Trim stroke pad texture dispatch

docs/modernization/tasks.md

@@ -509,6 +509,11 @@ Done Checks:
 
 Progress Notes:
 
+- 2026-06-13: `Canvas::stroke_draw()` now routes the pad-stroke destination
+  texture dispatch through a local helper lambda, so the repeated bind/unbind
+  callback construction is centralized while the pad executor still owns the
+  face loop and copy timing. Next slice should target another narrow canvas
+  stroke execution seam without reopening landed pad or sample helpers.
 - 2026-06-13: `Canvas::stroke_draw_mix()` now routes mix-pass plane planning
   through `plan_legacy_canvas_stroke_mix_pass_planes(...)` and wraps retained
   framebuffer setup/teardown with

src/canvas.cpp

@@ -846,6 +846,19 @@ void Canvas::stroke_draw()
             .slot = 1,
         },
     };
+    const auto make_pad_destination_texture_dispatch = [&](int face_index) {
+        return pp::panopainter::LegacyCanvasStrokeTextureInputDispatch {
+            .activate_texture_unit = [&](int texture_slot) {
+                set_active_texture_unit(texture_slot);
+            },
+            .bind_stroke_destination = [&] {
+                m_tex[face_index].bind();
+            },
+            .unbind_stroke_destination = [&] {
+                m_tex[face_index].unbind();
+            },
+        };
+    };
     [[maybe_unused]] const auto pad_result = pp::panopainter::execute_legacy_canvas_stroke_pad_faces(
         pp::panopainter::LegacyCanvasStrokePadExecutionRequest {
             .context = "Canvas::stroke_draw",
@@ -863,14 +876,7 @@ void Canvas::stroke_draw()
             .bind_destination_texture = [&](int face_index) {
                 pp::panopainter::bind_legacy_canvas_stroke_texture_inputs(
                     pad_destination_texture_binding,
-                    pp::panopainter::LegacyCanvasStrokeTextureInputDispatch {
+                    make_pad_destination_texture_dispatch(face_index));
-                        .activate_texture_unit = [&](int texture_slot) {
-                            set_active_texture_unit(texture_slot);
-                        },
-                        .bind_stroke_destination = [&] {
-                            m_tex[face_index].bind();
-                        },
-                    });
             },
             .copy_framebuffer_to_destination_texture =
                 [&](const pp::paint_renderer::CanvasStrokeCopyRegion& copy_region) {
@@ -885,14 +891,7 @@ void Canvas::stroke_draw()
             .unbind_destination_texture = [&](int face_index) {
                 pp::panopainter::unbind_legacy_canvas_stroke_texture_inputs(
                     pad_destination_texture_binding,
-                    pp::panopainter::LegacyCanvasStrokeTextureInputDispatch {
+                    make_pad_destination_texture_dispatch(face_index));
-                        .activate_texture_unit = [&](int texture_slot) {
-                            set_active_texture_unit(texture_slot);
-                        },
-                        .unbind_stroke_destination = [&] {
-                            m_tex[face_index].unbind();
-                        },
-                    });
             },
             .draw_pad = [&] {
                 m_brush_shape.draw_fill();