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// Rendering a page of a PDF document to a PNG image in less than 100 lines.
// Compile a debug build of mupdf, then compile and run this example:
//
// gcc -g -o build/debug/example -Iinclude docs/example.c \
// build/debug/libmupdf.a \
// build/debug/libfreetype.a build/debug/libjbig2dec.a \
// build/debug/libjpeg.a build/debug/libopenjpeg.a \
// build/debug/libmujs.a \
// build/debug/libz.a -lm
//
// (If this fails with errors about missing BIO_ and X509_ references
// try again with "-lcrypto" added to the end of that command).
//
// build/debug/example /path/to/document.pdf 1 200 25
// Include the MuPDF header file.
#include <mupdf/fitz.h>
void
render(char *filename, int pagenumber, int zoom, int rotation)
{
fz_context *ctx;
fz_document *doc;
int pagecount;
fz_page *page;
fz_matrix transform;
fz_rect bounds;
fz_irect bbox;
fz_pixmap *pix;
fz_device *dev;
// Create a context to hold the exception stack and various caches.
ctx = fz_new_context(NULL, NULL, FZ_STORE_UNLIMITED);
// Register the default file types.
fz_register_document_handlers(ctx);
// Open the PDF, XPS or CBZ document.
doc = fz_open_document(ctx, filename);
// Retrieve the number of pages (not used in this example).
pagecount = fz_count_pages(ctx, doc);
// Load the page we want. Page numbering starts from zero.
page = fz_load_page(ctx, doc, pagenumber - 1);
// Calculate a transform to use when rendering. This transform
// contains the scale and rotation. Convert zoom percentage to a
// scaling factor. Without scaling the resolution is 72 dpi.
fz_rotate(&transform, rotation);
fz_pre_scale(&transform, zoom / 100.0f, zoom / 100.0f);
// Take the page bounds and transform them by the same matrix that
// we will use to render the page.
fz_bound_page(ctx, page, &bounds);
fz_transform_rect(&bounds, &transform);
// Create a blank pixmap to hold the result of rendering. The
// pixmap bounds used here are the same as the transformed page
// bounds, so it will contain the entire page. The page coordinate
// space has the origin at the top left corner and the x axis
// extends to the right and the y axis extends down.
fz_round_rect(&bbox, &bounds);
pix = fz_new_pixmap_with_bbox(ctx, fz_device_rgb(ctx), &bbox);
fz_clear_pixmap_with_value(ctx, pix, 0xff);
// A page consists of a series of objects (text, line art, images,
// gradients). These objects are passed to a device when the
// interpreter runs the page. There are several devices, used for
// different purposes:
//
// draw device -- renders objects to a target pixmap.
//
// text device -- extracts the text in reading order with styling
// information. This text can be used to provide text search.
//
// list device -- records the graphic objects in a list that can
// be played back through another device. This is useful if you
// need to run the same page through multiple devices, without
// the overhead of parsing the page each time.
// Create a draw device with the pixmap as its target.
// Run the page with the transform.
dev = fz_new_draw_device(ctx, pix);
fz_run_page(ctx, page, dev, &transform, NULL);
fz_drop_device(ctx, dev);
// Save the pixmap to a file.
fz_write_png(ctx, pix, "out.png", 0);
// Clean up.
fz_drop_pixmap(ctx, pix);
fz_drop_page(ctx, page);
fz_drop_document(ctx, doc);
fz_drop_context(ctx);
}
int main(int argc, char **argv)
{
char *filename = argc >= 2 ? argv[1] : "";
int pagenumber = argc > 2 ? atoi(argv[2]) : 1;
int zoom = argc > 3 ? atoi(argv[3]) : 100;
int rotation = argc > 4 ? atoi(argv[4]) : 0;
render(filename, pagenumber, zoom, rotation);
return 0;
}
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