Note: Descriptions are shown in the official language in which they were submitted.
08937508 CA
GLYPH MANAGEMENT IN TEXTURE ATLASES
TECHNICAL FIELD
[0001] The present disclosure relates to glyph management in texture
atlases,
and in particular to the storage of glyphs within texture atlases for
rendering in a user
interface generated by a computing device.
BACKGROUND
[0002] Drawing text in a user interface (UI) is currently a time-
consuming and
memory-intensive process. For each character in the text to be displayed in
the Ul,
an outline description of the character must be rendered into pixels to create
a glyph
image, drawn into an off-screen buffer, and combined with any other Ul
elements that
are being drawn. In order for the text to be drawn in the Ul, the pixels of
the glyph that
have been rendered and drawn into the buffer are provided to a graphics
processor
as a texture. This may require several memory buffers, and copying of data
between
them. If a system has limited amounts of texture memory, repeated copying of
texture
data may be required in order to make the best use of the available memory.
[0003] A texture atlas improves the efficiency of drawing glyphs in a
Ul because
the texture atlas can be loaded into a graphics memory buffer once and avoids
repeated copying of small textures. However, if the texture atlas is created
prior to
use it must contain every glyph in every font that can possibly be drawn for
display in
the Ul. This can be inefficient if only a subset of glyphs are commonly used.
Furthermore, a given entry in a texture atlas is specific to the combination
of
parameters that apply to the glyph, for example the size of the font and the
font face
being used. Therefore each different combination of parameters for a given
glyph
require different entries in the texture atlas, which causes a strain on
memory
requirements.
[0004] Accordingly, additional, alternative, and/or improved methods
and
systems that provide glyph management using texture atlases remains highly
desirable.
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SUMMARY
[0005] In accordance with one aspect of the present disclosure there
is
provided a method of glyph management performed by a processor, comprising:
receiving one or more characters; generating a glyph image of each of the one
or
more characters; for each generated glyph image: storing the glyph image in
only one
of a plurality of red, green, blue, and alpha (RGBa) color channels of a
texture atlas
stored on a memory coupled with the processor; and creating an entry for the
glyph
image in an associated atlas index stored on the memory, the entry defining a
position
of the glyph image within the texture atlas; wherein an associated glyph image
can be
retrieved from one of the plurality of color channels of the texture atlas
when required
for rendering of an associated character in a user interface generated by an
application executed by the processor.
[0006] In accordance with another aspect of the present disclosure
there is
provided a system configured to perform glyph management, comprising: a memory
for storing a texture atlas comprising red, green, blue, and alpha (RGBa)
color
channels and an associated atlas index; and a processor operably coupled with
the
memory, the processor generating a glyph image for each for each of a received
one
or more characters and storing the generated glyph image to only one of the
color
channels of the texture atlas and storing an index for the glyph image in the
associated
atlas index, the index defining a position of the glyph image within the
texture atlas;
wherein an associated glyph image can be retrieved from one of the channels of
the
texture atlas using the atlas index when rendering of an associated character
in a user
interface generated by an application executed by the processor.
[0007] In accordance with another aspect of the present disclosure
there is
provided a non-transitory computer readable medium comprising computer-
executable glyph management instructions stored thereon, the glyph management
instructions comprising: receiving one or more characters; generating a glyph
image
of each of the one or more characters; for each generated glyph image: storing
the
glyph image in only one of a plurality of red, green, blue, and alpha (RGBa)
color
channels of a texture atlas stored on a memory coupled with the processor; and
creating an entry for the glyph image in an associated atlas index stored on
the
memory, the entry defining a position of the glyph image within the texture
atlas;
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wherein an associated glyph image can be retrieved from one of the plurality
of color
channels of the texture atlas when required for rendering of an associated
character
in a user interface generated by an application executed by a processor.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Further features and advantages of the present disclosure will
become
apparent from the following detailed description, taken in combination with
the
appended drawings, in which:
FIG. 1 shows an exemplary system that manages glyphs using texture atlases;
FIG. 2 shows a representation of a User Interface (UI) generation process;
FIG. 3 shows a representation of rendering a Ul;
FIG. 4 shows a method of generating a Ul using texture atlases;
FIG. 5 shows a method of generating a texture atlas;
FIG. 6 shows a method of storing glyphs within a texture atlas;
FIG. 7 shows a method of generating a Ul in accordance with received
characters;
FIG. 8 shows a method of dynamically adding glyphs to a texture atlas;
FIG. 9 shows an exemplary texture atlas generated in accordance with the
teachings
herein; and
FIGs. 10A thru 10D show respective red, green, blue, and alpha color channels
of the
texture atlas of FIG. 9.
