PDF generation with text, fonts, images, graphics, bookmarks, and compression. Create professional PDFs from scratch.

Overview

libharu is a free, cross-platform C library for generating PDF files. It supports text layout, built-in and TrueType fonts, JPEG and PNG images, vector graphics (lines, rectangles, circles, Bezier curves), outlines/bookmarks, and deflate compression.

Coordinate system: origin (0, 0) is the bottom-left corner of the page. 1 point = 1/72 inch. An A4 page is 595 × 842 points.

Quick Start

uses libharu;

var doc  := NewDoc();
EnableCompression(doc);
SetTitle(doc, 'My Report');
SetAuthor(doc, 'Alice');

var page := AddPage(doc);
SetPageSize(page, pdfA4, pdfPortrait);

var font := GetFont(doc, 'Helvetica-Bold');
SetFont(page, font, 24);
SetFillColorRGB(page, 0.2, 0.2, 0.7);
TextOut(page, 50, 780, 'Hello, PDF!');

var body := GetFont(doc, 'Times-Roman');
SetFont(page, body, 12);
SetFillColorRGB(page, 0, 0, 0);
TextRect(page, 50, 750, 545, 500,
  'This PDF was generated with libharu and PascalAI.',
  pdfAlignLeft);

SaveToFile(doc, '/tmp/report.pdf');
FreeDoc(doc);

Text Layout

var page := AddPage(doc);
SetPageSize(page, pdfA4, pdfPortrait);
var font := GetFont(doc, 'Helvetica');
SetFont(page, font, 14);
SetTextLeading(page, 20);  { 20pt line height }

BeginText(page);
MoveTextPos(page, 50, 750);
ShowText(page, 'Line 1');
NextLine(page);
ShowText(page, 'Line 2');
NextLine(page);
ShowText(page, 'Line 3');
EndText(page);

{ Measure text width before placing it }
var w := TextWidth(page, 'Centered heading');
var pageW := GetPageWidth(page);
TextOut(page, (pageW - w) / 2, 700, 'Centered heading');

Vector Graphics

{ Filled blue rectangle }
SetFillColorRGB(page, 0.15, 0.45, 0.85);
FillRect(page, 50, 600, 200, 40);

{ Red border rectangle }
SetStrokeColorRGB(page, 0.8, 0, 0);
SetLineWidth(page, 2);
Rectangle(page, 50, 550, 200, 40);
Stroke(page);

{ Dashed diagonal line }
SetDash(page, [8, 4], 0);
DrawLine(page, 50, 530, 545, 400);

{ Circle }
SetFillColorRGB(page, 0, 0.7, 0.3);
Circle(page, 300, 450, 30);
Fill(page);

Images

var img := LoadJpeg(doc, '/tmp/photo.jpg');
var iw  := GetImageWidth(img);
var ih  := GetImageHeight(img);

{ Draw image preserving aspect ratio, max 400pt wide }
var scale := 400.0 / iw;
DrawImage(page, img, 50, 300, 400, ih * scale);

{ PNG with transparency }
var logo := LoadPng(doc, '/tmp/logo.png');
DrawImage(page, logo, 450, 780, 80, 40);

Bookmarks (Outlines)

var page1 := AddPage(doc);
var page2 := AddPage(doc);
var page3 := AddPage(doc);

var ch1 := AddOutline(doc, 'Chapter 1');
SetOutlineDest(doc, ch1, page1);

var ch2 := AddOutline(doc, 'Chapter 2');
SetOutlineDest(doc, ch2, page2);

var sec := AddChildOutline(doc, ch2, 'Section 2.1');
SetOutlineDest(doc, sec, page3);

API Reference

Document

Function	Description
NewDoc	Create a new PDF document. Returns TPDFDoc.
FreeDoc(Doc)	Free document and all resources.
SaveToFile(Doc, Path)	Write PDF to file. Returns True on success.
SaveToBytes(Doc)	Return PDF as a byte string.
EnableCompression(Doc)	Enable deflate compression for all streams.
SetTitle/Author/Subject/Keywords(Doc, S)	Set metadata fields.

Pages

Function	Description
AddPage(Doc)	Append a new page. Returns TPDFPage.
InsertPage(Doc, Target)	Insert page before Target.
SetPageSize(Page, Size, Dir)	Standard size (pdfA4, pdfLetter, …) and orientation.
SetPageCustomSize(Page, W, H)	Custom size in points.
GetPageWidth/Height(Page)	Page dimensions in points.

Fonts & Text

Function	Description
GetFont(Doc, Name)	Load built-in font (Helvetica, Times-Roman, Courier, …).
LoadTTFFont(Doc, Path, Embed)	Load TrueType font from .ttf file.
SetFont(Page, Font, Size)	Set current font and size.
TextWidth(Page, Text)	Measure text width in points for the current font.
TextOut(Page, X, Y, Text)	Output text at absolute position.
TextRect(Page, L, T, R, B, Text, Align)	Wrapped text in a rectangle.
BeginText / EndText(Page)	Enter/exit text mode for manual positioning.
MoveTextPos(Page, X, Y)	Move text cursor to absolute position.
ShowText(Page, Text)	Output text at current cursor.
NextLine(Page)	Move cursor to next line using current leading.
SetTextLeading(Page, N)	Set line height in points.

Colors & Graphics

Function	Description
SetFillColorRGB(Page, R, G, B)	Fill color for text and shapes. 0.0–1.0 per channel.
SetStrokeColorRGB(Page, R, G, B)	Stroke color for lines and borders.
SetGrayFill(Page, Gray)	Grayscale fill (0=black, 1=white).
SetLineWidth(Page, W)	Line width in points.
SetLineCap / SetLineJoin(Page, Style)	Cap and join style.
SetDash(Page, Pattern, Phase)	Dash pattern for lines.
MoveTo / LineTo(Page, X, Y)	Path construction.
CurveTo(Page, X1,Y1,X2,Y2,X3,Y3)	Cubic Bezier curve.
Stroke / Fill / FillStroke(Page)	Paint the current path.
DrawLine(Page, X1,Y1,X2,Y2)	Shortcut: draw and stroke a line.
Rectangle / FillRect(Page, X,Y,W,H)	Rectangle (outline or filled).
Circle / Ellipse(Page, X,Y,R…)	Circle or ellipse.

Images & Bookmarks

Function	Description
LoadJpeg / LoadPng(Doc, Path)	Load image from file. Returns TPDFImage.
LoadJpegBytes(Doc, Data)	Load JPEG from in-memory bytes.
DrawImage(Page, Img, X,Y,W,H)	Draw image at position with given size in points.
GetImageWidth / Height(Img)	Image pixel dimensions.
AddOutline(Doc, Title)	Add root bookmark. Returns handle.
AddChildOutline(Doc, Parent, Title)	Add nested bookmark.
SetOutlineDest(Doc, Outline, Page)	Link bookmark to a page.