This example demonstrates an alternative 3D drawing method that uses shadows.
The standard way to draw a pie chart in 3D is to view the chart from an inclined angle. Using this method, the surface of a 3D pie will become an ellipse.
ChartDirector supports an alternative way to draw a pie chart in 3D - to draw the 3D portion like a shadow. The 3D pie will remain perfectly circular, and the sector areas will correctly reflect its percentages.
The 3D drawing method is configured using
PieChart.set3D.
[Standalone Version] pythondemo\shadowpie.py
#!/usr/bin/python
from pychartdir import *
def createChart(img) :
# the tilt angle of the pie
angle = int(img) * 90 + 45
# The data for the pie chart
data = [25, 18, 15, 12, 8, 30, 35]
# Create a PieChart object of size 100 x 110 pixels
c = PieChart(100, 110)
# Set the center of the pie at (50, 55) and the radius to 36 pixels
c.setPieSize(50, 55, 36)
# Set the depth, tilt angle and 3D mode of the 3D pie (-1 means auto depth,
# "true" means the 3D effect is in shadow mode)
c.set3D(-1, angle, 1)
# Add a title showing the shadow angle
c.addTitle("Shadow @ %s deg" % (angle), "arial.ttf", 8)
# Set the pie data
c.setData(data)
# Disable the sector labels by setting the color to Transparent
c.setLabelStyle("", 8, Transparent)
# Output the chart
c.makeChart("shadowpie%s.png" % img)
createChart("0")
createChart("1")
createChart("2")
createChart("3") |
[CGI Version] pythondemo_cgi\shadowpie.py
#!/usr/bin/python
from pychartdir import *
import cgi
# Get HTTP query parameters
query = cgi.FieldStorage()
# the tilt angle of the pie
angle = int(query["img"].value) * 90 + 45
# The data for the pie chart
data = [25, 18, 15, 12, 8, 30, 35]
# Create a PieChart object of size 100 x 110 pixels
c = PieChart(100, 110)
# Set the center of the pie at (50, 55) and the radius to 36 pixels
c.setPieSize(50, 55, 36)
# Set the depth, tilt angle and 3D mode of the 3D pie (-1 means auto depth, "true"
# means the 3D effect is in shadow mode)
c.set3D(-1, angle, 1)
# Add a title showing the shadow angle
c.addTitle("Shadow @ %s deg" % (angle), "arial.ttf", 8)
# Set the pie data
c.setData(data)
# Disable the sector labels by setting the color to Transparent
c.setLabelStyle("", 8, Transparent)
# Output the chart
print("Content-type: image/png\n")
binaryPrint(c.makeChart2(PNG)) |
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