JPS62204331A - Graphic display device - Google Patents

Abstract

PURPOSE:To reduce a memory or circuit quantity by using a clipping means to process a part of picking processing. CONSTITUTION:A single point is indicated by a light pen on a pattern C and the coordinates of said point are supplied. A CPU decides a small area including the input coordinates, i.e., a picking area 52. Then both minimum and maximum coordinates Xl, Xh, Yl and Yh in X and Y directions of the area 52 respectively are set by the CPU at four registers 46-49 in a clipping checker 38. The patterns A, B, C... are successively drawn again and a picking flag 51 is checked every time the drawing is through with a pattern. Here a point on the pattern C passes through the area 52, therefore the flag 51 is turned on after the pattern C is drawn by the function of the checker 38. In such a way, the selected pattern C is detected and the prescribed processing is applied to this pattern C.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an interactive graphic display device, and in particular to a graphic display device that improves the picking process for selecting a specific graphic from among displayed figures. Related to display devices.

[Prior Art] In conversational graphic display devices, it is extremely popular to use a light pen or the like to select a specific figure from among the displayed figures, and to move, rotate, delete, or otherwise process this figure. is important. In this type of processing, first, a small area on the display screen specified by a light pen or the like is set in a display control device, etc., and then the figure being displayed is sequentially transferred to the display memory (frame buffer). The shape that passes through this small area is selected. This process of selecting a specific figure from among the displayed figures is called picking.

[Problems to be Solved by the Invention] Incidentally, in the above-mentioned conventional graphic display device, a process called clipping is normally performed. This is a method of drawing and displaying only figures that fall within a preset specific area, and the above-mentioned picking and clipping have in common that they extract drawing points that fall within a specific area.

However, in conventional graphic display devices, these processes are performed by separate means, resulting in duplication of means. In other words, if these functions are implemented in software, some of them will be duplicated and the memory load will increase.
If this is implemented using hardware, there is a problem in that the number of circuits increases due to duplication.

The present invention has been made against such a background, and an object of the present invention is to provide a graphic display device in which a part of the picking process is performed using a clipping means, thereby reducing the memory m or the amount of circuitry. With the goal.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a clipping means that selects only points falling within a specific area on the display screen from a sequence of points constituting a given figure. , a drawing means for drawing the selected point in a display memory, an input means for inputting a picking area through which a part of the display figure to be selected passes, and a drawing means for drawing the selected point in the display memory, and an input means for inputting a picking area through which a part of the display figure to be selected passes, and a picking flag that is turned off when setting the picking area and turned on by the clipping means when drawing a point entering the picking area,
The figure displayed on the display screen is sequentially redrawn in the display memory by the drawing means, and each time the figure is drawn, the picking flag is checked to select a figure passing through the picking area.

[Operation] According to the above configuration, the clipping means can detect a figure passing through the picking area. That is, it is possible to perform part of the picking process by reusing the existing clipping means. This makes it possible to save on software or hardware for picking.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of a display device to which the present invention is applied. In the figure! is the CPU.

A memory 3 and a graphic display controller 4 are connected to the CPUI via a bus 2.

This CPU creates coordinate data and commands for figures to be displayed and supplies them to the graphic display controller 4. The graphic display controller 4 performs drawing (writing) in the vRAM (video RAM) 6 based on the coordinate data and commands sent from the CPUI. Further, the display data drawn in the VRAM 6 is sequentially read out, the read data is subjected to D/A conversion, etc., and is supplied to the crt'r display device 5 for graphic display.

VrtAMf3 has four display areas 7A, 7B, and 7G.

7D and one working area 8. Each of these aspects is
It corresponds to each pixel on the CRT display screen, and each surface has the same memory capacity. And the display area 7 on the 4th side
Color data (4 bits for each pixel) for determining the color of a pixel is stored in A, 7B, 7C, and 7D. Further, the work area 8 is used to perform various tasks.

FIG. 2 is a block diagram showing the internal configuration of the graphic display controller 4. As shown in FIG. In the figure, the CPU interface 11 is connected to the CPUI through eight data buses CDO to 7 and control buses such as boat select lines PS1 and chip select Ic5rt (for reading) and C3W (for writing).

