NAME

Rinchi::CIGIPP::SymbolControl - Perl extension for the Common Image Generator Interface - Symbol Control data packet. data packet. =head1 SYNOPSIS

  use Rinchi::CIGIPP::SymbolControl;
  my $sym_ctl = Rinchi::CIGIPP::SymbolControl->new();

  $packet_type = $sym_ctl->packet_type();
  $packet_size = $sym_ctl->packet_size();
  $symbol_ident = $sym_ctl->symbol_ident(44253);
  $inherit_color = $sym_ctl->inherit_color(Rinchi::CIGIPP->NotInherited);
  $flash_control = $sym_ctl->flash_control(Rinchi::CIGIPP->RestartFlash);
  $attach_state = $sym_ctl->attach_state(Rinchi::CIGIPP->Attach);
  $symbol_state = $sym_ctl->symbol_state(Rinchi::CIGIPP->Visible);
  $parent_symbol_ident = $sym_ctl->parent_symbol_ident(18590);
  $surface_ident = $sym_ctl->surface_ident(34382);
  $layer = $sym_ctl->layer(40);
  $flash_duty_cycle = $sym_ctl->flash_duty_cycle(84);
  $flash_period = $sym_ctl->flash_period(16.565);
  $position_u = $sym_ctl->position_u(77.791);
  $position_v = $sym_ctl->position_v(26.596);
  $rotation = $sym_ctl->rotation(36.297);
  $red = $sym_ctl->red(61);
  $green = $sym_ctl->green(0);
  $blue = $sym_ctl->blue(203);
  $alpha = $sym_ctl->alpha(39);
  $scale_u = $sym_ctl->scale_u(60.944);
  $scale_v = $sym_ctl->scale_v(75.746);

DESCRIPTION

The Symbol Control packet is used to specify position, rotation, and other attributes describing a symbol's state.

A symbol must be defined before the Host sends a Symbol Control packet referencing that symbol. Symbols may be predefined by the IG or may be created by the Host sending any one of the symbol definition packets.

Each symbol is identified by a unique Symbol ID value. When the IG receives a Symbol Control packet, the packet will be applied to the symbol corresponding to the specified symbol ID. If a symbol with that ID does not exist, then the IG will ignore the packet. Each symbol must be created independently with its own unique Symbol ID value even if two visually identical symbols are used.

Symbols can be attached to one another in a hierarchical relationship. In such a hierarchy, a child symbol's position and rotation are specified relative to its parent symbol's local coordinate system. The Host needs only to control the parent symbol's position and rotation in order to move all lower symbols in the hierarchy as a group. No explicit manipulation of a child symbol's position and rotation is necessary unless its position and rotation change with respect to its parent. Additionally, a child symbol may inherit certain display states from its parent.

The Attach State attribute of the Symbol Control packet determines whether a symbol is attached to a parent. If this attribute is set to Attach (1), the symbol is attached to the symbol specified by the Parent Symbol ID attribute.

The Symbol State field is used to control when a symbol is visible and when a symbol's geometry is unloaded. When a symbol is created, that symbol is hidden until the Host sends a Symbol Control packet with the Symbol State field set to Visible (1). Any immediate children of that symbol either remain hidden or become visible depending upon their individual states. The symbol and all of its children can be hidden at any time by setting Symbol State to Hidden (0). When the Symbol is no longer needed, Symbol State can be set to Destroyed (2) to direct the IG to unload the symbol and free any associated resources. Any children attached to the symbol are also destroyed.

The Red, Blue, Green, and Alpha attributes define the color and transparency of a symbol. Alternatively, child symbols may inherit these values directly from their parents. If the Inherit Color attribute is set to Inherited (1), then the Red, Blue, Green, and Alpha attributes are ignored and the values of the parent are used. The Inherit Color attribute is ignored for top-level (i.e., root) symbols. A symbol may flash or blink as determined by the Flash Period and Flash Duty Cycle Percentage attributes. The Flash Period attribute specifies the amount of time between two consecutive flashes. The Flash Duty Cycle Percentage attribute specifies the percentage of each flash cycle that the symbol is visible. If this attribute is set to 100%, then no flashing occurs and the symbol is always visible. If a symbol's duty cycle is less than 100%, then any descendents (child symbols, grandchildren, etc.) will inherit the symbol's duty cycle and flash period. The Flash Duty Cycle Percentage and Flash Period attributes of the descendents will be ignored. If a symbol flashes, then any descendents will flash in synchronization with that symbol.

If a symbol's flash period or duty cycle is changed, then that symbol's flash cycle will be restarted.

A symbol may be moved without resetting its flash cycle. If a Symbol Control packet's Flash Control attribute is set to Continue (0), and if the Flash Period and Flash Duty Cycle Percentage attributes have not changed for the given symbol, then the symbol's flash cycle will not be reset. If the Flash Control attribute is set to Reset (1), then the symbol's flash cycle will be restarted from the beginning.

