Coordinate Transformations

If you call more than one of these methods, the PDF specification recommends calling them in the following order: translate, rotate, scale, skew. Each change builds on the last, and you can get unexpected results when calling them in a different order.

CAUTION: a text object ($content) behaves a bit differently. Individual translate, rotate, scale, and skew calls cancel out any previous settings. If you want to combine multiple transformations for text, use the "transform" call.

$content->translate($dx,$dy)

Moves the origin along the x and y axes by $dx and $dy respectively.

$content->rotate($degrees)

Rotates the coordinate system counter-clockwise (anti-clockwise) around the current origin. Use a negative argument to rotate clockwise. Note that 360 degrees will be treated as 0 degrees.

Note: Unless you have already moved (translated) the origin, it is, and will remain, at the lower left corner of the visible sheet. It will not automatically shift to another corner. For example, a rotation of +90 degrees (counter-clockwise) will leave the entire visible sheet in negative Y territory (0 at the left edge, -original_width at the right edge), while X remains in positive territory (0 at bottom, +original_height at the top edge).

This "rotate()" call permits any angle. Do not confuse it with the page rotation "rotate" call, which only permits increments of 90 degrees (with opposite sign!), but does shift the origin to another corner of the sheet.

$content->scale($sx,$sy)

Scales (stretches) the coordinate systems along the x and y axes. Separate multipliers are provided for x and y.

$content->skew($skx,$sky)

Skews the coordinate system by $skx degrees (counter-clockwise/anti-clockwise) from the x axis and $sky degrees (clockwise) from the y axis. Note that 360 degrees will be treated the same as 0 degrees.

$content->transform(%opts)

Use one or more of the given %opts:

    $content->transform(
        -translate => [$dx,$dy],
        -rotate    => $degrees,
        -scale     => [$sx,$sy],
        -skew      => [$skx,$sky],
        -matrix    => [$a, $b, $c, $d, $e, $f],
        -point     => [$x,$y]
    )
    

A six element list may be given ("-matrix") for a further transformation matrix:

    $a = cos(rot) * scale factor for X 
    $b = sin(rot) * tan(skew for X)
    $c = -sin(rot) * tan(skew for Y)
    $d = cos(rot) * scale factor for Y 
    $e = translation for X
    $f = translation for Y
    

Performs multiple coordinate transformations at once, in the order recommended by the PDF specification (translate, rotate, scale, skew). This is equivalent to making each transformation separately, in the indicated order. A matrix of 6 values may also be given ("-matrix"). The transformation matrix is updated. A "-point" may be given (a point to be multiplied [transformed] by the completed matrix).

$content->transform_rel(%opts)

Makes transformations similarly to "transform", except that it adds to the previously set values, rather than replacing them (except for scale, which multiplies the new values with the old).

Unlike "transform", "-matrix" and "-point" are not supported.

$content->matrix($a, $b, $c, $d, $e, $f)

(Advanced) Sets the current transformation matrix manually. Unless you have a particular need to enter transformations manually, you should use the "transform" method instead.

 $a = cos(rot) * scale factor for X 
 $b = sin(rot) * tan(skew for X)
 $c = -sin(rot) * tan(skew for Y)
 $d = cos(rot) * scale factor for Y 
 $e = translation for X
 $f = translation for Y
    

In text mode, the text matrix is returned. In graphics mode, $self is returned.

Graphics State Parameters

$content->linewidth($width)

Sets the width of the stroke. This is the line drawn in graphics mode, or the outline of a character in text mode (with appropriate "render" mode). If no $width is given, the current setting is returned. If the width is being set, $self is returned so that calls may be chained.

$content->linecap($style)

Sets the style to be used at the end of a stroke. This applies to lines which come to a free-floating end, not to "joins" ("corners") in polylines (see "linejoin").

$content->linejoin($style)

Sets the style of join to be used at corners of a path (within a multisegment polyline).

$content->miterlimit($ratio)

Sets the miter limit when the line join style is a miter join.

