From f6fd3df6f578bb746fec2ea51a123e5a4a843a47 Mon Sep 17 00:00:00 2001
From: Paul McCarthy <pauld.mccarthy@gmail.com>
Date: Mon, 7 Dec 2015 16:57:26 +0000
Subject: [PATCH] Negative colour map implemented in GL14.
---
fsl/fsleyes/gl/gl14/glvolume_frag.prog | 38 ++++++++++++++++++++++++--
fsl/fsleyes/gl/gl14/glvolume_funcs.py | 3 +-
2 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/fsl/fsleyes/gl/gl14/glvolume_frag.prog b/fsl/fsleyes/gl/gl14/glvolume_frag.prog
index 387efb55e..3c43b5688 100644
--- a/fsl/fsleyes/gl/gl14/glvolume_frag.prog
+++ b/fsl/fsleyes/gl/gl14/glvolume_frag.prog
@@ -59,6 +59,8 @@ TEMP voxClipHi;
TEMP voxValue;
TEMP posColour;
TEMP negColour;
+TEMP useNegCmap;
+TEMP negVoxValue;
PARAM imageShape = program.local[4];
PARAM clipping = program.local[5];
@@ -80,9 +82,36 @@ MOV voxCoord, fragment.texcoord[1];
# look up image voxel value
# from 3D image texture
-TEX voxValue, fragment.texcoord[0], texture[0], 3D;
-
+TEX voxValue.x, fragment.texcoord[0], texture[0], 3D;
+# Figure out which negative colour map
+# should be used for this fragment.
+# We use the negative colour map ...
+#
+# if the voxel value is less than
+# texZero (the display range centre),
+SLT useNegCmap.x, voxValue.x, negCmap.y;
+
+# and the negative colour map is active.
+# The useNegCmap vector will be negative
+# if both of these conditions are true,
+# positive otherwise.
+MUL useNegCmap.x, useNegCmap.x, negCmap.x;
+SUB useNegCmap.x, useNegCmap.x, 0.5;
+MUL useNegCmap.x, useNegCmap.x, -1;
+
+# If using the negative colour map,
+# we need to flip the voxel value about
+# the display range centre.
+
+# Calculate the inverted voxel value
+ADD negVoxValue.x, negCmap.y, negCmap.y;
+SUB negVoxValue.x, negVoxValue.x, voxValue.x;
+
+# If we're using the negative colour
+# map, replace the original voxel
+# value with the inverted one.
+CMP voxValue.x, useNegCmap.x, negVoxValue.x, voxValue.x;
# Test the low clipping range
SUB voxClipLo, voxValue.x, clipping.x;
@@ -117,6 +146,9 @@ MAD voxValue, voxValue, voxValXform[0].x, voxValXform[3].x;
TEX posColour, voxValue.x, texture[1], 1D;
TEX negColour, voxValue.x, texture[2], 1D;
-MOV result.color, posColour;
+# useNegCmap is negative if the
+# negative colour map should be
+# used, positive otherwise.
+CMP result.color, useNegCmap.x, negColour, posColour;
END
diff --git a/fsl/fsleyes/gl/gl14/glvolume_funcs.py b/fsl/fsleyes/gl/gl14/glvolume_funcs.py
index d3462b447..9fa8aa1b5 100644
--- a/fsl/fsleyes/gl/gl14/glvolume_funcs.py
+++ b/fsl/fsleyes/gl/gl14/glvolume_funcs.py
@@ -93,11 +93,10 @@ def updateShaderState(self):
# And the clipping range, normalised
# to the image texture value range
- xform = self.imageTexture.invVoxValXform
-
invClip = 1 if opts.invertClipping else -1
useNegCmap = 1 if opts.enableNegativeCmap else 0
+ xform = self.imageTexture.invVoxValXform
clipLo = opts.clippingRange[0] * xform[0, 0] + xform[3, 0]
clipHi = opts.clippingRange[1] * xform[0, 0] + xform[3, 0]
texZero = 0.0 * xform[0, 0] + xform[3, 0]
--
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