Coordinate data and commands are sent from the CPUI through data buses CDO-7. The command is composed of an operation code and an operand, and is sent from the CPUI to the CPU interface 11. In this case, the operation code and operand are stored in separate boats, and their distinction is indicated by the boat select PS (1 bit).

There are also two types of commands: normal commands that instruct drawing, and immediate commands that instruct rewriting of the cursor, color table, etc., which will be described later, and are distinguished by the bit of CD7.

The CPU interface 11 discriminates these command quibs, temporarily stores normal commands in PIF'012, and sends immediate commands directly to each section.

Furthermore, the data sent from the CPUI is divided into address data specifying register numbers, etc., and other data and output.

The FIFO 12 is a write FIFO for temporarily storing normal commands and data from the CPUI,
Read FI for storing data sent to CPUI
It has an FO, a controller that controls writing and reading of these, and an I10 controller. I10
The controller determines the operation code and operand of a command, controls starting and stopping of the functional controller 20, which will be described later, and receives and transfers data to and from the functional controller 20. In addition, cursor pattern data is output based on data from CI) UI and supplied to the cursor controller 14.

The cursor controller 14 compares the cursor parameter register that stores the display coordinates (X, Y coordinates) of the cursor, the cursor pattern register that stores the cursor pattern, and the cursor coordinates and scanning position. It has a comparator and a blink counter to control the blinking of the kerful. Then, when the display coordinates of the cursor match the scanning position, a cursor-on signal is output to instruct the display of the cursor. The above cursor pattern is the one stored in VRAM6.
It is read out and taken out immediately before display.

A CR'rC (CRT controller) 15 performs display control, and sends timing signals to the CR'r display device 5,
That is, in addition to creating a vertical synchronization signal and a horizontal synchronization signal, it also forms an internal timing signal, outputs the read address of V1NAM6, and outputs the read address of VRAM interface 16.
supply to. That is, CRTCI 5 is V at the time of display.
The RAM address, the VRAM address of the cursor pattern, and the VRAM address at the time of VRAM refresh are output in the form of XY coordinates and supplied to the VRAM interface 16. Note that these addresses are VRA
M interface 16, from the X-Y coordinates to the actual VR
Converted to AM address.

The VRAM interface 16 generates a timing signal for accessing the VRAM 6 from the internal timing signal supplied from the CRT015 and outputs it. That is, R.A.
It outputs S (row address selection signal), CAS (column address selection signal) and R/W (read/write signal).

Also, from the VflAM address supplied from cR't'ct5, each 9-bit row and column address signal V I
'j AO~8 is formed and output. Furthermore, V RA
It has a register that stores M data, and has a 16-bit V
I? A M data VIjDO~15, VRAM6
interact with

Through the VRAM interface 16, the VRAM
The 4-bit data (color data) read from display areas 7A, 7B, 7C, and 7D of
It is supplied to a UT (Look Up Table) 17.

LUT 17 contains R, G from the above color data.

This is a conversion table designed to obtain a color value consisting of a total of 10 bits, 3 bits each and TP (transparent) bits. Specifically, it is composed of a RAM of IO bits/word x 16 words, the above 4-bit color data is used as an address signal, and any I word is read out as a color value. Note that the LUT 17 can be rewritten by the CPU 1.

The IO bit color value output from LUT 17 is supplied to display data generator 18. The main function of the display data generator I8 is to replace the color values of the cursor display timing with the cursor pattern provided by the cursor controller Ill. In other words, when the cursor on signal is on,
Make all colors and values transparent so that only the cursor is visible. Other functions of the display data generator 18 are to impose a border color on the border timing and to set the color value of the blanking timing to black so that it is not displayed.

The 9-bit signal output from the display data generator 18 is converted into an analog signal by a DAC (digital/analog converter) 19, and supplied to the CRT display device 5 for display.

Next, the functional controller 20 will be explained in detail with reference to FIG. The functional controller 20 is for controlling drawing. In FIG. 3, the data handler 21 is for receiving and passing data to and from FIFOI'2. In this case, F[F
Various data such as commands and coordinate data required for drawing are sent from the OI2 side. Further, from the functional controller 20 side, data to be transferred to the CPU 1 is sent to the FIFO I 2. Data from the FIFO 12 is supplied to the status register 22.

