make pixelDensity(displayDensity()) work properly, fixes #3436

core/src/processing/core/PApplet.java

@@ -1120,6 +1120,7 @@ public class PApplet implements PConstants {
           return 1;
         }
       }
+      // If nobody's density is 1 (or != 2, to be exact) then everyone is 2
       return 2;
     }
     return displayDensity(display);
@@ -1153,7 +1154,7 @@ public class PApplet implements PConstants {
               System.err.println("Only one display is currently known, use displayDensity(1).");
             } else {
               System.err.format("Your displays are numbered %d through %d, " +
-                "pass one of those numbers to displayDensity()", 1, devices.length);
+                "pass one of those numbers to displayDensity()%n", 1, devices.length);
             }
             throw new RuntimeException("Display " + display + " does not exist.");
           }

java/src/processing/mode/java/preproc/PdePreprocessor.java

@@ -329,6 +329,11 @@ public class PdePreprocessor {
     String[] pixelDensityContents = matchMethod("pixelDensity", searchArea);
     if (pixelDensityContents != null) {
       extraStatements.append(pixelDensityContents[0]);
+    } else {
+      pixelDensityContents = matchDensityMess(searchArea);
+      if (pixelDensityContents != null) {
+        extraStatements.append(pixelDensityContents[0]);
+      }
     }
 
     String[] sizeContents = matchMethod("size", searchArea);
@@ -433,6 +438,13 @@ public class PdePreprocessor {
   }
 
 
+  static protected String[] matchDensityMess(String searchArea) {
+    final String regexp =
+      "(?:^|\\s|;)pixelDensity\\s*\\(\\s*displayDensity\\s*\\([^\\)]*\\)\\s*\\)\\s*\\;";
+    return PApplet.match(searchArea, regexp);
+  }
+
+
   /**
    * Replace all commented portions of a given String as spaces.
    * Utility function used here and in the preprocessor.