| 摘要 |
<p>PURPOSE:To process an echo display at a high speed with a graphic display device in which data management is performed by utilizing a hierarchical structure by storing the position of a pick identifier necessary for echo control simultaneously with the retrieval of pick graphics. CONSTITUTION:In order to retrieve pick graphics from graphic data having a hierarchical structure, a stack for storing the information for restoration when a segment call is performed and for deleting the information for restoration when restoration is made is required. A pick identifier information section 72 is provided in the stack and positions of pick identifiers are stored together with the retrieval of pick graphics. Therefore, it becomes unnecessary to retrieve an echo range due to the positions of the pick identifiers stored in the stack and echo display can be made at a high speed.</p> |
