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Description  |
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BACKGROUND OF THE INVENTION
1. Field of The Invention
The present invention relates to a data display method in a graphic data
processing system which has display data structured in the hierarchy of
plural concept levels, especially to an improved method capable of
displaying a drawing of the different concept levels selected in response
to a window designated in a display screen.
2. Description of The Related Art
Generally a display screen, for example, in a computer aided design (CAD)
system for the design of large scale integration circuits (LSI), has a
limitation in the screen size available for display and therefore can not
display a general drawing showing the whole structure of a LSI on a
convenient scale for the design work.
Conventionally, to overcome this problem, there has been defined a window
within the display screen. A drawing of a part of the LSI which is now
being designed has been displayed in a main area of the display screen on
a convenient scale, while, in the area of the window, a general drawing of
the whole structure of the LSI has been displayed on a reduced scale in
order to make sure of what part of the whole structure is now being worked
on. A method and apparatus of this kind is disclosed in pp. 169 to 173 of
the journal "PIXEL" No.14, 1983, for example.
By the way, the general drawing does not need to be referred to so often
during the design work. Therefore, a window defined within the display
screen is preferred to be variable in its size, whereby a part which is
now being designed can be displayed on the convenient scale by reducing
the size of the window, in case the present size of the window impedes the
design work. In such a case, however, the rate of scale-down of the
general drawing is often changed and becomes very large depending on
circumstances. If the rate of scale-down becomes large to a certain
extent, characters in a displayed drawing are defaced or pairs of lines
therein become undistinguishable, so that the displayed drawing becomes
very indistinct as a whole.
It is to be noted that, even in this case, the amount of data to be
processed for the display does not change, and nevertheless the quality of
the displayed graphic is degraded. The problem mentioned above results
from the fact that the amount of data to be displayed does not change
irrespective of decrease of the size of the designated window. Conversely,
a certain amount of data is processed for the uninformative display.
Accordingly the efficiency of the processing considerably decreases.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a data display method in a
graphic data processing system which is capable of distinctly displaying a
drawing based on graphic data structured in the hierarchy of plural
concept levels and of improving the efficiency of the processing.
A feature of the present invention is that, in a data display method in a
graphic data processing system having a display screen, a storage in which
graphic data is stored and a pointing device for designating a window of a
given size at a desired position within the display screen, the size of
the window designated by the pointing device is judged, and graphic data
of a different concept level in response to the result of the above
judgement is selected from among the graphic data stored in the storage
and displayed within the designated window.
The size of the window, as mentioned above, is only an example of
parameters for the judgement in selecting the concept level of the data to
be displayed. As such a parameter indicating the feature or characteristic
of the designated window, there can be also used the rate of scale-up and
-down of the graphic data to be displayed within the designated window in
the coordinate transformation carried for displaying of the graphic data
stored in the storage, in place of the window size mentioned above. More
particularly, the method according to the present invention is
characterized by storing the graphic data structured in the hierarchy of
plural concept levels in the storage, setting in advance criteria for
judging a parameter of a window, each of the judging criteria being made
to correspond to a particular one of the concept levels of the graphic
data stored in the storage, designating a window, judging to what
criterion of the parameter the designated window belongs, selecting the
graphic data of the concept level corresponding to the criterion of the
parameter, to which the designated window belongs, from among the graphic
data stored in the storage, and displaying the selected graphic data
within the designated window.
In a CAD system for the design of LSI, for example, a storage stores
graphic data structured in the hierarchy of plural concept levels, e.g.
