| 摘要 |
PURPOSE:To attain high speed drawing by drawing a contour line of picture elements orientated in the picture element moving direction. CONSTITUTION:If a point before movement is set up as an original point, a moving point of a drawing point P becomes a picture point shown by X, Y coordinates on an one-picture point distance, and if the drawing point P is moved to (1, 1) for instance, the point P is set up on the picture point position shown by a triangle. An opposite contour line setting part 7 sets up a contour line orientated in the moving direction from the contour line of the picture elements in a picture element management part 2 based on the moving position data and sets up a reversed L-shape type contour line graphic constituted of the right and upper sides of the picture elements of the rectangle. An increment vector forming part 8 forms a vector constituted of the picture points of the two sides and writes the vector on the positions shown by dotted circles out of the picture elements of a frame memory 4. If the moving direction of the picture elements is continued in the same direction, a rectangular envelope image shown by a chain line can be drawn. |
