JPH0420505B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] A graphic output device that hatches the same pattern on adjacent figures drawn on a graphics screen, which uses the absolute coordinates of the hatching start point of each figure as a hatching pattern. By providing a conversion means for converting data into relative coordinates and a start point moving means for moving a hatching pattern data transfer start point to relative coordinates, it is possible to perform hatching without deviation.

[Industrial application field]

The present invention relates to a graphic output device that hatches the same pattern on a plurality of adjacent graphics, and particularly to a graphic output device that can eliminate deviations in hatching patterns.

In recent years, graphic display devices have come into widespread use as output terminals for various computers, word processors, and the like.

There is a need for a method that does not cause hatching misalignment when hatching the same pattern on a plurality of adjacent figures displayed by such an apparatus.

[Conventional technology]

Generally, when hatching a figure drawn on a graphics screen, a hatching start point indicating the hatching start position within the figure and a hatching pattern are specified, and the specified hatching pattern data is started from the hatching start point. A method is adopted in which the image is expanded to the entire area within the figure.

More specifically, in FIG. 5, the hatching start point is a reference point for hatching processing and represents a reference position for writing on the screen. Hatching pattern data is data forming a hatching pattern, and is usually defined as a rectangular area of m×n dots. The transfer start point is a reference point for reading hatching pattern data.

Therefore, when hatching a triangular figure, for example, first prepare fixed or user-defined rectangular hatching pattern data (for example, 8 x 8 dots) as shown by the broken line in the figure, and then This hatching pattern data read out sequentially from a specified transfer start point (for example, the upper left corner of a rectangular area) is searched for the boundary line of the figure from the specified hatching start point within the figure, and is transferred within the boundary line on the screen. A process of transferring data over the entire area is performed. Here, hatching is not displayed outside the border, but only inside the border.

This is equivalent to laying patterned tiles in a shape starting from the starting point, and is called “tiling”.
It is called.

[Problem that the invention seeks to solve]

According to the above conventional method, the transfer start point of the rectangular hatching pattern data is fixed, for example, the upper left point of the rectangular area as shown in FIG. It is uniquely determined by the relative coordinates of the hatching start point with respect to the figure.

This corresponds to, for example, "tiling" with only one type of pattern starting from the hatching start point.

However, with this method, depending on how the hatching starting points are taken, the hatching starting points for adjacent figures A and B may be shifted, so it is difficult to hatch figures A and B using the same pattern. However, there is a problem in that a "shift" occurs between the hatching patterns.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the present invention.

In the figure, 1 is a conversion means for two-dimensionally converting the absolute coordinates on the screen of a designated hatching start point of a figure to be hatched into relative coordinates within rectangular hatching pattern data, and 2 is a conversion means 1. The start point moving means moves the position of the transfer start point of the hatching pattern data to the relative coordinates converted by , and reconstructs the hatching pattern data.

Therefore, hatching is started from the position moved by the starting point moving means 2.

[Effect]

Find the absolute coordinates of each hatching start point specified in the hatching target figure on the graphic screen, two-dimensionally convert these absolute coordinates into relative coordinates in the rectangular hatching pattern data,
After the transfer start point of this hatching pattern data is shifted to the above-mentioned relative coordinates by the start point moving means 2, the hatching pattern data is transferred onto the screen.

This shift amount is uniquely determined by the absolute coordinates of the hatching start point, and is controlled so that the same hatching pattern is obtained in the same area in the absolute coordinates of the screen. will be resolved. (Refer to Figure 3) This corresponds to shifting the tile pattern according to the absolute coordinates of the hatching start point and then laying it all over the figure.Apparently, the interior is cut out from above the tile laid out on the absolute coordinates. It looks like a shape has been covered.

In this way, adjacent figures can be hatched in the same pattern without any "shift".

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 4. In FIG. 2, parts corresponding to those in FIG. 1 are shown surrounded by a dashed line. The same reference numerals indicate the same objects throughout the figures. FIG. 2 is a block diagram of a graphic display device.