data for the highest concept level such as the functional block diagram
level, data for the medium concept level such as the logical symbol
arrangement level and data for the lowest concept level such as the
circuit component arrangement level. One of the graphic data of the
different concept level is selected in response to the predetermined
parameter of a designated window, such as the size thereof or the rate of
scale-up and -down of the graphic data to be displayed within the
designated window, and displayed in the window. If, therefore, a small
size of a window is designated, for example, the graphic data of the
highest concept level is selected and displayed. As a result, the minimum
necessary information can be given to a user in the distinct form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a to 1c show examples of a data display according to an embodiment
of the present invention, in which there is indicated the relationship
between the size of a window and the concept level of a drawing to be
displayed in the window;
FIG. 2 is a block diagram schematically showing an apparatus for executing
the data display method according to the present invention;
FIG. 3 is an explanatory drawing of the relationship between a world
coordinate system and a device coordinate system utilized in a graphic
data processing system;
FIG. 4 is a drawing for explaining a method of designating window within a
display screen; and
FIG. 5 is an explanatory drawing of a table for determining the concept
level of graphic data to be displayed in a designated window in response
to the size of the window.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring at first to FIGS. 1a to 1c, there will be described the
relationship between the size of a window W designated within a display
screen S and the concept level of a graphic data to be displayed in the
window W, taking a data display in a CAD system for the design of LSI as
an example.
FIG. 1a shows the case where a small size of the window W is designated. In
this case, since the size of the window area is small, the graphic data of
the highest concept level is selected for the display; a functional block
diagram of an LSI in this example. In the remaining area of the display
screen S, a part of the LSI, which is now being designed, is displayed.
Accordingly, a designer can carry out his design work on the display
screen S, while referring to the general drawing of the whole structure of
LSI displayed within the window W. Thereby, the designer can have the
general idea of the relationship of a part, which is now being designed by
him, to the whole structure.
If the medium size of the window W is designated as shown in FIG. 1b, the
graphic data of the medium concept level is selected and displayed within
the designated window. The graphic data of the medium concept level in
this example is data for the arrangement of logical symbols. In this case,
the designer can be given the more detailed information of the whole
structure of the LSI. As shown in FIG. 1c, if the further large size of
the window W is allowed to be designated, there can be displayed in the
designated window the most detailed drawing of the whole structure which
is of the lowest concept level and is drawn by primitive circuit
components.
In this manner, according to the present invention, there is stored in an
appropriate storage the graphic data of various concept levels, and the
concept level of the graphic data to be displayed within the window is
determined in response to a certain parameter of the window, i.e., the
size of the window in the example shown. For example, if the circuit
component arrangement as shown in FIG. 1c were displayed within the window
of the size as shown in FIG. 1a by reducing the scale of the drawing of
the component arrangement, the designer could no longer read the exact
information of the whole structure from the display in the window, since
such a drawing displayed has the considerably large rate of scale-down and
is very indistinct.
Referring next to FIG. 2, the description will be made of an apparatus for
carrying out the method according to the present invention. Such an
apparatus is generally known as a work station. The work station has a
display screen 10, a central processing unit (CPU) 12, a main memory 14, a
graphic processor 16, a frame memory 18, a disk memory 20, a pointing
device 22 for designating a window, and an input device 24. Thereamong,
CPU 12, the main memory 14, the graphic processor 16, the disk memory 20,
the pointing device 22 and the input device 24 are connected to each other
through a bus. The display screen 10 is connected to the graphic processor
16 through the frame memory 18. Since the configuration shown is that of a
usual work station and respective components thereof as described above
are all known, the further detailed description thereof will be omitted.
When the design of a new LSI is carried out at this work station, a
designer usually starts the design of the functional concept by using
appropriate function and resources for the design work which are the same
as ones provided in a usual work station. This design work is carried out
within the memory space of the main memory 14 by the aid of CPU 12.
Therefore, when the functional block diagram is completed, all the graphic
data thereof is stored in the main memory 14, and thereafter the data of
the main memory 14 is transferred to and stored in the disk memory 20.
After that, the designer enters into the design of the logical arrangement,
whereby data for the arrangement of logical symbols is formed and stored
in the disk memory 20. During the design of the logical arrangement, the
designer can designate a window of the desired size at the desired
position within the display screen 10 by using the pointing device 22, and
the data of the functional block diagram is read out from the disk memory
20 and displayed within the designated window. Therefore, the designer can
refer to the window during the design work and have a general idea of the
relationship of a part, which is now being designed by him, to the whole
structure.