The ratio is the maximum length of the miter (inner to outer corner) divided by the line width. Any miter above this ratio will be converted to a bevel join. The practical effect is that lines meeting at shallow angles are chopped off instead of producing long pointed corners.

The default miter limit is 10.0 (approximately 11.5 degree cutoff angle). The smaller the limit, the larger the cutoff angle.

If no $ratio is given, the current setting is returned. If the ratio is being set, $self is returned so that calls may be chained.

$content->linedash()

$content->linedash($length)

$content->linedash($dash_length, $gap_length, ...)

$content->linedash(-pattern => [$dash_length, $gap_length, ...], -shift => $offset)

Sets the line dash pattern.

If called without any arguments, a solid line will be drawn.

If called with one argument, the dashes and gaps (strokes and spaces) will have equal lengths.

If called with two or more arguments, the arguments represent alternating dash and gap lengths.

If called with a hash of arguments, the -pattern array may have one or more elements, specifying the dash and gap lengths. A dash phase may be set (-shift), which is a positive integer specifying the distance into the pattern at which to start the dashed line. Note that if you wish to give a shift amount, using "-shift", you need to use "-pattern" instead of one or two elements.

If an odd number of dash array elements are given, the list is repeated by the reader software to form an even number of elements (pairs).

If a single argument of -1 is given, the current setting is returned. This is an array consisting of two elements: an anonymous array containing the dash pattern (default: empty), and the shift (offset) amount (default: 0). If the dash pattern is being set, $self is returned so that calls may be chained.

$content->flatness($tolerance)

(Advanced) Sets the maximum variation in output pixels when drawing curves. The defined range of $tolerance is 0 to 100, with 0 meaning use the device default flatness. According to the PDF specification, you should not try to force visible line segments (the curve's approximation); results will be unpredictable. Usually, results for different flatness settings will be indistinguishable to the eye.

The $tolerance value is silently clamped to be between 0 and 100.

If no $tolerance is given, the current setting is returned. If the tolerance is being set, $self is returned so that calls may be chained.

$content->egstate($object)

(Advanced) Adds an Extended Graphic State object containing additional state parameters.

Path Construction (Drawing)

$content->move($x,$y)

Starts a new path at the specified coordinates. Note that multiple x,y pairs can be given, although this isn't that useful (only the last pair would have an effect).

$content->close()

Closes and ends the current path by extending a line from the current position to the starting position.

$content->endpath()

Ends the current path without explicitly enclosing it. That is, unlike "close", there is no line segment drawn back to the starting position.

Straight line constructs

Note: None of these will actually be visible until you call "stroke" or "fill". They are merely setting up the path to draw.

$content->line($x,$y)

$content->line($x,$y, $x2,$y2,...)

Extends the path in a line from the current coordinates to the specified coordinates, and updates the current position to be the new coordinates.

Multiple additional "[$x,$y]" pairs are permitted, to draw joined multiple line segments. Note that this is not equivalent to a polyline (see "poly"), because the first "[$x,$y]" pair in a polyline is a move operation. Also, the "linecap" setting will be used rather than the "linejoin" setting for treating the ends of segments.

$content->hline($x)

$content->vline($y)

Shortcuts for drawing horizontal and vertical lines from the current position. They are like "line()", but to the new x and current y ("hline"), or to the the current x and new y ("vline").

$content->poly($x1,$y1, ..., $xn,$yn)

This is a shortcut for creating a polyline path. It moves to "[$x1,$y1]", and then extends the path in line segments along the specified coordinates. The current position is changed to the last "[$x,$y]" pair given.

The difference between a polyline and a "line" with multiple "[$x,$y]" pairs is that the first pair in a polyline are a move, while in a line they are a draw. Also, "linejoin" instead of "linecap" is used to control the appearance of the ends of line segments.

