Extract pad stroke face orchestration

docs/modernization/debt.md

@@ -86,9 +86,10 @@ agent or engineer to remove them without reconstructing context from chat.
   `execute_legacy_canvas_stroke_main_pass_frame_callbacks(...)`; the retained
   path still owns the concrete shader, sampler, and framebuffer wiring.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw()` pad-face
-  orchestration remains retained and is next targeted for helper extraction;
+  orchestration now routes through
-  pad destination dispatch already routes through a retained helper, but the
+  `execute_legacy_canvas_stroke_pad_face_callbacks(...)`; the retained path
-  pad face loop and copy timing still live in `Canvas`.
+  still owns the concrete brush shape, destination dispatch, and framebuffer
+  wiring.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw_samples()`
   now routes polygon triangulation, sample-point assembly, and retained
   destination-copy / upload / draw helper handoff through

docs/modernization/tasks.md

@@ -954,7 +954,7 @@ ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_ex
 
 ### STR-008 - Extract Pad Stroke Face Orchestration
 
-Status: Ready
+Status: Done
 Score: +1 renderer boundary and OpenGL parity
 Debt: `DEBT-0036`
 Scope: `src/canvas.cpp`, `src/legacy_canvas_stroke_execution_services.h`,
@@ -980,3 +980,9 @@ Validation:
 ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution" --output-on-failure
 & 'C:\Program Files\Microsoft Visual Studio\18\Community\MSBuild\Current\Bin\MSBuild.exe' out\build\windows-msvc-default\tests\pp_paint_renderer_stroke_execution_tests.vcxproj /p:Configuration=Debug /p:Platform=x64
 ```
+
+### Completed Task Log
+
+| Date | Task | Score | Validation | Commit |
+| --- | --- | ---: | --- | --- |
+| 2026-06-13 | STR-008 | +1 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution" --output-on-failure`; `MSBuild.exe out\build\windows-msvc-default\tests\pp_paint_renderer_stroke_execution_tests.vcxproj /p:Configuration=Debug /p:Platform=x64` | pending |

src/canvas.cpp

@@ -858,26 +858,23 @@ void Canvas::stroke_draw()
                 m_tex[face_index].unbind();
             });
     };
-    [[maybe_unused]] const auto pad_result = pp::panopainter::execute_legacy_canvas_stroke_pad_faces(
+    [[maybe_unused]] const auto pad_result = pp::panopainter::execute_legacy_canvas_stroke_pad_face_callbacks(
-        pp::panopainter::LegacyCanvasStrokePadExecutionRequest {
+        pad_faces,
-            .context = "Canvas::stroke_draw",
+        stroke_extent,
-            .extent = stroke_extent,
+        copy_stroke_destination,
-            .faces = pad_faces,
+        [&](std::span<const vertex_t> pad_quad) {
-            .copy_stroke_destination = copy_stroke_destination,
-            .upload_pad_vertices = [&](std::span<const vertex_t> pad_quad) {
             m_brush_shape.update_vertices(
                 const_cast<vertex_t*>(pad_quad.data()),
                 static_cast<int>(pad_quad.size()));
         },
-            .begin_face = [&](int face_index) {
+        [&](int face_index) {
             m_tmp[face_index].bindFramebuffer();
         },
-            .bind_destination_texture = [&](int face_index) {
+        [&](int face_index) {
             pp::panopainter::bind_legacy_canvas_stroke_texture_inputs(
                 pad_destination_texture_binding,
                 make_pad_destination_texture_dispatch(face_index));
         },
-            .copy_framebuffer_to_destination_texture =
         [&](const pp::paint_renderer::CanvasStrokeCopyRegion& copy_region) {
             copy_framebuffer_to_texture_2d(
                 copy_region.x,
@@ -887,17 +884,16 @@ void Canvas::stroke_draw()
                 copy_region.width,
                 copy_region.height);
         },
-            .unbind_destination_texture = [&](int face_index) {
+        [&](int face_index) {
             pp::panopainter::unbind_legacy_canvas_stroke_texture_inputs(
                 pad_destination_texture_binding,
                 make_pad_destination_texture_dispatch(face_index));
         },
-            .draw_pad = [&] {
+        [&] {
             m_brush_shape.draw_fill();
         },
-            .finish_face = [&](int face_index) {
+        [&](int face_index) {
             m_tmp[face_index].unbindFramebuffer();
-            },
         });
 
     // DRAW DUAL BRUSH

src/legacy_canvas_stroke_execution_services.h

@@ -248,6 +248,9 @@ struct LegacyCanvasStrokePadExecutionResult {
     std::size_t padded_faces = 0;
 };
 
+[[nodiscard]] inline LegacyCanvasStrokePadExecutionResult execute_legacy_canvas_stroke_pad_faces(
+    const LegacyCanvasStrokePadExecutionRequest& request);
+
 struct LegacyCanvasStrokeMixPassPlane {
     int index = 0;
