GLG 3.0 Release: New
Features and Enhancements
The major features of the
new release are related to the GLG Graphics Builder look and feel and
interface improvements, enhanced tag
data access interface, new GIS
capabilities, gradient rendering, control over the resize policy and
coordinate system, as well as many other new features.
New Look and Feel of the Graphics Builder
The new GLG Graphics Builder uses highlighting icons, gradients,
dimming and shading to provide cleaner and sharper visual appearance,
as shown in the picture on the right.
New icons for common object transforming actions, such as flipping,
rotation and scaling, were added to the control panel on the left of
the drawing area.
The Data, History, Aliases
and Xform indicators in the
status panel at
the bottom of the Builder were replaced with buttons that allow
direct access to the corresponding object properties.
New Tag Interface
The new tag interface
introduces additional tag properties to
facilitate the process of remapping tags defined in the drawing to the
fields of the process database or PLC at run time.
Previously, a tag had only one attribute that defined a tag source,
while the new release introduced a Tag
Name attribute in addition to
the Tag Source. A persistent Tag Name makes it possible to
identify the tag even after its Tag
Source has been changed by
assigning a database variable to it. An additional Tag Comment
attribute has also been added for storing user comments and any
All tag properties are now stored in a tag object, which has to be
explicitly created and attached to a resource object. In the Graphics
Builder, a new dialog is provided to display and edit all tag object
The Tag Browser interface has been changed to display both the Tag Name
and Tag Source attributes of
each tag. New toggles have been added to
the Tag Browser to browse tags by either Tag Name or Tag Source.
The Tag Import/Export
features have been extended to export
TagName/TagSource pairs, which
allows for more precise handling of tags
with the same tag sources.
The String Import/Export
features have also been extended to export
string Name/Value pairs, which allows the application to use different
translations for similar strings used in different places in the
Compatibility Note: The Tag attribute has been changed to TagSource. The
name "Tag" is still supported
for backward compatibility and mapped to
Panning by Dragging the Drawing or Map
with the Mouse
Panning the drawing by dragging it with the mouse is now possible by
using the Ctrl-drag binding.
It is supported both in the Graphics
Builder when editing a drawing, as well as at run-time (if enabled by
the viewport's ZoomEnabled
attribute). In the GIS Zoom Mode, the
feature may be used to drag the map with the mouse.
A programmatic interface to start dragging under the control of the
application, when certain conditions are met, is also provided via the
New Options for Creating
Widgets and SubDrawings with Different Resize
New options for creating drawings with different resize policies were
added to the Graphics Builder. The New
Widget option creates a widget
with a drawing surface that uses world coordinates and stretches when
the widget is resized. This resizing behavior is commonly used by
process control and monitoring applications which still want to display
the whole drawing with a bigger or smaller magnification when a widget
The New Widget (No Stretch/Resize)
option creates a widget with the
drawing area that uses screen coordinates and does not stretch when the
widget is resized. When the widget's window is resized, it shows a
bigger or smaller portion of the drawing area, which is the default
behavior of many GUI and image-editing tools. The non-resizable
drawings may still be zoomed in or out.
These convenient options may be used without learning the advanced
attributes of a viewport, as it was the case in the previous releases.
The coordinate system of the Builder's Drawing Area is also adjusted to
match a widget's resize policy. This allows the user to define a
precise screen size in pixels for widgets with the No Stretch resize
policy. The Set Width and Set Height options of the Layout
be used for setting the widget's width and height in pixels.
Two new options for creating subdrawings are also introduced. The New
SubDrawing option is used to create resizable subdrawings for
with the Stretch resize
policy. The New SubDrawing (No
option may be used to create subdrawings for widgets with the No
Stretch resize policy or to create fixed size subdrawings. These
options set the coordinate system of the Builder' Drawing Area to an
appropriate value for the selected subdrawing creation mode. The
coordinate system setting is saved with the subdrawing's drawing and is
restored when it is loaded in the Builder.
In a program, the resize policy of the viewport's drawing area may be
controlled by the CoordSystem
attribute of the viewport's screen.
Setting Coordinate System on
This feature allows mixing world and screen coordinate systems in the
GLG drawing by setting an object's CoordFlag
attribute. The available
coordinate systems include the GLG-standard world coordinate system, as
well as two screen coordinate systems.
The screen coordinate systems define coordinates in screen pixels
relatively to a drawing area's upper left corner. Screen coordinates
may be used to specify an absolute object position on the screen which
does not change when the drawing is zoomed or resized. This provides a
convenient mechanism for positioning text message overlays by
a fixed offset from the edge of the drawing.
