ssfltlf2.qry

# ssfltlf2.qry
# This is a sample script to draw a right-lateral strike slip
# fault line symbol (dashed) with solid half-arrows.
# Modified for legend samples August 2002.
# Modified to declare all variables, October 2005
# Version Dec. 2007
# Requires TNTmips 2007:73 or later.
# Modified to adjust scale based on georeference map units and to
# place displacement symbols only at the center of the lines
numeric red, green, blue;
numeric scale, widthMap, width, dashMap, dashSize, halfDash, arrowLengthMap, arrowSize;
numeric flipSize, angle, headBase, offset, lineCheck;
numeric symbDrawn;	# flag to indicate whether arrow symbol has been drawn
class RVC_GEOREFERENCE vGeoref;
class SR_COORDREFSYS vectCRS;
class STRING coordUnit$;
###################### Set Parameters ##############################
# Red, green, blue variables define the color of the line
red = 255;			green = 0;			blue = 0;
# This variable defines the denominator of the intended map scale.
# It is used as the basis for defining line width and symbol size
# and spacing.
# Example: for 1:24,000 map scale, Scale = 24000
scale = 24000;
# This variable controls the width of the lines.
# WidthMap is the desired map width in mm, assuming vector
# coordinates are in meters.
widthMap = 0.3;
# This variable sets the length of the dashes
# DashMap is the desired dash length in mm, assuming vector
# coordinates are in meters:
dashMap = 3;
# These variables control the length of the arrows
# ArrowLengthMap is the desired arrow length in mm, assuming vector
# coordinates are in meters:
arrowLengthMap = 5;
# Check if vector has geographic coordinates (units of degrees instead of meters)
# and if so adjust scale factor to draw symbols of appropriate size.
Vect.GetDefaultGeoref(vGeoref);
vectCRS = vGeoref.GetCoordRefSys();
if (vectCRS.IsProjected() <> 1) {
	if (vectCRS.IsLocal() <> 1) {
		scale = scale * 0.000009;
		}
	}
else {	# CRS is projected; check coordinate units to adjust scale
	# get coordinate unit from the first axis of the planar coordinate system
	coordUnit$ = vectCRS.Coordsys.GetAxis(1).Unit.GetSymbol();
	scale = scale * GetUnitConvDist("m", coordUnit$);
	}
# set final dimensions for drawing
if (DrawingLegendView == 1) {		# set dimensions for LegendView based on sample size
	width = 0.1 * SampleRect.GetHeight();
	dashSize = 0.3 * SampleRect.GetHeight();
	arrowSize = 0.5 * SampleRect.GetWidth();
	}
else {		# set dimensions for drawing elements in view
	scale = scale / 1000;	# conversion from meters to millimeters
	width = widthMap * scale;
	dashSize = dashMap * scale;
	arrowSize = arrowLengthMap * scale;
	}
halfDash = dashSize * 0.5;
# This variable controls the length of the arrow head
flipSize = 0.4 * arrowSize;
# This variable controls the sweep angle of the arrow in degrees
angle = 30;	 # 30 degree angle
headBase = flipSize * sind(angle);
# This variable controls how far from the base line to draw arrows
offset = 0.2 * arrowSize;
# get length of line and set check location dashSize less than
# the midpoint; to be used to trigger placement of arrow symbols
lineCheck = (LineStyleGetDistanceTo(3) * 0.5) - dashSize;
######################## Process ###########################
# Set line color, width, and draw fault line.
LineStyleSetColor(red,green,blue);
LineStyleSetLineWidth(width);
# initialize flag indicating if arrow symbols have been drawn
symbDrawn = 0;
# draw dashed fault line with arrow symbols near middle
LineStyleRollPen(dashSize); # start line with dash
while (LineStyleRoll(halfDash) != 1) {	# while not at end of line roll length of half dash
	# draw arrow symbol when absolute position along line (in object units)
	# passes the check location near midpoint and set flag to indicate it has been drawn
	if (LineStyleGetPosition(1) > lineCheck && symbDrawn == 0 ) {
		# Draw dash between arrows
		LineStyleRollPen(halfDash);
		LineStyleDropAnchor(0);		# anchor at center of dash for centering arrows
		LineStyleRollPen(halfDash);
		# Draw first half-arrow
		LineStyleMoveToAnchor(0);
		LineStyleMoveTo(90, offset);
		LineStyleMoveTo(0, arrowSize * 0.5);	# move forward parallel to line to center arrows
		LineStyleRecordPolygon(1);				# start recording polygon vertices for arrow head
		LineStyleLineTo(180, arrowSize);		# draw arrow shaft backward parallel to line
		LineStyleDropAnchor(1);
		LineStyleMoveTo(angle, flipSize);	# arrowhead side
		LineStyleMoveTo(-90, headBase);		# arrowhead base
		LineStyleDrawPolygon(1);				# draw filled polygon
		# draw the other half-arrow
		LineStyleMoveToAnchor(1);
		LineStyleMoveTo(-90, 2 * offset);	# offset to other side of line
		LineStyleRecordPolygon(1);
		LineStyleLineTo(0, arrowSize);		# draw arrow shaft forward parallel to line
		LineStyleMoveTo(180 + angle, flipSize);
		LineStyleMoveTo(90, headBase);
		LineStyleDrawPolygon(1);
		symbDrawn = 1;
		}
	else {	# draw dash along line
		LineStyleRollPen(dashSize);
		}
	}