From fd6cc955e218d1666da9da19eb1979370c6693fd Mon Sep 17 00:00:00 2001
From: Luke Campagnola <luke.campagnola@gmail.com>
Date: Sun, 16 Mar 2014 13:45:26 -0400
Subject: [PATCH] Fixed GLGridItem.setSize, added setSpacing

---
 CHANGELOG                            |  1 +
 pyqtgraph/opengl/items/GLGridItem.py | 38 +++++++++++++++++++++-------
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 11db18ac..b9e56d51 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -76,6 +76,7 @@ pyqtgraph-0.9.9  [unreleased]
     - Allow images with NaN in ImageView
     - MeshData can generate edges from face-indexed vertexes
     - Fixed multiprocess deadlocks on windows
+    - Fixed GLGridItem.setSize
 
 pyqtgraph-0.9.8  2013-11-24
 
diff --git a/pyqtgraph/opengl/items/GLGridItem.py b/pyqtgraph/opengl/items/GLGridItem.py
index 2c4642c8..a8d1fb7a 100644
--- a/pyqtgraph/opengl/items/GLGridItem.py
+++ b/pyqtgraph/opengl/items/GLGridItem.py
@@ -1,3 +1,5 @@
+import numpy as np
+
 from OpenGL.GL import *
 from .. GLGraphicsItem import GLGraphicsItem
 from ... import QtGui
@@ -16,8 +18,9 @@ class GLGridItem(GLGraphicsItem):
         self.setGLOptions(glOptions)
         self.antialias = antialias
         if size is None:
-            size = QtGui.QVector3D(1,1,1)
+            size = QtGui.QVector3D(20,20,1)
         self.setSize(size=size)
+        self.setSpacing(1, 1, 1)
     
     def setSize(self, x=None, y=None, z=None, size=None):
         """
@@ -33,8 +36,22 @@ class GLGridItem(GLGraphicsItem):
         
     def size(self):
         return self.__size[:]
-    
-    
+
+    def setSpacing(self, x=None, y=None, z=None, spacing=None):
+        """
+        Set the spacing between grid lines.
+        Arguments can be x,y,z or spacing=QVector3D().
+        """
+        if spacing is not None:
+            x = spacing.x()
+            y = spacing.y()
+            z = spacing.z()
+        self.__spacing = [x,y,z]
+        self.update() 
+        
+    def spacing(self):
+        return self.__spacing[:]
+        
     def paint(self):
         self.setupGLState()
         
@@ -47,12 +64,15 @@ class GLGridItem(GLGraphicsItem):
         glBegin( GL_LINES )
         
         x,y,z = self.size()
+        xs,ys,zs = self.spacing()
+        xvals = np.arange(-x/2., x/2. + xs*0.001, xs) 
+        yvals = np.arange(-y/2., y/2. + ys*0.001, ys) 
         glColor4f(1, 1, 1, .3)
-        for x in range(-10, 11):
-            glVertex3f(x, -10, 0)
-            glVertex3f(x,  10, 0)
-        for y in range(-10, 11):
-            glVertex3f(-10, y, 0)
-            glVertex3f( 10, y, 0)
+        for x in xvals:
+            glVertex3f(x, yvals[0], 0)
+            glVertex3f(x,  yvals[-1], 0)
+        for y in yvals:
+            glVertex3f(xvals[0], y, 0)
+            glVertex3f(xvals[-1], y, 0)
         
         glEnd()