JPH051950B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a graphic display method and a graphic display device for displaying a graphic using a raster scan method based on data read from a memory storing data necessary for displaying the graphic. It is something. [Prior Art] Conventionally, in order to display characters or figures by digital signal processing, a figure display device has been used which displays data read from a character generator as figures by a raster scan method. ing. As shown in Fig. 22, this display first forms raster A0 at the right edge of the screen, and then sequentially moves the scanning position to the left side of the screen to form raster A0.
The figure is displayed by displaying A2 to An (this figure uses a common cathode ray tube rotated 90 degrees). FIG. 23 is a block diagram showing an example of a device that performs such display, in which 1 is a processing device for processing digital signals, 2 is an H counter for specifying the horizontal scanning position of the cathode ray tube, and 3 is a cathode ray tube. a V counter for specifying the vertical scanning position of the character generator; 4 a map section storing read address order data specifying the read address order of the character generator; 5 a character generator; 6 a shift register; 7 is a cathode ray tube, and H counter 2 and V counter 3 constitute a read signal generator that generates a read signal represented by orthogonal coordinates. The map section 4 and the character generator 5 constitute a memory for displaying figures corresponding to the video RAM in a graphic display. In the device configured as described above, a readout signal is generated based on the output signals of the H counter 2 and V counter 3 controlled by the processing device 1, and the readout signal stored in the map 4 is generated by this readout signal. Address order data is read out sequentially for each display section,
Graphic data representing a graphic is read out from the character generator 5 according to the read address order data that has been read out. For example, as shown in FIG. 24, when the character A is stored in the character generator 5, the data of each row of the character A is read out and stored in the shift register 6. This data is then sequentially converted into video signals as shown in FIGS. 25b to 25f, and the letter A is displayed on the cathode ray tube 7 as shown in FIG. 25a. In this way, the data stored in the character generator 5 is read out and displayed on the cathode ray tube, so if a plurality of character generators are provided, it is possible to display figures of any shape and size. can. At this time, by shifting the reading start position of the data stored in the character generator in the horizontal or vertical direction, the displayed screen can also be shifted in the horizontal or vertical direction. Furthermore, as shown in FIG. 2, coordinates are exchanged by rotating the readout signal represented by orthogonal coordinates having the X and Y axes by an angle θ as shown by the dotted line.
Switch to a new Cartesian coordinate represented by the axis − y axis,
If data is read out from the character generator and displayed using the readout signal expressed by the new orthogonal coordinates, rotation can be given to the displayed figure. [Problems to be Solved by the Invention] When a part of the memory for displaying figures is composed of three display sections as shown in FIG. The timing of the change is determined so that it changes every time the horizontal double line is crossed. When the coordinates are exchanged, the coordinate axis of the readout signal is tilted as shown by the solid line in FIG. You need to access both. However, since the section representing the letter F and the section representing the letter C are different sections, the data of the read signal is different, but a change in the data of the read signal only occurs every time a horizontal double line is crossed. Therefore, even when the timing for displaying the character C arrives, the data of the readout signal does not change, resulting in a drawback that normal display cannot be performed. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a graphic display method and a graphic display device that allow normal display when a displayed graphic is rotated. [Means for solving the problems] In order to achieve such an object, this invention has the following features:
When representing a readout signal using orthogonal coordinates, the coordinate axes are swapped and the data change direction of the readout signal on the coordinate axes is swapped depending on the rotation angle and rotation direction of the figure, and the data necessary for displaying the figure is combined with the coordinate axes. The data is read from the memory corresponding to the . Hereinafter, the present invention will be explained in detail using drawings showing embodiments. [Operation] Figures can be rotated and displayed normally. [Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, and the same parts as in FIG. 23 are designated by the same symbols. 10 is a readout signal expressed in orthogonal coordinates,
11 is a V counter that generates a signal specifying one coordinate axis; 11 is an H counter that generates a signal specifying the other coordinate axis; 12 is a coordinate rotation processing unit that rotates the coordinate system of the read signal; 13 is the map unit 4; 14 is a character generator read signal generator that generates a signal to read out graphic data from the character generator; 15 is a character generator; The generator section 16 is a figure assembling section that assembles the data read from the character generator section 15 into figures. Here, giving rotation to the coordinate axes means the second
As shown in the figure, the output signal of the V counter 10 is
The output signal of the H counter 11 is made to correspond to the coordinate axis in the Y direction, and the orthogonal coordinates expressed by making it correspond to the coordinate axis in the Y direction are tilted by an angle θ as shown by the dotted line to create a new coordinate expressed by the x axis - y axis. It is a conversion to Cartesian coordinates. Video on graphic display
When the display content is determined by sequentially reading data representing figures or characters to be displayed from video RAM, such as RAM, the device equivalent to video RAM is referred to as memory in this invention. . The apparatus shown in FIG. 1 reads data from the character generator section 15 based on a signal obtained by accessing the map section 4, and displays figures or characters based on the data. Therefore, the map section 4 and the character generator section 15 constitute a memory, and the memory in this device is arranged as shown in FIG. Figure 3 consists of four frames, and each frame represents one screen of a cathode ray tube.The area indicated by symbol A on the right shoulder of the memory is the absolute origin, and Direction to access downwards is positive,
The horizontal direction of the memory is defined as the horizontal direction, and the vertical direction is defined as the vertical direction. Further, the right shoulder of the display screen of the cathode ray tube, indicated by the symbol B, is defined as the origin of the cathode ray tube. This device has a V counter 10 as shown in FIG.
