From f03dc3754fed6b74dfb02720dcf30e6bd9f57e48 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Mon, 1 Sep 2014 11:32:17 +0100
Subject: [PATCH] start adding python operator overloads

---
 TODO                 | 12 ++++++++++++
 python/try4.py       |  2 --
 python/try5.py       | 18 ++++++++++++++++++
 python/vips8/vips.py | 24 +++++++++++++++++++++++-
 4 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100755 python/try5.py

diff --git a/TODO b/TODO
index 21c50c95..a8705c61 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,15 @@
+- mysterious
+
+from gi.repository import Vips
+from vips8 import vips
+
+a = Vips.Image.new_from_file("/home/john/pics/k2.jpg")
+a.linear(1,2)
+	works
+a.linear([1],[2])
+	fails !?!?
+
+
 - python:
 
 	- add more constructors
diff --git a/python/try4.py b/python/try4.py
index 50c4fb29..489f8fb4 100755
--- a/python/try4.py
+++ b/python/try4.py
@@ -14,6 +14,4 @@ b = Vips.Image.new_from_file(sys.argv[2])
 
 c = a.join(b, Vips.Direction.HORIZONTAL, expand = True)
 
-d = c.linear(2, 3)
-
 d.write_to_file(sys.argv[3])
diff --git a/python/try5.py b/python/try5.py
new file mode 100755
index 00000000..e6df5de3
--- /dev/null
+++ b/python/try5.py
@@ -0,0 +1,18 @@
+#!/usr/bin/python
+
+import sys
+
+#import logging
+#logging.basicConfig(level = logging.DEBUG)
+
+from gi.repository import Vips 
+from vips8 import vips
+
+a = Vips.Image.new_from_file(sys.argv[1])
+
+# test operator overloads
+b = a + 12
+b = a + [12, 0, 0]
+b = a + b
+
+b.write_to_file(sys.argv[2])
diff --git a/python/vips8/vips.py b/python/vips8/vips.py
index bde30dbf..b72bacb7 100644
--- a/python/vips8/vips.py
+++ b/python/vips8/vips.py
@@ -14,10 +14,11 @@ from gi.repository import Vips
 # start up vips!
 Vips.init(sys.argv[0])
 
-# need the gtypes for the vips array types
+# need the gtypes for various vips types
 vips_type_array_int = GObject.GType.from_name("VipsArrayInt")
 vips_type_array_double = GObject.GType.from_name("VipsArrayDouble")
 vips_type_array_image = GObject.GType.from_name("VipsArrayImage")
+vips_type_image = GObject.GType.from_name("VipsImage")
 
 class Error(Exception):
 
@@ -203,6 +204,24 @@ def vips_image_write_to_file(self, vips_filename, **kwargs):
 
     _call_base(saver, [filename], kwargs, self, option_string)
 
+def vips_add(self, other):
+    if isinstance(other, Vips.Image):
+        return self.add(other)
+    else:
+        return self.linear(1, other)
+
+def vips_sub(self, other):
+    if isinstance(other, Vips.Image):
+        return self.subtract(other)
+    else:
+        return self.linear(1, -1 * other)
+
+def vips_mul(self, other):
+    if isinstance(other, Vips.Image):
+        return self.multiply(other)
+    else:
+        return self.linear(other, 0)
+
 # paste our methods into Vips.Image
 
 # class methods
@@ -211,6 +230,9 @@ setattr(Vips.Image, 'new_from_file', classmethod(vips_image_new_from_file))
 # instance methods
 Vips.Image.write_to_file = vips_image_write_to_file
 Vips.Image.__getattr__ = vips_image_getattr
+Vips.Image.__add__ = vips_add
+Vips.Image.__sub__ = vips_sub
+Vips.Image.__mul__ = vips_mul
 
 # Add other classes to Vips
 Vips.Error = Error