The status register 22 interprets drawing commands and has all data related to drawing. It has data such as drawing address, clipping area address, picking area address (described later), data transfer source and destination block sizes and addresses, drawing color information, background color information, etc. ing. It is also connected to all the blocks described below via an internal bus and exchanges data.

Next, the transfer controller 23 transfers data within the VRAMB, transfers data from the data area of the CPU 1 to the VRAM 13, or transfers data in the opposite direction.
Since this is done pixel by pixel or 4 pixel by pixel, the transfer direction is controlled, the data format is converted, etc.

The enlargement/reduction circuit 24 connects the transfer source (CPU l or V
The size of the data area (rectangular area) in IIAM6) and the transfer destination (VRAM6 or i,t CPU 1
) The transferred figure is automatically enlarged or reduced according to the size of the data area.

The rectangle drawing circuit 25 receives the two diagonal vertices of the rectangle from the data handler 2I and converts them into a four-sided straight line drawing command. This straight line drawing command is issued to the DDA2G.

A DDA (digital differential analyzer) 26 is a well-known means for generating dot coordinates of a straight line from the coordinate difference between the starting point and the ending point of the straight line to be drawn. The above components 25 and 26 provide the data necessary to draw a rectangle.

Next, the components necessary for filling a polygon will be explained.

The polygon filling controller 27 receives the vertex address of the polygon shape from the data handler 2I, and controls whether to draw the outline or not to fill it. The polygon outline drawing controller 28 has display areas 7Δ, 7B, 7G,
It is possible to control the drawing of polygons to 7D. That is, the starting point and ending point of each side are supplied to the DDA 26 to sequentially generate straight lines.

Next, the polygon work area drawing circuit 29 performs control to draw a figure (filled frame) corresponding to the outer shape of the polygon in the work area 8 based on the dot data supplied from the DDA 26.

The polygon filling circuit 30 instructs the scanner 3I to read data in the work area 8 within the minimum rectangular range that includes the polygon to be filled. Scanner 31
Scan the work area 8 and find the address of the range to be crushed.

Once the straight lines to be drawn and the horizontal line segments to be filled are determined as described above, the dots forming these are supplied one by one to the texture generator 32. The texture generator 32 determines whether or not to display the dots in accordance with instructions such as whether to display these straight lines as solid lines or broken lines. First, the texture generator 32 supplies the X-Y coordinates of the dot to a pattern memory 33 that stores textures for lines and filling.
Reads the dot data according to the specified texture and coordinates, and calculates the value on the texture corresponding to the above dot (
“1”, “0”).

Once the coordinates and values of the point to be drawn are determined, the point drawing circuit 3
4 performs drawing for one pixel. This drawing is performed under the following various conversions or restrictions.

First, the point expander 35 expands the drawing of ■ pixels to the size of 1 bell. Here, l pel is
A logical pixel size, for example, a normal line is made up of IXI pixels, a thick line is made up of 2×3 pixels, and so on. Note that the size of l-pel is stored in the status register 22.

Next, the transparency checker 36 checks whether the color to be drawn is a color that should be made transparent, and if it is made transparent, it is not drawn. This instruction is given by a command from the CPUf side and is supplied via the color register 37. For example, when drawing a dotted line, you want to erase the background color between the dots and make them transparent to make it look like a dotted line. What is the effect in such cases?

The color register 37 records color data (4 bits) to be input into the display areas 7A, 713.7C, and 7D of the VRAM 6, and also records the color data (4 bits) into the display areas 7A, 713.7C, and 7D of the VRAM 6.
It stores the color data read from 7B, 7C, and 7D, and is connected to the VnAMG via the VRAM interface 16.

The clipping checker 38 checks whether the point to be drawn is inside or outside the clipping/picking area and determines whether or not to draw the point, the details of which will be described later.

Next, the masking checker 39 compares the masking pattern formed in the work area 8 with the points to be drawn and determines whether or not to mask the drawing points. When masking, do not draw. In other words, it does not output drawing addresses.

Finally, the drawing controller 40 controls the display areas 7Δ, 7
It switches the drawing to B, 7C, 7D and the work area 8, and outputs the VRAM address in the form of coordinate data. As a result, the color data stored in the color register 37 is drawn at the corresponding address in the VRAM 6 via the VRAM interface 16. In addition,
The above coordinate data is converted into an actual VRAM address by the VRAM interface 16.

FIG. 4 is a block diagram showing the configuration of the clipping checker 38. In the figure, 4! is a switch. The drawing address (X, Y) is supplied from the transparent checker 36 to the switch 4I, and these addresses are separated into an X address and a Y address, and the former is sent to the comparator 4.
2, 43, the latter is connected to a comparator 44, 4.
5, respectively. These comparators 42 to 45 are for checking whether the drawing address falls within the clipping area or the picking area. This clipping area or picking area is given by a rectangle, and the minimum coordinates of this rectangle in the horizontal direction (X direction) Y0. and the maximum coordinate Yh are respectively set in four registers 46-49 and supplied to the second input terminals of each of the comparators 42-45.

The checker 50 checks whether the drawing address falls within the clipping area or the picking area based on the output results of these comparators 42 to 45. When the area is within the area, the drawing address (X, Y) is output, and when it is not, the drawing address is not output. Furthermore, when it is within the area, the picking flag 5I in the status register 22 is turned on.

Next, pigging processing, which is the gist of this embodiment, will be explained. In this case, it is assumed that four figures A to D are displayed on the CR'r display device 5, as shown in FIG. 5, and figure C is selected. It is assumed that these figures A to D are all filled in.

(1) Picking area input.

Using a light pen (not shown), one point on figure C is set as (2) the picking area.

A small area including manually entered coordinates, that is, a picking area 52 is determined by the CPU 1, and the picking area 5
2. Minimum and maximum coordinates in each of the X and Y directions XQ, XJYQ, Y
l+ is sent to the CPUI or the functional controller 20 and set in four registers 46-49 in the clipping checker 38, respectively.

(3) Redrawing the displayed figure.

Starting from figure A, each figure is redrawn in sequence, B, C, and so on. That is, the figures A, B, . . . , which have already been drawn in the display area 7, are redrawn so as to trace them.

(4) Every time you finish drawing one figure, pick
Check flag 51. In this case, since the point on the figure C passes through the picking area 52, the picking flag 51 is turned on after the figure C is drawn due to the action of the clipping checker 38.

When the selected figure C is detected in this way, this figure C is subjected to predetermined processing, such as movement, rotation, deletion, etc.

[Effects of the Invention] As described above, in the present invention, a part of the picking process is carried out by using the clipping means, so that the apparatus configuration can be simplified. That is, when picking is performed using software, the amount of memory can be saved, and when performing picking is performed using hardware, the picking circuit can be simplified.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, and FIG. 2 is a graphic display diagram of the embodiment.
A block diagram showing the configuration of the controller, FIG. 3 is a block diagram showing the configuration of the functional φ controller of the graphic display controller, and FIG. 4 is a block diagram showing the configuration of the clipping checker 38.
FIG. 5 is a front view showing graphics A-D displayed on the "CR'I" display device and the picking area 52. 1...CPU, 4...Graphics.
Display controller (control means), 5...
・・CRT display device (display device), 6・・・・・・VR
AM17 (7A, 7B. 7C, 7D)...Display area (display memory),
8...Work area (work memory), 20...
...Functional controller (drawing means),
38... Clipping checker (clipping means).

Claims (1)

[Claims] A graphic display device comprising: clipping means for selecting only points falling within a specific area on a display screen from a sequence of points constituting a given figure; and drawing means for rendering the selected points in a display memory. , an input means for inputting a picking area through which a part of the display figure to be selected passes; a setting means for setting this picking area in the clipping means; and a setting means that is turned off when setting the picking area and enters the picking area. a picking flag that is turned on by the clipping means when drawing a point; the figure displayed on the display screen is sequentially redrawn in the display memory by the drawing means; A graphic display device that selects a graphic that passes through the picking area by checking a picking flag.