The display state is defined as follows depending on whether the output signal of the H counter 11 is used for accessing the memory in the vertical direction or in the horizontal direction. (a) Display state A (state shown in Figure 4 a) The output signal of the V counter 10 is used for horizontal access to the memory, the output signal of the H counter 11 is used for vertical access, and the horizontal access position is Negative memory over time (right)
, and the vertical access position advances in the negative (upward) direction of memory. (b) Display state B (state shown in Figure 4b) The output signal of the V counter 10 is used for vertical access to the memory, the output signal of the H counter 11 is used for horizontal access, and the vertical access position is Negative memory over time (top)
direction, and the horizontal access position advances in the positive (left) direction of memory. (c) Display state C (state shown in Fig. 4c) The output signal of the V counter 10 is used for horizontal access to the memory, the output signal of the H counter 11 is used for vertical access, and the horizontal access position is Positive memory over time (left)
, and the vertical access position advances in the negative (downward) direction of memory. (d) Display state D (state shown in Figure 4 d) The output signal of the V counter 10 is used for memory vertical access, the output signal of the H counter 11 is used for horizontal access, and the vertical access position is As time progresses, the memory progresses in the positive (downward) direction, and the horizontal access position advances in the negative (right) direction of the memory. The V counter 10 performs a down count when the display state signal supplied from the processing device 1 represents display state A or display state B, and performs an up count when the display state signal represents display state C or D. It's summery. The H counter 11 counts up when the display status signal supplied from the processing device 1 represents display states B and C, and counts down when it represents display states A and D. ing. The coordinate rotation processing unit 12 inputs a display state signal, a rotation amount signal, an origin signal representing the cathode ray tube origin in absolute coordinates, a V signal,
It is designed to generate V4 signal, H signal, H4 signal, CHG・AD (V) signal, CHG・AD (H) signal, and CHG・NO signal. The map read signal generation section 13 supplies a V4L signal and
It is designed to generate H4 signal. As shown in FIG. 5, the coordinate rotation processing unit 12 includes a component origin register 12b and a vertical component origin register 12.
c, a selector 12d, a selector 12e, rotation signal calculation units 12f, 12g, and adders 12h to 12k. The lateral component origin register 12b is adapted to generate a signal representing a lateral component with respect to the absolute origin of the cathode ray tube origin coordinate in response to an origin signal supplied from the processing device 1. Further, the vertical component origin register 12c is adapted to generate a signal representing a vertical component. The selector 12d is
The display state signal from the processing device 1 is the display state A, C.
When representing the horizontal component origin register 12b, the signal supplied from the horizontal component origin register 12b is output, and when representing the display states B and D, the signal supplied from the vertical component origin register 12c is output. The selector 12e outputs the signal supplied from the vertical component origin register 12c when the display state signal from the processing device 1 represents display states A and C, and outputs the signal supplied from the horizontal component origin register 12c when the display state signal from the processing device 1 represents display states B and D. 1
The signal supplied from 2b is output. The rotation signal calculation units 12f and 12g are configured to apply rotation to the signals supplied from the V counter 10 and the H counter 11 in accordance with the signal representing the amount of rotation supplied from the processing device 1,
Performing affin transformation. The adder 12i receives a 5-bit V signal representing the position on one coordinate of the map section 4, a 2-bit CHG/AD(V) signal representing the position on the vertical coordinate axis of the character generator, and the figure assembly section 16. It is designed to generate a 2-bit CHG/NO signal that is supplied to the The adder 12k receives a 5-bit H signal representing the position on the other coordinate axis of map 4, a 2-bit CHG/AD (H) signal representing the position on the horizontal coordinate axis of the character generator, and 2 representing the master timing. It is designed to generate bit M and T signals. Of these, the lower 1 bit of the V signal and the lower 1 bit of the H signal are used as the H4 signal and V4 signal necessary for the operation of the character generator read signal generating section 14. As shown in FIG. 6, the map read signal generating section 13 is composed of a latch 13a, a correction data generator 13b, an adder 13c, selectors 13d to 13i, and an EOR circuit 13j. The correction data generator 13b is adapted to generate the signals shown in Table 1 in response to the left and right signals representing the rotation direction and the display state signal representing the display state supplied from the processing device 1.

