From 4759dd32501fdcd8dea8c758adbab77cd712d548 Mon Sep 17 00:00:00 2001
From: Paul McCarthy <pauld.mccarthy@gmail.com>
Date: Wed, 21 May 2014 15:39:20 +0100
Subject: [PATCH] GLImageData stuff separated from SliceCanvas.
---
fsl/fslview/glimagedata.py | 296 +++++++++++++++++++++++++++++++++++
fsl/fslview/slicecanvas.py | 306 +++----------------------------------
2 files changed, 316 insertions(+), 286 deletions(-)
create mode 100644 fsl/fslview/glimagedata.py
diff --git a/fsl/fslview/glimagedata.py b/fsl/fslview/glimagedata.py
new file mode 100644
index 000000000..177eb10b6
--- /dev/null
+++ b/fsl/fslview/glimagedata.py
@@ -0,0 +1,296 @@
+#!/usr/bin/env python
+#
+# glimagedata.py - Create OpenGL data to render 2D slices of a 3D image.
+
+# A GLImageData object encapsulates the OpenGL information necessary
+# to render 2D slices of a 3D image.
+#
+# A slice from one image is rendered using four buffers and two textures.
+
+# The first buffer, the 'geometry buffer' simply contains the 3D
+# coordinates (single precision floating point) of four vertices, which
+# define the geometry of a single voxel (using triangle strips).
+
+# The remaining buffers contain the X, Y, and Z coordinates of the voxels
+# in the slice to be displayed. These coordinates are stored as single
+# precision floating points, and used both to position a voxel, and to
+# look up its value in the 3D data texture (see below).
+
+# The image data itself is stored as a 3D texture, with each voxel value
+# stored as a single unsigned byte in the range 0-255.
+
+# Finally, a 1D texture is used is used to store a lookup table containing
+# an RGBA8 colour map, to colour each voxel according to its value.
+#
+# All of these things are created when a GLImageData object is
+# instantiated. They are available as attributes of the object:
+#
+# - dataBuffer
+# - xBuffer
+# - yBuffer
+# - zBuffer
+# - geomBuffer
+# - colourBuffer
+#
+# Author: Paul McCarthy <pauldmccarthy@gmail.com>
+#
+
+import numpy as np
+
+import OpenGL.GL as gl
+import OpenGL.arrays.vbo as vbo
+
+# This extension provides the GL_R8 constant,
+# which is built into modern versions of OpenGL.
+import OpenGL.GL.ARB.texture_rg as arbrg
+
+class GLImageData(object):
+
+ def __init__(self, image, xax, yax, imageDisplay=None):
+ """
+ Initialise the OpenGL data buffers required to render the given image.
+ Parameters:
+
+ - image: A fsl.data.fslimage.Image object.
+
+ - xax: The image axis which maps to the screen x axis.
+
+ - yax: The image axis which maps to the screen y axis.
+
+ - imageDisplay: Optional. A fsl.data.fslimage.ImageDisplay object
+ which describes how the image is to be displayed.
+ If not provided, the default image.display instance
+ is used (see fsl.data.fslimage.ImageDisplay for
+ details).
+ """
+
+ self.image = image
+ self.xax = xax
+ self.yax = yax
+
+ if imageDisplay is not None: self.display = imageDisplay
+ else: self.display = image.display
+
+ # Maximum number of colours used to draw image data.
+ # Keep this to a power of two, as some GL implementations
+ # will complain/misbehave if it isn't.
+ self.colourResolution = 256
+
+ self.initGLImageData()
+
+
+ def initGLImageData(self):
+ """
+ Creates and initialises the OpenGL data for the fslimage.Image
+ object that was passed to the GLImageData constructor.
+ """
+
+ image = self.image
+ xax = self.xax
+ yax = self.yax
+
+ # The geometry buffer defines the geometry of
+ # a single voxel, rendered as a triangle strip.
