Make usage of libtiff optional

* libtiff can be disabled by defining `APR_USE_LIBTIFF=OFF` when running
  cmake
* TiffUtils has been adjusted to provide shims in that case, which might
  break some examples

Author: skalarproduktraum

CMakeLists.txt

@@ -12,6 +12,7 @@ option(APR_INSTALL "Install APR library" OFF)
 option(APR_BUILD_SHARED_LIB "Builds shared library" ON)
 option(APR_BUILD_STATIC_LIB "Builds static library" OFF)
 option(APR_BUILD_EXAMPLES "Build APR examples" OFF)
+option(APR_USE_LIBTIFF "Use LibTIFF" ON)
 option(APR_TESTS "Build APR tests" OFF)
 option(APR_PREFER_EXTERNAL_GTEST "When found, use the installed GTEST libs instead of included sources" OFF)
 option(APR_PREFER_EXTERNAL_BLOSC "When found, use the installed BLOSC libs instead of included sources" OFF)
@@ -52,7 +53,13 @@ message("Configuring for APR version: " ${APR_VERSION_STRING})
 ###############################################################################
 find_package(HDF5 REQUIRED)
 find_package(ZLIB REQUIRED)
-find_package(TIFF REQUIRED)
+if(APR_USE_LIBTIFF)
+    find_package(TIFF)
+    set(CMAKE_C_FLAGS "${CMAKE_CFLAGS} -DHAVE_LIBTIFF")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXXFLAGS} -DHAVE_LIBTIFF")
+else()
+    message(WARNING "LibTIFF support disable, this disables TIFF writing functionality.")
+endif()
 
 # Handle OpenMP
 find_package(OpenMP)

src/io/TiffUtils.hpp

@@ -8,7 +8,9 @@
 
 
 #include <string>
-#include <tiffio.h>
+#ifdef HAVE_LIBTIFF
+    #include <tiffio.h>
+#endif
 #include <sstream>
 #include "data_structures/Mesh/PixelData.hpp"
 
@@ -56,7 +58,9 @@ namespace TiffUtils {
                     outputStr << "NOT SUPPORTED";
             }
             outputStr << ", Photometric: " << iPhotometric;
+#ifdef HAVE_LIBTIFF
             outputStr << ", StripSize: " << TIFFStripSize(iFile);
+#endif /* HAVE_LIBTIFF */
 
             return outputStr.str();
         }
@@ -67,7 +71,12 @@ namespace TiffUtils {
         bool isFileOpened() const { return iFile != nullptr; }
 
         TiffType iType = TiffType::TIFF_INVALID;
+#ifdef HAVE_LIBTIFF
         TIFF *iFile = nullptr;
+#else
+        void* iFile = nullptr;
+        typedef unsigned int uint32;
+#endif /* HAVE_LIBTIFF */
         std::string iFileName = "";
         uint32 iImgWidth = 0;
         uint32 iImgHeight = 0;
@@ -81,6 +90,12 @@ namespace TiffUtils {
         TiffInfo(const TiffInfo&) = delete; // make it noncopyable
         TiffInfo& operator=(const TiffInfo&) = delete; // make it not assignable
 
+        friend std::ostream& operator<<(std::ostream &os, const TiffInfo &obj) {
+            os << obj.toString();
+            return os;
+        }
+
+#ifdef HAVE_LIBTIFF
         /**
          * opens TIFF
          **/
@@ -142,12 +157,21 @@ namespace TiffUtils {
             }
         }
 
-        friend std::ostream& operator<<(std::ostream &os, const TiffInfo &obj) {
-            os << obj.toString();
-            return os;
+#else
+        bool open(const std::string &aFileName) {
+            std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+            std::cerr << "Trying to open file " << aFileName << ", returning false." << std::endl;
+            return false;
         }
+
+        void close() {
+            std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+            std::cerr << "Shim-closing TIFF file" << std::endl;
+        }
+#endif /* HAVE_LIBTIFF */
     };
 
+#ifdef HAVE_LIBTIFF
 
     /**
      * Reads TIFF file to mesh
@@ -287,6 +311,46 @@ namespace TiffUtils {
         PixelData<uint16_t> mesh16{aData, true /*copy data*/};
         saveMeshAsTiff(filename, mesh16);
     }
+#else
+    template<typename T>
+    PixelData<T> getMesh(const std::string &aFileName) {
+        std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+        std::cerr << "getMesh() called for " << &aFileName << ", returning empty mesh." << std::endl;
+
+        PixelData<T> mesh(1, 1, 1);
+        return mesh;
+    }
+
+    template<typename T>
+    PixelData<T> getMesh(const TiffInfo &aTiff) {
+        std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+        std::cerr << "getMesh() called for TiffInfo, returning empty mesh." << std::endl;
+
+        PixelData<T> mesh(1, 1, 1);
+        return mesh;
+    }
+
+    template<typename T>
+    void getMesh(const TiffInfo &aTiff, PixelData<T> &aInputMesh) {
+        std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+        std::cerr << "getMesh() called for inputMesh, returning empty inputMesh." << std::endl;
+
+        PixelData<T> mesh(1, 1, 1);
+        aInputMesh.swap(mesh);
+    }
+
+    template<typename T>
+    void saveMeshAsTiff(const std::string &aFileName, const PixelData<T> &aData) {
+        std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+        std::cerr << "saveMeshAsTiff() called for " << aFileName << ", not doing anything." << std::endl;
+    }
+
+    template<typename T>
+    void saveMeshAsTiffUint16(const std::string &filename, const PixelData<T> &aData) {
+        std::cerr << "libapr compiled without LibTIFF support, simulating TIFF reader functionality" << std::endl;
+        std::cerr << "saveMeshAsTiff() called for " << filename << ", not doing anything." << std::endl;
+    }
+#endif
 }
 
 #endif