mapnik/tests/visual_tests/compare.py
2014-08-31 08:08:52 +00:00

71 lines
2 KiB
Python

# -*- coding: utf-8 -*-
import os
import sys
import mapnik
import platform
try:
import json
except ImportError:
import simplejson as json
COMPUTE_THRESHOLD = 16
# testcase images are generated on OS X
# so they should exactly match
if platform.uname()[0] == 'Darwin':
COMPUTE_THRESHOLD = 2
# returns true if pixels are not identical
def compare_pixels(pixel1, pixel2, alpha=True):
if pixel1 == pixel2:
return False
r_diff = abs((pixel1 & 0xff) - (pixel2 & 0xff))
g_diff = abs(((pixel1 >> 8) & 0xff) - ((pixel2 >> 8) & 0xff))
b_diff = abs(((pixel1 >> 16) & 0xff)- ((pixel2 >> 16) & 0xff))
if alpha:
a_diff = abs(((pixel1 >> 24) & 0xff) - ((pixel2 >> 24) & 0xff))
if(r_diff > COMPUTE_THRESHOLD or
g_diff > COMPUTE_THRESHOLD or
b_diff > COMPUTE_THRESHOLD or
a_diff > COMPUTE_THRESHOLD):
return True
else:
if(r_diff > COMPUTE_THRESHOLD or
g_diff > COMPUTE_THRESHOLD or
b_diff > COMPUTE_THRESHOLD):
return True
return False
# compare two images and return number of different pixels
def compare(actual, expected, alpha=True):
im1 = mapnik.Image.open(actual)
try:
im2 = mapnik.Image.open(expected)
except RuntimeError:
return 99999990
diff = 0
pixels = im1.width() * im1.height()
delta_pixels = (im2.width() * im2.height()) - pixels
if delta_pixels != 0:
return delta_pixels
for x in range(0,im1.width(),2):
for y in range(0,im1.height(),2):
if compare_pixels(im1.get_pixel(x,y),im2.get_pixel(x,y),alpha=alpha):
diff += 1
return diff
def compare_grids(actual, expected, threshold=0, alpha=True):
global errors
global passed
im1 = json.loads(open(actual).read())
try:
im2 = json.loads(open(expected).read())
except RuntimeError:
return 9999990
equal = (im1 == im2)
# TODO - real diffing
if not equal:
return 99999999
return 0