fix: iOS rendering if GeneralPaths

When rendering shapes in iOS, it generates an alpha texture mask for the shape.  It tries to cache these textures so that they can be reused when the same shape needs to be rendered, but the hashing function to identity equivalent shapes was returning false positives, which resulting in rendering the wrong shapes.  This PR reimplements this hashing function so that it should only return a match when the shape is actually the same.

This may fix several of the open issues related to iOS shape rendering.  Including:
#3403
#3305
#3302
#3106
#3037

Ports/iOSPort/src/com/codename1/impl/ios/IOSImplementation.java

@@ -2333,80 +2333,80 @@ void add(Shape s, Stroke stroke, TextureAlphaMask mask){
          * @return The string ID used in the map.
          */
         long getShapeID(Shape shape, Stroke stroke){
-            long id = 0;
-
-
-            //float[] bounds = shape.getBounds2D();
-            float x = 0;
-            float y = 0;//bounds[1];
+            long result = 17; // Prime number to start the hash computation
+
+            float referenceX = 0;
+            float referenceY = 0;
             boolean referencePointSet = false;
-
-
-            int ctr = 0;
-            //StringBuilder sb = new StringBuilder();
+
             PathIterator it = shape.getPathIterator();
             float[] buf = new float[6];
-            float tx, ty, tx2, ty2, tx3, ty3;
-
-            //sb.append(it.getWindingRule());
-            id = id ^ it.getWindingRule();
-            //sb.append(";");
-            while ( !it.isDone() ){
-                ctr++;
+
+            result = 31 * result + it.getWindingRule();
+
+            while (!it.isDone()){
                 int type = it.currentSegment(buf);
+
                 if (!referencePointSet && type != PathIterator.SEG_CLOSE) {
                     referencePointSet = true;
-                    x = buf[0];
-                    y = buf[1];
+                    referenceX = buf[0];
+                    referenceY = buf[1];
                 }
-                switch ( type ){
+
+                float tx, ty, tx2, ty2, tx3, ty3;
+
+                switch (type) {
                     case PathIterator.SEG_MOVETO:
-                       tx = buf[0]-x;
-                       ty = buf[1]-y;
-                        //sb.append("M:").append((int)tx).append(",").append((int)ty);
-                       id = id ^ (ctr * (int)tx * (int)ty * type);
+                        tx = buf[0] - referenceX;
+                        ty = buf[1] - referenceY;
+                        result = 31 * result + Float.floatToIntBits(tx);
+                        result = 31 * result + Float.floatToIntBits(ty);
                         break;
                     case PathIterator.SEG_LINETO:
-                       tx = buf[0]-x;
-                       ty = buf[1]-y;
-                        //sb.append("L:").append((int)tx).append(",").append((int)ty);
-                       id = id ^ (ctr * (int)tx * (int)ty * type);
-
+                        tx = buf[0] - referenceX;
+                        ty = buf[1] - referenceY;
+                        result = 31 * result + Float.floatToIntBits(tx);
+                        result = 31 * result + Float.floatToIntBits(ty);
                         break;
                     case PathIterator.SEG_QUADTO:
-                        tx = buf[0]-x;
-                        ty = buf[1]-y;
-                        tx2 = buf[2]-x;
-                        ty2 = buf[3]-y;
-                        //sb.append("Q:").append((int)tx).append(",").append((int)ty).append(",").append((int)tx2).append(",").append((int)ty2);
-                        id = id ^ (ctr * (int)tx * (int)ty * type + 10 * (int)tx2 * (int)ty2);
+                        tx = buf[0] - referenceX;
+                        ty = buf[1] - referenceY;
+                        tx2 = buf[2] - referenceX;
+                        ty2 = buf[3] - referenceY;
+                        result = 31 * result + Float.floatToIntBits(tx);
+                        result = 31 * result + Float.floatToIntBits(ty);
+                        result = 31 * result + Float.floatToIntBits(tx2);
+                        result = 31 * result + Float.floatToIntBits(ty2);
                         break;
                     case PathIterator.SEG_CUBICTO:
-                        tx = buf[0]-x;
-                        ty = buf[1]-y;
-                        tx2 = buf[2]-x;
-                        ty2 = buf[3]-y;
-                        tx3 = buf[4]-x;
-                        ty3= buf[5]-y;
-                        //sb.append("C:").append((int)tx).append(",").append((int)ty).append(",").append((int)tx2).append(",").append((int)ty2)
-                        //        .append(",").append((int)tx3).append(",").append((int)ty3);
-                        id = id ^ (ctr * (int)tx * (int)ty * type  + 10 * (int)tx2 * (int)ty2 + 100 *  (int)tx3  * (int)ty3 );
+                        tx = buf[0] - referenceX;
+                        ty = buf[1] - referenceY;
+                        tx2 = buf[2] - referenceX;
+                        ty2 = buf[3] - referenceY;
+                        tx3 = buf[4] - referenceX;
+                        ty3 = buf[5] - referenceY;
+                        result = 31 * result + Float.floatToIntBits(tx);
+                        result = 31 * result + Float.floatToIntBits(ty);
+                        result = 31 * result + Float.floatToIntBits(tx2);
+                        result = 31 * result + Float.floatToIntBits(ty2);
+                        result = 31 * result + Float.floatToIntBits(tx3);
+                        result = 31 * result + Float.floatToIntBits(ty3);
                         break;
-
                     case PathIterator.SEG_CLOSE:
-                        id = id ^ ctr;
-
+                        result = 31 * result + type;
+                        break;
                 }
+
                 it.next();
             }
-            if ( stroke != null ){
-                id = id ^ stroke.hashCode();
-
-                //sb.append(stroke.hashCode()).append(":");
+
+            if (stroke != null) {
+                result = 31 * result + stroke.hashCode();
             }
-            return id;
-
+
+            return result;
         }
+
     }