$content->rect($x,$y, $w,$h)

$content->rect($x1,$y1, $w1,$h1, ..., $xn,$yn, $wn,$hn)

This creates paths for one or more rectangles, with their lower left points at "[$x,$y]" and specified widths (+x direction) and heights (+y direction). Negative widths and heights are permitted, which draw to the left (-x) and below (-y) the given corner point, respectively. The current position is changed to the "[$x,$y]" of the last rectangle given. Note that this is the starting point of the rectangle, not the end point.

$content->rectxy($x1,$y1, $x2,$y2)

This creates a rectangular path, with "[$x1,$y1]" and "[$x2,$y2]" specifying opposite corners. They can be Lower Left and Upper Right, or Upper Left and Lower Right, in either order, so long as they are diagonally opposite each other. The current position is changed to the "[$x1,$y1]" (first) pair.

Curved line constructs

Note: None of these will actually be visible until you call "stroke" or "fill". They are merely setting up the path to draw.

$content->circle($xc,$yc, $radius)

This creates a circular path centered on "[$xc,$yc]" with the specified radius. It does not change the current position.

$content->ellipse($xc,$yc, $rx,$ry)

This creates a closed elliptical path centered on "[$xc,$yc]", with axis radii (semidiameters) specified by $rx (x axis) and $ry (y axis), respectively. It does not change the current position.

$content->arc($xc,$yc, $rx,$ry, $alpha,$beta, $move, $dir)

$content->arc($xc,$yc, $rx,$ry, $alpha,$beta, $move)

This extends the path along an arc of an ellipse centered at "[$xc,$yc]". The semidiameters of the elliptical curve are $rx (x axis) and $ry (y axis), respectively, and the arc sweeps from $alpha degrees to $beta degrees. The current position is then set to the endpoint of the arc.

Set $move to a true value if this arc is the beginning of a new path instead of the continuation of an existing path. Either way, the current position will be updated to the end of the arc. Use "$rx == $ry" for a circular arc.

The optional $dir arc sweep direction defaults to 0 (false), for a counter-clockwise/anti-clockwise sweep. Set to 1 (true) for a clockwise sweep.

$content->pie($xc,$yc, $rx,$ry, $alpha,$beta, $dir)

$content->pie($xc,$yc, $rx,$ry, $alpha,$beta)

Creates a pie-shaped path from an ellipse centered on "[$xc,$yc]". The x-axis and y-axis semidiameters of the ellipse are $rx and $ry, respectively, and the arc sweeps from $alpha degrees to $beta degrees. It does not change the current position. Depending on the sweep angles and direction, this can draw either the pie "slice" or the remaining pie (with slice removed). Use "$rx == $ry" for a circular pie. Use a different "[$xc,$yc]" for the slice, to offset it from the remaining pie.

The optional $dir arc sweep direction defaults to 0 (false), for a counter-clockwise/anti-clockwise sweep. Set to 1 (true) for a clockwise sweep.

This is a shortcut to draw a section of elliptical (or circular) arc and connect it to the center of the ellipse or circle, to form a pie shape.

$content->curve($cx1,$cy1, $cx2,$cy2, $x,$y)

This extends the path in a curve from the current point to "[$x,$y]", using the two specified control points to create a cubic Bezier curve, and updates the current position to be the new point ("[$x,$y]").

Within a text object, the text's baseline follows the Bezier curve.

Note that while multiple sets of three "[x,y]" pairs are permitted, these are treated as independent cubic Bezier curves. There is no attempt made to smoothly blend one curve into the next!

$content->qbspline($cx1,$cy1, $x,$y)

This extends the path in a curve from the current point to "[$x,$y]", using the two specified points to create a quadratic Bezier curve, and updates the current position to be the new point.

Internally, these splines are one or more cubic Bezier curves (see "curve") with the two control points synthesized from the two given points (a control point and the end point of a quadratic Bezier curve).

Note that while multiple sets of two "[x,y]" pairs are permitted, these are treated as independent quadratic Bezier curves. There is no attempt made to smoothly blend one curve into the next!

Further note that this "spline" does not match the common definition of a spline being a continuous curve passing through all the given points! It is a piecewise non-continuous cubic Bezier curve. Use with care, and do not make assumptions about splines for you or your readers. You may wish to use the "bspline" call to have a continuously smooth spline to pass through all given points.

