From c434c2b62c911c082a52e0ef757dd573e3bb60c8 Mon Sep 17 00:00:00 2001
From: Bert Peters <bert@bertptrs.nl>
Date: Mon, 30 Apr 2018 13:40:12 +0200
Subject: [PATCH] Implement interaciton paths for labels.

---
 src/fmri/ActivityAnimation.cpp  |  2 +-
 src/fmri/LabelVisualisation.cpp | 30 +++++++++++++++++++++++++-----
 src/fmri/LabelVisualisation.hpp |  1 +
 src/fmri/glutils.cpp            |  9 +++++++++
 src/fmri/glutils.hpp            | 10 +++++++++-
 5 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/src/fmri/ActivityAnimation.cpp b/src/fmri/ActivityAnimation.cpp
index 8b58b0f..4d60d13 100644
--- a/src/fmri/ActivityAnimation.cpp
+++ b/src/fmri/ActivityAnimation.cpp
@@ -75,7 +75,7 @@ void ActivityAnimation::draw(float timeScale)
     glDrawArrays(GL_POINTS, 0, bufferLength / 3);
     glDisableClientState(GL_COLOR_ARRAY);
     if (RenderingState::instance().renderInteractionPaths()) {
-        glColor4fv(RenderingState::instance().pathColor().data());
+        setGlColor(RenderingState::instance().pathColor());
         glVertexPointer(3, GL_FLOAT, 0, startingPos.data());
         glDrawElements(GL_LINES, lineIndices.size(), GL_UNSIGNED_INT, lineIndices.data());
     }
diff --git a/src/fmri/LabelVisualisation.cpp b/src/fmri/LabelVisualisation.cpp
index d73ba37..831402c 100644
--- a/src/fmri/LabelVisualisation.cpp
+++ b/src/fmri/LabelVisualisation.cpp
@@ -1,22 +1,27 @@
 #include <GL/gl.h>
 #include "LabelVisualisation.hpp"
 #include "glutils.hpp"
+#include "RenderingState.hpp"
 
 using namespace fmri;
 
 void LabelVisualisation::draw(float)
 {
+    if (RenderingState::instance().renderInteractionPaths()) {
+        setGlColor(RenderingState::instance().pathColor());
+        glEnableClientState(GL_VERTEX_ARRAY);
+        glVertexPointer(3, GL_FLOAT, 0, nodePositions_.data());
+        glDrawElements(GL_LINES, nodeIndices.size(), GL_UNSIGNED_INT, nodeIndices.data());
+        glDisableClientState(GL_VERTEX_ARRAY);
+    }
+
     glPushMatrix();
     glTranslatef(LAYER_X_OFFSET, 0, 0);
 
     for (auto i = 0u; i < nodeLabels.size(); ++i) {
         glPushMatrix();
         glTranslatef(nodePositions_[3 * i], nodePositions_[3 * i + 1], nodePositions_[3 * i + 2]);
-        if constexpr (alphaEnabled()) {
-            glColor4fv(colorBuffer[i].data());
-        } else {
-            glColor3fv(colorBuffer[i].data());
-        }
+        setGlColor(colorBuffer[i]);
         renderText(nodeLabels[i]);
         glPopMatrix();
     }
@@ -32,6 +37,7 @@ LabelVisualisation::LabelVisualisation(const std::vector<float> &positions, cons
 
     auto nodeInserter = std::back_inserter(nodePositions_);
 
+    // First, determine all nodes elegible to be rendered.
     for (auto i = 0u; i < limit; ++i) {
         if (prevData[i] < DISPLAY_LIMIT) {
             continue;
@@ -42,5 +48,19 @@ LabelVisualisation::LabelVisualisation(const std::vector<float> &positions, cons
         nodeLabels.emplace_back(labels[i]);
     }
 
+    // Now fix the points for the interaction paths.
+    nodeIndices.reserve(2 * nodeLabels.size());
+    for (auto i = 0u; i < nodeLabels.size(); ++i) {
+        nodeIndices.push_back(i);
+        nodeIndices.push_back(i + nodeLabels.size());
+    }
+
+    // Make sure the end positions exist.
+    std::copy_n(nodePositions_.begin(), nodePositions_.size(), nodeInserter);
+    for (auto i = nodePositions_.size() / 2; i < nodePositions_.size(); i += 3) {
+        nodePositions_[i] = LAYER_X_OFFSET;
+    }
+
+
     patchTransparancy();
 }
diff --git a/src/fmri/LabelVisualisation.hpp b/src/fmri/LabelVisualisation.hpp
index a429322..dd84afc 100644
--- a/src/fmri/LabelVisualisation.hpp
+++ b/src/fmri/LabelVisualisation.hpp
@@ -16,5 +16,6 @@ namespace fmri
 
         std::vector<std::string> nodeLabels;
         std::vector<float> nodePositions_;
+        std::vector<int> nodeIndices;
     };
 }
diff --git a/src/fmri/glutils.cpp b/src/fmri/glutils.cpp
index 9d30cd4..585e169 100644
--- a/src/fmri/glutils.cpp
+++ b/src/fmri/glutils.cpp
@@ -136,3 +136,12 @@ void fmri::registerErrorCallbacks()
     LOG(INFO) << "Compiled without freeglut, error handlers not available.";
 #endif
 }
+
+void fmri::setGlColor(const Color &c)
+{
+    if constexpr (alphaEnabled()) {
+        glColor4fv(c.data());
+    } else {
+        glColor3fv(c.data());
+    }
+}
diff --git a/src/fmri/glutils.hpp b/src/fmri/glutils.hpp
index 8286d2e..63bb723 100644
--- a/src/fmri/glutils.hpp
+++ b/src/fmri/glutils.hpp
@@ -52,7 +52,15 @@ namespace fmri {
     drawImageTiles(int n, const float *vertexBuffer, const float *textureCoords, const Texture &texture, float alpha);
 
     /**
-     * Attempmt to register
+     * Attempt to register error handlers in GLUT.
+     *
+     * Only works in Freeglut.
      */
     void registerErrorCallbacks();
+
+    /**
+     * Set GL drawing color from internal color.
+     * @param c
+     */
+    void setGlColor(const Color& c);
 }