Build OpenCL program as soon as the OpenCL device is initialized.

Before this, the program was built when the first frame arrives and the following frames were dropped, because building the program takes a while.
Now, the program is built before the device is started. When the first frame arrives, it only needs to be initialized, which is quite fast.

Author: HenningJ

examples/protonect/src/opencl_depth_packet_processor.cpp

@@ -138,10 +138,14 @@ class OpenCLDepthPacketProcessorImpl
   cl::Buffer buf_filtered;
 
   bool deviceInitialized;
+  bool programBuilt;
   bool programInitialized;
   std::string sourceCode;
 
-  OpenCLDepthPacketProcessorImpl(const int deviceId = -1) : deviceInitialized(false), programInitialized(false)
+  OpenCLDepthPacketProcessorImpl(const int deviceId = -1) 
+    : deviceInitialized(false)
+    , programBuilt(false)
+    , programInitialized(false)
   {
     newIrFrame();
     newDepthFrame();
@@ -350,7 +354,8 @@ class OpenCLDepthPacketProcessorImpl
       std::cerr << OUT_NAME("init") "ERROR: " << err.what() << "(" << err.err() << ")" << std::endl;
       throw;
     }
-    return true;
+
+    return buildProgram(sourceCode);
   }
 
   bool initProgram()
@@ -360,16 +365,13 @@ class OpenCLDepthPacketProcessorImpl
       return false;
     }
 
+    if (!programBuilt)
+      if (!buildProgram(sourceCode))
+        return false;
+
     cl_int err = CL_SUCCESS;
     try
     {
-      std::string options;
-      generateOptions(options);
-
-      cl::Program::Sources source(1, std::make_pair(sourceCode.c_str(), sourceCode.length()));
-      program = cl::Program(context, source);
-      program.build(options.c_str());
-
       queue = cl::CommandQueue(context, device, 0, &err);
 
       //Read only
@@ -454,14 +456,6 @@ class OpenCLDepthPacketProcessorImpl
     catch(const cl::Error &err)
     {
       std::cerr << OUT_NAME("init") "ERROR: " << err.what() << "(" << err.err() << ")" << std::endl;
-
-      if(err.err() == CL_BUILD_PROGRAM_FAILURE)
-      {
-        std::cout << OUT_NAME("init") "Build Status: " << program.getBuildInfo<CL_PROGRAM_BUILD_STATUS>(device) << std::endl;
-        std::cout << OUT_NAME("init") "Build Options:\t" << program.getBuildInfo<CL_PROGRAM_BUILD_OPTIONS>(device) << std::endl;
-        std::cout << OUT_NAME("init") "Build Log:\t " << program.getBuildInfo<CL_PROGRAM_BUILD_LOG>(device) << std::endl;
-      }
-
       throw;
     }
     programInitialized = true;
@@ -517,6 +511,38 @@ class OpenCLDepthPacketProcessorImpl
     return !source.empty();
   }
 
+  bool buildProgram(const std::string& sources)
+  {
+    try
+    {
+      std::cout<< OUT_NAME("buildProgram") "building OpenCL program..." <<std::endl;
+
+      std::string options;
+      generateOptions(options);
+
+      cl::Program::Sources source(1, std::make_pair(sources.c_str(), sources.length()));
+      program = cl::Program(context, source);
+      program.build(options.c_str());
+      std::cout<< OUT_NAME("buildProgram") "OpenCL program built successfully" <<std::endl;
+    }
+    catch(const cl::Error &err)
+    {
+      std::cerr << OUT_NAME("buildProgram") "ERROR: " << err.what() << "(" << err.err() << ")" << std::endl;
+
+      if(err.err() == CL_BUILD_PROGRAM_FAILURE)
+      {
+        std::cout << OUT_NAME("buildProgram") "Build Status: " << program.getBuildInfo<CL_PROGRAM_BUILD_STATUS>(device) << std::endl;
+        std::cout << OUT_NAME("buildProgram") "Build Options:\t" << program.getBuildInfo<CL_PROGRAM_BUILD_OPTIONS>(device) << std::endl;
+        std::cout << OUT_NAME("buildProgram") "Build Log:\t " << program.getBuildInfo<CL_PROGRAM_BUILD_LOG>(device) << std::endl;
+      }
+
+      programBuilt = false;
+      return false;
+    }
+    programBuilt = true;
+    return true;
+  }
+
   void startTiming()
   {
     timing_current_start = cv::getTickCount();
@@ -578,8 +604,23 @@ OpenCLDepthPacketProcessor::~OpenCLDepthPacketProcessor()
 void OpenCLDepthPacketProcessor::setConfiguration(const libfreenect2::DepthPacketProcessor::Config &config)
 {
   DepthPacketProcessor::setConfiguration(config);
+
+  if ( impl_->config.MaxDepth != config.MaxDepth 
+    || impl_->config.MinDepth != config.MinDepth)
+  {
+    // OpenCL program needs to be rebuilt, then reinitialized
+    impl_->programBuilt = false;
+    impl_->programInitialized = false;
+    impl_->buildProgram(impl_->sourceCode);
+  }
+  else if (impl_->config.EnableBilateralFilter != config.EnableBilateralFilter
+    || impl_->config.EnableEdgeAwareFilter != config.EnableEdgeAwareFilter)
+  {
+    // OpenCL program only needs to be reinitialized
+    impl_->programInitialized = false;
+  }
+
   impl_->config = config;
-  impl_->programInitialized = false;
 }
 
 void OpenCLDepthPacketProcessor::loadP0TablesFromCommandResponse(unsigned char *buffer, size_t buffer_length)