Pairs of points (control point and end point) are consumed in a loop. If one point or coordinate is left over at the end, it is discarded (as usual practice for excess data to a routine). There is no check for duplicate points or other degeneracies.

$content->bspline($ptsRef, %opts)

$content->bspline($ptsRef)

This extends the path in a curve from the current point to the end of a list of coordinate pairs in the array referenced by $ptsRef. Smoothly continuous cubic Bezier splines are used to create a curve that passes through all the given points. Multiple control points are synthesized; they are not supplied in the call. The current position is updated to the last point.

Internally, these splines are one cubic Bezier curve (see "curve") per pair of input points, with the two control points synthesized from the tangent through each point as set by the polyline that would connect each point to its neighbors. The intent is that the resulting curve should follow reasonably closely a polyline that would connect the points, and should avoid any major excursions. See the discussions below for the handling of the control points at the endpoints (current point and last input point). The point at the end of the last line or curve drawn becomes the new current point.

%opts

Special cases

Adjacent points which are duplicates are consolidated. An extra coordinate at the end of the input point list (not a full "[x,y]" pair) will, as usual, be ignored.

0 given points (after duplicate consolidation)

This leaves only the current point (unchanged), so it is a no-op.

1 given point (after duplicate consolidation)

This leaves the current point and one point, so it is rendered as a line, regardless of %opt flags.

2 given points (after duplicate consolidation)

This leaves the current point, an intermediate point, and the end point. If the three points are colinear, two line segments will be drawn. Otherwise, both segments are curves (through the tangent at the intermediate point). If either end segment mode is requested to be a line or constraint, it is treated as a line1 mode request instead.

N colinear points at beginning or end

N colinear points at beginning or end of the point set causes N-1 line segments ("line2" or "constraint2", regardless of the settings of "-firstseg", "-lastseg", and "-colinear".

$content->bogen($x1,$y1, $x2,$y2, $radius, $move, $larger, $reverse)

$content->bogen($x1,$y1, $x2,$y2, $radius, $move, $larger)

$content->bogen($x1,$y1, $x2,$y2, $radius, $move)

$content->bogen($x1,$y1, $x2,$y2, $radius)

(German for bow, as in a segment (arc) of a circle. This is a segment of a circle defined by the intersection of two circles of a given radius, with the two intersection points as inputs. There are four possible resulting arcs, which can be selected with $larger and $reverse.)

This extends the path along an arc of a circle of the specified radius between "[$x1,$y1]" to "[$x2,$y2]". The current position is then set to the endpoint of the arc ("[$x2,$y2]").

Set $move to a true value if this arc is the beginning of a new path instead of the continuation of an existing path. Note that the default ($move = false) is not a straight line to P1 and then the arc, but a blending into the curve from the current point. It will often not pass through P1!

Set $larger to a true value to draw the larger ("outer") arc between the two points, instead of the smaller one. Both arcs are drawn clockwise from P1 to P2. The default value of false draws the smaller arc.

Set $reverse to a true value to draw the mirror image of the specified arc (flip it over, so that its center point is on the other side of the line connecting the two points). Both arcs are drawn counter-clockwise from P1 to P2. The default (false) draws clockwise arcs.

The $radius value cannot be smaller than half the distance from "[$x1,$y1]" to "[$x2,$y2]". If it is too small, the radius will be set to half the distance between the points (resulting in an arc that is a semicircle). This is a silent error.

Path Painting (Drawing)

$content->stroke()

Strokes the current path.

$content->fill($use_even_odd_fill)

Fill the current path's enclosed area. It does not stroke the enclosing path around the area.

If the path intersects with itself, the nonzero winding rule will be used to determine which part of the path is filled in. This basically fills in everything inside the path. If you would prefer to use the even-odd rule, pass a true argument. This basically will fill alternating closed sub-areas.

See the PDF Specification, section 8.5.3.3, for more details on filling.