[Table] In Table 1, "left" means that the figure is displayed by rotating it to the left, and "right" means that the figure is displayed by rotating it to the right. The selectors 13d to 13g output signals on the input terminal a side when the display state signal indicates display states A and C, and when the display state signal indicates display states B and D,
, the signal on the input terminal b side is output. selector 13h, selector 13
i is connected to the input terminal a1, a2 side or the input terminal b1, b depending on the signal supplied from the EOR circuit 13j.
The signal from the second side is output. As shown in FIG. 7, the map section 4 includes maps 4a,
4b, latches 4c and 4d, and this map is composed of 16
A portion corresponding to ×16 pixels constitutes one unit, and these 32 × 32 units collectively constitute the map 4a or the map 4b. Also, when a 1-unit map is specified, the 16×16
The information in the map is read out no matter which pixel in the map is scanned. That is, when the access shown by the solid line in FIG. 8 is performed, data F is read out from the portion corresponding to pixel 1 to the portion corresponding to pixel 11. As shown in FIG. 9, the character generator read signal generating section 14 includes selectors 14a to 14f, switch circuits 14g and 14j, a latch 14h, shift registers 14i and 14k, an EOR circuit 14m, and
14n. Selector 14a~
Input terminal a or input terminal b of 14f is selected depending on the signal supplied to input terminal c. The switch circuits 14g and 14j combine the signals supplied to the input terminals a to d and the output terminals g to j that output the signals according to the left and right signals or display status signals supplied to the input terminals e and f. mode 1 or mode 2 in Table 2. Whether "Mode 1" or "Mode 2" is selected is determined by the criteria in Table 3. The shift register 14i is a 1-bit four-stage shift register, and the shift register 14k is a 2-bit four-stage shift register.

【table】

[Table] The character generator section 15 includes character generators 15a to 15d as shown in No. 10.
Each character generator is configured to select two types of graphic patterns, V-shape and H-shape, which will be described later, according to a display state signal supplied from the processing device 1. ,
Graphic data is read out from the selected graphic pattern in response to a signal supplied from the character generator read signal generating section 14. Figure 11 shows a V-shaped pattern among the character generator patterns, and the horizontal numbers 00 to 11 outside the frame are output from the adder 12h.
This is the address specified by the CHG/AD (H) signal, and the vertical number is output from the adder 12i.
This is the address specified by the CHG/AD(V) signal. The area within one frame is divided into four parts a to d, and the data of these parts a to d correspond to the character generators 15a to 15d, respectively. Data of 4 pixels in the vertical direction is stored.
That is, a frame designated by one address in each direction stores data for 4×4 pixels. One storage unit of the character generator is 4×4 addresses, that is, 16×16 pixels. As shown in FIG. 12, the graphic assembly section 16 has shift registers 16a to 16d, selectors 16e,
It is composed of a shift register 16f. In each shift register, when the display state signal supplied from the processing device 1 is in display state A or B, the MSB (most significant bit) is output first, and when the display state signal is in display state C or D, the LSB (least significant bit) is output first. bits) are output first. The selector 16e selects the fourth shift register according to the signal supplied from the shift register 16f.
The input signal is selected and sent out as shown in the table.

[Table] The shift register 16f is a 2-bit, 8-stage shift register. The operation of the device configured as described above is as follows. First, a display operation when a figure is not rotated will be explained. At this time, as shown in FIG.
An origin signal is supplied to c. At this time, the screen is scanned as shown in FIG. 22, and this state corresponds to display state C, and V
The horizontal position of the screen shown in FIG. 22 is determined by the output signal of the counter 10, and the vertical position is determined by the output signal of the H counter 11. The output signal of the H counter 11 is supplied to the adder 12k and the rotation signal calculation section 12g, but in this case, since no rotation is given to the figure, the rotation signal calculation section 12f and the rotation signal calculation section 12g input the output signal. It has not occurred. When the display state signal output from the processing device 1 indicates the display state C, the selector 12d
The selector 12e selects and outputs signals generated from the horizontal component origin register 12b and the vertical component origin register 12c, respectively. As a result, the signal output from the adder 12h is the output signal of the V counter 10 and the horizontal component origin register 12.