There are two screen coordinate systems that differ in the direction of
the Y axis.
Fixed Size Icons
Support for fixed size icons that do not change their size when the
drawing is zoomed or resized has been added to the Toolkit via the
FixedSize attribute of the
reference and container objects. Fixed size
icons use the screen coordinate system for rendering their graphics,
while providing a user-friendly editing interface that
transparently handles all complexities of the coordinate system
The fixed size icons automatically maintain their pixel size and X/Y
ratio when the drawing is zoomed or resized, while they may still be
independently scaled under the program control to increase or decrease
the icons' size.
The GIS and AirTraffic Control demos have been updated to use
fixed-size airplane icons. The updated Map demo uses the fixed size
icons to automatically maintain the icon's X/Y ratio when the drawing
is resized, with no source code required. These demos provide examples
of using fixed size icons in an application.
New GIS Editing Mode
A new GIS Editing Mode has
been added to the Graphics Builder, allowing
the user to draw polygons and place dynamic icons on top of the GIS map
using the GIS lat/lon coordinates directly. In the GIS Editing mode,
the user simply draws GLG objects with the mouse, and the Builder
positions them on the map, converting the screen coordinates of the
mouse to the GIS lat/lon. The converted lat/lon coordinates are then
stored as the coordinate values of the objects' points. The GIS Editing
Mode transparently handles GIS projections, allowing the user to draw
objects on the globe in the orthographic projection. To start the GIS
Editing mode, the user goes down "into" the GIS object by selecting it
and pressing the Hierarchy Down
Positioning Objects in GIS
With this new functionality, the GIS object now serves as a container
object which holds icons, polygons and other objects drawn on top of
the map. The GLG API may be used to add dynamic icons at run time and
position them on the map by setting their lat/lon coordinates.
The coordinates of control points of objects added to the map as
children of the GIS object are specified directly in lat/lon
coordinates with no coordinate conversion required in previous
releases. When the map is resized, zoomed or panned, the objects
maintain their position on the map automatically. Specifying
coordinates directly using lat/lon with no coordinate conversion
greatly simplifies and reduces the amount of code for GIS applications.
The objects drawn on top of the map inside the GIS Object are
automatically clipped to the GIS Object's boundaries, which eliminates
a need for workarounds for wrap-around problems of the GDI driver in
the previous releases. In the ORTHOGRAPHIC
projection, the icons and
lines drawn on top of the map inside the GIS Object are also clipped to
the visible side of the globe, eliminating the objects located on the
invisible back side.
Persistent GIS Zoom Mode and New
GIS Pan Options
In the GIS Editing Mode, the Zoom and Pan controls of the Graphics
Builder automatically switch to the GIS
Zoom Mode, zooming and panning
the map instead of the whole drawing. This allows the user to zoom and
pan the map during editing, without the need to start the Run mode. The
map may also be dragged with the mouse via the Ctrl-drag binding, both
in the Edit mode and at run time if enabled by the viewport's
The GIS Zoom Mode may be permanently stored in the drawing by using the
new "Set as parent viewport's
GISObject" option of the Arrange
Once it is done, the viewport containing the GIS Object will always use
the GIS Zoom Mode while being edited or prototyped.
Integrated pan scrollbars of the viewport can now be used in the GIS
Zoom mode to pan the map. They are activated by the viewport's Pan
New Line Fill Attribute and Line
A new EDGE_WITH_LINE_FILL
fill type was added to polygons and all other
objects that inherit polygon attributes, such as arcs or splines. When
this fill type is used for lines with LineWidth
greater than 3, the
outline of the line is drawn using the EdgeColor, and the middle part
of the line will be drawn using the FillColor,
as shown in the first picture on the right.
A new Line Width gradient was
added to facilitate easier rendering of
fixed-width 3D pipes. In the earlier versions of the Toolkit, 3D pipes
were rendered using filled polygons with gradient, which was tedious to
create. In the new release, all segments of a 3D pipe may be rendered
as a single polygon with FillType=EDGE
and the Line Width gradient.
The Line Width gradient works
with arrows, as shown in the second picture on the right.
An elliptical gradient is similar to the spherical gradient, but it
also stretches with the object to create more realistic rendering. The
spherical gradient did not change its shape when the object was
stretched and always maintained a perfectly circular shape even when
the object was stretched.
Independent X and Y Panning and
Support for independent activation of the X and Y panning scrollbars
was added to a viewport object. Previously, the X and Y scrollbars
could be enabled or disabled only simultaneously.
