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# -*- mode: python; coding: utf-8 -*-
#
# Pigment Python binding cairo integration example using the gradient cairo
# snippets translated to Python.
#
# Copyright © 2006, 2007, 2008 Fluendo Embedded S.L.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
# Author: Loïc Molinari <loic@fluendo.com>
import sys, math, array, pgm, cairo
# Terminate the mainloop on a delete event
def on_delete(viewport, event):
pgm.main_quit()
# Draw a gradient in a memory buffer with Cairo
def cairo_drawing(width, height):
# Store the Cairo surface in an array
data = array.array('c', chr(0) * width * height * 4)
surface = cairo.ImageSurface.create_for_data (data, cairo.FORMAT_ARGB32,
width, height, width * 4)
# Create the context
ctx = cairo.Context(surface)
ctx.scale(width, height)
# Draw a sphere
pat = cairo.RadialGradient(0.45, 0.4, 0.1, 0.4, 0.4, 0.5)
pat.add_color_stop_rgba(0, 0.8, 0.8, 1, 1)
pat.add_color_stop_rgba(1, 0, 0, 1, 1)
ctx.set_source(pat)
ctx.arc(0.5, 0.5, 0.3, 0, 2 * math.pi)
ctx.fill()
# And return the buffer as a Python string
return data.tostring()
# Entry point
def main():
# OpenGL viewport creation
gl = pgm.viewport_factory_make('opengl')
gl.title = 'Sphere'
# Canvas and image drawable creation
cvs = pgm.Canvas()
cvs.size = (800.0, 600.0)
# Bind the canvas to the OpenGL viewport
gl.set_canvas(cvs)
# Draw a gradient with cairo and put it in a Pigment Image
img = pgm.Image()
data = cairo_drawing(400, 400)
img.set_from_buffer(pgm.IMAGE_BGRA, 400, 400, 400 * 4, 400 * 400 * 4, data)
img.bg_color = (255, 255, 255, 0)
img.position = (200.0, 100.0, 0.0)
img.size = (400.0, 400.0)
img.show()
# Add the drawable to the middle layer of the canvas
cvs.add(pgm.DRAWABLE_MIDDLE, img)
# Let's connect our callbacks and start the mainloop
gl.connect('delete-event', on_delete)
gl.show()
pgm.main()
if __name__ == '__main__':
sys.exit(main())
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