WPILib Reorganization

This is a major restructuring of the WPILib repository to simply build
procedures and remove the remnants of Maven from everything except the
eclipse plugins. Gradle files have been largely simplified or rewritten,
taking advantage of splitting up parts of the build into separate build
files for ease of reading.

The eclipse plugins are now in a separate project, as is ntcore. All
dependencies are resolved via Maven dependencies, with the
Jenkins-maintained WPILib repo. Project structures have also been
simplified: we no longer have separate subprojects inside wpilibc and
wpilibj. Where possible, these changes hav been done with git renames,
to make sure we still have full history for all repositories. Other
unrelated subprojects have also been broken out: OutlineViewer is now a
separate project.

Change-Id: Ib4e2a6e1a2f66427a14f16612b0e0d69ed661878

wpilibc/Athena/src/CameraServer.cpp

@@ -0,0 +1,257 @@
+#include "CameraServer.h"
+#include "WPIErrors.h"
+#include "Utility.h"
+
+#include <iostream>
+#include <chrono>
+#include <cstring>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <netdb.h>
+
+constexpr uint8_t CameraServer::kMagicNumber[];
+
+CameraServer* CameraServer::GetInstance() {
+  static CameraServer instance;
+  return &instance;
+}
+
+CameraServer::CameraServer()
+    : m_camera(),
+      m_serverThread(&CameraServer::Serve, this),
+      m_captureThread(),
+      m_imageMutex(),
+      m_newImageVariable(),
+      m_dataPool(3),
+      m_quality(50),
+      m_autoCaptureStarted(false),
+      m_hwClient(true),
+      m_imageData(nullptr, 0, 0, false) {
+  for (int i = 0; i < 3; i++) m_dataPool.push_back(new uint8_t[kMaxImageSize]);
+}
+
+void CameraServer::FreeImageData(
+    std::tuple<uint8_t*, unsigned int, unsigned int, bool> imageData) {
+  if (std::get<3>(imageData))
+    imaqDispose(std::get<0>(imageData));
+  else if (std::get<0>(imageData) != nullptr) {
+    std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+    m_dataPool.push_back(std::get<0>(imageData));
+  }
+}
+
+void CameraServer::SetImageData(uint8_t* data, unsigned int size,
+                                unsigned int start, bool imaqData) {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  FreeImageData(m_imageData);
+  m_imageData = std::make_tuple(data, size, start, imaqData);
+  m_newImageVariable.notify_all();
+}
+
+void CameraServer::SetImage(Image const* image) {
+  unsigned int dataSize = 0;
+  uint8_t* data =
+      (uint8_t*)imaqFlatten(image, IMAQ_FLATTEN_IMAGE, IMAQ_COMPRESSION_JPEG,
+                            10 * m_quality, &dataSize);
+
+  // If we're using a HW camera, then find the start of the data
+  bool hwClient;
+  {
+    // Make a local copy of the hwClient variable so that we can safely use it.
+    std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+    hwClient = m_hwClient;
+  }
+  unsigned int start = 0;
+  if (hwClient) {
+    while (start < dataSize - 1) {
+      if (data[start] == 0xFF && data[start + 1] == 0xD8)
+        break;
+      else
+        start++;
+    }
+  }
+  dataSize -= start;
+
+  wpi_assert(dataSize > 2);
+  SetImageData(data, dataSize, start, true);
+}
+
+void CameraServer::AutoCapture() {
+  Image* frame = imaqCreateImage(IMAQ_IMAGE_RGB, 0);
+
+  while (true) {
+    bool hwClient;
+    uint8_t* data = nullptr;
+    {
+      std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+      hwClient = m_hwClient;
+      if (hwClient) {
+        data = m_dataPool.back();
+        m_dataPool.pop_back();
+      }
+    }
+
+    if (hwClient) {
+      unsigned int size = m_camera->GetImageData(data, kMaxImageSize);
+      SetImageData(data, size);
+    } else {
+      m_camera->GetImage(frame);
+      SetImage(frame);
+    }
+  }
+}
+
+void CameraServer::StartAutomaticCapture(char const* cameraName) {
+  std::shared_ptr<USBCamera> camera =
+      std::make_shared<USBCamera>(cameraName, true);
+  camera->OpenCamera();
+  StartAutomaticCapture(camera);
+}
+
+void CameraServer::StartAutomaticCapture(std::shared_ptr<USBCamera> camera) {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  if (m_autoCaptureStarted) return;
+
+  m_camera = camera;
+  m_camera->StartCapture();
+
+  m_captureThread = std::thread(&CameraServer::AutoCapture, this);