$content->fillstroke($use_even_odd_fill)

Fill the enclosed area and then stroke the current path.

$content->clip($use_even_odd_fill)

$content->clip()

Modifies the current clipping path by intersecting it with the current path. Initially (a fresh page), the clipping path is the entire media. Each definition of a path, and a "clip()" call, intersects the new path with the existing clip path, so the resulting clip path is no larger than the new path, and may even be empty if the intersection is null.

If any $use_even_odd_fill parameter is given, use even-odd fill (W*) instead of winding-rule fill (W). It is common usage to make the "endpath()" call (n) after the "clip()" call, to clear the path (unless you want to reuse that path, such as to fill and/or stroke it to show the clip path). If you want to clip text glyphs, it gets rather complicated, as a clip port cannot be created within a text object (that will have an effect on text). See the object discussion in "Rendering Order" in PDF::Builder::Docs.

 my $grfxC1 = $page->gfx();
 my $textC  = $page->text();
 my $grfxC2 = $page->gfx();
  ...
 $grfxC1->save();
 $grfxC1->endpath();
 $grfxC1->rect(...);
 $grfxC1->clip();
 $grfxC1->endpath();
  ...
 $textC->  output text to be clipped
  ...
 $grfxC2->restore();
    

Colors

$content->fillcolor($color)

$content->strokecolor($color)

Sets the fill (enclosed area) or stroke (path) color. The interior of text characters are filled, and (if ordered by "render") the outline is stroked.

    # Use a named color
    # -> RGB color model
    # there are many hundreds of named colors defined in 
    # PDF::Builder::Resource::Colors
    $content->fillcolor('blue');

    # Use an RGB color (# followed by 3, 6, 9, or 12 hex digits)
    # -> RGB color model
    # This maps to 0-1.0 values for red, green, and blue
    $content->fillcolor('#FF0000');   # red

    # Use a CMYK color (% followed by 4, 8, 12, or 16 hex digits)
    # -> CMYK color model
    # This maps to 0-1.0 values for cyan, magenta, yellow, and black
    $content->fillcolor('%FF000000');   # cyan

    # Use an HSV color (! followed by 3, 6, 9, or 12 hex digits)
    # -> RGB color model
    # This maps to 0-360 degrees for the hue, and 0-1.0 values for 
    # saturation and value
    $content->fillcolor('!FF0000');

    # Use an HSL color (& followed by 3, 6, 9, or 12 hex digits)
    # -> L*a*b color model
    # This maps to 0-360 degrees for the hue, and 0-1.0 values for 
    # saturation and lightness. Note that 360 degrees = 0 degrees (wraps)
    $content->fillcolor('&FF0000');

    # Use an L*a*b color ($ followed by 3, 6, 9, or 12 hex digits)
    # -> L*a*b color model
    # This maps to 0-100 for L, -100 to 100 for a and b
    $content->fillcolor('$FF0000');
    

In all cases, if too few digits are given, the given digits are silently right-padded with 0's (zeros). If an incorrect number of digits are given, the next lowest number of expected digits are used, and the remaining digits are silently ignored.

    # A single number between 0.0 (black) and 1.0 (white) is an alternate way
    # of specifying a gray scale.
    $content->fillcolor(0.5);

    # Three array elements between 0.0 and 1.0 is an alternate way of specifying
    # an RGB color.
    $content->fillcolor(0.3, 0.59, 0.11);

    # Four array elements between 0.0 and 1.0 is an alternate way of specifying
    # a CMYK color.
    $content->fillcolor(0.1, 0.9, 0.3, 1.0);
    

In all cases, if a number is less than 0, it is silently turned into a 0. If a number is greater than 1, it is silently turned into a 1. This "clamps" all values to the range 0.0-1.0.

    # A single reference is treated as a pattern or shading space.

    # Two or more entries with the first element a Perl reference, is treated 
    # as either an indexed colorspace reference plus color-index(es), or 
    # as a custom colorspace reference plus parameter(s).
    

