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TECHNICAL FIELD
The present invention relates generally to computer graphics and, more
specifically, to a system and method for creating and displaying dynamic
special effects on graphic text objects.
BACKGROUND OF THE INVENTION
For many reasons, users of computer application programs, such as word
processing, database, and spreadsheet programs, have desired the ability
to highlight particular text displayed on a computer display screen. Many
application programs include utilities, such as bolding and italicizing
utilities, that allow selected text of a document to be highlighted on a
display screen and on a printed paper copy. While such highlighting
utilities have proved useful, many users have found existing highlighting
utilities to be inadequate for several reasons.
First, some users have desired more highlighting utilities, in addition to
the conventional bolding and italicizing. For example, many application
programs are now directed primarily to children, who often enjoy many
special effects and new features. It is unlikely that many children find
the existing highlighting utilities to be new and exciting. In addition,
it is likely that many adults would also find other highlighting utilities
to be enjoyable and useful.
Second, some users would like to display highlighted text and print the
text without highlighting, but existing highlighting utilities, such as
bolding and italicizing, alter the way that the text is both displayed and
printed. In fact, one reason why more highlighting types have not been
created might be because developers thought that users would want to print
any highlighting that was displayed, but printer technology did not allow
some other highlighting types to be printed. However, as computer networks
have proliferated, many documents, such as electronic mail, are passed
between users without being printed. As a result, users may wish to
highlight certain portions of text with new highlighting types without
concern about whether the highlighting type could be printed. In addition,
many users, particularly children, enjoy displaying fancy text and
graphics, without caring whether such text and graphics can be printed.
Third, existing highlighting features are static in nature. That is, when a
user alters a text portion with an existing highlighting feature, such as
bolding, the highlighted text remains highlighted until the user manually
turns off the highlighting feature. It is well known that a dynamic
feature, such as a flashing traffic light, stands out more than a static
feature like bolding.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for creating and
displaying dynamic special effects on graphic text objects. Preferably,
the special effects are displayed in stages or animation frames, such that
the special effects appear to move. In addition, the special effects are
displayed for a predetermined period and then the original text objects
are redisplayed without the special effects.
The invention includes alternate embodiments for displaying at least three
different dynamic special effects: fade-out, shimmer, and sparkle. the
fade-out embodiment erases progressively larger portions of a selected
text object with each animation frame. The shimmer embodiment shifts
consecutive rows or column of pixels of the selected text object in
opposite directions with each animation frame. The sparkle embodiment
displays random pixel patterns, referred to as sparkle grids, over random
locations of the selected text object.
By providing dynamic special effects, the invention allows users to
highlight text objects in ways previously unavailable. The invention
enables children's application programs to be much more enjoyable and
exciting to the children who use them. In addition, the invention enables
users of computer networks to more noticeably highlight passages of text
with dynamic special effects without concern for whether the special
effects can be printed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a computer system according to the present
invention.
FIG. 2A is a flow diagram of a method of inputting a special effects
selection according to the,present invention.
FIG. 2B is a flow diagram of a method of preparing a page for display
according to the present invention.
FIG. 3 is a flow diagram of a special effect controller according to the
present invention.
FIG. 4 is a flow diagram of a fade-out special effect generator method
according to the present invention.
FIGS. 5A to 5K are examples of a text block being faded out according to
the method shown in FIG. 4.
FIG. 6 is a flow diagram of a shimmer special effect generator method
according to the present invention.
FIG. 7A to 7J are examples of a text block being shimmered according to the
method shown in FIG. 6.
FIG. 8 is a flow diagram of a sparkle special effect generator method
according to the present invention.
FIG. 9A to 9K are examples of a text block being sparkled according to the
method shown in FIG. 8.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a system and method for creating and
displaying dynamic special effects on graphic text objects. The special
effects change the way in which the text objects are displayed on a
computer display and include, for example, "fade out," "shimmer," and
"sparkle" special effects. Preferably, the special effects are displayed
in stages or animation flames, such that the special effects appear to
move, that is, the special effects are "dynamic". In addition, the special
effects preferably are displayed for a predetermined period and then the
original text objects are redisplayed without the special effects.
By providing dynamic special effects, the invention allows users to
highlight text objects in ways previously unavailable. The invention
enables children's application programs to be much more enjoyable and
exciting to the children who use them. In addition, the invention enables
users of computer networks to more noticeably highlight passages of text
with dynamic special effects without concern for whether the special
effects can be printed.