[0009] It will be noted that throughout the appended drawings, like
features are
identified by like reference numerals.
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DETAILED DESCRIPTION
[0010] In accordance with one aspect of the present disclosure there
is
provided a method of glyph management performed by a processor, comprising:
receiving one or more characters; generating a glyph image of each of the one
or
more characters; for each generated glyph image: storing the glyph image in
only one
of a plurality of red, green, blue, and alpha (RGBa) color channels of a
texture atlas
stored on a memory coupled with the processor; and creating an entry for the
glyph
image in an associated atlas index stored on the memory, the entry defining a
position
of the glyph image within the texture atlas; wherein an associated glyph image
can be
retrieved from one of the plurality of color channels of the texture atlas
when required
for rendering of an associated character in a user interface generated by an
application executed by the processor.
[0011] In accordance with another aspect of the present disclosure
there is
provided a system configured to perform glyph management, comprising: a memory
for storing a texture atlas comprising red, green, blue, and alpha (RGBa)
color
channels and an associated atlas index; and a processor operably coupled with
the
memory, the processor generating a glyph image for each for each of a received
one
or more characters and storing the generated glyph image to only one of the
color
channels of the texture atlas and storing an index for the glyph image in the
associated
.. atlas index, the index defining a position of the glyph image within the
texture atlas;
wherein an associated glyph image can be retrieved from one of the channels of
the
texture atlas using the atlas index when rendering of an associated character
in a user
interface generated by an application executed by the processor.
[0012] In accordance with another aspect of the present disclosure
there is
provided a non-transitory computer readable medium comprising computer-
executable glyph management instructions stored thereon, the glyph management
instructions comprising: receiving one or more characters; generating a glyph
image
of each of the one or more characters; for each generated glyph image: storing
the
glyph image in only one of a plurality of red, green, blue, and alpha (RGBa)
color
channels of a texture atlas stored on a memory coupled with the processor; and
creating an entry for the glyph image in an associated atlas index stored on
the
memory, the entry defining a position of the glyph image within the texture
atlas;
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wherein an associated glyph image can be retrieved from one of the plurality
of color
channels of the texture atlas when required for rendering of an associated
character
in a user interface generated by an application executed by a processor.
[0013] Other aspects and features will become apparent to those
ordinarily
skilled in the art upon review of the following description of specific
embodiments of
the disclosure in conjunction with the accompanying figures.
[0014] The present disclosure provides methods and systems of font
management using texture atlases that may, among other things, improve User
Interface (UI) performance and quality, as well as reduce memory requirements
for
storing glyph images. Stored within a memory of a computing device, such as a
set-
top box, mobile device, desktop computer, smartTV, etc.., are software
applications
that may be used for generating and updating a texture atlas. Required glyphs
to be
displayed in a Ul may be provided from the texture atlas to a graphics
processor, and
the graphics processor can use texture information, for example from a UV
array, to
render the Ul. The UV array defines the mapping from a 2D to 3D model.
[0015] When an image of a glyph is generated (that is, the character
has been
rendered into pixels using a specific font face, size and variant, e.g. bold
or italic),
because glyphs are typically monochrome the glyph image may be stored in any
one
of the red, green, blue, or alpha (referred to as `RGBa' herein) color
channels that
exist within the texture memory. This allows for up to four times the storage
capacity
for storing glyphs within a given texture atlas. When a character is to be
drawn in a
Ul, the relevant glyph image is combined with a color that the glyph is to be
drawn in,
thus rendering the necessary glyphs in the correct color. Parameters
associated with
glyphs in the texture atlas may be stored in an associated atlas index, and
the position
.. of respective glyphs within the texture atlas may also be stored to
facilitate retrieval
of glyphs to be rendered. By using the discrete texture atlas channels for
storing
glyphs memory utilization on the computing device is improved four fold.
