Extract pad destination dispatch overload

docs/modernization/debt.md

@@ -18,6 +18,10 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: `LATER-003` was narrowed again. `Canvas::stroke_draw()` now
+  routes pad destination texture dispatch through retained helper overloads,
+  so the face-index callback wiring is no longer built inline in the pad
+  branch.
 - 2026-06-13: `LATER-003` was narrowed again. `Canvas::stroke_draw()` now
   routes its main live-pass bind, execute, and unbind sequence through
   `execute_legacy_canvas_stroke_main_pass(...)`; the retained adapter still

docs/modernization/tasks.md

@@ -575,6 +575,9 @@ Done Checks:
 
 Progress Notes:
 
+- 2026-06-13: `Canvas::stroke_draw()` now routes pad destination texture
+  dispatch through retained helper overloads, so the face-index callback
+  wiring is no longer built inline in the pad branch.
 - 2026-06-13: `Canvas::stroke_draw()` now routes its main live-pass bind,
   execute, and unbind sequence through
   `execute_legacy_canvas_stroke_main_pass(...)`; the retained adapter still

src/canvas.cpp

@@ -863,18 +863,6 @@ void Canvas::stroke_draw()
             .slot = 1,
         },
             };
-    const auto make_pad_destination_texture_dispatch = [&](int face_index) {
-        return pp::panopainter::make_legacy_canvas_stroke_pad_destination_texture_dispatch(
-            [&](int texture_slot) {
-                set_active_texture_unit(texture_slot);
-            },
-            [&] {
-                m_tex[face_index].bind();
-            },
-            [&] {
-                m_tex[face_index].unbind();
-            });
-    };
     [[maybe_unused]] const auto pad_result = pp::panopainter::execute_legacy_canvas_stroke_pad_face_callbacks(
         pad_faces,
         stroke_extent,
@@ -890,7 +878,17 @@ void Canvas::stroke_draw()
         [&](int face_index) {
             pp::panopainter::bind_legacy_canvas_stroke_texture_inputs(
                 pad_destination_texture_binding,
-                make_pad_destination_texture_dispatch(face_index));
+                pp::panopainter::make_legacy_canvas_stroke_pad_destination_texture_dispatch(
+                    [&](int texture_slot) {
+                        set_active_texture_unit(texture_slot);
+                    },
+                    [&](int dst_face_index) {
+                        m_tex[dst_face_index].bind();
+                    },
+                    [&](int dst_face_index) {
+                        m_tex[dst_face_index].unbind();
+                    },
+                    face_index));
         },
         [&](const pp::paint_renderer::CanvasStrokeCopyRegion& copy_region) {
             copy_framebuffer_to_texture_2d(
@@ -904,7 +902,17 @@ void Canvas::stroke_draw()
         [&](int face_index) {
             pp::panopainter::unbind_legacy_canvas_stroke_texture_inputs(
                 pad_destination_texture_binding,
-                make_pad_destination_texture_dispatch(face_index));
+                pp::panopainter::make_legacy_canvas_stroke_pad_destination_texture_dispatch(
+                    [&](int texture_slot) {
+                        set_active_texture_unit(texture_slot);
+                    },
+                    [&](int dst_face_index) {
+                        m_tex[dst_face_index].bind();
+                    },
+                    [&](int dst_face_index) {
+                        m_tex[dst_face_index].unbind();
+                    },
+                    face_index));
         },
         [&] {
             m_brush_shape.draw_fill();

src/legacy_canvas_stroke_execution_services.h

@@ -140,6 +140,22 @@ struct LegacyCanvasStrokeTextureInputDispatch {
     };
 }
 
+[[nodiscard]] inline LegacyCanvasStrokeTextureInputDispatch make_legacy_canvas_stroke_pad_destination_texture_dispatch(
+    std::function<void(int)> activate_texture_unit,
+    std::function<void(int)> bind_stroke_destination,
+    std::function<void(int)> unbind_stroke_destination,
+    int face_index)
+{
+    return make_legacy_canvas_stroke_pad_destination_texture_dispatch(
+        std::move(activate_texture_unit),
+        [bind_stroke_destination = std::move(bind_stroke_destination), face_index]() {
+            bind_stroke_destination(face_index);
+        },
+        [unbind_stroke_destination = std::move(unbind_stroke_destination), face_index]() {
+            unbind_stroke_destination(face_index);
+        });
+}
+
 struct LegacyCanvasStrokeSamplerDispatch {
     std::function<void(int)> bind_brush_tip_sampler;
     std::function<void()> unbind_brush_tip_sampler;

tests/paint_renderer/stroke_execution_tests.cpp

@@ -361,6 +361,27 @@ void retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_cal
     PP_EXPECT(h, events == expected_events);
 }
 
+void retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_face_wiring(pp::tests::Harness& h)
+{
+    std::vector<std::string> events;
+    const auto dispatch = pp::panopainter::make_legacy_canvas_stroke_pad_destination_texture_dispatch(
+        [&](int slot) { events.emplace_back("activate:" + std::to_string(slot)); },
+        [&](int face_index) { events.emplace_back("bind:" + std::to_string(face_index)); },
+        [&](int face_index) { events.emplace_back("unbind:" + std::to_string(face_index)); },
+        4);
+
+    dispatch.activate_texture_unit(1);
+    dispatch.bind_stroke_destination();
+    dispatch.unbind_stroke_destination();
+
+    const std::vector<std::string> expected_events {
+        "activate:1",
+        "bind:4",
+        "unbind:4",
+    };
+    PP_EXPECT(h, events == expected_events);
+}
+
 void retained_stroke_destination_texture_dispatch_helper_builds_expected_callback_wiring(pp::tests::Harness& h)
 {
     std::vector<std::string> events;
@@ -1791,6 +1812,9 @@ int main()
     harness.run(
         "retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_callback_wiring",
         retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_callback_wiring);
+    harness.run(
+        "retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_face_wiring",
+        retained_stroke_pad_destination_texture_dispatch_helper_builds_expected_face_wiring);
     harness.run(
         "retained_stroke_brush_tip_texture_dispatch_helper_builds_expected_callback_wiring",
         retained_stroke_brush_tip_texture_dispatch_helper_builds_expected_callback_wiring);