FIG. 1 shows a special effect system 10 used to create and display dynamic
special effects on graphic text objects. The system 10 includes a computer
12 connected to receive input from an input device 14 and send display
output to a display 16. The computer 12 can be implemented as any
conventional computer, such as a conventional desktop computer. The input
device 14 also is conventional and can include such devices as a keyboard,
a mouse, and an electronic pen with a digitizing tablet. The display 16 is
also conventional and preferably is a high-resolution, color display, such
as a cathode ray tube (CRT) monitor.
As is conventional, the computer 12 includes a central processing unit 18
and a working memory 20. Stored in the working memory 20 is an operating
system 22, an application program 24, an effect controller 26, and one or
more effect generators 28. In a preferred embodiment, the effect
generators 28 include a fade-out effect generator 28A, a shimmer effect
generator 28B, and a sparkle effect generator 28C. The operating system 22
can be any conventional operating system such as Microsoft Windows.TM..
The operating system 22 interfaces the application 24 with the input
device 14 and a display 16 such that the application program 24 can
receive user input from the input device and can display data on the
display 16. In some embodiments, the effect controller 26 and the effect
generators 28 are a part of the operating system 22 or the application
program 24. However, preferably the effect controller and the effect
generators are independent utility programs so that many application
programs can use their special effects abilities without copying them into
each application program. In a preferred embodiment, the application
program is generally a conventional text processor that has been modified
slightly to interface with the effect controller 26 and the effect
generators 28.
FIG. 2A shows a flow diagram of a method used by the application program 24
to obtain user input for the effect controller 26 and the effect
generators 28. In step 30, the application program receives a text object
selection from the user via the input device 14. The selected text object
includes a string of one or more characters, and a portion of the
background surrounding the characters, such that the characters and the
background portion form a rectangular text object. Such a text object
selection step typically is accomplished by dragging a cursor across the
selected text using a mouse as the input device 14. In step 32, the
application program receives from the user a special effects selection
that indicates which special effect the user desires to be displayed. Such
a special effect selection is similar to the way conventional word
processors select bolding or italicizing of selected text.
In step 34, the application program 24 updates a text object table stored
in the working memory, such that the text object table indicates that the
text object selected in step 30 is associated with the special effect
selected in step 32. The text object table is a device typically used in
application programs to indicate the font, bolding, italicizing, and
similar features, and associated with each string of text. The text object
table stores the location of each text object and codes that indicate the
features associated with the text object. By storing in the text object
table a code associating the special effect with the selected text object,
the text object can be edited and the special effect is automatically
associated with the edited text object. The following Table A shows an
example of a preferred text object table.
TABLE A
__________________________________________________________________________
File Name File Pos.
Char. Pos.
Feature 1
Feature 2
Feature N
__________________________________________________________________________
Object 1
File 1.txt
80 0 Bold
Object 2
File 2.txt
10 40 Fade-Out
Object 3
File 1.txt
130 60 Italics
Shimmer
Object N
__________________________________________________________________________
In the example shown in Table A, only the text objects for a single display
line of text are shown for simplicity, but the same table preferably would
store feature information for all of the text objects of the document.
Text objects 1 and 3 are stored in a first file, File 1.txt, at positions
80 and 130. Text object 2 is stored in a second file, File 2.txt, at
position 10. The character position field stores the position of the first
character of each text object. The length of each text object can be
computed for each text object by subtracting the character position for
that text object from the character position for the next text object, so
the first text object has a length of 40 (40-0). Preferably, each text
object can have a variable number of features specified, ranging from 0
features, which displays the text object with a default character format,
to a number of features N limited only by the amount of memory available.
In order to display the text objects with special effects, the page on
which the text objects are located must be formatted. As shown in step 35
of FIG. 2B, one method of triggering the application program to format the
page is by receiving from the operating system 22 a format request, such
as a Microsoft Windows.TM. WM.sub.13 Paint message. In step 36, the
application program sets a page special effect (SFX) flag which indicates
that the page on which the selected text object is located includes such a
text object that has been selected to receive a special effect. The page
SFX flag preferably is a part of a stored page descriptor table that
describes characteristics of each page such as the print and display
margins of the page. Such a page descriptor table is a well known device
for storing page formatting information. Of course, the application
program may perform other formatting in addition to setting the page SFX
flag, such as adjusting margins or conventional formatting.
Shown in FIG. 3 is a flow diagram of a method employed by the effect
controller 26 to cause the selected special effects to be displayed. In
step 38, the effect controller receives an idle message from the operating
system 22, indicating that the effect controller can spend processor time
to display the selected special effects. When the application program is
not processing data, it sends such an idle message via the operating
system 22. Of course, one skilled in the art could easily employ the
invention in non-message-based systems.
