From efbea6a275ba3a9afeb16db80f8eca9675471d79 Mon Sep 17 00:00:00 2001
From: arjones6 <arjones6@gmail.com>
Date: Wed, 15 Dec 2021 11:07:18 -0500
Subject: [PATCH] dc.DrawLinesFromBuffer demo and test to intc data type. 
 Updated documentation.

---
 demo/DrawLinesFromBuffer.py             | 14 +++++++++++---
 etg/dc.py                               | 14 +++++++++++++-
 unittests/test_dcDrawLinesFromBuffer.py |  5 +++--
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/demo/DrawLinesFromBuffer.py b/demo/DrawLinesFromBuffer.py
index f4c948fc..1761e3b7 100644
--- a/demo/DrawLinesFromBuffer.py
+++ b/demo/DrawLinesFromBuffer.py
@@ -22,8 +22,9 @@ def TestLinesFromBuffer(dc, log):
         y2 = np.sin(vs * 16 * np.pi) * w/2 * vs + h/2
         
 
-        pts1 = np.append(x1, y1, 1).astype('int32')
-        pts2 = np.append(x2, y2, 1).astype('int32')
+        # Data has to be the same size as a C integer
+        pts1 = np.append(x1, y1, 1).astype('intc')
+        pts2 = np.append(x2, y2, 1).astype('intc')
 
         dc.SetPen(wx.BLACK_PEN)
         t1 = time.time()
@@ -110,9 +111,16 @@ the python buffer protocol.
     DrawLinesFromBuffer(pyBuff)
 </pre>
 
+The buffer object needs to provide an array of C integers organized as 
+x, y point pairs.  The size of a C integer is platform dependent.
+With numpy, the intc data type will provide the appropriate element size.
+
 If called with an object that doesn't support
 the python buffer protocol, or if the underlying element size does not
-match the size of a wxPoint, a TypeError exception is raised.
+match the size of a C integer, a TypeError exception is raised.  If 
+the buffer provided has float data with the same element size as a 
+C integer, no error will be raised, but the lines will not be drawn
+in the appropriate places.
 """
 
 
diff --git a/etg/dc.py b/etg/dc.py
index ccdc3b10..f4727c28 100644
--- a/etg/dc.py
+++ b/etg/dc.py
@@ -481,7 +481,19 @@ def run():
     c.addPyMethod('DrawLinesFromBuffer', '(self, pyBuff)',
         doc="""\
             Implementation of DrawLines that can use numpy arrays, or anything else that uses the
-            python buffer protocol, directly.
+            python buffer protocol directly without any element conversion.  This provides a 
+            significant performance increase over the standard DrawLines function.
+            
+            The pyBuff argument needs to provide an array of C integers organized as 
+            x, y point pairs.  The size of a C integer is platform dependent.
+            With numpy, the intc data type will provide the appropriate element size.
+
+            If called with an object that doesn't support
+            the python buffer protocol, or if the underlying element size does not
+            match the size of a C integer, a TypeError exception is raised.  If 
+            the buffer provided has float data with the same element size as a 
+            C integer, no error will be raised, but the lines will not be drawn
+            in the appropriate places.
 
             :param pyBuff:    A python buffer containing integer pairs
             """,
diff --git a/unittests/test_dcDrawLinesFromBuffer.py b/unittests/test_dcDrawLinesFromBuffer.py
index 20552341..3bed6053 100644
--- a/unittests/test_dcDrawLinesFromBuffer.py
+++ b/unittests/test_dcDrawLinesFromBuffer.py
@@ -48,8 +48,9 @@ class dcDrawLists_Tests(wtc.WidgetTestCase):
         ys.shape = ys.size, 1
         pts = np.append(xs, ys, 1)
 
-        dc.DrawLinesFromBuffer(pts.astype('int32'))
-        self.assertRaises(TypeError, dc.DrawLinesFromBuffer, pts.astype('int64'))
+        dc.DrawLinesFromBuffer(pts.astype('intc'))
+        self.assertRaises(TypeError, dc.DrawLinesFromBuffer, 
+                          pts.astype('int64') if np.intc(1).nbytes != np.int64(1).nbytes else pts.astype('int32'))
         self.assertRaises(TypeError, dc.DrawLinesFromBuffer, pts.tolist())
         del dc