If no value was passed in, the current fill color (or stroke color) array is returned, otherwise $self is returned.

$content->shade($shade, @coord)

Sets the shading matrix.

External Objects

$content->image($image_object, $x,$y, $width,$height)

$content->image($image_object, $x,$y, $scale)

$content->image($image_object, $x,$y)

$content->image($image_object)

    # Example
    my $image_object = $pdf->image_jpeg($my_image_file);
    $content->image($image_object, 100, 200);
    

Places an image on the page in the specified location (specifies the lower left corner of the image). The default location is "[0,0]".

If coordinate transformations have been made (see Coordinate Transformations above), the position and scale will be relative to the updated coordinates. Otherwise, "[0,0]" will represent the bottom left corner of the page, and $width and $height will be measured at 72dpi.

For example, if you have a 600x600 image that you would like to be shown at 600dpi (i.e., one inch square), set the width and height to 72. (72 Big Points is one inch)

$content->formimage($form_object, $x,$y, $scaleX, $scaleY)

$content->formimage($form_object, $x,$y, $scale)

$content->formimage($form_object, $x,$y)

$content->formimage($form_object)

Places an XObject on the page in the specified location (giving the lower left corner of the image) and scale (applied to the image's native height and width). If no scale is given, use 1 for both X and Y. If one scale is given, use for both X and Y. If two scales given, they are for (separately) X and Y. In general, you should not greatly distort an image by using greatly different scaling factors in X and Y, although it is now possible for when that effect is desirable. The "$x,$y" default is "[0,0]".

Note that while this method is named form image, it is also used for the pseudoimages created by the barcode routines. Images are naturally dimensionless (1 point square) and need at some point to be scaled up to the desired point size. Barcodes are naturally sized in points, and should be scaled at approximately 1. Therefore, it would greatly overscale barcodes to multiply by image width and height within "formimage", and require scaling of 1/width and 1/height in the call. So, we leave scaling alone within "formimage" and have the user manually scale images by the image width and height (in pixels) in the call to "formimage".

Text

All of the following parameters that take a size are applied before any scaling takes place, so you don't need to adjust values to counteract scaling.

$spacing = $content->charspace($spacing)

Sets additional spacing between characters in a line. This is in points, and is initially zero. It may be positive to give an expanded effect to words, or it may be negative to give a condensed effect to words. If $spacing is given, the current setting is replaced by that value and $self is returned (to permit chaining). If $spacing is not given, the current setting is returned.

CAUTION: be careful about using "charspace" if you are using a connected font. This might include Arabic, Devanagari, Latin cursive handwriting, and so on. You don't want to leave gaps between characters, or cause overlaps. For such fonts and typefaces, set the "charspace" spacing to 0.

$spacing = $content->wordspace($spacing)

Sets additional spacing between words in a line. This is in points and is initially zero (i.e., just the width of the space, without anything extra). It may be negative to close up sentences a bit. If $spacing is given, the current setting is replaced by that value and $self is returned (to permit chaining). If $spacing is not given, the current setting is returned.

Note that it is a limitation of the PDF specification (as of version 1.7, section 9.3.3) that only spacing with an ASCII space (x20) is adjusted. Neither required blanks (xA0) nor any multiple-byte spaces (including thin and wide spaces) are currently adjusted.

$scale = $content->hscale($scale)

Sets the percentage of horizontal text scaling (relative sizing, not spacing). This is initally 100 (percent, i.e., no scaling). A scale of greater than 100 will stretch the text, while less than 100 will compress it. If $scale is given, the current setting is replaced by that value and $self is returned (to permit chaining). If $scale is not given, the current setting is returned.

Note that scaling affects all of the character widths, interletter spacing, and interword spacing. It is inadvisable to stretch or compress text by a large amount, as it will quickly make the text unreadable. If your objective is to justify text, you will usually be better off using "charspace" and "wordspace" to expand (or slightly condense) a line to fill a desired width. Also see the "text_justify()" calls for this purpose.

