JPH0758508B2 - Calculation method of figure area by CAD - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the invention; (Industrial field of application) This invention relates to construction, site area of civil engineering, weight of mechanical materials,
Or CAD based on area calculation such as cost calculation
The present invention relates to a method of calculating the figure area by CAD here is a computer graphics technique.

(Prior Art) Normally, in order to calculate the area of a drawing figure by CAD, when the shape of the figure corresponds to the object formalized by mathematical analysis, it is calculated manually using this. or,
Even if the shape of a figure is complicated, if it can be divided and geometrical regularity can be found, the area of the original figure is calculated by adding the area after calculating the area of each divided area. . To calculate the area of the drawing figure by CAD itself, if it is a simple figure, it is possible to enter the formula, but as a subordinate to the formula contents entered in advance, point sequences and line segments The element itself must be specified for each side and the figure itself must be drawn and read. In addition, in order to calculate the area of a figure such as a framework, it is necessary to determine the operation code for the predetermined direction in order to subtract the blank portion corresponding to the inside.

(Problems to be solved by the invention) When calculating the figure area as described above, if the formula is entered or if the figure can be applied by combining them, it is highly useful. Is required to support arbitrary figures with various shapes.
However, in order to be able to calculate the area of various figures, it is necessary to enter a huge number of formulas, and irregular figures that are not defined by the formulas will be excluded from the target, so it will be put to practical use. Is a challenge. That is, there is a limit to the conventional method of inputting a formula and calculating it, and it does not reach the range of use until the area of an arbitrary figure is calculated. The present invention has been made in view of the above circumstances, and an object of the present invention is to quickly calculate an area of a figure for an arbitrary shape without relying on a mathematical or geometrically analyzed formula input means. Easy to use and highly useful
It is to provide a method of calculating the figure area by CAD.

Configuration of the Invention; (Means for Solving the Problems) The present invention relates to a CRT and a CRT that draw and display a shape in dot units.
The present invention relates to a method for calculating a figure area by CAD including a PU, and the above-mentioned object of the present invention is a CRT for drawing and displaying a shape in dot units and a method for calculating a figure area by CAD including a CPU, in which the unit dot of the CRT is used. Is set by the CPU so as to be converted into a predetermined unit area, and a search start point and a search end point for searching a target graphic for a previously colored drawing graphic in the CRT screen are set. Then
The number of colored dots is counted from the second dot of the coloring by performing a parallel reciprocal search in parallel in a diagonal direction from the search start point to the search end point.
This is achieved by configuring so that the area of the drawn figure having an arbitrary shape can be calculated from the count processing by the CPU.

(Operation) A figure drawn by CAD is formed in dot units, and in the present invention, the figure is colored to make it a judgment element to facilitate the counting process.
The search area is provided for drawing figures so that the figure to be calculated can be selected and the ratio of drawing figures on the CRT screen is taken into consideration, and the search range is specified for efficient counting processing. This is because That is, only the range within the search area frame is the target of the counting process, the search start point to the search end point of the search area frame are searched, and the process of counting the dots forming the figure is performed. On the other hand, when the search area is not provided, the entire range within the frame of the CRT screen is subject to the counting process. In addition, the fact that the search direction regarding the count of the number of dots is set to the diagonal direction is based on the XY axis as a standard plane (two-dimensional) display diagram including perspective, whereas parallel search is performed. This is for avoidance and depends on practical convenience. However, there is a characteristic problem in displaying the scale in dot units on the CRT screen, which is that the boundary points are included in the distance of the interval concept defined in one dimension. The scale is increased. Therefore, according to the present invention, when the number of dots for calculating the figure area is counted row by row in the predetermined oblique direction, the second dot is read, or, for example, a triangle is fully considered, Analysis processing is performed assuming that it is a rectangle. That is, if the unit dot is converted into a predetermined unit area, the figure area can be calculated by counting and adding the number of dots of the colored drawing figure, and the area of the triangle calculated as a quadrangle can be calculated by halving. It is what is done.

(Example) Hereinafter, the present invention will be described in detail with reference to examples.

