Qt: OpenIGTLink: send received images

Also handling client reconnection, since this is where we have to
detect disconnects.

Author: ClaudioHoffmann

examples/solum_qt/solum/openigtlink.cpp

@@ -2,6 +2,7 @@
 
 SolumIGTL::SolumIGTL()
 {
+    msg_ = igtl::ImageMessage::New();
     QObject::connect(&clientConnectTimer_, &QTimer::timeout, [this]()
     {
         client_ = server_->WaitForConnection(1); // 0 would wait forever.
@@ -33,6 +34,37 @@ void SolumIGTL::setNodeName(const QString &name)
     nodeName_ = name.toStdString();
 }
 
+void SolumIGTL::sendImage(const void* img, int w, int h, int bpp, size_t sz)
+{
+    if (!isClientConnected())
+        return;
+
+    assert(bpp == 32);
+
+    int wPrev, hPrev, zPrev;
+    msg_->GetDimensions(wPrev, hPrev, zPrev);
+    if ((wPrev != w) || (hPrev != h))
+    {
+        msg_->SetDimensions(w, h, 1);
+        msg_->SetSpacing(1.0f, 1.0f, 5.0f); // required for reslicing to not crash
+        msg_->SetScalarType(igtl::ImageMessage::TYPE_UINT32);
+        msg_->SetSubVolume(w, h, 1, 0, 0, 0); // determines the buffer size!
+        msg_->SetDeviceName(nodeName_);
+        msg_->AllocateScalars();
+    }
+
+    // Also necessary to force a repack below.
+    msg_->SetMessageID(msg_->GetMessageID() + 1);
+
+    // Even C++23 does not have output ranges anyway...
+    // (https://thephd.dev/output-ranges)
+    memcpy(msg_->GetScalarPointer(), img, sz);
+
+    msg_->Pack();
+    if (client_->Send(msg_->GetPackPointer(), msg_->GetPackSize()) == 0)
+        reconnectClient();
+}
+
 void SolumIGTL::disconnectClient()
 {
     clientConnectTimer_.stop();

examples/solum_qt/solum/openigtlink.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "igtlImageMessage.h"
 #include "igtlServerSocket.h"
 
 /// OpenIGTLink module
@@ -14,6 +15,7 @@ class SolumIGTL : public QObject
     void close();
 
     void setNodeName(const QString& name);
+    void sendImage(const void* img, int w, int h, int bpp, size_t sz);
 
     bool isServing() const;
     bool isClientConnected() const;
@@ -29,4 +31,7 @@ class SolumIGTL : public QObject
     igtl::Socket::Pointer client_;
     QTimer clientConnectTimer_;
     std::string nodeName_;
+
+    // Sharing an allocation for all images of the same size.
+    igtl::ImageMessage::Pointer msg_;
 };

examples/solum_qt/solum/solumqt.cpp

@@ -695,6 +695,7 @@ void Solum::setProgress(int progress)
 /// @param[in] imu the imu data if valid
 void Solum::newProcessedImage(const void* img, int w, int h, int bpp, int sz, const QQuaternion& imu)
 {
+    igtl_.sendImage(img, w, h, bpp, sz);
     image_->loadImage(img, w, h, bpp, sz);
     if (!imu.isNull())
         render_->update(imu);