Internal SilverScreen Structures

PRIM_NODE	information common to all primitive nodes
LINE_NODE	line information
ROUND_NODE	circle, ellipse, and arc information
POLYGON_NODE	polygon information
POLYLINE_NODE	polyline information
POINT_NODE	point information
CURVE_NODE	curve (Bezier and spline) information
SPOINT_NODE	information for point of spline curve
BPOINT_NODE	information for point of Bezier curve

FONT_NODE	information about the font used in a TEXT_NODE
TAG_NODE	Information about data that has been attached to a BOS_NODE
LIGHT_NODE	light source information
SURFACE_NODE	surface property information
MODEL_NODE	information about a model that is attached to a SYMBOL_NODE
ATTRIBUTE_NODE	attribute information
SCHEMA_NODE	schema information that is attached to a BOS_NODE
TEXTURE_DATA	texture information
SS_PATTERN	pattern information

BOS_NODE
   {
   int bits1;
   int bits2;
   SS_XYZ high;
   SS_XYZ low;
   SS_XYZ center;
   SS_XYZ top_axis;
   SS_XYZ bottom_axis;
   SS_XYZ local_horz;
   SS_XYZ local_vert;
   SS_XYZ local_base;
   NAME name;
   int force_style_color;
   RGB force_rgb;
   BOS_NODE *next_bos;
   BOS_NODE *prev_bos;
   BLOCK_NODE *parent;
   };

For bits1, the following are used:

E_BLOCK	is a BLOCK_NODE .
E_OBJECT	is a OBJECT_NODE .
E_SYMBOL	is a SYMBOL_NODE .
E_TEXT	is a TEXT_NODE .
E_DETAIL	is a DETAIL_NODE .
HAS_HIGHLOW	high-low extents are current.
HAS_CENTER	center of rotation is set.
HAS_AXIS	axis of rotation is set.
IS_FORCE_COLOR	has force color applied.
IS_FORCE_LINESTYLE	has force linestyle applied.
IS_FORCE_WIDTH	has force width applied.
IS_VISIBLE	is visible.

For bits2, the following are used:

IS_ANNOTATE	is an annotation block (blocks only).
IS_SOLID	is a valid solid. (objects only).
IS_NONSOLID	is not a valid solid. (objects only).
IS_DELETED	has been deleted.

Field descriptions:

bits1	see description above
bits2	see description above
high	maximum extent values (if HAS_HIGHLOW)
low	minimum extent values (if HAS_HIGHLOW)
center	center of rotation (if HAS_CENTER)
top_axis	top of the axis of rotation (if HAS_AXIS)
bottom_axis	bottom of the axis of rotation (if HAS_AXIS)
local_horz	horizontal displacement of e-space
local_vert	vertical displacement of e-space
local_base	base point of e-space
name	nameof the entity
force_style_color	force bits
force_rgb force	RGB if color is forced
next_bos	pointer to next BOS_NODE
prev_bos	pointer to previous BOS_NODE
parent	pointer to parent block

BLOCK_NODE
   {
   // Common BOS_NODE section omitted
   BOS_NODE *first_bos;
   SCHEMA_NODE *first_schema;
   TAG_NODE *first_tag;
   void *unused1;
   void *unused2;
   };

Field descriptions:

first_bos	pointer to the first entity contained within the block. NULL if the block contains no entities.
first_schema	pointer to the first schema associated with the block.
first_tag	pointer to the first tag associated with the block.

OBJECT_NODE
   {
   // Common BOS_NODE section omitted
   SCHEMA_NODE *first_schema;
   void *unused1;
   void *unused2;
   void *unused3;
   PRIM_NODE *first_node;
   PRIM_NODE *last_node;
   int primitives;
   int high_id;
   EDGE edges;
   VERTEX vertices;
   double pattern_scale;
   int pattern_color;
   RGB pattern_rgb;
   SURFACE_NODE sn;
   };

Field descriptions:

first_schema	pointer to the first schema associated with object
first_node	pointer to the first primitive in object
last_node	pointer to the last primitive in object
primitives	bit field identifying types of primtives in object
high_id	highest id number of any primitive in object
edges	number of edges in object
vertices	number of vertices in object
pattern_scale	scale applied to patterns
pattern_color	color used to display patterns
pattern_rgb	RGB color value used to display patterns
sn	structure of surface characteristics

SYMBOL_NODE
   {
   // Common BOS_NODE section omitted
   MATRIX matrix;
   double pattern_scale;
   MODEL_NODE *model;
   SCHEMA_NODE *first_schema;
   TAG_NODE *first_tag;
   NAME model_name;
   FILE_NAME library_name;
   RGB pattern_rgb;
   RGB surface_rgb;
   int bits_surface;
   int pattern_color;
   int surface_pattern_color;
   };