In step 40, the effect controller 26 determines whether the page SFX flag
has been set for the current page displayed by the application program.
Although the invention is easily applicable to application programs that
can display multiple pages at one time, the discussion herein is limited
to a single current page for simplicity. If the page SFX flag is not set,
then the effect controller returns processing to the operating system 22.
If the page SFX flag is set, then in step 42, the effect controller gets
the first text object selected to receive a special effect (SFX text
object). The effect controller locates the first SFX text object by
searching through the text object table until it finds a text object with
a special effect indicator associated with it. In step 44, the effect
controller calls the effect generator 28 for the special effect associated
with the text object. The effect generator generates a first animation
frame of the special effect on the text object, examples of which are
discussed below with respect to FIGS. 4-9. Preferably, the special effects
are displayed in the order in which the SFX text objects appear in the
text object table. However, any order could be employed, such as
displaying the special effects on all SFX text objects having a first
special effect selection before displaying any other special effects.
When the effect generator 28 is done generating the special effect on the
selected text object, the effect controller 26 determines whether there
are more SFX text objects in step 46. The effect controller determines
whether there are more SFX text objects by searching through the text
object table beginning with the text object immediately following the
previous SFX text object. If there are more SFX text objects, then in step
48, the effect controller gets the next SFX text object. Steps 44-48 are
then repeated until no more SFX text objects are found for the current
page in step 46.
If there are no more SFX text objects for the current page, then the effect
controller 26 determines whether a frame counter equals a maximum counter
value (MAX) in step 50. The frame counter counts the number of animation
frames of the special effect to be displayed and is initialized by the
operating system when the effect controller is loaded. In a preferred
embodiment, there are 8 animation frames for each special effect, so the
frame counter is incremented from 1 to 8 for all of the text objects.
Preferably, one animation frame for each text object is displayed before
displaying the next animation frame for any of the text objects.
Alternatively, all animation frames of the special effect for one text
object could be displayed before displaying any animation frames for the
next text object.
If the frame counter is not equal to MAX, then in step 52, the effect
controller increments the frame counter and returns control to the
operating system. Upon each subsequent idle message sent from the
operating system 22, the effect controller repeats steps 38-52 until the
frame counter equals MAX as determined in step 50. As will be appreciated,
steps 38-52 enable a special effect to be displayed for each text object
one animation frame at a time with each animation frame being counted by
the frame counter. When the frame counter equals MAX, then in step 54 the
effect controller resets the frame counter to zero for the next set of
animation frames. In step 56, the effect controller calls the application
program 24 and requests the application program to redraw each text object
without the selected special effects. The application program redraws the
text object without the selected special effects. When the application
program 24 is finished processing, the operating system 22 sends another
idle message to the effect controller 26 to start the process of
displaying the special effects again. Preferably, each selected text block
is displayed without a special effect for an amount of time at least as
long as one animation frame.
Shown in FIG. 4 is a method employed by the fade-out effect generator 28A
to progressively fade out or erase the text block. In step 58, the
fade-out effect generator 28A receives the frame counter and the
coordinates of the selected text block. Typically, the upper-left and
lower-right coordinates are the only coordinates used to describe each
text block. In step 60, the width or height of the text block is computed.
The width is computed if the fade out is performed in a left-to-right or a
right-to-left direction. Likewise, the height is computed if the fade out
will proceed from top to bottom or bottom to top. For simplicity, the
remainder of the discussion will assume that the fade out occurs from left
to right, although the fade-out method in the other directions will be
completely understood from that discussion.
In step 62, the fade-out effect generator 28A computes X-Y coordinates of
an erase block that is displayed instead of increasing portions of the
text block to thereby erase the text block. The erase block is the same
color and pattern, if any, of the background of the text block, so
displaying the erase block instead of the text block erases the text piece
of the text block. Given that the fade out begins from the left side in
this example, the X-Y coordinates of the upper left corner of the erase
block are the same as the coordinates of the upper left corner of the text
block. In a preferred embodiment, the fade out occurs over the entire
height of the text block so that the Y coordinate of the lower right
corner of the erase block is the same as the Y coordinate of the lower
right corner of the text block. The X coordinate of the lower right corner
of the erase block is equal to the width of the text block multiplied by
the frame counter and divided by the maximum frame counter value (MAX).
