8266040: Lanai: Incorrect calculations of clipping boundaries

Reviewed-by: jdv

Author: Alexey Ushakov

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLClip.m

@@ -156,7 +156,8 @@ - (void)beginShapeClip:(BMTLSDOps *)dstOps context:(MTLContext *)mtlc {
         }
 
         _clipShapeSize = MTLSizeMake(0, 0, 1);
-        _clipShapeOrigin = MTLOriginMake(0, 0, 0);
+        // Use out of bounds origin to correctly calculate shape boundaries
+        _clipShapeOrigin = MTLOriginMake((NSUInteger) dstOps->width, (NSUInteger) dstOps->height, 0);
 
         MTLRenderPassDescriptor* clearPassDescriptor = [MTLRenderPassDescriptor renderPassDescriptor];
         // set color buffer properties

src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLRenderer.m

@@ -470,8 +470,8 @@ void MTLRenderer_FillSpans(MTLContext *mtlc, BMTLSDOps * dstOps, jint spanCount,
 
     jfloat shapeX1 = mtlc.clip.shapeX;
     jfloat shapeY1 = mtlc.clip.shapeY;
-    jfloat shapeX2 = shapeX1 + mtlc.clip.shapeWidth;
-    jfloat shapeY2 = shapeY1 + mtlc.clip.shapeHeight;
+    jfloat shapeX2 = (mtlc.clip.shapeWidth > 0)?  shapeX1 + mtlc.clip.shapeWidth : 0;
+    jfloat shapeY2 = (mtlc.clip.shapeHeight > 0)? shapeY1 + mtlc.clip.shapeHeight : 0;
 
     int counter = 0;
     for (int i = 0; i < spanCount; i++) {