Field descriptions:

matrix	transformation matrix for the associated model
pattern_scale	scale applied to patterns
model	pointer to the model associated with the symbol
first_schema	pointer to the first schema
first_tag	pointer to the first tag associated with the block
model_name	name of the model associated with the symbol
library_name	name of the library which is associated with the symbol (drawing name if symbol is internal)
pattern_rgb	RGB color value used to display patterns
surface_rgb	surface color of the symbol if a surface color is forced
bits_surface	information about forced surface colors
pattern_color	color for pattern display
surface_pattern_color	pattern number and surface color if forced

TEXT_NODE
{
   // Common BOS_NODE section omitted
   MATRIX matrix;
   SS_XYZ where;
   SS_XYZ xyz2;
   double height;
   double width_ratio;
   double spacing_ratio;
   double slant;
   double angle;
   double total_width;
   double total_height;
   char *text;
   FONT_NODE *font_ptr;
   int underscore;
   int overscore;
   int direction;
   int justification;
   RGB text_rgb;
   int text_width_style;
   int is_filled;
   };

Field descriptions:

matrix	transformation matrix used to orient the text.
where	start point for display of the text.
xyz2	dependent upon the text justification: IS_RIGHT:It is the right point of the text IS_CENTER: It is the center point of the text IS_ALIGNED: It is the right point of the text
height	height of the text.
width_ratio	height/width ratio of the text.
spacing_ratio	spacing ratio.
slant	angle of slant applied to the text (degrees).
angle	angle of rotation applied to the text.
total_width	total width of the text.
total_height	total height of the text.
text	pointer to the string of text being displayed.
font_ptr	pointer to the FONT_NODE that describes the font being used to display the text. (See below.)
underscore	0 for no underscore 1 for single underscore 2 for double underscore
overscore	0 no overscore 1 for single overscore
direction	indicates the direction of text: IS_HORIZONTAL: text is horizontal IS_VERTICAL: text is vertical IS_DIAGONAL: text is diagonal IS_ALIGNED: text is aligned
justification	tests to indicate justification of text: IS_RIGHT: text is right justified IS_LEFT: text is left justified IS_CENTER: text is centered IS_ALIGNED: text is aligned
text_rgb	RGB for text
is_filled	TRUE if TrueType font is filled

PRIM_NODE
   {
   int bits;
   int id;
   PRIM_NODE *next_node;
   PRIM_NODE *prev_node;
   OBJECT_NODE *parent;
   };

Settings for the bits field:

P_LINE	is a line node
P_POLYGON	is a polygon node
P_POLYLINE	is a polyline node
P_SPLINE	is a spline node
P_ROUND	is a round node
P_BEZIER	is a bezier node
P_SPOINT	is a spline control point node
P_BPOINT	is a bezier control point node
P_POINT	is a point node
P_ARC	is an arc (only for round node)
P_CIRCLE	is a cirlipse (only for round node)
IS_PHANTOM	is a phantom (only for round node)
IS_CLOSED	is a closed (only for curve node)
IS_HOLE	is a hole (only for cirlipses, polygons and closed curves)
IS_REVERSED	node normal is to be reversed in direction from computed setting (polygons only)
IS_SINGLE	Bezier curve only: Bezier curve is drawn with single degree of control
IS_DELETED	has been deleted

Field descriptions:

bits	see description above
id	a number which uniquely identifies a primitive within its parent object
next_node	pointer to the next primitive.
prev_node	pointer to the previous primitive.
parent	pointer to the object containing the primitive. (Not used for polygon and polyline nodes.)

ROUND_NODE
   {
   // Common PRIM_NODE section omitted
   PRIM_NODE *first_hole;
   SS_XYZ horizontal;
   SS_XYZ vertical;
   double start_angle;
   double stop_angle;
   SURFACE_NODE *sn;
   RGB surface_rgb;
   RGB round_rgb;
   int unused2;
   int unused3;
   VERTEX center;
   int unused4;
   TEXTURE_DATA *texture;
   };

Field descriptions:

first_hole	pointer to first hole (applicable only to cirlipses)
horizontal	displacement from the center indicating the horizontal direction of the cirlipse or arc
vertical	displacement from the center indicating the vertical direction of the cirlipse or arc
start_angle	start angle in radians (applicable only to arcs)
stop_angle	stop angle in radians (applicable only to arcs)
sn	pointer to surface information (possibly NULL)
surface_rgb	surface color (applicable only to cirlipses)
round_rgb	edge color
center	vertex number of the center point
texture	pointer to texture data (possibly NULL)

POLYGON_NODE
   {
   // Common PRIM_NODE section omitted
   PRIM_NODE *first_hole;
   SURFACE_NODE *sn;
   RGB surface_rgb;
   int unused;
   PRIM_NODE *first_node;
   PRIM_NODE *first_phantom;
   TEXTURE_DATA *texture;
   };

Field descriptions:

first_hole	pointer to first hole
sn	pointer to surface information (possibly NULL)
surface_rgb	surface color
first_node	pointer to first node in polygon
first_phantom	pointer to first phantom the polygon
texture	pointer to texture data (possibly NULL)

POINT_NODE
   {
   // Common PRIM_NODE section omitted
   VERTEX point;
   int type;
   int unused2;
   double size;
   RGB line_rgb;
   };

Field descriptions:

point	vertex number
type	possible values: 0: common point 1: XY-point 2: YZ-point 3: ZX-point 4: triad point
size	width of the point (if not type 0).
line_rgb	color of the point and the lines.