Support for custom panning scrollbars has been added. It allows an
application to use any GLG slider or scrollbar widget instead of the
default native scrollbars for the integrated viewport scrolling. This
is especially important for Qt and GTK integration where native
scrollbars may not be available.
The use of the custom scrollbars is controlled by the
configuration resource. If this resource is
set to 1, custom GLG scrollbars will be used. The
GlgVScrollbarRef and GlgHScrollbarRef global
resources may be used to provide the filenames of drawings that contain
custom panning controls.
A string concatenation transformation has been introduced to facilitate
an easier creation of text labels that display several strings, where
each string may be controlled by a separate resource. One such example
is a text object used in GLG gauges to display a label, value and units
in one object. Previously, such text label had to be assembled using
nested format transformations. The string concatenation transformation
simplifies the process of creating such labels.
Support for rendering attributes has been extended to the viewport
objects, making it easier to use gradients for the viewport's
background. In the new release, the gradient may be used for the
viewport's background using viewport's rendering attributes, the same
way as for other objects. This yields proper rendering with no gaps
regardless of how much the drawing is zoomed in or out.
Alternative Behavior for
Sliders and Knobs
Support for the IncrementOnClick
resource was added to the slider and
knob interaction handlers to provide an alternative run-time behavior.
If the resource is set to 0, the slider will move to the position of
the mouse click, which was the only choice in previous versions.
Setting this resource to 1 changes behavior of the slider and knob
controls. If the mouse click occurs outside of the slider's moving
element, it is moved in the direction of the mouse click by the amount
of the slider's increment resource, doing it repeatedly until either
the mouse is released or the slider reaches the mouse location. The
user can still move the slider or knob with the mouse by clicking on
its moving element and dragging it with the mouse.
Support for the PageIncrement
resource and PageIncrease/PageDecrease
buttons and key bindings has been also added to the Slider and Knob
All slider widgets have been changed to support SliderSize,
StartPosition and EndPosition resources. The SliderSize resource
controls the size of the slider's moving element, while the
StartPosition and EndPosition resources control the
extent of its
movement. When these resources are modified, all other resources of the
slider widgets get adjusted automatically.
A new FonttableFile viewport attribute
may be used to specify a fonttable from an external file to be used for
the drawing. A fonttable may be edited in the Builder, saved into a
referenced by multiple drawings. The font changes applied to the
fonttable will be reflected in all drawings that reference it. This
feature enables applications to modify fonts used at run-time by simply
changing a single external fonttable file using the GLG Graphics
The FonttableFile attribute
may be edited in the Properties
dialog of the viewport's Screen
The following new widgets were added to the Controls Widget Set:
- The GLG scrollbar
widgets were added to the Sliders palette
- Several new custom
gauges were added to the Dials and Meters palette
- An icon button with
gradient highlight was added to the Buttons and
An alarm bar widget was added to the Special Widgets palette.
- A value display text
object with separate resources to control its
Label, Value and Units was added to the Buttons and Indicators palette
Miscellaneous New Features
Support for string transformations was added to LabelString resource of
native buttons as well as the TooltipString
transformation may be used to provide a list of strings for the
button's label or tooltip, so that they may be dynamically changed by
selecting a desired string from the list depending on some condition.
Added support for the OnState
resource for native push buttons to allow
using them as toggles with changing labels.
Added support for handling MouseOverState
for invisible objects to
allow making them visible on mouse-over via the MouseOverState
Support for handling new line ('\n')
and quoted strings was added to
the GLG Script.
A new ZoomRectangle subaction
was added for the ZoomTo
action to allow
the program to change attributes of the ZoomTo dragging rectangle.
The "Empty history" message
was disabled at run-time to allow setting
Factors of the Series object
to 0, which is useful for the graph
Graphics Builder Interface Improvements
A new button for immediate editing of all objects in a group was added
to the group properties dialog. The new button saves an extra mouse
click by allowing the user to start editing a group of similar objects
without selecting an object to define an attribute set for editing. The
old option which allows selecting the set of attributes for editing is
available as well. The Add/Delete
buttons of the group dialog were
reordered to the end of the group properties' list.
A new interface has been added to allow the user to mark and reuse text
boxes, rendering attributes, light objects and font tables, as well as
adding constrained copies of them to groups of objects.
A toggle was added to the Layout Toolbox to allow the user to apply the
width, height and other settings to either all objects in a group or to
the group itself.
A feedback indicator was added to the Select
Anchor Object icon in the
Layout Toolbox. The color of the icon changes to green when the layout
anchor is defined.
The interface of browsing all resources of the drawing was changed to
show resources of the viewport with the editing focus instead of the
resources of the whole top-level drawing.