+ geomData = np.zeros((4, 3), dtype=np.float32)
+ geomData[:, [xax, yax]] = [[-0.5, -0.5],
+ [ 0.5, -0.5],
+ [-0.5, 0.5],
+ [ 0.5, 0.5]]
+
+ geomData = geomData.ravel('C')
+ geomBuffer = vbo.VBO(geomData, gl.GL_STATIC_DRAW)
+
+ # x/y/z coordinates are stored as VBO arrays
+ voxData = []
+ for dim in image.shape:
+ data = np.arange(0, dim, dtype=np.float32)
+ voxData.append(data)
+
+ # the screen x coordinate data has to be repeated (ydim)
+ # times - we are drawing row-wise, and opengl does not
+ # allow us to loop over a VBO in a single instance
+ # rendering call
+ voxData[xax] = np.tile(voxData[xax], image.shape[yax])
+
+ xBuffer = vbo.VBO(voxData[0], gl.GL_STATIC_DRAW)
+ yBuffer = vbo.VBO(voxData[1], gl.GL_STATIC_DRAW)
+ zBuffer = vbo.VBO(voxData[2], gl.GL_STATIC_DRAW)
+
+ # The colour buffer, containing a map of
+ # colours (stored on the GPU as a 1D texture)
+ # This is initialised in the updateColourBuffer
+ # method
+ colourBuffer = gl.glGenTextures(1)
+
+ self.dataBuffer = self.initImageBuffer()
+ self.voxXBuffer = xBuffer
+ self.voxYBuffer = yBuffer
+ self.voxZBuffer = zBuffer
+ self.geomBuffer = geomBuffer
+ self.colourBuffer = colourBuffer
+
+ # Add listeners to this image so the view can be
+ # updated when its display properties are changed
+ self.configDisplayListeners()
+
+ # Create the colour buffer for the given image
+ self.updateColourBuffer()
+
+
+ def initImageBuffer(self):
+ """
+ Initialises the OpenGL buffer used to store the data for the given
+ image. The buffer is stored as an attribute of the image and, if it
+ has already been created (e.g. by another SliceCanvas object), the
+ existing buffer is returned.
+ """
+
+ image = self.image
+
+ texShape = 2 ** (np.ceil(np.log2(image.shape)))
+ pad = [(0, l - s) for (l, s) in zip(texShape, image.shape)]
+ self.imageTexShape = texShape
+
+ try: imageBuffer = image.getAttribute('glImageBuffer')
+ except: imageBuffer = None
+
+ if imageBuffer is not None:
+ return imageBuffer
+
+ # The image data is normalised to lie
+ # between 0 and 255, and cast to uint8
+ imageData = np.array(image.data, dtype=np.float32)
+ imageData = 255.0 * (imageData - imageData.min()) / \
+ (imageData.max() - imageData.min())
+
+ # and each dimension is padded so it has a
+ # power-of-two length. Ugh. This is a horrible,
+ # but as far as I'm aware, necessary hack. At
+ # least it's necessary using the OpenGL 2.1
+ # API on OSX mavericks. It massively increases
+ # image load time, too.
+ imageData = np.pad(imageData, pad, 'constant', constant_values=0)
+ imageData = np.array(imageData, dtype=np.uint8)
+
+ # Then flattened, with fortran dimension ordering,
+ # so the data, as stored on the GPU, has its first
+ # dimension as the fastest changing.
+ imageData = imageData.ravel(order='F')
+
+ # Image data is stored on the GPU as a 3D texture
+ imageBuffer = gl.glGenTextures(1)
+ gl.glBindTexture(gl.GL_TEXTURE_3D, imageBuffer)
+ gl.glTexParameteri(gl.GL_TEXTURE_3D,
+ gl.GL_TEXTURE_MAG_FILTER,
+ gl.GL_NEAREST)
+ gl.glTexParameteri(gl.GL_TEXTURE_3D,
+ gl.GL_TEXTURE_MIN_FILTER,
+ gl.GL_NEAREST)
+ gl.glTexParameteri(gl.GL_TEXTURE_3D,
+ gl.GL_TEXTURE_WRAP_S,
+ gl.GL_CLAMP_TO_EDGE)
+ gl.glTexParameteri(gl.GL_TEXTURE_3D,
+ gl.GL_TEXTURE_WRAP_T,
+ gl.GL_CLAMP_TO_EDGE)
+ gl.glTexParameteri(gl.GL_TEXTURE_3D,
+ gl.GL_TEXTURE_WRAP_R,
+ gl.GL_CLAMP_TO_EDGE)
+
+ gl.glTexImage3D(gl.GL_TEXTURE_3D,
+ 0,
+ arbrg.GL_R8,
+ texShape[0],
+ texShape[1],
+ texShape[2],
+ 0,
+ gl.GL_RED,
+ gl.GL_UNSIGNED_BYTE,
+ imageData)
+
+ # And added as an attribute of the image, so
+ # other things which want to render the image
+ # don't need to duplicate all of that data.
