Extract stroke commit request assembly

docs/modernization/tasks.md

@@ -1247,6 +1247,12 @@ Validation:
 ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution|pp_paint_renderer_compositor" --output-on-failure
 ```
 
+### Completed Task Log
+
+| Date | Task | Score | Validation | Commit |
+| --- | --- | ---: | --- | --- |
+| 2026-06-13 | STR-014 | +1 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_stroke_execution|pp_paint_renderer_compositor" --output-on-failure` | `pending` |
+
 ### STR-011 - Extract Preview Main Pass Orchestration
 
 Status: Done

src/canvas.cpp

@@ -531,11 +531,13 @@ static auto make_canvas_stroke_mix_pass_shell(
         });
 }
 
+template <typename SetActiveTextureUnit>
 static auto make_canvas_stroke_commit_callbacks(
     Canvas& canvas,
     const glm::vec4& vp,
     const glm::vec4& cc,
     bool blend,
+    SetActiveTextureUnit&& set_active_texture_unit,
     ActionStroke* action,
     const Stroke* current_stroke,
     const pp::paint_renderer::CanvasStrokeCommitSequencePlan& sequence,
@@ -734,6 +736,19 @@ static auto make_canvas_stroke_commit_callbacks(
         });
 }
 
+static auto make_canvas_stroke_commit_request(
+    const std::array<pp::panopainter::LegacyCanvasStrokeCommitFace, 6>& faces,
+    const pp::paint_renderer::CanvasStrokeCommitSequencePlan& sequence,
+    const pp::panopainter::LegacyCanvasStrokeCommitCallbacks& callbacks)
+{
+    return pp::panopainter::LegacyCanvasStrokeCommitRequest {
+        .context = "Canvas::stroke_commit",
+        .faces = faces,
+        .sequence = sequence,
+        .callbacks = callbacks,
+    };
+}
+
 glm::vec4 Canvas::stroke_draw_samples(
     int i,
     std::vector<vertex_t>& P,
@@ -1315,31 +1330,30 @@ void Canvas::stroke_commit()
             .pattern_enabled = stroke_material.composite_pass.use_pattern,
         });
 
-    std::array<pp::panopainter::LegacyCanvasStrokeCommitFace, 6> faces {};
-    for (int i = 0; i < 6; ++i) {
-        faces[i] = pp::panopainter::LegacyCanvasStrokeCommitFace {
-            .index = i,
-            .dirty = m_dirty_face[i],
-        };
-    }
-
     const auto commit_callbacks = make_canvas_stroke_commit_callbacks(
         *this,
         vp,
         cc,
         blend,
+        [&](int texture_slot) {
+            set_active_texture_unit(texture_slot);
+        },
         action,
         m_current_stroke,
         sequence,
         stroke_material);
 
+    const std::array<pp::panopainter::LegacyCanvasStrokeCommitFace, 6> faces {
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 0, .dirty = m_dirty_face[0] },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 1, .dirty = m_dirty_face[1] },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 2, .dirty = m_dirty_face[2] },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 3, .dirty = m_dirty_face[3] },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 4, .dirty = m_dirty_face[4] },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 5, .dirty = m_dirty_face[5] },
+    };
+
     [[maybe_unused]] const auto commit_result = pp::panopainter::execute_legacy_canvas_stroke_commit_sequence(
-        pp::panopainter::LegacyCanvasStrokeCommitRequest {
+        make_canvas_stroke_commit_request(faces, sequence, commit_callbacks));
-            .context = "Canvas::stroke_commit",
-            .faces = faces,
-            .sequence = sequence,
-            .callbacks = commit_callbacks,
-        });
 }
 
 void Canvas::stroke_commit_timelapse()

tests/paint_renderer/compositor_tests.cpp

@@ -1922,6 +1922,56 @@ void retained_stroke_commit_face_input_binder_forwards_sequence_slots(pp::tests:
     PP_EXPECT(h, bound_samplers[3].second == 3);
 }
 
+void retained_stroke_commit_request_builder_preserves_dirty_face_order(pp::tests::Harness& h)
+{
+    const pp::panopainter::LegacyCanvasStrokeCommitCallbacks callbacks {
+        .mark_commit_started = []() {},
+        .capture_render_state = []() {},
+        .prepare_render_state = []() {},
+        .restore_render_state = []() {},
+        .publish_history = []() {},
+        .capture_timelapse_frame = []() {},
+        .bind_layer_framebuffer = [](int) {},
+        .capture_history_region = [](int) {},
+        .apply_layer_dirty_region = [](int) {},
+        .copy_layer_to_commit_destination = [](int) {},
+        .bind_commit_inputs = [](int) {},
+        .execute_erase_composite = [](int) {},
+        .execute_paint_composite = [](int) {},
+        .copy_committed_to_dilate_source = [](int) {},
+        .execute_commit_dilate = [](int) {},
+        .unbind_layer_framebuffer = [](int) {},
+    };
+    const auto sequence = plan_canvas_stroke_commit_sequence(
+        CanvasStrokeCommitRequest {
+            .erase_mode = false,
+            .alpha_locked = false,
+            .selection_mask_active = true,
+            .dual_stroke_enabled = true,
+            .pattern_enabled = true,
+        });
+    const std::array<pp::panopainter::LegacyCanvasStrokeCommitFace, 6> faces {
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 0, .dirty = false },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 1, .dirty = true },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 2, .dirty = false },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 3, .dirty = true },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 4, .dirty = false },
+        pp::panopainter::LegacyCanvasStrokeCommitFace { .index = 5, .dirty = true },
+    };
+
+    const auto request = pp::panopainter::LegacyCanvasStrokeCommitRequest {
+        .context = "test",
+        .faces = faces,
+        .sequence = sequence,
+        .callbacks = callbacks,
+    };
+
+    PP_EXPECT(h, request.faces[0].index == 0);
+    PP_EXPECT(h, request.faces[1].index == 1);
+    PP_EXPECT(h, request.faces[3].dirty);
+    PP_EXPECT(h, request.faces[5].index == 5);
+}
+
 void retained_stroke_commit_dilate_copy_uses_layer_scratch_slot(pp::tests::Harness& h)
 {
     const auto sequence = plan_canvas_stroke_commit_sequence(