This is the sum of the data with the output signal of b.
Since the rotation signal calculation unit 12g does not generate an output signal, the adder 12i outputs the output signal of the adder 12h as it is. Similarly, the adder 12j outputs the output signal of the vertical component origin register 12c, and the adder 12k outputs the output signal of the vertical component origin register 12c.
That is, the output signal of the vertical component origin register 12c
A signal obtained by adding the output signal of and the data of the H counter 11 is output. The output signals of adder 12i and adder 12k are supplied to latch 13a and selector 13g, as shown in FIG. Correction data generator 13b
Normally, there is no need to generate an output signal when there is no need to rotate the figure, but since no special measures are taken for this purpose, correction data is generated. Then, this data is added to the adder 13c.
Therefore, corrected data is output from the adder 13c. However, since this data is unnecessary when the figure is not rotated, it is ignored and not used by the character generator read signal generating section 14, which will be described later. As described above, the selectors 13d to 13g output the signal on the input terminal a side in the display state C, so the selector 13d and the selector 13e output the output signal of the adder 13c, and the selector 13
f, selector 13g outputs the output signal of adder 12k. As described above, the selector 13h and the selector 13i are adapted to output the signals supplied to the input terminals a1, a2 or b1, b2 in accordance with the signal supplied from the EOR circuit 13j.
In FIG. 22, the V4L signal supplied to one side of the EOR circuit 13j does not change during the period shown in FIG. In Figure 22,
Since the address is specified in the vertical direction over the range H, V4L is specified as shown in Figure 13b.
It alternates during the duration of the signal. Therefore, the output signals of the selectors 13h and 13i are alternately switched between the input terminals a1 and a2 and the input terminals b1 and b2. As shown in FIG. 7, the output signals of the selectors 13h and 13i are supplied to the map section 4, so that the stored contents are read from the maps 4a and 4b, and the read stored contents are stored in the latches 4c and 4d. , are supplied to selector 14a and selector 14b shown in FIG. These selectors are EOR circuit 14m which is supplied with H4 signal and V4L signal.
Since the signal from selector 13 is being supplied,
h, input terminals a and b are switched in synchronization with the selector 13i. The signals read from the selectors 14a and 14b are supplied to selectors 14c to 14f, respectively, and are selected and output according to the signals supplied to terminals c of these selectors. At this time,
The signals supplied to the terminals b of the selectors 14c to 14f are data that has not been corrected by the correction data generator 13b of the map readout signal generator 13, and the data supplied to the terminal a is corrected data. be. However, when the displayed figure is not rotated, the corrected data is not necessary. Therefore, the signal sent from the switch circuit 14g selects the terminals b of the selectors 14c to 14f, and the signal supplied to the terminal a is ignored. A signal representing the number of the character generator supplied from the adder 12i is stored in the shift register 14k, and the stored signal is supplied to the switch circuit 14j. When the switch circuit 14j does not rotate the displayed figure, it is in the state of mode 1 in Table 2 mentioned above.
Signals are sent out from opposing output terminals. The signal generated by the character generator read signal generating section 14 is supplied to character generators 15a to 15d, as shown in FIG. As described above, each character generator selects a V-shaped or H-shaped pattern, which will be described later, according to the display status signal supplied from the processing device 1. If not, the processing device 1 is in display state C.
, the V-shaped pattern is selected. As mentioned above, the unit read out by the map section 4 in the V-shaped pattern is as shown in FIG. ing. In FIG. 11, addresses written horizontally outside the frame are output from the adder 12i in FIG.
The addresses specified by the CHG·AD(V) signal and written in the vertical direction are specified by the CHG·AD(H) signal output from the adder 12k in FIG. Therefore, adder 12i, adder 12k
by the V signal and H signal supplied from the first
You can specify 16 types of blocks indicated as ~ in Figure 1. This ~ block is further composed of four fine blocks, and the fine blocks correspond to each character generator. That is, the parts labeled a, b, c, and d are the character generator 15a, the character generator 15b, and the character generator 1, respectively.