[0016] Commonly used characters may be used to generate an initial
texture
atlas or texture atlases. Texture atlases may also be dynamically updated as
additional glyphs are needed. This may involve, upon receiving character data
to be
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presented in a Ul, determining if glyphs within the data for display exist
within the
texture atlas, and if a corresponding glyph is not currently within the
texture atlas,
adding that glyph to the texture atlas so that it may be rendered for display.
[0017] While the use of the term 'glyph' throughout the specification
may be
.. described with reference to font or textual glyphs, it should be noted that
the teachings
herein should not be limited to such. In particular, a glyph may include any
monochrome element, including but not limited to textual characters, symbols,
emojis,
and the like.
[0018] Embodiments are described below, by way of example only, with
reference to Figs. 1-10.
[0019] FIG. 1 shows an exemplary system that manages glyphs using
texture
atlases. The devices 102a, 102b, 102c (collectively, device(s) 102) are
capable of,
and configured to, present data to be displayed in a Ul in accordance with the
teachings herein. Device 102a is exemplary depicted as a TV, device 102b is
.. exemplary depicted as a laptop computer, and device 102c is exemplary
depicted as
a mobile phone device, though these examples of devices 102 are non-limiting
and
the teachings herein may be implemented on any device that has a Ul. Any
computing
device having a display, or coupled to a display, where memory conservation
may be
required may implement the described system and methods.
[0020] The devices 102 comprise various hardware and software components,
including but not limited to a CPU 110, memory 112, GPU 114, and an I/O
interface
116. The CPU 110 is configured to execute instructions stored on the memory
112.
The memory 112 may comprise instructions for generating a Ul, such as a
software
application depicted as a Ul generator 200. More particularly, the Ul
generator 200
is responsible for generating texture atlases and locating glyphs to be
rendered in a
Ul. The memory 112 and/or Ul generator 200 may comprise further software
applications and/or storage capabilities. Storage components may also be
located in
a non-volatile storage component of device 102 (not shown), but for clarity
will be
described herein as being within the memory 112.
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[0021] The CPU 110, when executing instructions stored within the
memory
112, and in particular when executing the Ul generator 200, may provide glyphs
stored
within a texture atlas or atlases to the GPU 114 for generating or rendering a
Ul 130.
Executing the Ul generator 200 may be performed in response to receiving Ul
data
120, for example through the I/O interface 116. The GPU 114 may, for example,
use
UV array information associated with the glyph image to be rendered in order
to
generate the texture within the Ul 130. The Ul 130 may be drawn on a screen
and
provided from the GPU 114 to the screen of the device 102 through the I/O
interface
116. The methods for generating texture atlases and providing glyphs to the
GPU 114
will be further described herein.
[0022] The Ul data to be rendered and displayed in the Ul may be
received
from a third party entity, exemplary depicted as external servers 140, and
provided to
the appropriate device 102. The Ul data 120 may be provided to the device 102
in
several different manners, for example over a network 150, broadcast
connection,
etc. The Ul data 120 may comprise any type of data that may be displayed in a
Ul.
The Ul data 120 may, for example, be any one or more of EPG data, channel list
data,
data from media-on-demand catalogues or app stores, and HTML data.
[0023] FIG. 2 shows a schematic of a Ul generation process. More
particularly,
FIG. 2 schematically depicts the actions that CPU 110 may perform when
executing
the Ul generator 200 stored within memory 112. The Ul generator 200 may be
operated on top of a browser, for example an HTML5 browser, though various
implementations are possible as will be readily appreciated by a person
skilled in the
art.
[0024] The Ul generator 200 may comprise a font renderer 202, which
receives
characters or text to be displayed in a user interface, identifies respective
glyphs
within the text, and determines at least one parameter associated with each of
the
respective glyphs, for example, the font family (e.g. Anal), font size (e.g.