After the completion of the logical arrangement, the designer sets about
the design of the circuit component arrangement. Also in the course of
this design work, the designer can designate a window of the desired size
at the desired position within the display screen 10 by the pointing
device 22 and display a graphic data read out from the disk memory 20. The
graphic data displayed at this time can be either one of data for the
functional block diagram or that for the logical arrangement in response
to the size of the window designated by the designer. Also, data of the
circuit component arrangement obtained with the completion of the design
of the circuit component arrangement is stored in the disk memory 20.
In this manner, the graphic data structured in the hierarchy of the plural
concept levels are successively stored in the disk memory 20 with the
progress of the design or the LSI, and when the design of the LSI has been
completed, the graphic data for the design of the LSI is stored in the
disk memory 20 for every hierarchical level.
Thereafter, when the design of the LSI is proofread or becomes necessary to
be changed, the graphic data stored in the disk memory 20 is corrected or
edited. At that time, data of the necessary concept level is transferred
from the disk memory 20 to the main memory 14. The designer carries out
the processing such as the correction or edition of data transferred in
the main memory 14 by the aid of CPU 12, referring to a drawing displayed
on the display screen 10. The processed data is transferred to and stored
in the disk memory 20 again.
Also during this correction or edition, it is possible to designate a
desired window and display a general drawing therein thereby to make sure
of the relationship of a part, which is now being designed, to the general
drawing. In this case, it is of course evident that it is not always
necessary to transfer data for the general drawing to the main memory 14,
but it is sufficient to transfer one a necessary part of the data thereof
to the main memory 14 as it is needed.
Further, when data is transferred from the disk memory 20 to the main
memory 14 and vice versa, the data can be subject to some processing by
CPU 12. For example, data is stored in the main memory 14 in the data form
by which CPU 12 and the graphic processor 16 can easily refer to it, and
when data in the main memory 14 is transferred to the disk memory 12, it
is converted into a data form by which data to be stored occupies as small
a storage space of the disk memory 20 as possible.
Next the description will be made of the processing in the display
processor 16. The processor 16 begins executing instructions successively
read out from the main memory 14, when it receives from CPU 12 a start
command and an entrance address in the main memory 14, at which a starting
instruction is stored. As the instructions for the graphic processor 16,
there are instructions for drawing basic figures such as a line and an
arc, instructions for block transfer or arithmetic operation between data
in the main memory 14 and that in the frame memory 18, various kinds of
control instructions such as "jump" and "end", and so on.
Each of the figure drawing instructions fetched in the graphic processor 16
has an operand which designates the location where a certain figure is to
be drawn. The operand is given in the form of values in a coordinate
system mentioned below. The coordinate system in which the operand is
given is capable of existing irrespective of the arrangement of pixels on
the display screen 10 and can be arbitrarily defined by a user of the work
station (this is generally called a world coordinate system). Therefore,
the user can assume a given coordinate system as a world coordinate system
and make up a series of figure drawing instructions in the world
coordinate system by the aid of CPU 12. The graphic processor 16 carries
out the transformation of the thus formed figure drawing instructions from
the world coordinate system to a coordinate system in which one point of
the coordinates physically corresponds to one pixel of the display screen
10 (the latter is generally called a device coordinate system). In this
sense, the coordinate transformation carried by the graphic processor 16
can be said to be a transformation for display of the graphic data stored
in the main memory 14 (or the disk memory 20) on the display screen 10.
FIG. 3 is a diagram for explaining the coordinate transformation from the
world coordinate system to the device coordinate system. In the figure,
reference character U denotes world coordinates which are defined by two
points (0, 0) and (32767, 32767) on the diagonal and reference character V
a window set within the world coordinates, which is defined by two points
(x.sub.1, y.sub.1) and (x.sub.2, y.sub.2) on the diagonal. Further,
reference character S represents device coordinates which have the
coordinate value 768 on the X axis and that 1024 on the Y axis, which
absolutely correspond the numbers of pixels on the X and Y axes of the
display screen 10, respectively. Within the device coordinates S of the
display screen 10, a window W can be designated by two points (X.sub.1,
Y.sub.1) and (X.sub.2, Y.sub.2) on the diagonal thereof. If the user
designates the two points (x.sub.l, y.sub.1) and (x.sub.2, y.sub.2) on the
world coordinate system and the two points (X.sub.1, Y.sub.1) and
(X.sub.2, Y.sub.2) on the device coordinate system, the graphic processor
16 carries out the coordinate transformation in accordance with the
following formula;
P=A.multidot.p-B (1)
wherein
p : a point in the world coordinates;
P : a point in the device coordinates;
##EQU1##
Referring next to FIG. 4, the explanation will be made of how to designate
a window W on a display screen S by the pointing device 22. In the figure,
an arrow represents a graphic cursor. For the simplification, it is
assumed that a general drawing of the whole structure of the LSI is always
displayed in the window W of the device coordinates S and the window V in
the world coordinates U of FIG. 3 is set so as to wholly cover the general
drawing. Further, even if the size and location of the window W changes in
the device coordinates S (display screen), the window V in the world
coordinates U is always fixed.