The calculation unit 1a has a function of converting the hatching start point of each figure from absolute coordinates on the screen to relative coordinates within the rectangular hatching pattern data when hatching the same pattern on adjacent figures A and B. have For example, as shown in Figure 3a,
When hatching figure A using rectangular hatching pattern data of m×n dots, the absolute coordinates on the screen of the hatching start point of figure A are x _a , y _a
is converted to the relative coordinates i _a , j _a in the rectangular hatching pattern data as follows: i _a = x _a mod m, j _a = y _a mod n (here mod indicates the remainder operation) . However, the origin of the rectangular hatching pattern data on the screen was set to the upper left point.

Similarly, for figure B, if the relative coordinates i _b and j _b in the hatching pattern data correspond to the absolute coordinates x _b and y _b on the screen of the hatching start point, i _b = x _b mod m, j _b = y _b mod n.

The starting point moving unit 2a is, for example, a figure A in FIG. 3b.
As _shown in the case of _FIG .

That is, the hatching pattern is circulated in the X and Y directions and reconfigured (the tile pattern is shifted) so that the transfer start point is at the upper left corner of the rectangular area.

The graphic pattern memory 3 is a memory in which patterns of various figures including hatching or patterns of graphic elements are stored.

The graphic processing section 4 has a function of reading a graphic pattern from the graphic pattern memory 3 based on input from the keyboard 5 and processing the size, position, direction, etc. of the graphic pattern.

6 is a display (hereinafter referred to as CRT), 7 is
A data memory in which data to be displayed on the CRT 6 is stored; 8 indicates a main control section.

With such a configuration and function, CRT
The operation when hatching the same pattern on adjacent figures A and B displayed in Figure 6 will be explained using the flowchart in Figure 4. First, when the hatching start point and pattern of figure A are specified, The graphic processing unit 4 reads the specified hatching pattern data from the graphic pattern memory 3 and determines the absolute coordinates x _a and y _a of the hatching starting point on the graphic screen.

Next, the absolute coordinates x _a , y _a are computed with a remainder in the calculation unit 1a and converted into relative coordinates i _a , j _a within the rectangular hatching pattern data.

The start point moving unit 2a shifts the transfer start point of the rectangular pattern data to relative coordinates i _a and j _a .

Lay out the hatching pattern.

Shape B is also hatched in the same manner as the flow of ~ with absolute coordinates x _b , y _b and relative coordinates i _b , j _b .

In this way, by shifting the transfer start point of the hatching pattern data using the absolute coordinates of the hatching start points of figures A and B, and then performing hatching, as shown in Figure 3c, It is possible to draw the same hatching pattern without any "shift".

〔Effect of the invention〕

As explained above, according to the present invention, when hatching the same pattern in adjacent figures,
This has the effect of eliminating misalignment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the invention, Fig. 3 is an explanatory diagram of Fig. 2, Fig. 4 is a flowchart of Fig. 2, and Fig. 5 is a block diagram of an embodiment of the invention. An explanatory diagram of the hatching method, FIG. 6 is an explanatory diagram of the conventional method. In the figure, 1 is a conversion means, 1a is an arithmetic unit, and 2
2a is a starting point moving means, 2a is a starting point moving unit, 3 is a graphic pattern memory, 4 is a graphic processing unit, 6 is a CRT,
7 is a data memory, and 8 is a main control section.

Claims (1)

[Claims] 1. A plurality of adjacent figures drawn on the output screen,
An output device that performs hatching in the same pattern, comprising: a conversion means 1 that two-dimensionally converts the absolute coordinates of the hatching start point of each of the adjacent figures into relative coordinates within hatching pattern data; and the conversion means. a starting point moving means 2 for reconfiguring the hatching pattern data by moving the transfer starting point of the hatching pattern data to the relative coordinates converted by 1; A graphic output device characterized in that hatching of each graphic starts from a moved position.