12pt.), glyph
character (e.g. `a'), etc. The characters for being displayed in a user
interface may
be received from the Ul data 120, or may be loaded into the memory 112 of
device
102 during a configuration process, as will be further described herein. The
at least
one parameter associated with each of the respective characters may also be
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received with the characters or defined as an associated parameter, as opposed
to
the font renderer 202 determining the glyph parameters.
[0025] The font atlas 204 comprises instructions/rules for how to
build an atlas
index 206 and how the texture atlas is defined. For example, for each
character
received at the font renderer 202, the font atlas 204 takes a generated image
of the
glyph (e.g. in pixels) and stores the glyph image with associated parameters
(e.g. font
family, font size, etc.) in an appropriate location within the atlas index 206
based on
the instructions/rules for building the atlas index 206. The atlas index 206
is used in
generating a texture atlas 210, which comprises a texture with various images
(not
just limited to glyphs) and a list of texture atlas entries. In particular,
the texture atlas
210 comprises four color channels comprising images of Ul elements, the four
color
channels being a red channel 210a, green channel 210b, blue channel 210c, and
alpha channel 210d, referred to herein as RGBa color channels. As will be
described
further herein, because glyphs can be stored as monochrome elements all four
color
channels of the texture memory may be used to store separate sets of glyphs,
thus
realizing up to four times the memory savings. The glyphs may be stored in one
of
the RGBa color channels irrespective of the actual color of the glyph. When
the
glyphs are to be drawn in the Ul, the GPU 114 (using an OpenGL shader, for
example)
may combine the relevant glyph image within the texture atlas with the color
that the
character is to be drawn in, thus rendering the necessary glyphs in the
correct color.
The other images that may be stored in a texture atlas aside from the glyphs
may be
multicolored (i.e. not monochrome) and would therefore be stored on multiple
RGBa
color channels. In some embodiments, such images may be stored on separate
texture atlases that store the images on all four RGBa color channels, and
texture
atlases may have a parameter that indicates whether it contains multi-colored
images
or monochrome glyphs.
[0026] The generated images of the glyphs may be provided to the frame
buffer
208 prior to being added to one of the RGBa color channels in the texture
atlas 210.
The atlas index 206 may further comprise other character parameters associated
with
the glyph, such as UV array information for rendering the glyph texture, a
width and
height of the original image of the glyph before it was added to the texture
atlas 210,
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and a position of the glyph image within the texture atlas 210. The position
of the glyph
image within the texture atlas 210 may be identified by the image height and
width as
is stored in the texture atlas 210, co-ordinates of the 2D position within the
texture
atlas 210, and the respective RGBa color channel that the glyph image is
stored on.
[0027] Generated texture atlases 210 may be stored in a texture atlas
storage
212. Multiple texture atlases 210 may be created and dynamically updated, as
will be
further described herein. The texture atlases 210 may vary in size, and may
only be
limited by compliance with appropriate application programming interfaces (for
example, a hard limitation of 2048x2048 pixels for each texture atlas was
established
by the OpenGL ES APIs). Only physical limitations, such as the available
storage in
memory 112 may limit the number of texture atlases 210 that can be stored in
the
texture atlas storage 212. Glyphs may be retrieved from a texture atlas 210
within the
texture atlas storage 212 and provided to the GPU 114 for rendering the glyphs
when
generating the Ul.
[0028] In some scenarios, such as that described above, a glyph of a
character
may be added to a texture atlas 210, and/or a new texture atlas 210 may need
to be
created. This may occur during an initial configuration of a Ul application
running on
the device 102, or it may occur if Ul data requires a glyph of a character to
be
displayed that does not currently exist within a texture atlas.
[0029] In another scenario, a glyph that is to be rendered in a Ul may
already
be stored in a texture atlas 210 within the texture atlas storage 212. Upon
this
determination, the position of the glyph within the corresponding texture
atlas may be
determined from atlas index 206 and accordingly the glyph can be provided to
the
GPU without needing to generate an image of the glyph, add the glyph and
associated
parameters to the atlas index 206, upload to the frame buffer 208, etc., as
shown by
the arrow in FIG. 2 connecting the font renderer 202 directly to the atlas
index 206,
and the atlas index 206 directly to the texture atlas 210.