+ image.setAttribute('glImageBuffer', imageBuffer)
+
+ return imageBuffer
+
+
+ def updateColourBuffer(self):
+ """
+ Regenerates the colour buffer used to colour image voxels.
+ """
+
+ display = self.display
+ colourBuffer = self.colourBuffer
+
+ # Here we are creating a range of values to be passed
+ # to the matplotlib.colors.Colormap instance of the
+ # image display. We scale this range such that data
+ # values which lie outside the configured display range
+ # will map to values below 0.0 or above 1.0. It is
+ # assumed that the Colormap instance is configured to
+ # generate appropriate colours for these out-of-range
+ # values.
+
+ normalRange = np.linspace(0.0, 1.0, self.colourResolution)
+ normalStep = 1.0 / (self.colourResolution - 1)
+
+ normMin = (display.displayMin - display.dataMin) / \
+ (display.dataMax - display.dataMin)
+ normMax = (display.displayMax - display.dataMin) / \
+ (display.dataMax - display.dataMin)
+
+ newStep = normalStep / (normMax - normMin)
+ newRange = (normalRange - normMin) * (newStep / normalStep)
+
+ # Create [self.colourResolution] rgb values,
+ # spanning the entire range of the image
+ # colour map
+ colourmap = display.cmap(newRange)
+
+ # The colour data is stored on
+ # the GPU as 8 bit rgba tuples
+ colourmap = np.floor(colourmap * 255)
+ colourmap = np.array(colourmap, dtype=np.uint8)
+ colourmap = colourmap.ravel(order='C')
+
+ # GL texture creation stuff
+ gl.glBindTexture(gl.GL_TEXTURE_1D, colourBuffer)
+ gl.glTexParameteri(gl.GL_TEXTURE_1D,
+ gl.GL_TEXTURE_MAG_FILTER,
+ gl.GL_NEAREST)
+ gl.glTexParameteri(gl.GL_TEXTURE_1D,
+ gl.GL_TEXTURE_MIN_FILTER,
+ gl.GL_NEAREST)
+ gl.glTexParameteri(gl.GL_TEXTURE_1D,
+ gl.GL_TEXTURE_WRAP_S,
+ gl.GL_CLAMP_TO_EDGE)
+
+ gl.glTexImage1D(gl.GL_TEXTURE_1D,
+ 0,
+ gl.GL_RGBA8,
+ self.colourResolution,
+ 0,
+ gl.GL_RGBA,
+ gl.GL_UNSIGNED_BYTE,
+ colourmap)
+
+
+ def configDisplayListeners(self):
+ """
+ Adds a bunch of listeners to the fslimage.ImageDisplay object which
+ defines how the given image is to be displayed. This is done so we
+ can update the colour texture when image display properties are
+ changed.