The new Builder makes a better use of spinners in the resource dialog,
allowing the user to use them to set values of many additional
resources such as Factors of
the series, and other resources with
New buttons were added to the Scale,
Rotate and some other
transformation dialogs to set the Center
attribute to the center of the
object, as well as to reset the Center
New logic has been added for detection of constraint loop problems.
Constraint loops may be created in the Builder when the user constrains
the Buffer attributes of two Transfer transformations. This condition
is now checked and reported, which makes it easier to diagnose and
In the new Builder, separate ZoomBy
and ScaleBy factors are
for convenience. This allows the user to set factors for zoom and scale
The GIS Object interface has been changed to regenerate the map when
the object's Verbosity value
was changed. This eliminates the need to
reset the drawing to see the verbose output after changing the
A new "Save Direct OpenGL Image"
option for saving images was added to
get around limitations of OpenGL drivers which may use a low-quality
software-based OpenGL renderers when rendering into an off-screen
pixmap. Instead of rendering into the off-screen pixmap, the new image
saving option copies bits from the screen, preserving the quality of
the hardware-accelerated OpenGL rendering in the generated image.
The move point display of non-resizable viewports has been fixed. The
display of an inoperative move point for viewports with HandlerDisabled
has been eliminated to avoid confusion.
Drawing area scrollbars are now disabled in the Run Mode to eliminate
The Save Image Full option
for saving the image of the whole drawing
(instead of just the visible part of it) was changed to automatically
exclude the drawing's pan sliders from being rendered in the saved
The menus presenting choices of attribute values and transformations
are now scrollable for greater convenience.
When widgets are added to the drawing from a palette, they are now
inserted at the center of the visible portion of the drawing instead of
the origin of the coordinate system, which may be scrolled out.
The Hierarchy Down operation
for series and reference objects in a
non-resizable drawing was improved by placing the origin of the
coordinate system in the center of the drawing for more convenient
editing of their templates.
The initial grid size is now automatically adjusted when a new widget
is created depending on the type of the widget's coordinate system.
The display of the buffer attribute of the transfer transformation was
improved to show the updated buffer value when the UseValue attribute
Performance Improvements and Bug
Clipping performance for objects that are completely clipped out was
improved to speed up rendering of drawings with huge zoom factors.
A more detailed error message is now provided for SetResource methods
to facilitate debugging. The new error message provides a complete
resource path and differentiates between default attribute names and
OpenGL Renderer: Detection of
the GLXBadDrawable X error
added on Linux systems, with a message that describes possible remedies.
OpenGL Renderer: A check for
the GLX BadMatch error was
added to catch
a depth mismatch between the default visual and the supported OpenGL
visuals. If a depth mismatch is detected, GLG switches to the GDI
renderer and generates a warning message describing possible remedies.
A coordinate overflow at very high zoom factors in the GDI renderer was
eliminated for objects that were completely clipped out. The OpenGL
renderer (which uses double coordinate values) presents an even better
The zoom limit check that prevented coordinate overflow was eliminated
for the OpenGL renderer.
The widget's minimum width/height in Qt integration was set to a
default value different from 0 to avoid problems with some layout
The value of the Z coordinate of the points outside of the visible part
of the globe, returned as a result of the GlgGISConvert() method, was
changed from -1.0 to the GLG_GIS_OUTSIDE_VALUE
defined constant equal
-2000., to be consistent with the default extent of the GLG
OpenGL Renderer: Line caps were
fixed for lines with even line width.
OpenGL Renderer: Rendering of
line arrows was fixed for ARROW FILL
& EDGE, and rendering of arrows with FILL arrow style was improved
by using anti-aliasing.
Arrow rendering was improved by making the arrow ends always round,
even for lines with an even line width.
was added to the GlgLayoutObjects()
to control the method's behavior for groups. If the parameter is set to
True, the layout action is
applied to all elements of the group. If the
parameter is set to False,
the method applies the action (such as
SET_WIDTH) to the group itself.
Due to the new tag object interface, the GlgHasTagObject method was
replaced with the GlgHasTagName
and GlgHasTagSource methods.
by_name parameter has been
added to the GlgGetTagObject
method to allow
to query a tag object by either its TagName
Windows ActiveX Control: The UpdateGlg method has been added to
using the Update method that
conflicts with OLE interfaces in the new
versions of the VisualStudio.NET. The new GetGlgMajorVersion and
provide GLG version information.
Windows ActiveX Control:
Persistence of the UseOpenGL
properties on saving the ActiveX control was fixed.