$leading = $content->leading($leading)

$leading = $content->leading()

Sets the text leading, which is the distance between baselines. This is initially zero (i.e., the lines will be printed on top of each other). The unit of leading is points. If $leading is given, the current setting is replaced by that value and $self is returned (to permit chaining). If $leading is not given, the current setting is returned.

Note that "leading" here is defined as used in electronic typesetting and the PDF specification, which is the full interline spacing (text baseline to text baseline distance, in points). In cold metal typesetting, leading was usually the extra spacing between lines beyond the font height itself, created by inserting lead (type alloy) shims.

$leading = $content->lead($leading)

$leading = $content->lead()

Deprecated, to be removed after March 2023. Use "leading()" now.

Note that the "$self-"{' lead'}> internal variable is no longer available, having been replaced by "$self-"{' leading'}>.

$mode = $content->render($mode)

Sets the text rendering mode.

$dist = $content->rise($dist)

Adjusts the baseline up or down from its current location. This is initially zero. A $dist greater than 0 moves the baseline up the page (y increases).

Use this for creating superscripts or subscripts (usually along with an adjustment to the font size). If $dist is given, the current setting is replaced by that value and $self is returned (to permit chaining). If $dist is not given, the current setting is returned.

%state = $content->textstate(charspace => $value, wordspace => $value, ...)

This is a shortcut for setting multiple text state parameters at once. If any parameters are set, an empty hash is returned. This can also be used without arguments to retrieve the current text state settings (a hash of the state is returned).

Note: This does not work with the "save" and "restore" commands.

$content->font($font_object, $size)

Sets the font and font size.

    # Example (12 point Helvetica)
    my $pdf = PDF::Builder->new();
    my $fontname = $pdf->corefont('Helvetica');
    $content->font($fontname, 12);
    

Positioning Text

$content->distance($dx,$dy)

This moves to the start of the previously-written line, plus an offset by the given amounts, which are both required. "[0,0]" would overwrite the previous line, while "[0,36]" would place the new line 36pt above the old line (higher y). The $dx moves to the right, if positive.

"distance" is analogous to graphic's "move", except that it is relative to the beginning of the previous text write, not to the coordinate origin. Note that subsequent text writes will be relative to this new starting (left) point and Y position! E.g., if you give a non-zero $dx, subsequent lines will be indented by that amount.

$content->cr()

$content->cr($vertical_offset)

$content->cr(0)

If passed without an argument, moves (down) to the start of the next line (distance set by "leading"). This is similar to "nl()".

If passed with an argument, the "leading" distance is ignored and the next line starts that far up the page (positive value) or down the page (negative value) from the current line. "Y" increases upward, so a negative value would normally be used to get to the next line down.

An argument of 0 would simply return to the start of the present line, overprinting it with new text. That is, it acts as a simple carriage return, without a linefeed.

$content->nl()

$content->nl($indent)

$content->nl(0)

Moves to the start of the next line (see "leading"). If $indent is not given, or is 0, there is no indentation. Otherwise, indent by that amount (outdent if a negative value). The unit of measure is hundredths of a "unit of text space", or roughly 88 per em.

($tx,$ty) = $content->textpos()

Returns the current text position on the page (where next write will happen) as an array.

Note: This does not affect the PDF in any way. It only tells you where the the next write will occur.

$width = $content->advancewidth($string, %opts)

$width = $content->advancewidth($string)

Options %opts:

Rendering Text

Single Lines

$width = $content->text($text, %opts)

$width = $content->text($text)

Adds text to the page (left justified). The width used (in points) is returned.

Options:

$width = $content->textHS($HSarray, $settings, %opts)

$width = $content->textHS($HSarray, $settings)

Takes an array of hashes produced by HarfBuzz::Shaper and outputs them to the PDF output file. HarfBuzz outputs glyph CIDs and positioning information. It may rearrange and swap characters (glyphs), and the result may bear no resemblance to the original Unicode point list. You should see examples/HarfBuzz.pl, which shows a number of examples with Latin and non-Latin text, as well as vertical writing. examples/resources/HarfBuzz_example.pdf is available in case you want to see some examples and don't yet have HarfBuzz::Shaper installed.