+ """
+
+ def colourUpdateNeeded(*a):
+ self.updateColourBuffer()
+
+ display = self.display
+ lnrName = 'GlImageData_{}'.format(id(self))
+
+ display.addListener('displayMin', lnrName, colourUpdateNeeded)
+ display.addListener('displayMax', lnrName, colourUpdateNeeded)
+ display.addListener('rangeClip', lnrName, colourUpdateNeeded)
+ display.addListener('cmap', lnrName, colourUpdateNeeded)
diff --git a/fsl/fslview/slicecanvas.py b/fsl/fslview/slicecanvas.py
index 1cb2d23e2..1c15f308f 100644
--- a/fsl/fslview/slicecanvas.py
+++ b/fsl/fslview/slicecanvas.py
@@ -6,298 +6,21 @@
# Author: Paul McCarthy <pauldmccarthy@gmail.com>
#
-import numpy as np
+import numpy as np
-import wx
-import wx.glcanvas as wxgl
+import wx
+import wx.glcanvas as wxgl
-import OpenGL.GL as gl
-import OpenGL.arrays.vbo as vbo
+import OpenGL.GL as gl
# Under OS X, I don't think I can request an OpenGL 3.2 core profile
# using wx - I'm stuck with OpenGL 2.1 I'm using these ARB extensions
# for functionality which is standard in 3.2.
import OpenGL.GL.ARB.instanced_arrays as arbia
import OpenGL.GL.ARB.draw_instanced as arbdi
-import OpenGL.GL.ARB.texture_rg as arbrg
-
-import fsl.data.fslimage as fslimage
-
-
-class GLImageData(object):
- """
- A GLImageData object encapsulates the OpenGL information necessary
- to render 2D slices of a 3D image.
-
- A slice from one image is rendered using four buffers and two textures.
-
- The first buffer, the 'geometry buffer' simply contains the 3D
- coordinates (single precision floating point) of four vertices, which
- define the geometry of a single voxel (using triangle strips).
-
- The remaining buffers contain the X, Y, and Z coordinates of the voxels
- in the slice to be displayed. These coordinates are stored as single
- precision floating points, and used both to position a voxel, and to
- look up its value in the 3D data texture (see below).
-
- The image data itself is stored as a 3D texture, with each voxel value
- stored as a single unsigned byte in the range 0-255.
-
- Finally, a 1D texture is used is used to store a lookup table containing
- an RGBA8 colour map, to colour each voxel according to its value.
- """
-
- def __init__(self, image, canvas):
- """
- Initialise the OpenGL data buffers required to render the given image.
- Parameters:
- - image: A fsl.data.fslimage.Image object.
- - canvas: The SliceCanvas object which is rendering the image.
- """
-
- self.image = image
- self.canvas = canvas
-
- # Maximum number of colours used to draw image data.
- # Keep this to a power of two, as some GL implementations
- # will complain/misbehave if it isn't.
- self.colourResolution = 256
-
- self.initGLImageData()
-
-
- def initGLImageData(self):
- """
- Creates and initialises the OpenGL data for the fslimage.Image
- object that was passed to the GLImageData constructor.
- """
-
- image = self.image
- canvas = self.canvas
-
- # The geometry buffer defines the geometry of
- # a single voxel, rendered as a triangle strip.
- geomData = np.zeros((4, 3), dtype=np.float32)
- geomData[:, [canvas.xax, canvas.yax]] = [[-0.5, -0.5],
- [ 0.5, -0.5],
- [-0.5, 0.5],
- [ 0.5, 0.5]]
-
- geomData = geomData.ravel('C')
- geomBuffer = vbo.VBO(geomData, gl.GL_STATIC_DRAW)
-
- # x/y/z coordinates are stored as VBO arrays
- voxData = []
- for dim in image.shape:
- data = np.arange(0, dim, dtype=np.float32)
- voxData.append(data)
-
- # the screen x coordinate data has to be repeated (ydim)
- # times - we are drawing row-wise, and opengl does not
- # allow us to loop over a VBO in a single instance
- # rendering call
- voxData[canvas.xax] = np.tile(voxData[ canvas.xax],
- image.shape[canvas.yax])
-
- xBuffer = vbo.VBO(voxData[0], gl.GL_STATIC_DRAW)
- yBuffer = vbo.VBO(voxData[1], gl.GL_STATIC_DRAW)
- zBuffer = vbo.VBO(voxData[2], gl.GL_STATIC_DRAW)
-
- # The colour buffer, containing a map of
- # colours (stored on the GPU as a 1D texture)
- # This is initialised in the updateColourBuffer
- # method
- colourBuffer = gl.glGenTextures(1)
-
- self.dataBuffer = self.initImageBuffer()
- self.voxXBuffer = xBuffer
- self.voxYBuffer = yBuffer
- self.voxZBuffer = zBuffer
- self.geomBuffer = geomBuffer
- self.colourBuffer = colourBuffer
-
- # Add listeners to this image so the view can be
- # updated when its display properties are changed
- self.configDisplayListeners()
-
- # Create the colour buffer for the given image
- self.updateColourBuffer()
-
-
- def initImageBuffer(self):
- """
- Initialises the OpenGL buffer used to store the data for the given
- image. The buffer is stored as an attribute of the image and, if it
- has already been created (e.g. by another SliceCanvas object), the
- existing buffer is returned.