[0030] FIG. 3 shows a schematic of rendering a Ul. A text string 302,
exemplary depicted as the characters 'CAT', is received at a device 102 within
Ul data
120 to be rendered for display on the device. The CPU 110 of the device 102
may
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then execute the Ul generator 200 functionality. As will be further described
herein,
the Ul generator 200 determines parameters of the text string 302 by
identifying the
characters 'C', 'A', and 'T', and for example, the font family and the font
size. The Ul
generator 200 uses the one or more parameters of the characters received in
the text
string 302 to create and/or retrieve corresponding glyph images from a texture
atlas
that correspond to the parameters of the glyphs received in the text string
302.
[0031] As mentioned above and will be further described herein, the
corresponding glyph images may already exist in a texture atlas within the
texture
atlas storage 212 (texture atlases are exemplary shown as texture atlases
310a,
310b, and 310c), or the glyphs may have to be added to either an existing
texture
atlas or to a new texture atlas. In FIG. 3, the corresponding glyphs required
for
rendering the text string 302 are depicted as being located within the red
color channel
of texture atlas 310c. The appropriate glyphs, i.e. 'C', 'A', and 'T' are
retrieved from
the texture atlas 310c and provided to the GPU 114. The GPU 114 may use the UV
array information associated with the glyph textures to render the glyphs for
display,
as well as adding the appropriate color that the glyph is to be displayed in.
Accordingly, the Ul 130 is generated with the text string 'CAT' having been
appropriately rendered therein.
[0032] FIG. 4 shows a method 400 of generating a Ul. An initial
configuration
process (410-440) for generating texture atlases from input characters is
performed,
and a Ul generation process (450-480) can utilize glyphs stored in texture
atlases to
generate the Ul. The initial configuration process may be optionally performed
upon
start-up of a Ul application on a device and may generate texture atlases with
commonly used glyphs. For example, if the Ul application is used for
displaying EPG
data for display to customers in the United States of America, where English
is
predominantly spoken, characters to be added during the initial configuration
may
correspond to textual characters within the English alphabet (e.g., 'A', 'B',
'C', 'D',
etc.), numbers (e.g. '1', '2', '3', etc.), and other commonly used characters
(e.g. 1', '?',
etc.). The configuration file may vary depending on geographic location and/or
the language commonly spoken by a user. In another example, such as in western
European markets, the configuration file may include characters within the
English
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alphabet and further include character variants with diacritical marks. The
application
providing the Ul is started (410) and a configuration file or the like may be
received
(420). The configuration file may comprise the commonly used characters and
parameters such as font size, font family, etc. Glyph images for the
associated
character is generated (430) and stored to a channel of a texture atlas (440).
An atlas
index is updated to identify the position within the texture atlas of the
glyph image.
The use of each color channel to store different glyphs can provide a 4x
improvement
in memory utilization. In addition, as will be described below, the texture
atlas can be
dynamically updated to include new glyph images as new characters are required
by
an associated application for display.
[0033] Text may be received (450) within Ul data to be rendered for
display at
the device running the Ul application. It is determined if respective
characters within
the text to be rendered exist within a texture atlas (460). If a character
that is to be
rendered in the Ul does not exist within a texture atlas (NO at 460), the
texture atlas
is dynamically updated with the new glyph (470). Despite the initial
configuration
process used to add commonly used glyphs to texture atlases, scenarios may
arise
where a glyph to be rendered does not exist in a texture atlas. For example,
referring
to an example where EPG data as the Ul data, a movie title may contain a
character
such as the letter V. Depending on what was deemed to be commonly-used
characters within the configuration file, this character may not be considered
to be
commonly-used and may not exist within a texture atlas. Accordingly, the glyph
for
character may be added to a texture atlas. Being able to add the glyph
dynamically
circumvents the need to store every conceivable glyph that could be required
to be
displayed upon initial configuration. Once the glyph has been added to a
texture atlas,
it may be used for generating the Ul (480). If a glyph that is to be rendered
in the Ul
already exists within a texture atlas (YES at 460), the Ul may be generated
using the
existing glyph (480).
