GL buffer handle is now stored in fslimage.Image object. Removed notion of...

GL buffer handle is now stored in fslimage.Image object. Removed notion of 'master' canvas from SliceCanvas - a shared GL context may be passed in directly. BUT if a shared context is not used, and the program attempts to share image buffers, it will segfault. Need to think about that one.

fsl/data/fslimage.py

 #!/usr/bin/env python
 #
-# fslimage.py - Classes representing a 3D image, and the display
-# properties of a 3D image.
+# fslimage.py - Classes representing a 3D image, the display
+# properties of a 3D image, and a collection of 3D images.
 #
 # Author: Paul McCarthy <pauldmccarthy@gmail.com>
 #
@@ -51,6 +51,8 @@ class Image(object):
         self.ylen  = ylen
         self.zlen  = zlen
 
+        self.glBuffer = None
+
 
 class ImageDisplay(props.HasProperties):
     """
@@ -107,3 +109,14 @@ class ImageDisplay(props.HasProperties):
         self.dataMax    = self.image.data.max() 
         self.displayMin = self.dataMin    # use cal_min/cal_max instead?
         self.displayMax = self.dataMax
+
+        
+class ImageList(object):
+
+    def __init__(self, images=None, displays=None):
+        
+        if images   is None: images   = []
+        if displays is None: displays = []
+        
+        self._images   = images
+        self._displays = displays

fsl/utils/imageview.py

@@ -51,9 +51,9 @@ class ImageView(wx.Panel):
         self.xcanvas = slicecanvas.SliceCanvas(
             self.canvasPanel, self.imageDisplay, zax=0)
         self.ycanvas = slicecanvas.SliceCanvas(
-            self.canvasPanel, self.imageDisplay, zax=1, master=self.xcanvas)
+            self.canvasPanel, self.imageDisplay, zax=1, context=self.xcanvas.context)
         self.zcanvas = slicecanvas.SliceCanvas(
-            self.canvasPanel, self.imageDisplay, zax=2, master=self.xcanvas)
+            self.canvasPanel, self.imageDisplay, zax=2, context=self.xcanvas.context)
 
         self.mainSizer   = wx.BoxSizer(wx.VERTICAL)
         self.canvasSizer = wx.BoxSizer(wx.HORIZONTAL)

fsl/utils/slicecanvas.py

@@ -39,8 +39,7 @@ import fsl.data.fslimage as fslimage
 # The third buffer, the 'image buffer' contains the image data itself,
 # scaled to lie between 0.0 and 1.0. It is used to calculate voxel
 # colours, and may be shared between multiple SliceCanvas objects
-# which are displaying the same image - see the 'master' parameter to
-# the SliceCanvas constructor.
+# which are displaying the same image.
 #
 # Finally, the texture, the 'colour buffer', is used to store a
 # lookup table containing colours. 
@@ -190,7 +189,8 @@ class SliceCanvas(wxgl.GLCanvas):
         self._colourResolution = colourResolution
 
 
-    def __init__(self, parent, image, zax=0, zpos=None, master=None, **kwargs):
+    def __init__(
+            self, parent, image, zax=0, zpos=None, context=None, **kwargs):
         """
         Creates a canvas object. The OpenGL data buffers are set up in
         _initGLData the first time that the canvas is displayed/drawn.
@@ -204,12 +204,11 @@ class SliceCanvas(wxgl.GLCanvas):
         
           zax    - Axis perpendicular to the plane to be displayed
                    (the 'depth' axis), default 0.
+
+          context - 
         
           zpos   - Initial slice to be displayed. If not provided, the
                    middle slice is used.
-        
-          master - Another SliceCanvas object with which to share the
-                   GL context and the image buffer data.
         """
 
         realImage    = None
@@ -229,10 +228,8 @@ class SliceCanvas(wxgl.GLCanvas):
         
         wxgl.GLCanvas.__init__(self, parent, **kwargs)
 
-        if master is not None: context = master.context
-        else:                  context = wxgl.GLContext(self)
+        if context is None: context = wxgl.GLContext(self)
 
-        self.master  = master
         self.context = context
 
         # TODO Currently, the displayed x/horizontal and
@@ -267,11 +264,10 @@ class SliceCanvas(wxgl.GLCanvas):
 
         self._colourResolution = 256
 
-        # these attributes are created by _initGLData,
-        # which is called on the first EVT_PAINT event
-        self.geomBuffer     = None
-        self.positionBuffer = None
-        self.imageBuffer    = None
+        # This flag is set by the _initGLData method
+        # when it has finished initialising the OpenGL
+        # data buffers
+        self.glReady = False
 
         self.Bind(wx.EVT_PAINT, self.draw)
 
@@ -360,6 +356,8 @@ class SliceCanvas(wxgl.GLCanvas):
         self.colourBuffer = gl.glGenTextures(1)
         self.updateColourBuffer()
 
+        self.glReady = True
+
         
     def _initImageBuffer(self):
         """
@@ -370,8 +368,8 @@ class SliceCanvas(wxgl.GLCanvas):
 
         # If a master canvas was passed to the
         # constructor, let's share its image data.
-        if self.master is not None:
-            return self.master.imageBuffer
+        if self.image.glBuffer is not None:
+            return self.image.glBuffer
 
         # The image data is cast to single precision floating
         # point, and normalised to lie between 0.0 and 1.0
@@ -385,6 +383,8 @@ class SliceCanvas(wxgl.GLCanvas):
         imageData = imageData.ravel(order='F')
         imageBuffer = vbo.VBO(imageData, gl.GL_STATIC_DRAW)
 
+        self.image.glBuffer = imageBuffer
+
         return imageBuffer
 
 
@@ -473,7 +473,7 @@ class SliceCanvas(wxgl.GLCanvas):
         """
 
         # image data has not been initialised.
-        if not self.imageBuffer:
+        if not self.glReady:
             wx.CallAfter(self._initGLData)
             return