FIG. 2 is a flow chart showing a general operation process relating to the method of calculating the figure area by CAD according to the present invention, and for convenience sake, the process elements will be described in the following description. CA
To draw a figure by D, CRT, CPU, mouse,
A light pen, a keyboard, a tablet for command selection, a plotter for drawing output, a digitizer for shape input, and the like can be given as an example of the main configuration. Thus
When a drawing figure is input by a digitizer or the like as shown in FIG. 2 (step S1), it is first determined whether the shape is a triangle or not based on the number of sides (step S2).
If it is not a triangle, it is colored with paint as it is (step S4). In the case of a triangle, the side with the maximum length (hereinafter referred to as the “hypotenuse”) was selected, a line-symmetrical triangle for this hypotenuse was drawn, and a quadrangle having a shape united with the original triangle was formed. Above (step S3), it is colored with paint (step S4). Here, the reason why it is necessary to form a quadrangle by a separate process in the case of a triangle will be described. Generally, when displaying dimensions on a CRT screen by CAD, for example, a scale of 5 m as shown in Fig. 10 (B)
The line of dots drawn on the CRT for m is 6 dots including the reference point zero as shown in FIG.
If it is compared with the scale of FIG. 6B, it is actually 6 mm. This is because the number of dots corresponds to the number of scale scales themselves.Therefore, the unit dots are converted to unit areas by setting the number of dots to be counted by subtracting the extra unit dots. This makes it possible to calculate the area of most shapes, but in the case of a triangle, the appearance becomes even more exceptional. For example, when an isosceles right triangle as shown in FIG. 9 (A) is displayed on the CRT screen, it is regular as shown in FIG. 9 (B), or as a right triangle as shown in FIG. 6 (A). In this case, the area is irregular as shown in FIG. 7B, or the triangles are drawn differently. Therefore, it is difficult to apply the area calculation according to the dot number counting method of the present invention. However, the dot number counting method of the present invention can be applied by halving the total dot number count after processing as a square. Furthermore, regarding the processing method (step S3) of a quadrangle formed when the input figure is a triangle, the case where it is not a right triangle in FIG. 3A and the right triangle is shown in FIG. Each case is explained in terms of analysis.

First, in each case, after the number of sides is recognized, the length of each side is based on the coordinates of the vertices P, Q, and R in each figure.
, L3 corresponding to the space and RP are calculated, and the hypotenuse is selected. Next, the coordinates of both ends of the hypotenuse are taken in, and the lower Y-axis value is used as the reference point, and the X-axis in the XY coordinate direction in each figure is used.
The direction angles of the hypotenuse and the sides forming an included angle with respect to the axial direction are obtained.

In FIG. 3 (A), ∠a and ∠ (a + b), and in FIG. 3 (B), only ∠b. Thus straight line PQ and straight line RQ
The positional relationship of is obtained, but if ∠c is obtained for each figure, the line symmetric movement becomes easy. ∠c is an angle formed by a straight line orthogonal to the hypotenuse and the X-axis direction in each figure, and in FIG. 3 (A), ∠a
And ∠b are obtained, ∠c = {π / 2− (∠a + ∠
b)}, in the figure (B), if ∠b is given, ∠c = (π
/ 2−∠b) is calculated. That is, the length of the line segment L4 that connects the intersection point D and the point R, which is formed by the orthogonal line with respect to the hypotenuse in each figure, is obtained, and the length of the straight line 2 is extended.
E point can be obtained at a distance of double. In each figure, the point E is nothing but the coordinate point to which the point R is converted when it moves line-symmetrically with respect to the hypotenuse. When the point E is obtained in this way, a quadrangle PRQE connected to the points P and Q is formed on each figure.

In the above, the triangle of the input figure is processed as a quadrangle,
Although the process up to painting like other figures has been described, the input setting of an arbitrary search area frame B for the figure A drawn on the CRT screen c as shown in FIG. 8 is performed (step S5). Done. Here, the figure A is an arbitrary figure excluding a triangle, and the area of this figure is calculated (step
For the purpose of S6), FIG. 1 shows an operation example relating to the area calculation processing method of the present invention by a flowchart, and FIGS. 4 to 7 show examples of area calculation of some basic figures by the processing. Is explained.

