Fix pdf issues on printers

pyCairo by default renders the PDF surfaces with a resolution of 72
dpi which is so low that the bitmap gets blurred compared to original.

Since pyCairo 1.12.0, a new method set_device_scale(x_scale, y_scale)
is added, which allows changing the canvas resolution.

1 files changed, 9 insertions, 4 deletions

diff --git a/libmat2/pdf.py b/libmat2/pdf.py
index e258512..fc5f7dc 100644
--- a/libmat2/pdf.py
+++ b/libmat2/pdf.py
@@ -32,7 +32,7 @@ class PDFParser(abstract.AbstractParser):
     def __init__(self, filename):
         super().__init__(filename)
         self.uri = 'file://' + os.path.abspath(self.filename)
-        self.__scale = 2  # how much precision do we want for the render
+        self.__scale = 200 / 72.0  # how much precision do we want for the render
         try:  # Check now that the file is valid, to avoid surprises later
             Poppler.Document.new_from_file(self.uri, None)
         except GLib.GError:  # Invalid PDF
@@ -90,8 +90,8 @@ class PDFParser(abstract.AbstractParser):
             page_width, page_height = page.get_size()
             logging.info("Rendering page %d/%d", pagenum + 1, pages_count)
 
-            width = int(page_width) * self.__scale
-            height = int(page_height) * self.__scale
+            width = int(page_width * self.__scale)
+            height = int(page_height * self.__scale)
             img_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
             img_context = cairo.Context(img_surface)
 
@@ -105,7 +105,12 @@ class PDFParser(abstract.AbstractParser):
             buf.seek(0)
 
             img = cairo.ImageSurface.create_from_png(buf)
-            pdf_surface.set_size(page_width*self.__scale, page_height*self.__scale)
+            if cairo.version_info < (1, 12, 0):
+                pdf_surface.set_size(width, height)
+            else:
+                print("lol")
+                pdf_surface.set_size(page_width, page_height)
+                pdf_surface.set_device_scale(1 / self.__scale, 1 / self.__scale)
             pdf_context.set_source_surface(img, 0, 0)
             pdf_context.paint()
             pdf_context.show_page()  # draw pdf_context on pdf_surface