     bool visible = true;
@@ -368,6 +371,35 @@ std::size_t execute_legacy_canvas_stroke_main_pass_frame_callbacks(
         pass_dirty_faces);
 }
 
+template <typename Faces, typename UploadPadVertices, typename BeginFace, typename BindDestinationTexture, typename CopyFramebufferToDestinationTexture, typename UnbindDestinationTexture, typename DrawPad, typename FinishFace>
+std::size_t execute_legacy_canvas_stroke_pad_face_callbacks(
+    Faces&& faces,
+    pp::renderer::Extent2D extent,
+    bool copy_stroke_destination,
+    UploadPadVertices&& upload_pad_vertices,
+    BeginFace&& begin_face,
+    BindDestinationTexture&& bind_destination_texture,
+    CopyFramebufferToDestinationTexture&& copy_framebuffer_to_destination_texture,
+    UnbindDestinationTexture&& unbind_destination_texture,
+    DrawPad&& draw_pad,
+    FinishFace&& finish_face)
+{
+    return execute_legacy_canvas_stroke_pad_faces(
+        LegacyCanvasStrokePadExecutionRequest {
+            .context = "Canvas::stroke_draw",
+            .extent = extent,
+            .faces = std::forward<Faces>(faces),
+            .copy_stroke_destination = copy_stroke_destination,
+            .upload_pad_vertices = std::forward<UploadPadVertices>(upload_pad_vertices),
+            .begin_face = std::forward<BeginFace>(begin_face),
+            .bind_destination_texture = std::forward<BindDestinationTexture>(bind_destination_texture),
+            .copy_framebuffer_to_destination_texture = std::forward<CopyFramebufferToDestinationTexture>(copy_framebuffer_to_destination_texture),
+            .unbind_destination_texture = std::forward<UnbindDestinationTexture>(unbind_destination_texture),
+            .draw_pad = std::forward<DrawPad>(draw_pad),
+            .finish_face = std::forward<FinishFace>(finish_face),
+        }).padded_faces;
+}
+
 [[nodiscard]] inline LegacyCanvasStrokeDualPassResult execute_legacy_canvas_stroke_dual_pass(
     const LegacyCanvasStrokeDualPassRequest& request)
 {

tests/paint_renderer/stroke_execution_tests.cpp

@@ -1437,6 +1437,72 @@ void retained_stroke_main_pass_frame_callbacks_preserve_order(pp::tests::Harness
     PP_EXPECT(h, events == expected_events);
 }
 
+void retained_stroke_pad_face_callbacks_preserve_order(pp::tests::Harness& h)
+{
+    const std::array<bool, 3> dirty_faces { true, false, true };
+    const std::array<glm::vec4, 3> pass_dirty_boxes {
+        glm::vec4(5.0F, 10.0F, 20.0F, 30.0F),
+        glm::vec4(0.0F, 0.0F, 0.0F, 0.0F),
+        glm::vec4(60.0F, 15.0F, 70.0F, 25.0F),
+    };
+    const auto faces = pp::panopainter::make_legacy_canvas_stroke_pad_faces(dirty_faces, pass_dirty_boxes);
+
+    std::vector<std::string> events;
+    std::vector<pp::paint_renderer::CanvasStrokeCopyRegion> copy_regions;
+    std::array<vertex_t, 4> uploaded_quad {};
+
+    const auto result = pp::panopainter::execute_legacy_canvas_stroke_pad_face_callbacks(
+        std::span<const LegacyCanvasStrokePadFace>(faces),
+        pp::renderer::Extent2D { .width = 100, .height = 80 },
+        true,
+        [&](std::span<const vertex_t> vertices) {
+            events.emplace_back("upload:" + std::to_string(vertices.size()));
+            std::copy(vertices.begin(), vertices.end(), uploaded_quad.begin());
+        },
+        [&](int face_index) {
+            events.emplace_back("begin:" + std::to_string(face_index));
+        },
+        [&](int face_index) {
+            events.emplace_back("bind:" + std::to_string(face_index));
+        },
+        [&](const pp::paint_renderer::CanvasStrokeCopyRegion& copy_region) {
+            events.emplace_back("copy");
+            copy_regions.push_back(copy_region);
+        },
+        [&](int face_index) {
+            events.emplace_back("unbind:" + std::to_string(face_index));
+        },
+        [&] {
+            events.emplace_back("draw");
+        },
+        [&](int face_index) {
+            events.emplace_back("finish:" + std::to_string(face_index));
+        });
+
+    PP_EXPECT(h, result == 2U);
+    const std::vector<std::string> expected_events {
+        "upload:4",
+        "begin:0",
+        "bind:0",
+        "draw",
+        "unbind:0",
+        "finish:0",
+        "upload:4",
+        "begin:2",
+        "bind:2",
+        "copy",
+        "draw",
+        "unbind:2",
+        "finish:2",
+    };
+    PP_EXPECT(h, events == expected_events);
+    PP_EXPECT(h, copy_regions.size() == 1U);
+    PP_EXPECT(h, faces[0].dirty);
+    PP_EXPECT(h, !faces[1].dirty);
+    PP_EXPECT(h, faces[2].dirty);
+    PP_EXPECT(h, uploaded_quad.size() == 4U);
+}
+
 void retained_stroke_pad_executor_copies_destination_for_dirty_faces_only(pp::tests::Harness& h)
 {
     const std::array<bool, 3> dirty_faces { true, false, true };