JPH01116888A - Segment display device - Google Patents

Abstract

PURPOSE:To smoothly display by obtaining the variation of other variable from a variation at the time of changing the angle of a segment obtained from start point and end point coordinates and a variable by a minimum unit and connecting a saturation point and the end point by a straight line a when the variation is saturated. CONSTITUTION:When a start point coordinate (x1, y1) and an end point coordinate (x2, y2) are inputted, the difference of the x coordinates DELTAx=x2-x1 and the difference of the y coordinates DELTAy=y2-y1 are operated and based on the values, tantheta=DELTAy/DELTAx, cottheta=DELTAx/DELTAy is operated. If the gradient of the plotted straight line is >=45 deg., tantheta is larger than 1, so that cottheta is selected. Since the variation of (x) at this time is smaller than the variation of (y), (x) is changed by the minimum unit and a horizontal line is plotted and a vertical line is plotted by the quantity of the value of y obtained from the variation of (x) and the value of tantheta and rounded. This is repeated until x=x2, the plotting is completed if y=y2 at that time and if y is not y2, the vertical line is drawn to the end point. Thereby, smooth display is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line segment display device for displaying line segments on the display section of, for example, a digital telephone equipped with a dot-configured display section.

[Conventional technology]

Digital telephones that have been developed in recent years are capable of providing various additional services in addition to the call services provided by conventional analog telephones.

One of these services is to transmit and display simple graphical data. For example, this means that the coordinate data from a 1024 x 824 dot tablet is 147 points or 7 points per second.
There is a 3-point receiver and a screen that displays it multiplied by 1/8 in an area of 128 x 104 dots on the LCD.

In order to perform this display, conventionally, the coordinates of the starting point and the ending point were specified in a rectangular coordinate system, and the drawing was performed while interpolating between them using a straight line equation.

[Problem that the invention seeks to solve]

However, such conventional devices perform the above-mentioned processing using CP.
This will be done by UK, but the C
The PU does not only handle display data, but rather the display data has a low priority, so conventional methods require a large amount of processing for display, making it difficult to match the processing speed and display speed, making it difficult to display smoothly. could not be done.

[Means for solving problems]

In order to solve the problems described above, the present invention provides a means for determining the tangent or cosecant based on the coordinates of the starting point and the end point, and a means for displaying a line segment in an unsaturated region based on the determined result. and a means for displaying the saturated region.

[Effect]

For each minimum unit of change of one variable, other variables are calculated based on the trigonometric function value and a non-saturated region is drawn, and when one variable reaches its final value, that point and the coordinates of the end point are connected by the shortest distance. It will be done.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, 1 is a tangent operator, 2 is a cosecant operator,
Tan θ and coto are calculated based on data representing input starting point coordinates and ending point coordinates in a rectangular coordinate system. 3 is a drawing device, and one variable expressed in the orthogonal coordinate system is changed in the smallest unit, and the t obtained earlier is
Based on the value of ane or coto, the value of the other variable is determined and line segments are drawn sequentially. At this time, tIL
For the value of nθ or coto, a value larger than “1” is used to simplify the calculation process, and the decimal places are rounded down. In addition, for variables that are changed in the smallest unit, the one with the smallest amount of change is used. This drawing device also uses non-saturated area drawing that sequentially draws line segments by changing one variable in the minimum unit of change while calculating the value of the other variable based on the value of tanθ or coto determined by the above-mentioned criteria. means and
When the value of one of the variables reaches a final value, a saturated region drawing means is provided that connects the point to the final coordinate with a line segment having the shortest distance.

The operation of the apparatus configured in this way is shown in the flowchart shown in FIG. Starting point coordinates (xl.

y+) and end point coordinates (zz+yz) are input.
Difference in coordinates ΔX=12 Difference in Xl and y coordinates ΔF=7
271 is calculated (steps 100, 101),
Based on that value, tanθ=jy/Δz, eotθ=
ΔX/Δy is calculated (steps 102, 103
). Based on this calculation result, either tan # or coto is selected. Here, if the straight line to be drawn has an inclination of 45 degrees or more as shown in Figure 3, then tan θ
is larger than l, so that is selected (step 104). At this time, the amount of change in X is smaller than the amount of change in y, so a horizontal line is drawn while changing X in the smallest unit,
The rounded y calculated from the amount of change in X and the value of tanθ
Vertical lines are drawn by the amount of the value (step 105). Repeat this until it becomes 1'::X2.

Step 106), if 7 = 72 at that point, the drawing is finished, and if it is not 7")'2, a vertical line is drawn to the end point (step 108). In the example of Fig. 3, X = When F = 12, F = 72 is not reached, so a vertical line with symbol A is drawn.The example in Figure 4 is an example where the slope is 45 degrees or less, and in this case, coto is selected in step 104. However, the variable to be changed the least is y, and it is determined in step 106 that 7=72. If it is "YES", y = 12 is determined in step 107, and if rNOj, step 108 is the horizontal line at the symbol entrance. This is an example of drawing.

〔Effect of the invention〕

As explained above, this invention calculates the amount of change in other variables from the angle of the line segment found from the coordinates of the starting point and the end point, and the amount of change when the - variable is changed by the minimum unit, and then When the saturation point and the end point are connected by a straight line k
Therefore, compared to the conventional one, it has the effect of reducing the processing amount of the CPU and allowing smooth display.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing its operation, and FIGS. 3 and 4 are diagrams showing examples of display states. 1... Tangent operator, 2... Cosecant operator, 3...
...Drawer, 4...Display device.

Claims (1)

[Claims] In a line segment display device that specifies a start point and an end point on a screen and displays a line segment between them, at least a tangent value or a cosecant value is calculated based on data of start point coordinates and end point coordinates. A trigonometric function calculator that calculates one variable, and a non-saturated area drawer that sequentially draws line segments by calculating the value of the other variable based on the calculation results of the trigonometric function calculator while changing one variable in the minimum change unit. , and a saturated area drawer that connects the point to the end point coordinates with a line segment of the shortest distance when the value of one of the variables reaches the final value.