For example, assuming that MAX equals 8 and the first frame counter value
is 1, then the width of the erase block is 1/8th of the width of the text
block. Upon each increment of the frame counter, the erase block increases
by 1/8th of the text block until the erase block equals the size of the
text block when the frame counter equals 8 . At that time, the erase block
completely replaces the text block which, in effect, erases the text
block. Upon completion of the last animation frame, the effect controller
sends a message to the application program 24 to re-draw the text block in
place of the erase block.
In step 64, the fade-out effect generator 28A determines whether the text
block is displayed over a pattern background or a plain white background.
For example, in a preferred embodiment, the application program allows the
text to be displayed over any of numerous pattern backgrounds, such as a
background picture of a teddy bear. If there is a pattern background, then
in step 66, the portion of the pattern background corresponding to the
coordinates of the erase block is retrieved. In step 68, the fade-out
effect generator creates the erase block from either the pattern
background retrieved in step 66 or a plain white background if there is no
pattern background. In step 70, the fade-out effect generator displays the
erase block over the text block, which in effect erases the left-most
1/8th of the text block according to the example above. Each time that the
fade-out effect generator is called, steps 58-70 are repeated to erase an
additional 1/8th of the text block as described above. In a preferred
embodiment, steps 66-70 are actually one combined step in which the effect
generator simply displays whatever background corresponds to the
coordinates computed in step 62.
Shown in FIG. 5 is an example of a text block being faded out by the
fade-out effect generator 28A as described in FIG. 4. Frame (a) shows the
text block in its original form without any special effect. Frames (b)-(j)
show the text block being faded out and frame (k) shows the text block as
re-drawn by the application program.
Referring again to the method shown in FIG. 4, the fade-out effect
generator 28A receives a frame counter of 1 and text block coordinates of
(0,0) and (9,12) in step 58. In step 60, the X value (9) of the
lower-right corner minus the X value (0) of the upper-left corner equals
the width (9) of the text block. In step 62, the X value of the
lower-right corner of the first erase block is computed to be 1, which
equals the text block width (9) multiplied by the frame counter (1)
divided by the maximum frame counter (MAX), which is 9 in this example. As
discussed above, the upper-left coordinates and the lower-right Y
coordinates remain the same, resulting in erase block coordinates of (0,0)
and (1,12). In this example, there is no background pattern, so the
fade-out effect generate creates and displays a white erase block in steps
68 and 70 as shown in frame (b). Frames (c) through 0) are generated in a
similar manner.
Shown in FIG. 6 is a method employed by the shimmer effect generator 28B
that causes a selected text block to "shimmer." The shimmer effect is
implemented by shifting odd pixel rows of the text block in one direction
while shifting even pixel rows in the opposite direction. Each time the
frame counter is incremented, each pixel row shifts in a direction
opposite to the direction that the row shifted on the previous frame
counter.
In step 72, the shimmer effect generator 28B receives the frame counter and
the coordinates of the selected text block. In step 74, the shimmer effect
generator determines whether the frame counter is an odd number. In the
preferred embodiment, the frame counter starts at 1, which is odd, so
execution proceeds to step 76 where the shimmer effect generator
determines whether the current pixel row is odd. Since the first row is
odd, the shimmer effect generator shifts the pixel row to the right X
number of pixels in step 78. In step 80, the shimmer effect generator
determines whether there are more rows to be shifted. If so, then
execution returns to perform steps 74 and 76 again. In step 76, the
shimmer effect generator determines that the second row is not odd so it
shifts the second pixel row left X pixels in step 82. Steps 74-82 are
repeated until all the rows have been shifted as determined by step 80.
When there are no more rows, then in step 82, the shimmer effect generator
determines whether the frame counter equals 1. If so, then in step 84, the
X value, which equals the number of pixels each row is shifted, is
multiplied by 2. That multiplication by 2 enables each subsequent
animation frame of the shimmer effect to be shifted twice as far when the
frame counter equals 2-8 as when the frame counter equals 1. Otherwise,
when each pixel row is shifted in the opposite direction when the frame
counter is incremented, the rows would simply be returned by their initial
state.
After the frame counter is incremented to 2 by the effect controller in
step 54 (FIG. 3), then in step 74 (FIG. 6) the frame counter is determined
to be not odd. As a result, in step 86 the shimmer effect generator 28B
determines whether the current row is odd. Because the first row is odd,
the first row is shifted left X pixels in step 82. Steps 78, 80, 82, and
86 are repeated until all rows are shifted as determined in step 80.
