Extract pad stroke face orchestration

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 };