5c and character generator 15d. Each character generator stores 4-bit data in the vertical direction of the figure, and the shaded part in the figure stores data of ``1'', and the other parts store data of ``0''. has been done. Therefore, the CHG・DAD(V) signal and CHG・
When the data of the AD (H) signals are both 00, the four small blocks marked in the upper right corner of FIG. ”, “0011” from the character generator 15c, and “0011” from the character generator 15d. Data read from these character generators is supplied to and stored in shift registers 16a to 16d. When displaying the first raster, a signal for selecting the shift register 16a is supplied from the shift register 16e of FIG. 9 to the selector 16e. As a result, only the data in the shift register 16a, that is, the data read from the character generator 15a, is selected, and the remaining shift register 16b is selected.
Data from ~16d are discarded. At this time, the timings of the shift registers 16a and 16f are synchronized. Next, when the data of the CHG/AD (H) signal becomes 01, the block shown in FIG.
Only data read from is selected. Similarly, when the data of the CHG/AD (H) signal changes to 10 and 11, the block shown in FIG. 11 is selected and the character generator 15a of that part is selected.
Only data read from is selected. After the data in the bold line in FIG. 11 is read out, the data in the dotted line below is read out in the same way, and by performing these operations one after another, the first raster That is, raster A0 of FIG. 22 is formed. After raster A0 is formed, adjacent rasters are sequentially formed in the same manner, and the final raster shown in FIG.
By forming An, one display screen is formed. That is, a V-shaped pattern is specified by the processing device 1, and the character generator readout signal generating section 14 generates a pattern such as shown in FIG.
A collection of 16 blocks is selected and CHG/AD
By (H) signal and CHG/AD (V) signal ~
One block is selected among the blocks in
By this, the character generator 15a
~4 each from character generator 15d
Bit data is read. The CHG・AD(V) signal changes every round trip of the raster, but the CHG・AD(H) signal changes as the scanning progresses.For example, in FIG. 11, the CHG・AD(V) CHG/AD when the signal is 00
As the (H) signal changes to 00, 01, 10, 11, data is sequentially read from the rightmost block, . The data read from the character generators 15a to 15d is the 12th
The signal is supplied to and stored in shift registers 16a to 16d shown in the figure. Then, in response to the signal supplied from the shift register 16f,
The selector 16e selects the signals supplied to the terminals a to d, and sends them to the cathode ray tube 7 for display. By sequentially performing scanning in this manner, a signal representing the figure read out from the character generator section 15 is displayed on the screen. At this time, by changing the origin data, the display screen can be moved horizontally or vertically. Next, the operation when rotating a figure will be explained. In addition to the operation described above assuming that the figure is not rotated, the fifth coordinate rotation processing section 12 performs a rotation signal calculation section on the signals supplied to the terminals a of the adders 12i and 12j. 1
2f and the output signal supplied from the rotation signal calculation section 12g are added together. Therefore, the signal representing the orthogonal coordinates output from the coordinate rotation processing section 12 rotates the coordinate system by an angle corresponding to the output signal supplied from the rotation signal calculation section 12f and the rotation signal calculation section 12g, as shown in FIG. This will be shown by the dotted line. In this way, due to the rotation of the coordinate system, even if the output signals of the V counter 10 and H counter 11 are the same values as when no rotation is applied to the figure, the memory stores different positions. will be accessed. Now, in the memory space shown by the rectangle in FIG. 14, the horizontal position is V address (V counter 10
The coordinates specified by are defined as V address), and the vertical position is specified as H address (H
When no rotation is given to the coordinate system represented by the orthogonal coordinates specified by the coordinates specified by the counter 11 (the coordinates specified by the counter 11 are defined as the H address), the value of the V counter 10 is fixed, and the value of the H counter 11 is When , the access is performed in the direction shown by the solid line of symbol A. However, when rotation is given to the coordinate system, access is performed in the direction indicated by the dotted line of symbol B. In other words, when the coordinate system is rotated, the memory space is accessed diagonally. The map section 4, from which data is read out by the signal supplied from the map read signal generating section 13, stores independent display contents for each area surrounded by 16 pixels in the vertical and horizontal directions of the cathode ray tube 7. For example, this map section 4 has data as shown in FIG. 8, that is, when the part surrounded by the double line in the center is accessed, data representing the letter F is read out, and the part to the right of it is accessed. When the character B is accessed, the data representing the character B is read out, and when the left neighbor is accessed, the data representing the character C is read out, and the coordinate rotation processing unit 1