- """
-
- image = self.image
-
- texShape = 2 ** (np.ceil(np.log2(image.shape)))
- pad = [(0, l - s) for (l, s) in zip(texShape, image.shape)]
- self.imageTexShape = texShape
-
- try: imageBuffer = image.getAttribute('glBuffers')
- except: imageBuffer = None
-
- if imageBuffer is not None:
- return imageBuffer
-
- # The image data is normalised to lie
- # between 0 and 255, and cast to uint8
- imageData = np.array(image.data, dtype=np.float32)
- imageData = 255.0 * (imageData - imageData.min()) / \
- (imageData.max() - imageData.min())
-
- # and each dimension is padded so it has a
- # power-of-two length. Ugh. This is a horrible,
- # but as far as I'm aware necessary hack. At
- # least it's necessary using the OpenGL 2.1
- # API on OSX mavericks. It massively increases
- # image load time, too.
- imageData = np.pad(imageData, pad, 'constant', constant_values=0)
- imageData = np.array(imageData, dtype=np.uint8)
-
- # Then flattened, with fortran dimension ordering,
- # so the data, as stored on the GPU, has its first
- # dimension as the fastest changing.
- imageData = imageData.ravel(order='F')
-
- # Image data is stored on the GPU as a 3D texture
- imageBuffer = gl.glGenTextures(1)
- gl.glBindTexture(gl.GL_TEXTURE_3D, imageBuffer)
- gl.glTexParameteri(gl.GL_TEXTURE_3D,
- gl.GL_TEXTURE_MAG_FILTER,
- gl.GL_NEAREST)
- gl.glTexParameteri(gl.GL_TEXTURE_3D,
- gl.GL_TEXTURE_MIN_FILTER,
- gl.GL_NEAREST)
- gl.glTexParameteri(gl.GL_TEXTURE_3D,
- gl.GL_TEXTURE_WRAP_S,
- gl.GL_CLAMP_TO_EDGE)
- gl.glTexParameteri(gl.GL_TEXTURE_3D,
- gl.GL_TEXTURE_WRAP_T,
- gl.GL_CLAMP_TO_EDGE)
- gl.glTexParameteri(gl.GL_TEXTURE_3D,
- gl.GL_TEXTURE_WRAP_R,
- gl.GL_CLAMP_TO_EDGE)
-
- gl.glTexImage3D(gl.GL_TEXTURE_3D,
- 0,
- arbrg.GL_R8,
- texShape[0],
- texShape[1],
- texShape[2],
- 0,
- gl.GL_RED,
- gl.GL_UNSIGNED_BYTE,
- imageData)
-
- # And added as an attribute of the image, so
- # other things which want to render the image
- # don't need to recreate all of those buffers.
- image.setAttribute('glBuffers', imageBuffer)
-
- return imageBuffer
-
-
- def updateColourBuffer(self):
- """
- Regenerates the colour buffer used to colour image voxels.
- """
-
- display = self.image.display
- colourBuffer = self.colourBuffer
-
- # Here we are creating a range of values to be passed
- # to the matplotlib.colors.Colormap instance of the
- # image display. We scale this range such that data
- # values which lie outside the configured display range
- # will map to values below 0.0 or above 1.0. It is
- # assumed that the Colormap instance is configured to
- # generate appropriate colours for these out-of-range
- # values.
