer owns the sample-request
+  construction inline.
+- Regression coverage proves the helper preserves destination binding, copy,
+  and brush draw ordering.
+- `docs/modernization/debt.md` records the reduced preview sample-pass surface.
+
+Validation:
+
+```powershell
+ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_compositor|pp_paint_renderer_stroke_execution" --output-onfailure
+cmake --build --preset windows-msvc-default --config Debug --target PanoPainter
+```
+
 ### STR-010 - Extract Remaining Draw Merge Composite Orchestration
 
 ### STR-016 - Extract Draw Merge Layer Composite Execution

src/node_stroke_preview.cpp

@@ -322,23 +322,15 @@ std::array<pp::paint_renderer::CanvasStrokePoint, 4> make_stroke_preview_sample_
     };
 }
 
-void upload_stroke_preview_brush_vertices(DynamicShape& brush_shape, std::span<const vertex_t> vertices)
-{
-    brush_shape.update_vertices(
-        const_cast<vertex_t*>(vertices.data()),
-        static_cast<int>(vertices.size()));
-}
-
-glm::vec4 execute_stroke_preview_sample_pass(
+pp::panopainter::LegacyStrokeSampleExecutionRequest make_stroke_preview_sample_request(
     std::array<vertex_t, 4>& vertices,
+    const std::array<pp::paint_renderer::CanvasStrokePoint, 4>& sample_points,
     glm::vec2 target_size,
     Texture2D& blend_texture,
     DynamicShape& brush_shape,
     bool copy_stroke_destination)
 {
-    const auto sample_points = make_stroke_preview_sample_points(vertices);
-    const auto result = pp::panopainter::execute_legacy_canvas_stroke_sample(
-        pp::panopainter::LegacyStrokeSampleExecutionRequest {
+    return pp::panopainter::LegacyStrokeSampleExecutionRequest {
         .context = "NodeStrokePreview::stroke_draw_samples",
         .target_size = target_size,
         .vertices = vertices,
@@ -371,7 +363,32 @@ glm::vec4 execute_stroke_preview_sample_pass(
         .draw_brush_shape = [&] {
             brush_shape.draw_fill();
         },
-        });
+    };
+}
+
+void upload_stroke_preview_brush_vertices(DynamicShape& brush_shape, std::span<const vertex_t> vertices)
+{
+    brush_shape.update_vertices(
+        const_cast<vertex_t*>(vertices.data()),
+        static_cast<int>(vertices.size()));
+}
+
+glm::vec4 execute_stroke_preview_sample_pass(
+    std::array<vertex_t, 4>& vertices,
+    glm::vec2 target_size,
+    Texture2D& blend_texture,
+    DynamicShape& brush_shape,
+    bool copy_stroke_destination)
+{
+    const auto sample_points = make_stroke_preview_sample_points(vertices);
+    const auto result = pp::panopainter::execute_legacy_canvas_stroke_sample(
+        make_stroke_preview_sample_request(
+            vertices,
+            sample_points,
+            target_size,
+            blend_texture,
+            brush_shape,
+            copy_stroke_destination));
     return result.dirty_bounds;
 }