Shown in FIG. 7 is an example of a text block being shimmered by the
shimmer effect generator 28B as described in FIG. 6. In this example, like
the example shown in FIG. 5, the frame counter is incremented from 1 to 8,
thereby producing animation frames (b) to (i). For the first animation
frame (b) each pixel row is shifted 1 pixel (x=1), while for each
subsequent animation frame each pixel row is shifted 2 pixels (x=2). Like
the example shown in FIG. 5, frames (a) and (j) show the text block before
and after being shimmered, respectively.
Shown in FIG. 8 is a method employed by the sparkle effect generator 28C
that causes a selected text block to "sparkle." The sparkle effect is
implemented by displaying random patterns or sparkle grids in random
locations over the text object. The sparkle grids are randomly selected
from a predetermined set of sparkle grids. The sparkle grids and colors
are changed upon each increment of the frame counter.
In step 88 the sparkle effect generator 28C receives the frame counter and
the coordinates of the selected text block. In step 90 the sparkle effect
generator computes the maximum number (MaxGrid) of sparkle grids that can
fit into the text block which equals the area of the text block divided by
the area of each sparkle grid. In the preferred embodiment each sparkle
grid is three pixels by three pixels so the sparkle grid area equals nine
pixels. In step 92 the sparkle effect generator computes the number of
sparkle grids to be displayed on the text block (Grid#) which equals
MaxGrid multiplied by a predetermined grid density. The grid density
corresponds to the fraction of the text block that is desired to be
covered by sparkle grids simultaneously, so is a number between zero and
one. Preferably that grid density is selectable by the user.
In step 94 in index counter I is initialized by setting it to equal one.
The index counter I counts the number of sparkle grids displayed over the
text block. In step 96, the sparkle effect generator 28C obtains a random
sparkle grid as the first sparkle grid to be displayed. The sparkle grid
is selected from a predetermined set of sparkle grids using a random
number generator to generate an index into the set of sparkle grids. The
random number generator can use any well-known function for generating a
random number. In a preferred embodiment the set of sparkle grids includes
various pixel patterns and colors such that each sparkle grid differs from
every other sparkle grid by the color of each pixel or the patterns caused
by different luminance values for each pixel of the sparkle grid.
In a preferred embodiment, the location of each sparkle grid remains
constant for eight animation frames and then is changed for the next eight
animation frames. As such, in step 97 the sparkle effect generator 28C
determines whether the frame counter equals its initial value of 1. If so,
then in step 98 the sparkle effect generator obtains a random sparkle grid
location for the current sparkle grid obtained in step 96. Like step 96,
step 98 uses a random number generated to generate an index, which in step
98 indexes a location on the text block rather than a sparkle grid. If
not, then execution proceeds directly to step 100 in which the sparkle
effect generator draws the current sparkle grid at the location previously
obtained in step 98. The sparkle effect generator draws the sparkle grid
by using a drawing function of the operating system 22. Such drawing
functions are well known in the art and are discussed in detail with
respect to the Windows graphic user interface on pages 605-658 of Petzold,
Programming Windows 3.1, published in 1992, which is incorporated by
reference herein in its entirety.
In step 102 the index counter I is incremented to get the next sparkle grid
to be displayed. In step 104 the sparkle effect generator determines
whether the index counter I is greater than Grid#, which is the number of
sparkle grids to be displayed. If the index counter I is greater than
Grid#, then the sparkle effect generator returns control to the operating
system until it is called again. If not, then the sparkle effect generator
repeats steps 96 through 104 until Grid# sparkle grids have been
displayed.
Shown in FIG. 9 is an example of a text block being sparkled as described
in FIG. 8. In this example, frames (b)-(j) are animation frames produced
as the frame counter is incremented from 1 to 9. FIG. 9 shows several
different sparkle grids having binary pixels, that is, pixels with only 2
different luminance values corresponding to black and white. In a
preferred embodiment, the pixels are also colored and have more than two
different luminance values.
As described above, the invention provides a system and method for creating
and displaying dynamic special effects on graphic text objects. The
preferred embodiment employs a frame counter to count animation frames for
each special effect. After a predetermined number of animation frames, the
text objects are redisplayed without special effects. Discussed above are
three examples of dynamic special effects produced according to the
invention, with numerous other special effects being apparent from that
discussion.
It is to be understood that even though various embodiments and advantages
of the present invention have been set forth in the foregoing description,
the above disclosure is illustrative only, and changes may be made in
detail, yet remain within the broad principles of the invention.
Therefore, the present invention is to be limited only by the appended
claims.
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