-
- normalRange = np.linspace(0.0, 1.0, self.colourResolution)
- normalStep = 1.0 / (self.colourResolution - 1)
-
- normMin = (display.displayMin - display.dataMin) / \
- (display.dataMax - display.dataMin)
- normMax = (display.displayMax - display.dataMin) / \
- (display.dataMax - display.dataMin)
-
- newStep = normalStep / (normMax - normMin)
- newRange = (normalRange - normMin) * (newStep / normalStep)
-
- # Create [self.colourResolution] rgb values,
- # spanning the entire range of the image
- # colour map
- colourmap = display.cmap(newRange)
-
- # The colour data is stored on
- # the GPU as 8 bit rgba tuples
- colourmap = np.floor(colourmap * 255)
- colourmap = np.array(colourmap, dtype=np.uint8)
- colourmap = colourmap.ravel(order='C')
-
- # GL texture creation stuff
- gl.glBindTexture(gl.GL_TEXTURE_1D, colourBuffer)
- gl.glTexParameteri(gl.GL_TEXTURE_1D,
- gl.GL_TEXTURE_MAG_FILTER,
- gl.GL_NEAREST)
- gl.glTexParameteri(gl.GL_TEXTURE_1D,
- gl.GL_TEXTURE_MIN_FILTER,
- gl.GL_NEAREST)
- gl.glTexParameteri(gl.GL_TEXTURE_1D,
- gl.GL_TEXTURE_WRAP_S,
- gl.GL_CLAMP_TO_EDGE)
-
- gl.glTexImage1D(gl.GL_TEXTURE_1D,
- 0,
- gl.GL_RGBA8,
- self.colourResolution,
- 0,
- gl.GL_RGBA,
- gl.GL_UNSIGNED_BYTE,
- colourmap)
-
-
- def configDisplayListeners(self):
- """
- Adds a bunch of listeners to the fslimage.ImageDisplay object
- (accessible as an attribute, called 'display', of the given image),
- which defines how the given image is to be displayed. This is done
- so we can refresh the image view when image display properties are
- changed.
- """
-
- def refreshNeeded(*a):
- """
- The view just needs to be refreshed (e.g. the alpha property
- has changed).
- """
- self.canvas.Refresh()
-
- def colourUpdateNeeded(*a):
- """
- The colour map for this image needs to be recreated (e.g. the
- colour map has been changed).
- """
- self.updateColourBuffer()
- self.canvas.Refresh()
-
- display = self.image.display
- lnrName = 'SliceCanvas_{{}}_{}'.format(id(self))
- refreshProps = ['alpha', 'enabled']
- colourUpdateProps = ['displayMin', 'displayMax', 'rangeClip', 'cmap']
-
- for prop in refreshProps:
- display.addListener(prop, lnrName.format(prop), refreshNeeded)
-
- for prop in colourUpdateProps:
- display.addListener(prop, lnrName.format(prop), colourUpdateNeeded)
+import fsl.data.fslimage as fslimage
+import fsl.fslview.glimagedata as glimagedata
# The vertex shader positions and colours a single vertex.
@@ -577,15 +300,26 @@ class SliceCanvas(wxgl.GLCanvas):
self.ypos = self.ypos
self.zpos = self.zpos
- # Create a GLImageData object
- # for any new images
+ # Create a GLImageData object for any new images,
+ # and attach a listener to their display properties
+ # so we know when to refresh the canvas.
for image in self.imageList:
try:
glData = image.getAttribute(self.name)
except:
- glData = GLImageData(image, self)
+ glData = glimagedata.GLImageData(image, self.xax, self.yax)
image.setAttribute(self.name, glData)
+ def refresh(*a):
+ self.Refresh()
+
+ image.display.addListener('enabled', self.name, refresh)
+ image.display.addListener('alpha', self.name, refresh)
+ image.display.addListener('displayMin', self.name, refresh)
+ image.display.addListener('displayMax', self.name, refresh)
+ image.display.addListener('rangeClip', self.name, refresh)
+ image.display.addListener('cmap', self.name, refresh)
+
self.Refresh()
--
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