The drawing order of symbols is determined by layer. Each symbol surface has 256 logical layers, which are rendered in order of increasing layer number. In other words, symbols assigned to Layer 0 are drawn first, followed by the symbols on Layer 1, then those on Layer 2, etc. Symbols on higher-numbered layers may occult those on any lower-numbered layers. Symbols assigned to the same layer will be drawn in order of increasing symbol ID.

The position of a top-level (root) symbol is always specified with respect to the surface's 2D coordinate system (see Section 3.4.5.1). The position of a child symbol is always specified with respect to the parent symbol's local coordinate system (see CIGI ICD Section 3.4.5.2).

The Scale U and Scale V attributes specify a symbol's scale along the symbol's local U and V axes, respectively. The symbol's apparent size is also affected by any ancestors' scaling factors as described in CIGI ICD Section 3.4.5.2.

Once a Symbol Control packet is sent to the IG, the state of the specified symbol will not change again until another Symbol Control or Short Symbol Control packet containing the same Symbol ID value is received, or until the symbol is implicitly deleted.

EXPORT

None by default.

#==============================================================================

new $sym_ctl = Rinchi::CIGIPP::SymbolControl->new()

Constructor for Rinchi::SymbolControl.

sub packet_type()

 $value = $sym_ctl->packet_type();

Data Packet Identifier.

This attribute identifies this data packet as the Symbol Control packet. The value of this attribute must be 34.

sub packet_size()

 $value = $sym_ctl->packet_size();

Data Packet Size.

This attribute indicates the number of bytes in this data packet. The value of this attribute must be 40.

sub symbol_ident([$newValue])

 $value = $sym_ctl->symbol_ident($newValue);

Symbol ID.

This attribute specifies the symbol to which this packet is applied. This value must be unique for each active symbol.

sub inherit_color([$newValue])

 $value = $sym_ctl->inherit_color($newValue);

Inherit Color.

This attribute specifies whether this symbol inherits its color from the symbol to which it is attached. If color is inherited, then this symbol's color, including the alpha component, is identical to the current color of the parent symbol. Note that the current color of the parent symbol may be inherited from another symbol.

If Attach State is set to Detach (0), this attribute is ignored.

    NotInherited   0
    Inherited      1

sub flash_control([$newValue])

 $value = $sym_ctl->flash_control($newValue);

Flash Control.

This attribute specifies whether the flash cycle is continued from its present point or whether it is restarted at the beginning.

This attribute is ignored if either Flash Duty Cycle Percentage or Flash Period is changed. This attribute may also be ignored if Flash Duty Cycle Percentage is set to 0 or 100.

    ContinueFlash   0
    RestartFlash    1

sub attach_state([$newValue])

 $value = $sym_ctl->attach_state($newValue);

Attach State.

This attribute specifies whether the symbol should be attached as a child to a parent symbol.

If this attribute is set to Detach (0), then the symbol becomes or remains a top-level (non-child) symbol. The Parent Symbol attribute is ignored. The U Position, V Position, and Rotation attributes specify the symbol's position and rotation relative to the symbol surface's local coordinate system (see CIGI ICD Section 3.4.5.1).

If this attribute is set to Attach (1), then the symbol becomes or remains attached to the symbol specified by the Parent Symbol ID attribute. The U Position, V Position, and Rotation attributes specify the symbol's position and rotation relative to the parent symbol's local coordinate system (see Section 3.4.5.2). The attach state of a symbol may be changed at any time. The attachment or detachment takes place immediately and remains in effect until changed with another Symbol Control packet or Short Symbol Control packet.

    Detach   0
    Attach   1

sub symbol_state([$newValue])

 $value = $sym_ctl->symbol_state($newValue);

Symbol State.

This attribute specifies whether the symbol should be hidden, visible, or destroyed. This attribute may be set to one of the following values:

Hidden – The symbol is hidden from view; however, it can be positioned, rotated, and scaled. It can also be attached to another symbol as a child. It can also be used as a parent by other symbols, although any children are also hidden. Visible – The symbol is drawn on the surface. It can be positioned, rotated, and scaled. It can also be attached to another symbol as a child. It can also be used as a parent by other symbols.

Destroyed – The symbol is deleted and any system resources are freed. Any children are also destroyed. All other attributes in this packet are ignored.

Note: Although the Symbol Control packet supports destruction of symbols, it is recommended that the Short Symbol Control packet be used for this purpose since all other attributes are ignored.

    Hidden      0
    Visible     1
    Destroyed   2

sub parent_symbol_ident([$newValue])

 $value = $sym_ctl->parent_symbol_ident($newValue);

Parent Symbol ID.

This attribute specifies the parent for the symbol. If the Attach State attribute is set to Detach (0), this attribute is ignored.

The value of this attribute may be changed without first detaching the symbol from its existing parent.

If the specified parent symbol is invalid, no change in the attachment will be made.

sub surface_ident([$newValue])

 $value = $sym_ctl->surface_ident($newValue);

Surface ID.

