v01

thirdparty/Pangolin/examples/SharedMemoryCamera/CMakeLists.txt

@@ -0,0 +1,7 @@
+if(UNIX)
+find_package(Pangolin 0.4 REQUIRED)
+include_directories(${Pangolin_INCLUDE_DIRS})
+
+add_executable(SharedMemoryCamera main.cpp)
+target_link_libraries(SharedMemoryCamera ${Pangolin_LIBRARIES})
+endif()

thirdparty/Pangolin/examples/SharedMemoryCamera/main.cpp

@@ -0,0 +1,53 @@
+#include <pangolin/pangolin.h>
+
+#include <pangolin/utils/posix/condition_variable.h>
+#include <pangolin/utils/posix/shared_memory_buffer.h>
+#include <pangolin/utils/timer.h>
+
+#include <cmath>
+#include <memory>
+
+// This sample acts as a soft camera. It writes a pattern of GRAY8 pixels to the
+// shared memory space. It can be seen in Pangolin's SimpleVideo sample using
+// the shmem:[size=640x480]//example video URI.
+
+using namespace pangolin;
+
+unsigned char generate_value(double t)
+{
+  // 10s sinusoid
+  const double d = std::sin(t * 10.0 / M_PI) * 128.0 + 128.0;
+  return static_cast<unsigned char>(d);
+}
+
+int main(/*int argc, char *argv[]*/)
+{
+  std::string shmem_name = "/example";
+
+  std::shared_ptr<SharedMemoryBufferInterface> shmem_buffer =
+    create_named_shared_memory_buffer(shmem_name, 640 * 480);
+  if (!shmem_buffer) {
+    perror("Unable to create shared memory buffer");
+    exit(1);
+  }
+
+  std::string cond_name = shmem_name + "_cond";
+  std::shared_ptr<ConditionVariableInterface> buffer_full =
+    create_named_condition_variable(cond_name);
+
+  // Sit in a loop and write gray values based on some timing pattern.
+  while (true) {
+    shmem_buffer->lock();
+    unsigned char *ptr = shmem_buffer->ptr();
+    unsigned char value = generate_value(std::chrono::system_clock::now().time_since_epoch().count());
+
+    for (int i = 0; i < 640*480; ++i) {
+      ptr[i] = value;
+    }
+
+    shmem_buffer->unlock();
+    buffer_full->signal();
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(10));
+  }
+}