基於參與者模式建構具擴充性的電腦輔助協同創作工具

Abstract

共同圖形編輯系統是一種群組軟體，同時也是電腦輔助協同工作系統的一類，這類系統常使用於多人會議討論的應用情境。近年來由於物聯網及數位互動藝術的興起，出現了許多基於類似技術的多人互動作品。然而，共同圖形編輯系統都無法避免一個固有難題，也就是多人同時編修同一份文件時的同步控制問題。以共同創作數位互動藝術的情境在例，在創作期間，複數參與者會同時對同一個區段進行修改，可能造成錯誤的結果。在傳統解決方案中，使用鎖、信號等方式予以控制，然隨著專案的規模增加，程式設計的邏輯複雜度也隨之上升，使得開發門檻高出許多。本研究提出將參與者模式應用於共同圖形編輯系統，開發一輔助函式庫工具，除了解決同步控制問題，藉由將後端服務以固定規格的 Actor 包裝，根據服務內容不同將其分為兩大類，對功能進行歸納，使創作者使用工具時更容易進行管理。研究的評估針對數名受測者做質性分析，供函式庫予具一定程式開發經驗的受測者進行實際操作與訪談，以了解此研究的實質成效。研究成果有效降低了共同圖形編輯系統的開發門檻，提供給數位互動藝術創作者更為直覺並具有擴充彈性的電腦輔助協同創作工具。

Collaborative Graphics Editing Systems (CGES) is a kind of groupware and is also a category of Computer Supported Cooperative Work (CSCW) systems. CGES has been widely used to realize multi-person on-line conferences. Recently, the emergence of IoT and digital interactive art has brought about a lot of applications of CGES to the creation of multi-user collaborative and interactive artworks. However, CGES usually faces concurrency control problems, which mean, there can be errors when multiple users modify data located at the same place. Classical approaches to deal with this issue are locks and semaphores. Nevertheless, the difficulty of development and complexity of the programs increase when the size of code expands. In this research, we combine the concept of Actor Model with CGES, provide a ready-made library to support the development of interactive arts with CGES. By wrapping the back-end service with actors, and dividing them into two categories according to the contents, not only solving concurrency control problem but facilitating the management of the toolkit. Finally, we use the qualitative experiment to assess the achievement of the research. According to the evaluation results, we conclude that this work can lower the threshold of development of CGES, and provide a more scalable, flexible computer supported cooperative art tool.