When the coordinate system is rotated to the right by 2, the map section 4 is accessed as shown by the solid line in FIG. Therefore, data for displaying the character F is read out from the 1st to 11th pixels, while data for displaying the character C is read out from the 12th to 16th pixels. On the other hand, since the display timing signal is generated every 16 pixels, it is generated every time the horizontal double line in FIG. 8 is crossed. As a result, when the coordinate system is rotated clockwise and the map is accessed in the direction of the solid arrow in Figure 8, two types of data for displaying letters F and C during one cycle of the display timing signal are obtained. It becomes necessary. In this way, when the coordinate system is rotated to the right, it is necessary to read out not only the stored content of the currently accessed part during the display timing signal period, but also the stored content of the part to the left of the currently accessed part. Furthermore, when the coordinate system is rotated to the left and accessed in the direction of the arrow shown by the dashed-dotted line in Figure 8, it is necessary to read out the memory content of the part to the right in addition to the memory content of the part being accessed. be. Therefore, the memory content of the part currently being accessed is defined as "now", the memory content of the part to the left is "next", and the memory content of the part to the right is defined as "back". The correction data generator 13b shown in FIG. 6 is provided for this purpose, and generates data as shown in Table 1 in response to the 5-bit signal for reading the map data supplied from the latch 13a. We are making some corrections. For example, in display state C, when the figure is rotated to the left, that is, when the coordinate system is rotated to the right, 1 is added to the signal supplied from the latch 13a; It is designed to subtract 1. In display state C, the signal provided by V counter 11 and stored in latch 13a indicates the lateral position of the map. Thus, the 5-bit signal provided by latch 13a identifies the lateral positions of FIG. 8, ie, the characters C, F, and B. If the 5-bit signal supplied from latch 13a is accessing the character F, adding 1 to it indicates that the character C is to be accessed, since it specifies a position to the left. Also,
Subtracting one represents accessing the character B. As a result, the signal at the input side terminal a of the adder 13c is the memory content of the part currently being accessed, that is, the "now" signal, but the output side terminal c
The signal from the correction data generator 13b is added to the signal according to the signal supplied from the processing device 1, and
It will represent a ``next'' or ``back'' signal. As mentioned above, the V signal output from the adder 12i is a signal specifying the horizontal position of the map at the time of access, and the correction by the correction data generator 13b is sent from the latch 13a to the adder 13c. This is done on the supplied signal.
Therefore, when a figure is rotated, for example, if access is performed as shown by the solid line in FIG. 8, the contents of the V signal, that is, the output signal of the adder 12i, change during the access. Therefore, during the repetition period of the display timing signal, the adder 12i
Even if the output signal of latch 1 changes, the contents of the V signal supplied to adder 13c do not change.
3a is provided to fix the data. Since the selectors 14a and 14b in FIG. 9 are switched in synchronization with the latch 13a and the correction data generator 13b in FIG.
is outputting a "next" or "back" signal, and the selector 14b is outputting a "now" signal. On the other hand, in display state C, the selection of each memory content in the horizontal direction in FIG. 8 is performed by the V signal, and the selection of the memory content in the vertical direction is performed by the H signal, as shown by the solid line arrow in FIG. When such an access is performed, the H4 signal does not change the data content when accessing the 1st pixel to the 16th pixel, but the V4 signal changes the data content from the time the 12th pixel is accessed. The content changes. For this reason, the EOR circuit and 14
Since the output signal of n changes after this point, it is determined based on this change that it is necessary to switch the displayed screen to "NEXT". The information determined by the EOR circuit 14n is stored in the shift register 14i and stored in the latch 14h. Then, the switch circuit 14 is activated by the left and right signals and display status signals supplied from the processing device 1.
An output signal controlled in mode 1 or mode 2 as shown in Table 2 is sent from g, and which selector among the selectors 14c to 14f selects the "now" data and which selector selects the "next" data. You can decide which one to choose. The data read out from the character generator unit 15 by the signal supplied from the character generator read signal generator 14 is sent to the figure assembly unit 16.
The images are assembled into figures and supplied to a cathode ray tube 7 for display. As a result, when no rotation is applied to the coordinate system, the first
As shown in Figure 5a, when a triangular figure is displayed on the screen, when the memory is accessed as shown by the solid arrow in Figure 8, the displayed figure moves to the left as shown in Figure 15b. Displayed as a rotated shape. Further, when the memory is accessed as shown by the dashed line in FIG. 8, the displayed figure is displayed as a figure rotated to the right as shown in FIG. 15c. FIG. 20 is a diagram for explaining the display state when the character F is stored in the character generator and this character generator is accessed using the orthogonal coordinates indicated by the thick line given rotation. . In the same figure, the data of the letter F is stored in the same way as in FIG. 11, so 00 of CHG/NO is stored in the character generator 15a, 01 is stored in the character generator 15b, and 10 is stored in the character generator 15c. , 11 is character generator 1
Compatible with 5d. The data read from the character generator is 4.