Under these circumstances, the window W in the device coordinates S can be
altered by designating two points P.sub.1 and P.sub.2 by the cursor (a
broken arrow and a solid arrow) which moves on the display screen in
accordance with the instruction from the pointing device 22. If a button
switch (not shown) of the pointing device 22 is pushed when the cursor is
positioned at a desired location on the display screen 10, CPU 12 executes
the processing by which the coordinate values are calculated and taken
thereinto. In this manner, the user can designate the window at the
desired location in the display screen freely.
Upon the completion of designation of the desired window W, CPU 12
calculates the size (a.times.b) of the window by using the coordinate
values taken thereinto and selects the graphic data of the appropriate
concept level from among data stored in the disk memory 20 on the basis of
the calculated size of the window W. The selected data is displayed within
the window W by the aid of the graphic processor 16.
FIG. 5 shows one of examples of a table which represents the relationship
of the criteria of the parameters of the window, i.e., the size of the
window in the example shown, and pointers. According to this example, the
lengths of respective sides of the designated rectangular window, which
sides cross with each other at right angle, are compared with the
predetermined criteria for judgement, which are set in advance in terms of
the number of pixels in the display screen S. Respective sets of the
judging criteria of size of the window have particular pointers, any one
of which is selected in response to the calculated size of the window. The
pointer is an indicator that indicates an entrance address of that
location of the disk memory 20 in which graphic data of the corresponding
concept level is stored.
In the example shown, if 0<a.ltoreq.10 and 0<b.ltoreq.10, a pointer, which
indicates an address of the location in which there is stored data of the
highest concept level, is selected so that data for the functional block
diagram is read from the disk memory 20. If 10<a.ltoreq.=100 and 10
<b.ltoreq.100, a pointer, which indicates an address of the location in
which there is stored data of the medium concept level, i.e., the data for
logical arrangement, is selected. Similarly, when 100<a.ltoreq.768 and
100<b.ltoreq.1024, a pointer, which indicates an address of the location
in which there is stored data of the lowest concept level, is selected so
that data for the circuit component arrangement is read out.
Further, the selection of the concept level of data to be displayed can be
also executed by the number of pixels covered by the designated window, in
place of the lengths of two sides of the window. This may be effective for
such a case where a window is designated in the nonrectangular form, for
example. Furthermore, the parameter of the window for the selection of the
concept level of data to be displayed can be provided by a rate of
scale-up and -down in the coordinate transformation of data from the
window V in the world coordinates U to the window W in the device
coordinates S, as shown in FIG. 3. The judging criteria of this rate of
scale-up and -down are set in the direction of the x axis and in the
direction of the y axis separately, and the actual rate of scale-up and
-down can be obtained on the basis of the values of elements (1, 1) and
(2, 2) of a matrix of the coefficient A in the formula (1).
As described above, according to the present invention, graphic data of the
appropriate concept level is selected in response to an appropriate
parameter of a window designated in a display screen such as the size
thereof or the rate of scale-up and -down of graphic data to be displayed
in the coordinate transformation, so that the efficiency of the data
processing for the display and the easiness to see is much improved.
Although there have been herein shown and described only a few forms of
methods embodying the present invention, it is understood that various
changes and modifications may be made therein within the scope of the
appended claims without departing from the spirit and scope of the preset
invention.
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