Reuse main stroke texture dispatch helper

docs/modernization/tasks.md

@@ -509,6 +509,12 @@ Done Checks:
 
 Progress Notes:
 
+- 2026-06-13: `Canvas::stroke_draw()` main-pass texture dispatch now reuses
+  retained helper builders for texture-unit, brush-tip, pattern, and mixer
+  callback wiring; the live adapter still owns the concrete textures and
+  sampler state. Next slice should target the remaining inline `stroke_draw()`
+  dispatch construction or another narrow seam without reopening landed pad or
+  dual-pass helpers.
 - 2026-06-13: `Canvas::stroke_draw()` dual-brush replay now reuses the new
   retained brush-tip texture dispatch helper for binding and unbinding; the
   live adapter still owns the concrete brush texture object and live-pass

src/canvas.cpp

@@ -758,27 +758,27 @@ void Canvas::stroke_draw()
         },
     };
     const pp::panopainter::LegacyCanvasStrokeTextureInputDispatch main_pass_texture_dispatch {
-        .activate_texture_unit = [&](int texture_slot) {
+        pp::panopainter::make_legacy_canvas_stroke_main_pass_texture_dispatch(
-            set_active_texture_unit(texture_slot);
+            [&](int texture_slot) {
-        },
+                set_active_texture_unit(texture_slot);
-        .bind_brush_tip = [&] {
+            },
-            brush->m_tip_texture->bind();
+            [&] {
-        },
+                brush->m_tip_texture->bind();
-        .unbind_brush_tip = [&] {
+            },
-            brush->m_tip_texture->unbind();
+            [&] {
-        },
+                brush->m_tip_texture->unbind();
-        .bind_pattern = [&] {
+            },
-            brush->m_pattern_texture ?
+            [&] {
-                brush->m_pattern_texture->bind() :
+                brush->m_pattern_texture ?
-                unbind_texture_2d();
+                    brush->m_pattern_texture->bind() :
-        },
+                    unbind_texture_2d();
-        .bind_mixer = [&] {
+            },
-            m_mixer.bindTexture();
+            [&] {
-        },
+                m_mixer.bindTexture();
-        .unbind_mixer = [&] {
+            },
-            m_mixer.unbindTexture();
+            [&] {
-        },
+                m_mixer.unbindTexture();
-    };
+            });
     pp::panopainter::bind_legacy_canvas_stroke_sampler_inputs(
         live_pass_sampler_bindings,
         live_pass_sampler_dispatch);

src/legacy_canvas_stroke_execution_services.h

@@ -86,6 +86,24 @@ struct LegacyCanvasStrokeTextureInputDispatch {
     std::function<void()> unbind_mixer;
 };
 
+[[nodiscard]] inline LegacyCanvasStrokeTextureInputDispatch make_legacy_canvas_stroke_main_pass_texture_dispatch(
+    std::function<void(int)> activate_texture_unit,
+    std::function<void()> bind_brush_tip,
+    std::function<void()> unbind_brush_tip,
+    std::function<void()> bind_pattern,
+    std::function<void()> bind_mixer,
+    std::function<void()> unbind_mixer)
+{
+    return LegacyCanvasStrokeTextureInputDispatch {
+        .activate_texture_unit = std::move(activate_texture_unit),
+        .bind_brush_tip = std::move(bind_brush_tip),
+        .unbind_brush_tip = std::move(unbind_brush_tip),
+        .bind_pattern = std::move(bind_pattern),
+        .bind_mixer = std::move(bind_mixer),
+        .unbind_mixer = std::move(unbind_mixer),
+    };
+}
+
 [[nodiscard]] inline LegacyCanvasStrokeTextureInputDispatch make_legacy_canvas_stroke_brush_tip_texture_dispatch(
     std::function<void(int)> activate_texture_unit,
     std::function<void()> bind_brush_tip,