The signals are simultaneously read out from the character generators and stored in the shift registers 16a to 16d. Initially, the 1st pixel to the 16th pixel is accessed, data of CHG/NO 01 is supplied from the shift register 16f to the selector 16e, and the shift register 16C storing the data of the character generator 15c is selected. A master timing signal is supplied to this shift register 16c, and data corresponding to the first pixel and data corresponding to the second pixel are successively read out. At this time, since the master timing signal is also supplied to the other shift registers, the data corresponding to the pixels represented by symbols B, C, RO, and C are also read out, but these data are not processed by the selector at the current timing. Since it is not selected in 16e, it is not output. Note that the data read from the shift register 16c at this timing is "0" because it is not the character F but a blank part. Next, data "11" is supplied from the shift register 16f to the selector 16e in order to read out the data necessary to correspond to the third pixel from the shift register 16d storing the data of the character generator 15d. . Data necessary for the third pixel is read out from this shift register 16d at the third bit of the master timing. Since this data is for displaying the letter F, it is "1". Similarly, data "1" corresponding to the fourth pixel is read out, but since the CHG/AD (V) data has changed, the read data is
This is a character generator compatible with CHG/AD(V) signals. Accesses are made one after another in the same manner. When the first access is completed, the columns of symbols A to P are accessed, and the columns of symbols A to P are sequentially accessed.
accesses are performed. As a result, a rotated figure of the letter F is displayed, as shown by the hatched area in FIG. In this device, CHG・AD(V)
The character generators specified by and CHG・AD(H) are read at the same time, and the necessary data is used from there, so the memory read speed is 4 times faster than when this memory is configured with one piece. 1, and the device can be constructed easily and economically. In the example shown in FIG. 20, the shift register 15c, 15d, 15a, and 15b are selected in order.
A signal is supplied from 6f, and this signal changes depending on the position of the character generator where access is started, and data is rearranged according to the access order. When there is no need to apply rotation to the displayed figure, the memory is accessed in the direction shown by the dotted line in FIG. This access direction is arbitrarily controlled. This control is the 16th
As shown in the figure, the pixel to be scanned next to the pixel currently being scanned is a pixel adjacent to the pixel currently being scanned. Therefore, the pixel to be scanned next to pixel P1 is one of P1 to P3, and the access direction is limited to a maximum of 45 degrees. As a result, when accesses are made in directions that differ by plus and minus 45 degrees, the figure displayed as the solid line in Figure 17 when no rotation is applied will be the 17th
It will rotate within the range from the position indicated by the dashed line to the position indicated by the dotted line in the figure. However, as it is, it is not possible to rotate the displayed figure by more than 45 degrees, but the adder 12 performs lateral access to the memory based on the H counter 11.
The memory is accessed in the vertical direction by the adder 12 based on the V counter 10 (this signal is defined as the H access signal).
When the signal generated from i (this signal is defined as the V access signal) is used, the figure displayed as shown in FIG. 17 is displayed as shown in FIG. 18b. As a result, the figure shown by the dashed line in FIG. 18b is obtained by rotating the figure shown by the solid line in FIG. 17 to the right by 135 degrees. on the other hand,
In FIG. 17, if the changing directions of the V access signal and the H access signal are reversed, the displayed figure becomes as shown in FIG. 18a. In FIG. 18a, the figure shown by the dashed line is the figure shown by the solid line in FIG. 17 rotated 225 degrees to the right. In Figure 18a, V
When the access signal and the H access signal are exchanged, the displayed figure becomes as shown in FIG. 18d. In FIG. 18d, the figure shown by the dashed line is the figure shown by the solid line in FIG. 17 rotated 315 degrees to the right. If the V access signal and H access signal are swapped in FIG. 18d and the data change direction of the V access signal is reversed, the displayed figure becomes as shown in FIG. 18c. Figure 18c is the figure shown in Figure 17 rotated 360 degrees to the right. In other words, by selecting the way the V access signal and the H access signal are handled and the direction in which the data changes, the graphic can be rotated to any angle and displayed. The display state of FIG. 18 corresponds to the display state of FIG. 3, and the display states of figures in the display states A, B, C, and D described above are
It becomes like c, d. Here, Fig. 18 a, c
18b and 18d, the V access signal and the H access signal are interchanged. In order to perform such exchange of access signals, selectors 13d to 13g shown in FIG. 6 are provided. The above explanation of giving rotation to the figure is based on the state in display state C, so the pattern of the character generator used is as shown in Fig. 11, with the horizontal position being CHG・AD(V ) signal, and used a V-shaped pattern whose vertical position is represented by the CHG/AD (H) signal. Even in display state A, the V-shaped pattern shown in FIG. 11 can be used because only the change direction of each signal changes and the combination of signals itself does not change. However, in display states B and D, the horizontal direction is the H access signal, and the vertical direction is the V access signal, so if you try to display the same figure as shown in FIG. 11 on the screen, the figure shown in FIG. V as shown
