Attachment 13428 Details for Bug 13871 – Python program to demonstrate artifacts

Python program to demonstrate artifacts

cairo_artifact_testcase.py (text/x-python), 3.06 KB, created by Karl Ostmo on 2007-12-30 15:21:22 UTC

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Filename:

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Creator: Karl Ostmo

Created: 2007-12-30 15:21:22 UTC

Size: 3.06 KB

patch

obsolete

>#!/usr/bin/env python
>
>'''
>Author:		Karl Ostmo
>Date:		12/30/2007
>Title:		cairo_artifact_testcase.py
>Description:
>A test case to demonstrate the rendering artifacts that appear on certain
>shapes.  They are single-pixel-wide vertical lines on the right edge of the
>shape bounding box.  They appear in the same color as the source color of
>the shape.
>
>To see the artifacts, resize the window.  While you are dragging the window
>corner around, the artifacts will appear intermittently.  The artifact is
>not present when the image is saved as a PNG at the same pixel dimensions.
>The artifact often disappears after another window is moved on top of the
>cairo surface and dragged off again, which forces a redraw of that part of
>the surface.
>
>Dependencies (for Ubuntu):
>* python-gtk2
>* python-cairo
>'''
>
>
>from pygtk import require
>require('2.0')
>import gtk, cairo
>
># ===========================
>
>class ArtifactTestcase:
>
>	def __init__(self):
>
>		window = gtk.Window()
>		window.connect("delete_event", gtk.main_quit)
>
>		main_vbox = gtk.VBox(False, 10)
>		window.add(main_vbox)
>
>		cairo_surface = CairoDraw()
>		cairo_surface.set_size_request(200, 200)
>
>		screenshot_button = gtk.Button("Capture image")
>
>		main_vbox.pack_start(screenshot_button, False, False)
>		main_vbox.pack_start(cairo_surface, True, True)
>		window.show_all()
>
>		screenshot_button.connect("clicked", cairo_surface.save_image_to_file, cairo_surface)
>
># ===========================
>
>class CairoDraw(gtk.DrawingArea):
>
>	# Draw in response to an expose-event
>	__gsignals__ = { "expose-event": "override" }
>
>	# ---------------------------------------
>
>	# Handle the expose-event by drawing
>	def do_expose_event(self, event):
>
>		# Create the cairo context
>		cr = self.window.cairo_create()
>
>		# Restrict Cairo to the exposed area; avoid extra work
>		cr.rectangle(event.area.x, event.area.y, event.area.width, event.area.height)
>		cr.clip()
>
>		self.draw(cr, *self.window.get_size())
>
>	# ---------------------------------------
>
>	def __init__(self):
>		gtk.DrawingArea.__init__(self)
>
>	# ---------------------------------------
>
>	def save_image_to_file(self, calling_widget, surface_object, raster=True):
>
>		surface_dimensions = surface_object.window.get_size()
>
>		print surface_dimensions
>		img_width, img_height = surface_dimensions
>		filename = "testcase_capture"
>	
>		if raster:
>			img = cairo.ImageSurface(cairo.FORMAT_ARGB32, img_width, img_height)
>			width, height = img.get_width(), img.get_height()
>			c = cairo.Context(img)
>			self.draw(c, width, height)
>			filename += ".png"
>			img.write_to_png(filename)
>		else:
>			filename += ".pdf"
>			surf = cairo.PDFSurface(filename, img_width, img_height)
>			cr = cairo.Context(surf)
>			self.draw(cr, img_width, img_height)
>			cr.show_page()
>
>		print "Wrote", filename, "at", img_width, "by", img_height, "pixels."
>
>	# ---------------------------------------
>
>	def draw(self, cr, width, height):
>
>		from math import pi
>
>		cr.arc( width/2.0, height/2.0, (min(width, height)-10)/2.0, 0, 2*pi)
>		cr.set_source_rgb(1.0, 0, 0)
>		cr.fill()
>
># ===========================
>
>if __name__ == "__main__":
>
>	display = ArtifactTestcase()
>	gtk.main()
>

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Attachments on bug 13871: 13428 | 13429 | 13549 | 13550

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