Fig. 4 shows the case where the input figure is a square, and Fig. 5 shows the case where it is a circle.
FIG. 6 shows the case of a triangle whose shape is converted into a quadrangle.
Each figure presents a figure (A) in which dimensions are displayed and a figure (B) displayed in dot units on the CRT screen, while FIG. 6 shows the same figure (D). This means that a triangle is treated as a quadrangle that is formed by coalescing with a triangle that is line-symmetrically moved with respect to its hypotenuse, and the figure (c) for explaining the counting of the number of dots includes each colored figure. A count start point S and an end point G in the search direction D with respect to the search area frame and a pattern of the count number are drawn. Note that the count search direction D may be selected from the other four corners of the search area frame other than the direction commonly shown in each figure, and the directionality thereof does not matter. It is decided in one direction and is performed consistently. The diagonal search direction of each column is set dependently by the array of the number of dots included in the search area frame, but it is important to read the counting method of the number of colored dots from the second for each column. It has become. In this way, if the unit dots are set to be converted into a unit area of 1 mm ² , the area can be calculated from the number of dots. For example, FIG. 4 shows a trapezoid as a quadrangle, and the area is calculated as (6 + 14) × 4/2 = 40 mm ² from the dimensional display given in FIG. If the CRT screen displayed on the number of dots 55 for as), FIG (c) in accordance with precise Come to match area calculation due to counting method of the present invention 40 mm ²
It can be seen that Also, in the case of the circle in FIG. 5, when the diameter is 10 mm, the area is πr ² = 25π = 78.5 mm ² , and the dot number is displayed at 92 in the CRT screen display of FIG. According to the counting method of the invention, 82 mm as shown in FIG.
Calculated as ² . Similar to a circle when the figure has a curvature, the area calculation from the dot unit display on the CRT is an approximate calculation, which causes an error, but even if it is a circle, the diameter is larger, for example, as shown in Fig. If there is about 30 mm, the calculated area is πr ² = 225π = 706.5 mm ² , whereas the area calculation method of the present invention by counting the number of dots in the search direction D as shown in FIG. According to 705 mm ²
And the closeness increases, and the error can be suppressed.
In addition, the count display of the number of dots in this figure is a two-digit number including 100. Further, in the case of a triangle as shown in FIG. 6, the area is 5 × 10/2 = 25 mm ^2, but on the CRT screen, the number of dots is changed to 41 as shown in FIG. The shape becomes unstable, but this is due to the area shown in Fig. 6 (D).
Count as shown in (C) of the figure after forming a quadrangle that is merged with a line-symmetrical moving figure with respect to the hypotenuse of 50 mm ² . By the way,
Although the number of dots on the CRT screen of this quadrangle is displayed at 63, the calculated area value of 50 mm ² can be obtained by the counting method of the present invention. That is, the area of a triangle is accurately calculated by first modeling a quadrangle, counting it as a quadrangle, and counting the total count in half.

Next, the operability of the above-described processing method relating to the area calculation of the arbitrary figure of the present invention shown in FIG. 1 will be described with a flowchart. This is the area calculation (step
It is the content contained in S6). First, for the search area frame (step S5) input in the preprocessing, for example, the coordinates of the lower left corner are set as the search start point and the upper right corner is set as the search end point, and the coordinates are set respectively (step S6-1). When the operation of counting the number of dots in the search area frame is started from the search start point, it is next checked whether or not the dot at this search point is colored (step S6-2). If not, the operation is performed. Although 1 is substituted into the register A for the above colorless determination (step S6-3), even if it is a colored dot, it is not counted if it is the end of the figure or a single dot, so the search point moves subsequently. Coordinates are calculated (step S6-4). Then, it is checked from the coordinates whether or not the search point is out of the search area frame (step S6-5), and if it is out, the next line is searched and switched to this (step S6-6). After it is judged whether it is the end point (step S6-7), while it is not reached, it is judged again for the colored dot so that the operation in this search direction can be searched back and forth one row at a time in parallel to the diagonal direction (step S6-7).
Returned before S6-2). If it is within the search area frame, it is continuously checked whether or not the content of the register A is 1 (step S6-8), and if it is 1, 0 is substituted into the register A ( Step S6-9)
After that, the process is returned to before the determination of the colored dot (step S6-2). This is a process for reading the colored dots by the search operation from the second position, and for maintaining the same function for the colored dots when the register A is moved by one column and is searched back and forth. In this way, when the register A is not 1, the second and subsequent rows in the row in which the colored dots are present are searched, and it is determined whether or not the colored dots are colored dots (step S6-10). In that case, the number is counted (step S6-11), and then the coordinates are returned to the previous stage of the coordinate calculation (step S6-4) for moving the search point so that the other columns can be sequentially operated. To do so. If the second and subsequent columns in the row where the colored dots are present are not colored (step S6-10), the coordinates are calculated to move the search point (step S6-1).
2) By returning before the determination of the colored dots (step S6-2), the main operation processing of the present invention is established. If the search point reaches the search end point and is regarded as the end point (step S6-7), the second
In the figure, the triangle is shaped like a quadrangle (step
S3), it is determined whether or not the original input figure is a triangle (step S6-13), and if it is a triangle, the counter total count is halved (step S6-4) to determine whether the figure is not a triangle. Similarly, the area calculation is completed.