CURVE_NODE
   {
   // Common PRIM_NODE section omitted
   PRIM_NODE *first_hole;
   SURFACE_NODE *sn;
   RGB surface_rgb;
   int unused4;
   int unused3;
   RGB line_rgb;
   PRIM_NODE *first_point;
   TEXTURE_DATA *texture;
   };

Field descriptions:

first_hole	pointer to first hole (only if closed)
sn	pointer to surface information (possibly NULL)
surface_rgb	surface color (only if closed)
line_rgb	line color
first_point	pointer to first node in curve
texture	pointer to texture data (possibly NULL)

FONT_NODE
   {
   int font_type;
   FILE_NAME font_name;
   USINT style;
   FILE_NAME screen_font_name;
   USINT screen_style;
   int space_out;
   BOS_NODE **the_chars;
   int first_char;
   int last_char;
   int default_char;
   double unused;
   FONT_NODE *next_font;
   };

Field descriptions:

font_name	name of font
style	style of font
screen_font_name	alternate screen font
screen_style	alternate screen style
space_out	TRUE for monospaced fonts
the_chars	an array of BOS_NODE pointers to represent characters
first_char	index of first character in array
last_char	index of last character in array
default_char	index of default character in array
next_font	pointer to next FONT_NODE

TAG_NODE
   {
   int type;
   NAME name;
   union
      {
      double tag_double;
      XYZ tag_xyz;
      char *tag_text;
      } data;
   TAG_NODE *next_tag;
   };

Field descriptions:

type	indicates data type contained in data
name	tag_double: value if type is DOUBLE_TAG tag_xyz: value if type is XYZ_TAG tag_text: value if type is TEXT_TAG
next_tag	pointer to next TAG_NODE

LIGHT_NODE
   {
   int type;
   int enabled;
   NAME light_name;
   char *light_shader;
   XYZ location;
   XYZ direction;
   double exponent;
   double constant_attenuation;
   double linear_attenuation;
   double quadratic_attenuation;
   double cone_angle;
   RGB light_rgb;
   LIGHT_NODE *next_light;
   };

Field descriptions:

type	type of light source
enabled	TRUE if light is enabled
light_name	name of light source
light_shader
location	location of light source
direction	vector indicating direction of light
exponent	exponent for light decrease with distance
constant_attenuation	three attenuation parameters
linear_attenuation
quadratic_attenuation
cone_angle	cone angle for cone light sources
light_rgb	color of light source
next_light	pointer to next LIGHT_NODE

typedef struct
   {
   int bits;
   int ambient_diffusion;
   int diffusion;
   int spectral_intensity;
   int spectral_power;
   double opacity;
   RGB spectral_color;
   } SURFACE_NODE;

Field descriptions:

bits	(bits & CASTS_A_SHADOW ): surface casts a shadow
ambient_diffusion	percentage of ambient light reflected by surface
diffusion	percentage of non-ambient light reflected by surface
spectral_intensity	percentage of spectral reflectance exhibited by surface
spectral_power	crispness of spectral reflection (range 1 - 200)
opacity	percentage of opacity of this surface (red, green, and blue components may be extracted with RED_COLOR, GREEN_COLOR, and BLUE_COLOR macros)
spectral_color	color of specular reflection

MODEL_NODE
   {
   int unused;
   NAME name;
   SS_XYZ high;
   SS_XYZ low;
   FILE_NAME library_name[12];
   BLOCK_NODE *root;
   MODEL_NODE *next_model;
   int high_low_set;
   };

Field descriptions:

name	name of the model
high	maximum values of the model in model space
low	minimum values of the model in model space
library_name	name of the library containing the model
root	block containing the geometry for the model
next_model	pointer to the next model of the drawing
high_low_set	TRUE if the extents for the model are set

ATTRIBUTE_NODE
   {
   int bits;
   int precision;
   double the_double;
   NAME name;
   char *value;
   ATTRIBUTE_NODE *next_attribute;
   };

Field descriptions:

bits	(bits & 0x0001): string value (bits & 0x0002): numeric value
precision	display precision for attribute
numeric_value	value if numeric
name	name of attribute
string_value	value if string
next_attribute	pointer to next attribute

BOS_NODE	information common to all entity nodes
BLOCK_NODE	block information
OBJECT_NODE	object information
SYMBOL_NODE	symbol information
TEXT_NODE	text node for both stroke and TrueType text