[sdl][sfml][flutter] Fix clipping, closes #2431

spine-flutter/src/spine_flutter.cpp

@@ -732,7 +732,10 @@ spine_render_command spine_skeleton_drawable_render(spine_skeleton_drawable draw
 	for (unsigned i = 0; i < skeleton->getSlots().size(); ++i) {
 		Slot &slot = *skeleton->getDrawOrder()[i];
 		Attachment *attachment = slot.getAttachment();
-		if (!attachment) continue;
+		if (!attachment) {
+            clipper.clipEnd(slot);
+            continue;
+        }
 
 		// Early out if the slot color is 0 or the bone is not active
 		if (slot.getColor().a == 0 || !slot.getBone().isActive()) {

spine-sdl/src/spine-sdl-c.c

@@ -74,7 +74,10 @@ void spSkeletonDrawable_draw(spSkeletonDrawable *self, struct SDL_Renderer *rend
 	for (int i = 0; i < skeleton->slotsCount; ++i) {
 		spSlot *slot = skeleton->drawOrder[i];
 		spAttachment *attachment = slot->attachment;
-		if (!attachment) continue;
+		if (!attachment) {
+            spSkeletonClipping_clipEnd(clipper, slot);
+            continue;
+        }
 
 		// Early out if the slot color is 0 or the bone is not active
 		if (slot->color.a == 0 || !slot->bone->active) {

spine-sdl/src/spine-sdl-cpp.cpp

@@ -70,7 +70,10 @@ void SkeletonDrawable::draw(SDL_Renderer *renderer) {
 	for (unsigned i = 0; i < skeleton->getSlots().size(); ++i) {
 		Slot &slot = *skeleton->getDrawOrder()[i];
 		Attachment *attachment = slot.getAttachment();
-		if (!attachment) continue;
+		if (!attachment) {
+            clipper.clipEnd(slot);
+            continue;
+        }
 
 		// Early out if the slot color is 0 or the bone is not active
 		if (slot.getColor().a == 0 || !slot.getBone().isActive()) {

spine-sfml/c/src/spine/spine-sfml.cpp

@@ -168,7 +168,10 @@ namespace spine {
 		for (int i = 0; i < skeleton->slotsCount; ++i) {
 			spSlot *slot = skeleton->drawOrder[i];
 			spAttachment *attachment = slot->attachment;
-			if (!attachment) continue;
+			if (!attachment) {
+                spSkeletonClipping_clipEnd(clipper, slot);
+                continue;
+            }
 
 			// Early out if slot is invisible
 			if (slot->color.a == 0 || !slot->bone->active) {

spine-sfml/cpp/src/spine/spine-sfml.cpp

@@ -94,7 +94,10 @@ namespace spine {
 		for (unsigned i = 0; i < skeleton->getSlots().size(); ++i) {
 			Slot &slot = *skeleton->getDrawOrder()[i];
 			Attachment *attachment = slot.getAttachment();
-			if (!attachment) continue;
+			if (!attachment) {
+                clipper.clipEnd(slot);
+                continue;
+            }
 
 			// Early out if the slot color is 0 or the bone is not active
 			if (slot.getColor().a == 0 || !slot.getBone().isActive()) {