$width = $content->advancewidthHS($HSarray, $settings, %opts)

$width = $content->advancewidthHS($HSarray, $settings)

Returns text chunk width (in points) for Shaper-defined glyph array. This is the horizontal width for LTR and RTL direction, and the vertical height for TTB and BTT direction. Note: You must define the font and font size before calling "advancewidthHS()".

Advanced Methods

$content->save()

Saves the current graphics state on a PDF stack. See PDF definition 8.4.2 through 8.4.4 for details. This includes the line width, the line cap style, line join style, miter limit, line dash pattern, stroke color, fill color, current transformation matrix, current clipping port, flatness, and dictname. This method applies to both text and gfx objects.

$content->restore()

Restores the most recently saved graphics state (see "save"), removing it from the stack. You cannot restore the graphics state (pop it off the stack) unless you have done at least one save (pushed it on the stack). This method applies to both text and gfx objects.

$content->add(@content)

Add raw content (arbitrary string(s)) to the PDF stream. You will generally want to use the other methods in this class instead, unless this is in order to implement some PDF operation that PDF::Builder does not natively support. An array of multiple strings may be given; they will be concatenated with spaces between them.

Be careful when doing this, as you are dabbling in the black arts, directly setting PDF operations!

One interesting use is to split up an overly long object stream that is giving your editor problems when exploring a PDF file. Add a newline add("\n") every few hundred bytes of output or so, to do this. Note that you must use double quotes (quotation marks), rather than single quotes (apostrophes).

Use extreme care if inserting BT and ET markers into the PDF stream. You may want to use "textstart()" and "textend()" calls instead, and even then, there are many side effects either way. It is generally not useful to suspend text mode with ET/textend and BT/textstart, but it is possible, if you really need to do it.

Another, useful, case is when your input PDF is from the Chrome browser printing a page to PDF with headers and/or footers. In some versions, this leaves the PDF page with a strange scaling (such as the page height in points divided by 3300) and the Y-axis flipped so 0 is at the top. This causes problems when trying to add additional text or graphics in a new text or graphics record, where text is flipped (mirrored) upsidedown and at the wrong end of the page. If this happens, you might be able to cure it by adding

    $scale = .23999999; # example, 792/3300, examine PDF or experiment!
     ...
    if ($scale != 1) {
        my @pageDim = $page->mediabox();     # e.g., 0 0 612 792
        my $size_page = $pageDim[3]/$scale;  # 3300 = 792/.23999999
        my $invScale = 1.0/$scale;           # 4.16666684
        $text->add("$invScale 0 0 -$invScale 0 $size_page cm");
    }
    

as the first output to the $text stream. Unfortunately, it is difficult to predict exactly what $scale should be, as it may be 3300 units per page, or a fixed amount. You may need to examine an uncompressed PDF file stream to see what is being used. It might be possible to get the input (original) PDF into a string and look for a certain pattern of "cm" output

    .2399999 0 0 -.23999999 0 792 cm
    

or similar, which is not within a save/restore (q/Q). If the stream is already compressed, this might not be possible.

$content->addNS(@content)

Like "add()", but does not make sure there is a space between each element and before and after the new content. It is up to you to ensure that any necessary spaces in the PDF stream are placed there explicitly!

$content->compressFlate()

Marks content for compression on output. This is done automatically in nearly all cases, so you shouldn't need to call this yourself.

The "new()" call can set the -compress parameter to 'flate' (default) to compress all object streams, or 'none' to suppress compression and allow you to examine the output in an editor.

$content->textstart()

Starts a text object (ignored if already in a text object). You will likely want to use the "text()" method (text context, not text output) instead.

Note that calling this method, besides outputting a BT marker, will reset most text settings to their default values. In addition, BT itself will reset some transformation matrices.

$content->textend()

Ends a text object (ignored if not in a text object).

Note that calling this method, besides outputting an ET marker, will output any accumulated poststream content.