Fixes for NULL pointer dereference (pxscene#930)

* Warnings scrub on macOS

* Unified type use for matrix calculations and templates

* Revert "Merge branch 'master' of https://github.com/FitzerIRL/pxCore"

This reverts commit 0fe607b, reversing
changes made to 99063c3.

* Revert "Unified type use for matrix calculations and templates"

This reverts commit 99063c3.

* Added checks for NULL pointers

src/mac/pxClipboardNative.mm

@@ -12,22 +12,35 @@
 
 std::string pxClipboardNative::getString(std::string type)
 {
-    printf("pxClipboardNative::getString() - ENTER\n");
+//    printf("pxClipboardNative::getString() - ENTER\n");
 
     NSPasteboard*  pasteBoard = [NSPasteboard generalPasteboard];
     NSString*        myString = [pasteBoard  stringForType: NSPasteboardTypeString];
-
+
+  if(myString)
+  {
     return std::string([myString UTF8String]);
+  }
+  else
+  {
+    return std::string("");
+  }
 }
 
 void pxClipboardNative::setString(std::string type, std::string clip)
 {
-    printf("pxClipboardNative::setString() - ENTER\n");
+//    printf("pxClipboardNative::setString() - ENTER\n");
 
     NSString *stringToWrite = [NSString stringWithUTF8String: clip.c_str()];
-
+
+  if(stringToWrite)
+  {
     NSPasteboard*  pasteBoard = [NSPasteboard generalPasteboard];
 
-    [pasteBoard declareTypes:[NSArray arrayWithObject:NSStringPboardType] owner:nil];
-    [pasteBoard setString:stringToWrite forType:NSStringPboardType];
+    if(pasteBoard)
+    {
+      [pasteBoard declareTypes:[NSArray arrayWithObject:NSStringPboardType] owner:nil];
+      [pasteBoard setString:stringToWrite forType:NSStringPboardType];
+    }
+  }
 }

src/mac/pxWindowNative.mm

@@ -825,8 +825,11 @@ - (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
 
           pxClipboardNative *clip = pxClipboardNative::instance();
 
+      if(clip && dropURL)
+      {
           clip->setString("TEXT", [dropURL UTF8String]);
       }
+    }
       else
       {
           // Handle Drag'n'Dropped >> TEXT
@@ -835,7 +838,10 @@ - (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
 
         pxClipboardNative *clip = pxClipboardNative::instance();
 
+      if(clip && text)
+      {
           clip->setString("TEXT", [text UTF8String]);
+      }
       }
 
         pxWindowNative::_helper_onKeyDown(mWindow, 86, 16);  // Fake a CTRL-V