[0034] In some cases, the initial configuration process shown (420-
440) may
be omitted and texture atlases are dynamically updated with glyphs the first
time that
the character is to be used. Furthermore, receiving the text for display (450)
may
occur at any time during running of the Ul application and may occur numerous
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different times (for example, EPG data may be provided or updated daily, and
therefore receiving text for display may occur daily).
100351 FIG. 5 shows a method 500 of generating a texture atlas. The
method
500 may correspond to the generation of a texture atlas (440) of the Ul
generation
method 400 described with reference to FIG. 4, and may be performed upon
execution of the Ul generator 200. A character is received (502) and one or
more
parameters associated with the character, such as font face, size, etc., are
received
(504), for example at the font renderer 202. Using, for example,
rules/instructions
contained with the font atlas 204, it is determined how to build an atlas
index (506).
An atlas index 206 is generated (508) with an entry corresponding to the
respective
character, and an image of the glyph for the character may be added to a frame
buffer
208 (510). The glyph image is stored within one of the RGBa color channels
within a
texture atlas 210 (512), irrespective of an underlying color of the glyph.
[0036] An atlas entry may comprise information defining a position of
the glyph
image within the texture atlas as well as parameters of the glyph represented
by the
image. For example, parameters associated with a character may comprise any
one
or more of: font size, font family, original image width, original image
height, and a
UV array used to render the texture and color channels required. Most
characters
may be rendered using monochrome data, however, as previously mentioned a
multicolored image may be stored on multiple channels if specific color
elements or
details are to be included. Information that may be used to define a position
of the
glyph image within the texture atlas may comprise an image height and width as
stored in the texture atlas, a color channel within the texture atlas, and two-
dimensional co-ordinates of the image within the respective color channel.
Sample
code for creating an atlas entry is provided below:
interface AtlasEntry {
x: number;
y: number;
width: number;
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height: number;
real Width: number;
realHeight: number;
uvArray: Float32Array;
uvCoords: WebGLBuffer;
colorchannel: number;
[0037] FIG. 6 shows a method 600 of storing glyphs within a texture
atlas. The
method 600 may correspond to storing a glyph (512) of the texture atlas
generation
method 500 described with reference to FIG. 5, and may be performed during
execution of the Ul generator 200.
[0038] The available space in a current color channel of a texture
atlas is
determined (602), for example by using a binary packing tree, and it is
determined if
there is available space to add the glyph image (604). If there is available
space to
add the glyph image in the current color channel (YES at 604), the image is
stored in
the current color channel (606) and the packing tree is updated accordingly
(612) to
reflect the added glyph.
[0039] If there is no available space in the current color channel to
add the
glyph image (NO at 604), such as for example by reference to the associated
binary
packing tree, it is determined if there is another color channel available
(608). For
example, the Ul generator 200 may attempt to add the glyph image in
consecutive
RGBa color channels within a texture atlas, and may begin with the red color
channel,
then the green color channel, then the blue color channel, and lastly the
alpha color
channel. If another color channel is available within the texture atlas (YES
at 608),
the packing tree is updated (612) to reflect the next color channel. The
procedure
returns to determining if there is available space in the current color
channel (602).
For example, if the original color channel was the red channel and there was
no
available space within the red color channel, it may be determined (608) that
space
is available in the green color channel within the same texture atlas. The
binary
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packing tree is updated (612) to reflect the green color channel and the
available
space in the green color channel is determined (602).
[0040] If all the color channels have been used within the texture
atlas (NO at
608), a new texture atlas is created (610). For example, if each of the red,
green, and
blue color channels within the texture atlas were previously determined to be
full (i.e.
no space to add the glyph image), and it is also determined (604) that there
is no
available space in the alpha color channel to add the glyph image, a new
texture atlas
must be created. The procedure may then update the packing tree (612) and
continue
for the next glyph entry. The packing tree is used to determine placement of
the glyph
within the texture atlas by tracking the position of the last glyph entry and
the
remaining horizontal and vertical space available within the atlas.