With such a configuration, the area of the colored figure stored in the search area frame is reciprocally searched in parallel in one row diagonally from one end of the search area frame to the other end of the diagonal, and the second colored dot is searched. From the dot number counting process which is continuously performed from the above, the calculation is performed almost accurately as shown in FIGS. 4 to 6 and the area is displayed (step S7), and all the processing operations are completed. In the above-described embodiment, the drawing figure to be calculated is an example in which the search start point and the search end point are set and the search range is specified. However, when the search range is not specified, the CRT is used. All figures of the corresponding color on the screen are targets for calculation, and the entire range within the frame of the CRT screen is processed as the search range.

EFFECTS OF THE INVENTION As described above, according to the present invention, with respect to the calculation of the figure area of an arbitrary shape drawn on the CRT screen, the scale display in the dot unit of the CRT has an extra unit dot in comparison with the normal distance display. With the epoch-making method of line-dividing and counting the figures displayed in dots, keeping in mind that they are added, a rapid and accurate method of calculating the figure area by CAD is realized. In particular, even if a figure with a complicated shape on the CRT screen has a large number of dots in the display configuration, it is possible to easily calculate the area even if it is difficult to calculate the area. Contribution to the basic industry cannot be made.

[Brief description of drawings]

FIG. 1 is a flow chart showing an operation example of a processing method relating to area calculation of the present invention, FIG. 2 is a flow chart showing a general processing operation of the present invention, and FIG. 3 is a preparatory process relating to the present invention. FIG. 4 is a diagram for explaining an example of processing a quadrangle according to the present invention, FIG. 5 is a diagram for explaining an example of processing a circle according to the present invention, and FIG.
FIG. 7 is a diagram for explaining a method for processing a triangle according to the present invention and an example of the result, FIG. 7 is a diagram showing another example for processing a circle according to the present invention, and FIG. 8 is on a CRT screen. Fig. 9 shows a simplified representation of the components of this invention. Fig. 9 shows a CRT with a triangle.
FIG. 10 is a diagram for explaining the display on the screen, and FIG. 10 is a diagram for explaining the relationship between the scale display and the actual distance display on the CRT according to the present invention. A ... Arbitrary figure, B ... Search area frame, C ... CRT screen, S ...
Search start point, G ... Search end point.

Claims (3)

[Claims] 1. A CRT and a C that draw and display a shape in dot units.
In the method of calculating the figure area by CAD with PU, the unit dot of the CRT is set to be converted into a predetermined unit area by the CPU, and the drawn figure pre-colored in the CRT screen is set. A search start point and a search end point for searching for a target graphic are set, and a reciprocal search is performed in parallel in a diagonal direction from the search start point to the search end point one column at a time. A method of calculating a figure area by CAD, wherein the area of the drawing figure of an arbitrary shape can be calculated from the counting process by the CPU that counts the number of colored dots from dots. 2. The search start point and the search end point are set after a search area frame for accommodating the target graphic is provided, and when the round trip search is performed, the dots of the search points indicate the search area frame. It is determined from the search area frame and the coordinate information of the search point whether or not it has gone out,
The method of calculating a figure area by CAD according to claim 1, wherein the counting process is performed with the search area frame being a search range. 3. The CPU determines whether or not the drawing figure is a triangle from the number of sides, and when the drawing figure is a triangle, calculates the length of each side based on the coordinates of each vertex. On the CRT screen, a maximum side is selected, and a quadrangle formed by combining the converted triangle by the line symmetric movement of the triangle based on the selected maximum side and the triangle is used as the target figure on the CRT screen. 3. The printing start point and the search end point are set after the printing is performed, and the total count of the number of colored dots is halved after the CPU performs the counting process. Calculation method of figure area by CAD described.