+  m_captureThread.detach();
+  m_autoCaptureStarted = true;
+}
+
+bool CameraServer::IsAutoCaptureStarted() {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  return m_autoCaptureStarted;
+}
+
+void CameraServer::SetSize(unsigned int size) {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  if (!m_camera) return;
+  if (size == kSize160x120)
+    m_camera->SetSize(160, 120);
+  else if (size == kSize320x240)
+    m_camera->SetSize(320, 240);
+  else if (size == kSize640x480)
+    m_camera->SetSize(640, 480);
+}
+
+void CameraServer::SetQuality(unsigned int quality) {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  m_quality = quality > 100 ? 100 : quality;
+}
+
+unsigned int CameraServer::GetQuality() {
+  std::lock_guard<priority_recursive_mutex> lock(m_imageMutex);
+  return m_quality;
+}
+
+void CameraServer::Serve() {
+  int sock = socket(AF_INET, SOCK_STREAM, 0);
+
+  if (sock == -1) wpi_setErrnoError();
+
+  int reuseAddr = 1;
+  if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseAddr,
+                 sizeof(reuseAddr)) == -1)
+    wpi_setErrnoError();
+
+  sockaddr_in address, clientAddress;
+
+  memset(&address, 0, sizeof(address));
+  address.sin_family = AF_INET;
+  address.sin_addr.s_addr = htonl(INADDR_ANY);
+  address.sin_port = htons(kPort);
+
+  if (bind(sock, (struct sockaddr*)&address, sizeof(address)) == -1)
+    wpi_setErrnoError();
+
+  if (listen(sock, 10) == -1) wpi_setErrnoError();
+
+  while (true) {
+    socklen_t clientAddressLen = sizeof(clientAddress);
+
+    int conn =
+        accept(sock, (struct sockaddr*)&clientAddress, &clientAddressLen);
+    if (conn == -1) {
+      wpi_setErrnoError();
+      continue;
+    }
+
+    Request req;
+    if (read(conn, &req, sizeof(req)) == -1) {
+      wpi_setErrnoError();
+      close(conn);
+      continue;
+    } else {
+      req.fps = ntohl(req.fps);
+      req.compression = ntohl(req.compression);
+      req.size = ntohl(req.size);
+    }
+
+    // TODO: Support the SW Compression. The rest of the code below will work as
+    // though this
+    // check isn't here
+    if (req.compression != kHardwareCompression) {
+      wpi_setWPIErrorWithContext(IncompatibleState,
+                                 "Choose \"USB Camera HW\" on the dashboard");
+      close(conn);
+      continue;
+    }
+
+    {
+      // Wait for the camera to be setw
+      std::unique_lock<priority_recursive_mutex> lock(m_imageMutex);
+      if (!m_camera) {
+        std::cout << "Camera not yet ready, awaiting first image" << std::endl;
+        m_newImageVariable.wait(lock);
+      }
+      m_hwClient = req.compression == kHardwareCompression;
+      if (!m_hwClient)
+        SetQuality(100 - req.compression);
+      else if (m_camera)
+        m_camera->SetFPS(req.fps);
+      SetSize(req.size);
+    }
+
+    auto period = std::chrono::microseconds(1000000) / req.fps;
+    while (true) {
+      auto startTime = std::chrono::steady_clock::now();
+      std::tuple<uint8_t*, unsigned int, unsigned int, bool> imageData;
+      {
+        std::unique_lock<priority_recursive_mutex> lock(m_imageMutex);
+        m_newImageVariable.wait(lock);
+        imageData = m_imageData;
+        m_imageData = std::make_tuple<uint8_t*>(nullptr, 0, 0, false);
+      }
+
+      unsigned int size = std::get<1>(imageData);
+      unsigned int netSize = htonl(size);
+      unsigned int start = std::get<2>(imageData);
+      uint8_t* data = std::get<0>(imageData);
+
+      if (data == nullptr) continue;
+
+      if (write(conn, kMagicNumber, sizeof(kMagicNumber)) == -1) {
+        wpi_setErrnoErrorWithContext(
+            "[CameraServer] Error sending magic number");
+        FreeImageData(imageData);
+        break;
+      }
+      if (write(conn, &netSize, sizeof(netSize)) == -1) {
+        wpi_setErrnoErrorWithContext("[CameraServer] Error sending image size");
+        FreeImageData(imageData);
+        break;
+      }
+      if (write(conn, &data[start], sizeof(uint8_t) * size) == -1) {
+        wpi_setErrnoErrorWithContext("[CameraServer] Error sending image data");
+        FreeImageData(imageData);
+        break;
+      }
+      FreeImageData(imageData);
+      std::this_thread::sleep_until(startTime + period);
+    }
+    close(conn);
+  }
+  close(sock);
+}