[0041] FIG. 7 shows a method 700 of generating a Ul in accordance with
received characters. The method 700 may provide further details on the
generation
of glyphs (440-470) of the Ul generation method 400 described with reference
to FIG.
4, and may be performed during execution of the Ul generator 200.
[0042] A string of text to be displayed in a Ul is received (702) and
parameters
associated with characters within the string of text are determined (704). The
character parameters, such as the font face, font size, etc., may be compared
with
parameters of glyphs that are stored in existing texture atlases (706). This
comparison may be performed by checking the atlas entries associated with the
glyphs stored in the texture atlases. A determination is made if a glyph
corresponding
to the character to be rendered exists in a texture atlas (708). The
determination may
be based on whether or not all of the parameters associated with the character
to be
rendered match with all of the parameters associated with a glyph stored in
the texture
atlas. If there is no corresponding glyph stored in an existing texture atlas
(NO at
708), the glyph must be dynamically added to a texture atlas, as described
with
reference to FIG. 8.
[0043] If a determination is made that a glyph corresponding to the
character
to be rendered exists in a texture atlas (YES at 708), the position of the
corresponding
glyph is determined (710), for example from the atlas entry associated with
the
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corresponding glyph that contains position information such as the color
channel that
the corresponding glyph is stored on within the texture atlas, the co-
ordinates of the
corresponding glyph within the color channel, etc. The corresponding glyph and
parameters associated with the glyph, such as the UV array information used
for
rendering the glyph texture, is provided to the GPU (712) for display in the
Ul.
[0044] FIG. 8 shows a method 800 of dynamically adding glyphs to a
texture
atlas. The method 800 may be performed during execution of the Ul generator
200
when it has been determined that a glyph to be displayed does not currently
exist
within a texture atlas (NO at 708 in method 700). The method 800 may be
similar to
.. the method 500 for generating a texture atlas, and using, for example, the
font atlas
204, it is determined how to build an atlas (802) based on the parameters
associated
with the received character (704) in FIG. 7. An entry within atlas index 206
is created
(804), and an image of the glyph may be added to a frame buffer 208 (806). The
glyph image is stored within one of the RGBa color channels within a texture
atlas
210 (808).
[0045] Since the glyph has been dynamically added to a texture atlas
in
response to the received text to be displayed (702), the position of the glyph
within
the texture atlas is determined (810) and provided to the GPU (812) along with
other
parameters associated with the character. The glyph image can be rendered in
the Ul
accordingly, and the newly-generated glyph remains stored in the texture atlas
for
possible future use.
[0046] FIG. 9 shows an exemplary texture atlas 900 generated in
accordance
with the teachings herein. As shown in the texture atlas 900, glyphs have been
stored
on all four RGBa color channels within the texture atlas 900. As previously
mentioned,
this allows for more efficient memory usage.
[0047] The glyphs stored on the respective RGBa color channels are
depicted
in FIGs. 10A thru 10D, where FIG. 10A shows the red color channel 900a of the
texture atlas 900, FIG. 10B shows the green color channel 900b of the texture
atlas
900, FIG. 10C shows the blue color channel 900c of the texture atlas 900, and
FIG.
10D shows the alpha color channel 900d of the texture atlas 900.
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[0048] Each element in the embodiments of the present disclosure may
be
implemented as hardware, software/program, or any combination thereof.
Software
codes, either in its entirety or a part thereof, may be stored in a computer
readable
medium or memory (e.g., as a ROM, for example a non-volatile memory such as
flash
memory, CD ROM, DVD ROM, Blu-rayTM, a semiconductor ROM, USB, or a magnetic
recording medium, for example a hard disk). The program may be in the form of
source code, object code, a code intermediate source and object code such as
partially compiled form, or in any other form.
[0049] It would be appreciated by one of ordinary skill in the art
that the system
and components shown in Figures 1-10 may include components not shown in the
drawings. For simplicity and clarity of the illustration, elements in the
figures are not
necessarily to scale, are only schematic and are non-limiting of the elements
structures. It will be apparent to persons skilled in the art that a number of
variations
and modifications can be made without departing from the scope of the
invention as
defined in the claims.
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