function Stroke($aImg)
{
// The way the path for the arrow is constructed is partly based
// on some heuristics. This is not an exact science but draws the
// path in a way that, for me, makes esthetic sence. For example
// if the start and end activities are very close we make a small
// detour to endter the target horixontally. If there are more
// space between axctivities then no suh detour is made and the
// target is "hit" directly vertical. I have tried to keep this
// simple. no doubt this could become almost infinitive complex
// and have some real AI. Feel free to modify this.
// This will no-doubt be tweaked as times go by. One design aim
// is to avoid having the user choose what types of arrow
// he wants.
// The arrow is drawn between (x1,y1) to (x2,y2)
$x1 = $this->ix1;
$x2 = $this->ix2;
$y1 = $this->iy1;
$y2 = $this->iy2;
// Depending on if the target is below or above we have to
// handle thi different.
if ($y2 > $y1) {
$arrowtype = ARROW_DOWN;
$midy = round(($y2 - $y1) / 2 + $y1);
if ($x2 > $x1) {
switch ($this->iPathType) {
case 0:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 1:
case 2:
case 3:
$c = array($x1, $y1, $x2, $y1, $x2, $y2);
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
//('Internal error: Unknown path type (='.$this->iPathType .') specified for link.');
exit(1);
break;
}
} else {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 2:
// Always extend out horizontally a bit from the first point
// If we draw a link back in time (end to start) and the bars
// are very close we also change the path so it comes in from
// the left on the activity
$c = array($x1, $y1, $x1 + $this->iPathExtend, $y1, $x1 + $this->iPathExtend, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($y2 - $midy < 6) {
$c = array($x1, $y1, $x1, $midy, $x2 - $this->iPathExtend, $midy, $x2 - $this->iPathExtend, $y2, $x2, $y2);
$arrowtype = ARROW_RIGHT;
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
//('Internal error: Unknown path type specified for link.');
exit(1);
break;
}
}
$arrow = new LinkArrow($x2, $y2, $arrowtype);
} else {
// Y2 < Y1
$arrowtype = ARROW_UP;
$midy = round(($y1 - $y2) / 2 + $y2);
if ($x2 > $x1) {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($midy - $y2 < 8) {
$arrowtype = ARROW_RIGHT;
$c = array($x1, $y1, $x1, $y2, $x2, $y2);
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
//('Internal error: Unknown path type specified for link.');
break;
}
} else {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 2:
// Always extend out horizontally a bit from the first point
$c = array($x1, $y1, $x1 + $this->iPathExtend, $y1, $x1 + $this->iPathExtend, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($midy - $y2 < 16) {
$arrowtype = ARROW_RIGHT;
$c = array($x1, $y1, $x1, $midy, $x2 - $this->iPathExtend, $midy, $x2 - $this->iPathExtend, $y2, $x2, $y2);
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
//('Internal error: Unknown path type specified for link.');
break;
}
}
$arrow = new LinkArrow($x2, $y2, $arrowtype);
}
$aImg->SetColor($this->iColor);
$aImg->SetLineWeight($this->iWeight);
$aImg->Polygon($c);
$aImg->SetLineWeight(1);
$arrow->SetColor($this->iColor);
$arrow->SetSize($this->iArrowSize);
$arrow->SetType($this->iArrowType);
$arrow->Stroke($aImg);
}
function Stroke(&$aImg)
{
$x1 = $this->ix1;
$x2 = $this->ix2;
$y1 = $this->iy1;
$y2 = $this->iy2;
if ($y2 > $y1) {
$arrowtype = ARROW_DOWN;
$midy = round(($y2 - $y1) / 2 + $y1);
if ($x2 > $x1) {
switch ($this->iPathType) {
case 0:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 1:
case 2:
case 3:
$c = array($x1, $y1, $x2, $y1, $x2, $y2);
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
exit(1);
break;
}
} else {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 2:
$c = array($x1, $y1, $x1 + $this->iPathExtend, $y1, $x1 + $this->iPathExtend, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($y2 - $midy < 6) {
$c = array($x1, $y1, $x1, $midy, $x2 - $this->iPathExtend, $midy, $x2 - $this->iPathExtend, $y2, $x2, $y2);
$arrowtype = ARROW_RIGHT;
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
exit(1);
break;
}
}
$arrow = new LinkArrow($x2, $y2, $arrowtype);
} else {
$arrowtype = ARROW_UP;
$midy = round(($y1 - $y2) / 2 + $y2);
if ($x2 > $x1) {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($midy - $y2 < 8) {
$arrowtype = ARROW_RIGHT;
$c = array($x1, $y1, $x1, $y2, $x2, $y2);
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
break;
}
} else {
switch ($this->iPathType) {
case 0:
case 1:
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
break;
case 2:
$c = array($x1, $y1, $x1 + $this->iPathExtend, $y1, $x1 + $this->iPathExtend, $midy, $x2, $midy, $x2, $y2);
break;
case 3:
if ($midy - $y2 < 16) {
$arrowtype = ARROW_RIGHT;
$c = array($x1, $y1, $x1, $midy, $x2 - $this->iPathExtend, $midy, $x2 - $this->iPathExtend, $y2, $x2, $y2);
} else {
$c = array($x1, $y1, $x1, $midy, $x2, $midy, $x2, $y2);
}
break;
default:
JpGraphError::RaiseL(6032, $this->iPathType);
break;
}
}
$arrow = new LinkArrow($x2, $y2, $arrowtype);
}
$aImg->SetColor($this->iColor);
$aImg->SetLineWeight($this->iWeight);
$aImg->Polygon($c);
$aImg->SetLineWeight(1);
$arrow->SetColor($this->iColor);
$arrow->SetSize($this->iArrowSize);
$arrow->SetType($this->iArrowType);
$arrow->Stroke($aImg);
}