JPS59111190A - Line generation processing system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a line generation processing method in a graphics device.

[Technical background of the invention and its problems j As the price of memory elements has decreased significantly with the increase in storage capacity, graphic devices using Rusk scan type CPT have rapidly become popular over the past 12 years. is. Also, even in relatively small-sized computers such as office computers, there is a growing demand for the ability to display/draw data (graph/image processing) in units of dots instead of simply displaying characters.

By the way, drawing 111 lines on a graphic device (printer/display device?) takes one screen or one screen.
This means that 6 pages of data are stored in the 11th position of DRA) for a page/gutturn memory with L1 capacity ;)1. For this reason, Begino! is also used in office computers, etc. Using a turn memory, the CPU generates and writes dot and turn data on the memory, and transfers it to a graphic output device (display device/printing device) to print or display desired data.

However, this method requires a /'P-turn memory with a large V capacity, and no matter how much the device price decreases,
This was a cost that could not be ignored in small, compact class computers that were still aiming for low prices.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and it is an object of the present invention to provide a line generation processing method for drawing straight lines by effectively using a line buffer memory.

[Summary of the Invention] The present invention relates to a graphic display or printing device that eliminates the need for a four-turn memory for large page pages by effectively using a line buffer memory. The first register to store the image position, the second register to store the number of horizontal dots per one vertical dot (about 1), and the next coordinate to calculate the next coordinate. A third register for storing necessary errors is provided, and the pattern generation section (
The CPU ) is a nematode; during the cutting process, it calculates the initial values to be set in each of the above registers, determines the next coordinate value while calculating the error, and sends the line dot pattern to all line buffers based on the determined coordinate values. Because of this, on the CPU side, the line generation process is carried out by a memory with a medium capacity for storing lines, which makes it possible to reduce the number of lines, making it possible to create an economically advantageous graphic device. [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In Figure 11, which is an example of the printing location, 11 is a CPU.CPU
Since the CPU 11 generates a line dot pattern by operating various registers to be described later, in the following, this CPU 11 will be used as a pattern generator.
This section will be referred to as the tone generation section and will be explained in the following. Reference numeral 12 denotes a line buffer memory for correcting the dot/mother turn data generated by the pattern generating section 11. Reference numeral 13 denotes a printing device that prints out the data on the printing paper ('P) based on the doratonoturn data stored in the line buffer memory 12.

14.15, 16.17 are registers 1 which are characteristic of the present invention.
It is Western.・The arm turn generation unit 1 uses these registers 11.
Based on No. 11, pure raw 1-pole treatment is performed according to the procedure shown in FIG. Registers 14 and 15 contain line buffer memory 12.
The X and Y coordinate values for writing the upper dot and turn are stored in the register 16, the number of horizontal dots (inclination) per vertical dot, and the error necessary to find the next coordinate is stored in the register 17. Itchy or set. The algorithm for this line generation process will be described later.

FIG. 2 is a diagram for explaining the present invention in detail, and shows the starting coordinates and ending point coordinates of a straight line.

Figure 3 is a flowchart for pure generation processing. The operation of the embodiment of the present invention will be explained in detail below.

The pattern generation unit 11 uses each register 14 for line generation processing.
, 15, 16.17 are calculated, and the initial values are set in each register 14, 15, 16.17. The starting coordinates (points with smaller y-coordinate values; xo+ya) of the lines shown in FIG.
), the number of dots in the X direction per dot of the Y mark is stored in the register 16 (W
LI) PR), and register I7 (CVDLN
).

Drawing a straight line with a graphics device means making data corrections in units of pits in a drawing memory that has a capacity of one screen or one page. The present invention replaces this with a memory having a capacity for one line. When printing or displaying a dot by drawing a dot on the intersection of a grid divided by fJ in the horizontal direction and by L in the vertical direction, the contents of the line buffer memory 12 are are printed or displayed one after another. Originally, since a straight line is an analog quantity whose value changes continuously, it is approximated as a dot on the intersection of a grid and converted into a grid.
It is necessary to do i.

Therefore, the most reliable method is to solve the equation.

Usually, the other coordinate value is calculated by moving the coordinates in minimum dot increments in the horizontal or vertical direction (starting from 'ln and changing by "l l n").The coordinate value obtained by solving the equation is Since it is a real number, it is approximated to an integer coordinate position by rounding off the decimal value.The error is within ±0.5 coordinates.Therefore, there is no error as an approximation to an integer coordinate grid.Only the state where the coordinate change occurs can be detected. For example, the coordinates of the drawing point can be calculated by calculating the coordinate values at the start of drawing that are stored in advance.In other words, we can focus only on the result of the decimal part operation and compare that result with "1/2. By comparing the magnitudes, the four parts can easily be geometrically compared.

The line generation processing operation will be explained with reference to the flowchart shown in FIG. After setting the above initial values,
The error value (CVI) LN) is determined and compared with 0.5. If greater than 0.5, Y C0I) E K 1
and (WLI)I3R+1) to X C0DE. If it is smaller than 0.5, add 1 to YCOJ)E and
Add WL I)P R to C0I)B. Next, from the obtained x C0DE and y C0DB, dot/IP p
- is sent to the line buffer memory 12. By controlling in this way, the line buffer memory 12
The completed pure dot pattern is printed out by the printer 13.

Although the practical examples of the present invention have been explained with reference to a printer, the present invention can be similarly applied to a display device.

〔Effect of the invention〕

As explained above, according to the present invention, line generation processing can be realized using only the line buffer memory on the main body side, so the memory capacity can be reduced by 1 1/2, making it possible to achieve an economically advantageous graphic device (printing device/ Display device 1ffi) can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic embodiment of the present invention, and FIGS. 2 and 3 are diagrams shown to explain the operation of the present invention. 11...CPU (line generation processing unit), 12...Line buffer memory, 13...Printer, 14゜15.1
6.17...Register group.

Claims (1)

[Claims] A line buffer that stores dot nozzle and turn data generated by the CPU, and a graphic data output device that sends the dot nozzle and turn data stored in this line buffer to the input/output device side for display or printing. Based on this, write down the coordinate position where the dot/mother turn on the line buffer should be inserted + 1
: A first register that stores the horizontal dot change (inclination) per one dot in the vertical direction, and a third register that stores the error necessary to find the next coordinate. The above CPU sets initial values in each of the above registers for the line generation process fψ, determines the next coordinate value while calculating the error, and transfers the obtained l11 (headline up line dot pattern to the above line buffer). Line generation, which is characterized by transfer, is also a logical method.