It is necessary to use an H-shaped pattern that is rotated 90 degrees. Therefore, the character generators 15a to 15d have a V-shaped pattern and an H-shaped pattern, and select the pattern according to the display state signal rotation signal supplied from the processing device 1. Note that the processing device 1 receives a display state signal, an origin signal,
A rotation amount signal and a left/right direction signal are generated, but these signals may be controlled manually by the operator, or
It may also occur due to software control. Also, although the maximum rotation angle is 45 degrees, it may be less than that, and the memory configured by the map and character generator may be RAM, so even if it is a graphic display, figures can be rotated at extremely high speed. Ru. Further, in order to give continuous rotation to the displayed figure, it is sufficient to continuously change the rotation amount signal generated from the processing device 1. [Effects of the Invention] As explained above, the present invention reads out both the data of a display section and the data of the section adjacent to the display section, and selects the data according to the display state. This has the effect that normal display can be performed when rotation is applied to the image.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a graph for explaining rotation of coordinates, FIG. 3 is a diagram for explaining the relationship between memory and display area, and FIG. 4 is a diagram for explaining the relationship between memory and display area. is a diagram for explaining the display state, and FIG. 5 is the coordinate rotation processing unit 12 in the first
6 is a block diagram showing details of the map readout signal generating section 13 in FIG. 1, FIG. 7 is a block diagram showing details of the map section 4 in FIG. 1, and FIG. 9 is a block diagram showing details of the character generator read signal generation section 14 in FIG. 1, and FIG. 10 is a diagram showing the character generator section 15 in FIG. 1. FIG. 11 is a block diagram showing details of the V-shaped pattern stored in the character generator, FIG. 12 is a block diagram showing details of the figure assembly section 16 in FIG. 1, and FIG. Figure 14 is a diagram showing the relationship between the V signal and H signal, Figure 14 is a diagram showing the memory access direction, Figure 15 is a diagram showing the state displayed when the display figure is rotated, and Figure 16 is the pixel. 17 is a diagram showing the rotation range of a displayed figure in display state C, and FIG. 18 is a display when the same figure is rotated in four display states A, B, C, and D. Figure 19 is a diagram showing the H-shaped pattern stored in the character generator, and Figure 20 is a diagram showing the character generator being accessed to explain the rotation of a figure. , FIG. 21 is a diagram showing the actual display state of figures, FIG. 22 is a diagram for explaining raster, FIG. 23 is a block diagram showing the configuration of a conventional device, and FIG. 24 is a memory of a character generator. A block diagram for explaining the contents, Figure 25 is the second
4 is a timing chart showing a state in which the signals read out in FIG. 4 are displayed.

Claims (1)

[Claims] 1. When a figure is displayed by displaying independent images in a plurality of sections, data necessary for displaying the figure is stored in a memory that is expressed in coordinates different from the coordinates of this memory. In a graphic display method that reads data by supplying a readout signal and displays the readout data, the data necessary for the section to be displayed is read out from memory, and the readout signal is corrected according to the display state. Then, a new readout signal is generated, data in a section adjacent to the section to be displayed is read out by this new readout signal, and the two types of read data are selected according to the display state. Characteristic graphic display method. 2. When displaying a figure by displaying independent images in multiple sections, a readout signal expressed in coordinates different from the coordinates of this memory is supplied to a memory that stores data necessary for displaying the figure. In a graphic display device that reads data and displays the read data, means for reading data in a section to be displayed, means for reading data in a section adjacent to the section to be displayed, A graphic display device comprising means for selecting data according to a display state. 3. When displaying a figure by displaying independent images in a plurality of sections, a readout signal expressed in coordinates different from the coordinates of this memory is supplied to a memory that stores data necessary for displaying the figure. Read the data, read out the data necessary for the section to be displayed from the memory, and generate a new read signal by correcting the read signal according to the display state. Therefore, in a graphical display method in which data of a section adjacent to a section to be displayed is read and two types of read data are selected depending on the display state, a readout signal to be supplied to the section to be displayed is stored. A figure display method characterized by the following: