JP3099480B2 - High-speed graphic drawing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed graphic drawing method and apparatus for a high-resolution graphic device and the like.
More specifically, the present invention relates to a high-speed graphic drawing method and an apparatus for shortening the output time when an output device such as a graphic display or a page printer having a high resolution and a simple output is sufficient for a layout study or the like.

[0002]

2. Description of the Related Art Conventionally, graphics output to an output device such as a graphic display or a page printer are often represented as a set of linear data, and a linear generating means (Digital Differential Analytic) is used for generating the linear data.
lyser; hereinafter referred to as DDA). FIG. 6 shows an example of the configuration, in which coordinate data and luminance data of both ends of a straight line are input to DDA (1), and DDA (1) generates straight line data based on the input data. Then, the generated straight line data is drawn in the frame memory (2), and the data drawn in the frame memory (2) is read and output to an output device such as a graphic display or a page printer.

However, in the above configuration example, the DDA
The data writing speed of the frame memory (2) is remarkably slower than the data generation speed of (1), and a substantial decrease in drawing speed is caused by this speed difference. Various attempts have been made such as providing a buffer for buffering a speed difference between the frame memory (2) and the frame memory (2), and using a high-speed write mode such as a page mode as an access mode of the memory (2).

[0004]

However, in any case,
A graphic device or the like having a high resolution does not significantly reduce the drawing speed, and performs a high-definition drawing based on the above-described series of operations even when the drawing accuracy is not particularly required for layout examination or the like. Therefore, there is a problem that it takes a long time to actually display the image on a graphic display or to perform a printer output.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to output straight line data to a frame memory in a high-definition graphic device when a simple output is sufficient for layout examination or the like. An object of the present invention is to provide a high-speed graphic drawing method and apparatus for improving the drawing speed.

[0006]

In order to achieve the above object, the high-speed graphic drawing method according to claim 1 receives line end point data, generates line data, and generates the generated line data graphically. In a drawing method for drawing in a memory having an area corresponding to an output area of an output device such as a display or a page printer, data at both end points of a straight line is compressed by a predetermined amount, and the compressed both end point data is received to generate straight line data. Then, the generated straight line data is expanded by a reproduction amount corresponding to the predetermined amount in the previous period, and the expanded straight line data is drawn in a memory, thereby enabling high-speed figure drawing.

According to a second aspect of the present invention, there is provided the high-speed graphic drawing method according to the first aspect, further comprising compressing both end point data of the straight line by a predetermined amount, and receiving the compressed both end point data to obtain a straight line. Data is generated, the generated linear data is expanded by a reproduction amount corresponding to the predetermined amount, and the expanded linear data is drawn in a memory, thereby enabling high-speed graphic drawing.

[0008]

[0009]

According to a second aspect of the present invention, there is provided a high-speed graphic drawing apparatus, comprising: a straight line generating means for receiving both end point data of a straight line and generating straight line data; and an area corresponding to an output area of an output device such as a graphic display or a page printer. Storage means for drawing straight line data generated in the previous period, and further comprising data number reduction means for reducing the number of generated straight line data drawn in the storage device in the previous period, wherein the data number reduction means is provided at both ends of the straight line. A compression means for compressing the point data by a predetermined amount, and a decompression means for decompressing the straight line data generated by the straight line generation means by a reproduction amount corresponding to the predetermined amount.

[0011]

According to a third aspect of the present invention, there is provided the high-speed graphic drawing apparatus according to the second aspect, further comprising a compression means as a shift-down means for shifting down both end point data of the straight line, and the generated straight line data. And extension means as shift-up means for shifting up.

[0013]

[0014]

According to the first aspect of the present invention, there is provided a high-speed graphics
Receiving both end point data of a straight line, generating straight line data,
When rendering the generated straight line data in a memory (2) having an area corresponding to an output area of an output device such as a graphic display or a page printer, data of both end points of the straight line is compressed by a predetermined amount, and the compressed end points are compressed. Receiving the data, generating straight line data, expanding the generated straight line data by the reproduction amount corresponding to the predetermined amount in the previous period, and drawing the expanded straight line data in the memory (2). When the layout does not require a high degree of accuracy, for example, when examining a layout, the total number of straight line data drawn in the memory (2) is reduced by the amount corresponding to the predetermined amount in the previous period, and high-speed drawing of figures becomes possible.

[0015]

[0016]

[0017]

According to a second aspect of the present invention, in the high-speed graphic drawing apparatus, the straight line generating means (1) receives both end point data of the straight line and generates straight line data, and the compression of the data number reducing means (3). Means compresses the data at both ends of the straight line by a predetermined amount, and expands the straight line data generated by the expanding means by a reproduction amount corresponding to the predetermined amount in the previous period, so that the data is output to an output area of an output device such as a graphic display or a page printer. Since the reduced linear data is drawn in the storage unit (2) having the corresponding area, the storage unit (2) can be used in a graphic device having a high resolution for a layout study or the like which does not require much accuracy. , The total number of straight line data to be drawn is reduced by the amount corresponding to the predetermined amount in the previous period, and high-speed drawing of figures becomes possible.

[0019]

According to a third aspect of the present invention, the shift down means (31) shifts down both end point data of the straight line by a predetermined amount, and the shift up means (32) is generated by the straight line generating means (1). Since the shifted straight line data is shifted up by the reproduction amount corresponding to the predetermined amount in the previous period, the straight line drawn in the storage means (2) when a high precision is not required for layout examination in a graphic device having a high resolution. The total number of data is reduced by the amount corresponding to the predetermined amount in the previous period, and high-speed drawing of figures becomes possible.

[0021]

[0022]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

An embodiment of the high-speed graphic drawing method according to the present invention will be described with reference to the flowchart of FIG.

When a graphic is output by a graphic display device or the like, the graphic is usually divided so as to be represented as a set of polygons, linearly interpolating between vertices of each polygon in the side direction, and further filling the interior of the polygon. In this case, the image is displayed on the screen by interpolating between the sides in the scan line direction. Therefore, in this embodiment, for example, in the case of the simple output mode such as the layout display, first, in step 1 (SP1),
When the end point data of the straight line to be interpolated is input, in step 2 (SP2), the end point data is compressed by a predetermined amount, and in step 3 (SP3), the data is compressed in step 2 (SP2). Line data is generated based on the end point data thus obtained, and in step 4 (SP4), the line data generated in the reproduction amount corresponding to the predetermined amount compressed in step 2 (SP2) is expanded. Thereafter, in step 5 (SP5), the expanded straight line data is drawn in the frame memory (2), and in step 6 (SP6), the contents of the frame memory (2) are displayed on a graphic display device, or transmitted to a page printer. Output.

As described above, in the present embodiment, when a display output for layout examination or the like is instructed, data at both end points of a straight line to be drawn is data-compressed, and a straight line generated based on the compressed data is obtained. Since the data is decompressed and output to the output device via the frame memory, the straight line data is drawn with missing dots, thereby reducing the amount of data to be accessed to the frame memory. Is possible.

More specifically, when both end point data of a straight line to be drawn are received, straight line data is usually generated in pixel units as shown in FIG. 2A. If it is not necessary and, for example, the pixel accuracy of a straight line as shown in FIG. 2B is sufficient, the coordinate data of both end points of the received straight line is first compressed to one half, As shown in FIG. 2B, the straight line data generated based on the point data is expanded and displayed twice.
As shown in FIG.

Therefore, when the display accuracy of the figure is required to be one half as in this example, the number of data accessed to the frame memory is reduced to about half.
The time output to a graphic display device or to a printer or the like is greatly reduced, and high-speed drawing of graphics can be performed.

[0028]

Embodiment 2 In the above embodiment, the drawing speed is increased by performing compression processing on the data at both ends of a straight line and further performing expansion processing on the straight line data generated by the DDA (1). In the example, instead of this compression / decompression processing, DDA
The drawing speed is increased by forcibly reducing the number of dots to be drawn at the output stage of the straight line data according to (1). That is, in the present embodiment, linear data is generated in the DDA (1) so as to interpolate between both end points without a gap. The display accuracy is 2
The display accuracy is set to 1/2 by setting it to double so that it becomes 1/2.
Is generated. Therefore, when this method is adopted, data compression / decompression becomes unnecessary, and the processing can be further simplified.

The embodiment of the above-described high-speed graphic drawing method is as follows.
This is related to the generation of straight line data with a display accuracy of one half, but if you want to be able to arbitrarily set the interval between dots to be drawn according to the required display accuracy, convert the compression / expansion rate. Of course, it is possible to make it possible.

[0030]

Embodiment 3 FIG. 4 is a block diagram showing another embodiment of the high-speed graphic drawing apparatus according to the present invention, wherein a shift-down means (31) for shifting down both end point data of a straight line and both end points shifted down are shown. It has a DDA (1) for generating linear data based on the data, and a shift-up means (32) for shifting up the generated linear data, and the data from the shift-up means (32) is transferred to a graphic display device. And output to an output device such as a page printer.
Drawing is performed in a frame memory (2) having an area corresponding to the output area.

With the above arrangement, first, coordinate data and luminance data of both ends corresponding to each side of the figure expressed in binary are transmitted to the shift-down means (31), and the shift-down means (31) transmits the coordinate data and the luminance data. Shift down is performed by ignoring the least significant bit of each data obtained. That is, each data of the vertices becomes a half value of the input data. Next, each down-shifted data is sent to DDA (1), and based on these data, DDA (1) generates linear data. Further, the straight line data generated by the DDA (1) is sent to the shift-up means (32), and the shift-up means (32) shifts up the sent straight line data point by point, and stores it in the frame memory (2). draw. At this time, each point of the shifted up straight line data has twice the value of each point of the generated straight line data. Therefore, in this case, the data drawn in the frame memory (2) is simply halved compared to the straight line data connecting the two end points which were initially input, and the output time (display on the graphic display device) is reduced with some accuracy. Time or output to a printer or the like). Further, in this embodiment, in order to halve the number of data to be drawn, each data (binary end point data and straight line data) represented by a binary number is simply shifted down or up, so that special calculation is required. It is not required and does not affect access speed. In this embodiment, the luminance data is also shifted down and up. However, the luminance data may be left as it is, and only the coordinate data may be shifted down and up.

In this embodiment, each vertex data is shifted down by one bit by the shift-down means (31) so that the number of generated linear data is reduced to half. 2 bits or 3
It is possible to change the bit and shift down amount and use it. In this case, it is needless to say that the same number of bits as the number of bits shifted down needs to be shifted up by the shift-up means (32). Furthermore, it is also possible to provide a mode control (4) or the like so that the selection can be made arbitrarily according to the required accuracy and drawing speed.

[0033]

Embodiment 4 FIG. 3 is a block diagram showing an embodiment of a high-speed graphic drawing apparatus according to the present invention. The DDA (1) for generating straight line data based on both end point data of a straight line and the DDA
(1) a data number reducing means (3) for generating an output permission signal for permitting output of the linear data at predetermined intervals, and outputting data from the data number reducing means (3) on a graphic display For output to an output device such as a page printer or the like, the image is drawn in a frame memory (2) having an area corresponding to the output area.

FIG. 5 shows an example of a specific configuration of the data number reduction means (3). The output terminal (Q) of the latch circuit (33) is used as an output terminal of the output enable signal (ENABLE). The inverted output terminal (Q bar) is connected to the input terminal (D), and the latch circuit (3) is supplied with the same signal as the clock (DDACLK) for operating the DDA (1).
3) is operated so that the data transmitted from the DDA (1) is output every two dots.

With the above arrangement, the coordinate data and luminance data of the vertices of the figure are sent to the DDA (1),
(1) generates straight line data based on both end point data corresponding to each side of the sent figure. The generated straight line data is sent to the data number reducing means (3), and the data number reducing means (3) gives an output permission signal at predetermined intervals in the sent straight line data, and is given output permission. The straight line data is drawn in the frame memory (2). In this embodiment, for example, for the straight line data sent from the DDA (1), the data number reducing means (3) as shown in FIG.
In the case where the output permission signal is given every two dots by adopting the above, since the data to be drawn is every two dots, the number of data to be drawn in the frame memory (2) is Approximately half the size of, which enables high-speed drawing of figures. Therefore, when a simple output is sufficient for layout study or the like, the output time (time for displaying on a graphic display device, time for outputting with a page printer, etc.) can be shortened to some extent with a decrease in accuracy.

When the output permission signal is given every three dots or every four dots, a combination of a data number reduction means (3) and a gate circuit as shown in FIG. 5, a buffer having a SAM port, etc. May be used to output the drawing permission signal in a circulating manner. Furthermore, it is also possible to provide a mode control means (4) and the like so that the mode can be arbitrarily selected according to the required accuracy and drawing speed.

[0037]

As described above, according to the high-speed graphic drawing method of the first aspect, if simple output is sufficient for a layout study or the like, the data on both ends is compressed by a predetermined amount, and the generated straight line data is compared with the previous one. Since the total number of data to be drawn by decompressing by the reproduction amount corresponding to the fixed amount is reduced, the drawing speed to the memory (2) is improved, and the output time on a graphic display or a page printer having a high resolution is shortened. It produces a special effect such as

[0038]

[0039]

[0040]

According to the second aspect of the present invention, if simple output is sufficient for layout study, etc., the end point data is compressed by a predetermined amount, and the generated straight line data is reproduced corresponding to the predetermined amount in the previous period. Since the total number of data to be drawn by expanding by the amount is reduced, the drawing speed to the frame memory (2) is improved, and the output time on a graphic display or a page printer having a high resolution is shortened. It works.

[0042]

According to the third aspect of the present invention, when simple output is sufficient for layout study, etc., the total number of data to be drawn by shifting both end point data and shifting up the generated straight line data is determined. Because of the reduction, the drawing speed to the frame memory (2) is improved, and a specific effect such as shortening the output time on a graphic display or a page printer having a high resolution is achieved.

[0044]

Also, in order to halve the number of data to be drawn, each data expressed in binary is merely shifted down or up, so that no special calculation is required and the access speed is affected. Do not give.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an embodiment of a high-speed graphic drawing method according to the present invention.

FIG. 2 is a diagram illustrating a state in which straight line data is output at predetermined intervals.

FIG. 3 is a block diagram showing an embodiment of a high-speed graphic drawing apparatus according to the present invention.

FIG. 4 is a block diagram showing another embodiment of the high-speed graphic drawing apparatus of the present invention.

FIG. 5 is a circuit diagram showing a specific configuration of a data number reduction unit.

FIG. 6 is a diagram showing a configuration of a conventional graphic display device.

[Explanation of symbols]

1. DDA 2. 2. Frame memory 3. Data reduction means Mode control means 31. Shift-up means 32. Shift down means 33. Latch circuit

Claims (3)

(57) [Claims] 1. A drawing which receives straight line data at both ends of a straight line, generates straight line data, and draws the generated straight line data in a memory (2) having an area corresponding to an output area of an output device such as a graphic display or a page printer. In the method, data at both end points of a straight line is compressed by a predetermined amount, and the compressed both end point data is received to generate straight line data;
A high-speed graphic drawing method characterized by expanding data of generated straight line data by a reproduction amount corresponding to a predetermined amount in the previous period and drawing the expanded straight line data in a memory (2). 2. A straight line generating means (1) for receiving both end point data of a straight line and generating straight line data, and an area corresponding to an output area of an output device such as a graphic display or a page printer. Storage means (2) for drawing straight line data; and data reduction means (3) for reducing the number of straight line data to reduce the number of straight line data and drawing the data in the storage means (2). The data reduction means (3) is a compression means for compressing data on both ends of a straight line by a predetermined amount, and a decompression means for expanding the straight line data generated by the straight line generation means by a reproduction amount corresponding to the predetermined amount. Characterized high-speed figure drawing device. 3. The compression means is shift-down means (31) for shifting down both end point data, and the expansion means is shift-up means (32) for shifting up linear data generated by the expansion means. Item 3. The high-speed graphic drawing apparatus according to Item 2.