This attribute specifies the symbol surface on which the symbol is drawn.

If the symbol is a child, then the top-level parent symbol's surface is used and this attribute is ignored.

If the specified surface is invalid and this symbol is not a child, then the symbol will not be drawn.

sub layer([$newValue])

 $value = $sym_ctl->layer($newValue);

Layer.

This attribute specifies the layer to which the symbol is assigned. Layers are drawn in order of increasing layer number. For example, Layer 0 will be drawn first, followed by Layer 1, etc. Symbols on higher-numbered layers may occlude symbols on lower-numbered layers. If two or more symbols occupy the same layer, then the symbols are drawn in order of increasing symbol ID.

Note that any two siblings in a symbol hierarchy may or may not be assigned to the same layer or to adjacent layers.

sub flash_duty_cycle([$newValue])

 $value = $sym_ctl->flash_duty_cycle($newValue);

Flash Duty Cycle Percentage.

This attribute specifies the duty cycle for a flashing symbol. This is the percentage of one flash cycle that the symbol will be visible.

If this value is set to zero (0), then the symbol is always invisible. If this value is set to 100%, then the symbol is always visible.

This attribute is ignored if this symbol inherits flashing behavior.

sub flash_period([$newValue])

 $value = $sym_ctl->flash_period($newValue);

Flash Period.

This attribute specifies the duration of a single flash cycle.

This attribute is ignored if Flash Duty Cycle Percentage is set to 0% or 100%.

This attribute is ignored if the symbol inherits its flashing behavior from its parent.

sub position_u([$newValue])

 $value = $sym_ctl->position_u($newValue);

Position U.

This attribute specifies the U component of the symbol's position.

For top-level (non-child) symbols, this position is defined with respect to the symbol surface's 2D coordinate system as described in CIGI ICD Section 3.4.5.1.

For child symbols, this position is defined with respect to the parent symbol's local coordinate system as described in CIGI ICD Section 3.4.5.2.

sub position_v([$newValue])

 $value = $sym_ctl->position_v($newValue);

Position V.

This attribute specifies the V component of the symbol's position.

For top-level (non-child) symbols, this position is defined with respect to the symbol surface's 2D coordinate system as described in CIGI ICD Section 3.4.5.1.

For child symbols, this position is defined with respect to the parent symbol's local coordinate system as described in Section 3.4.5.2.

sub rotation([$newValue])

 $value = $sym_ctl->rotation($newValue);

Rotation.

This attribute specifies a rotation for the symbol. This rotation is always counter-clockwise about the symbol's local origin.

Note that each child symbol is oriented relative to its parent's local coordinate system.

sub red([$newValue])

 $value = $sym_ctl->red($newValue);

Red.

This attribute specifies the red component of the symbol's color.

This value is ignored if Inherit Color is set to inherit (1).

sub green([$newValue])

 $value = $sym_ctl->green($newValue);

Green.

This attribute specifies the green component of the symbol's color.

This value is ignored if Inherit Color is set to inherit (1).

sub blue([$newValue])

 $value = $sym_ctl->blue($newValue);

Blue.

This attribute specifies the blue component of the symbol's color.

This value is ignored if Inherit Color is set to inherit (1).

sub alpha([$newValue])

 $value = $sym_ctl->alpha($newValue);

Alpha.

This attribute specifies the alpha component of the symbol's color. A value of zero (0) corresponds to fully transparent; a value of 255 corresponds to fully opaque. This value is ignored if Inherit Color is set to inherit (1).

sub scale_u([$newValue])

 $value = $sym_ctl->scale_u($newValue);

Scale U.

This attribute specifies the scaling factor of the symbol along the symbol's local U axis. A value less than 1.0 will cause the symbol to be reduced in size. A value greater than 1.0 will cause the symbol to be increased in size.

Note that a symbol's actual size and shape will be affected by the symbol's scaling factors, as well as those of any ancestor symbols.

sub scale_v([$newValue])

 $value = $sym_ctl->scale_v($newValue);

Scale V.

This attribute specifies the scaling factor of the symbol along the symbol's local V axis. A value less than 1.0 will cause the symbol to be reduced in size. A value greater than 1.0 will cause the symbol to be increased in size.

Note that a symbol's actual size and shape will be affected by the symbol's scaling factors, as well as those of any ancestor symbols.

sub pack()

 $value = $sym_ctl->pack();

Returns the packed data packet.

sub unpack()

 $value = $sym_ctl->unpack();

Unpacks the packed data packet.

sub byte_swap()

 $obj_name->byte_swap();

Byte swaps the packed data packet.

SEE ALSO

Refer the the Common Image Generator Interface ICD which may be had at this URL: http://cigi.sourceforge.net/specification.php

AUTHOR

Brian M. Ames, <bmames@apk.net>

COPYRIGHT AND LICENSE

Copyright (C) 2009 by Brian M. Ames

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.6 or, at your option, any later version of Perl 5 you may have available.