diff --git a/src/lib/aqdiagram/placement/0BUILD b/src/lib/aqdiagram/placement/0BUILD
index f769747..52c7176 100644
--- a/src/lib/aqdiagram/placement/0BUILD
+++ b/src/lib/aqdiagram/placement/0BUILD
@@ -61,6 +61,8 @@
 
 
     <headers dist="true" install="$(pkgincludedir)">
+      layout.h
+      o_layout.h
       o_hlayout.h
       o_hlayout-t.h
     </headers>
@@ -73,6 +75,8 @@
     <sources>
       $(local/typefiles)
       
+      layout.c
+      o_layout.c
       o_hlayout.c
       o_hlayout-t.c
     </sources>
diff --git a/src/lib/aqdiagram/placement/layout.c b/src/lib/aqdiagram/placement/layout.c
new file mode 100644
index 0000000..807e545
--- /dev/null
+++ b/src/lib/aqdiagram/placement/layout.c
@@ -0,0 +1,196 @@
+/****************************************************************************
+ * This file is part of the project AqDiagram.
+ * AqDiagram (c) by 2023 Martin Preuss, all rights reserved.
+ *
+ * The license for this file can be found in the file COPYING which you
+ * should have received along with this file.
+ ****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "./layout.h"
+
+
+static int _getSumOfElementWidths(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements);
+static int _getStretchableElements(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements);
+static int _getMaxElementWidth(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements);
+static void _placeAndStretch(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements, int borderBegin, int spacing, int stretch);
+static void _placeAndStretchWithEqualLength(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+                                            int borderBegin, int spacing, int itemLength, int stretch);
+static void _place(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements, int borderBegin, int spacing);
+
+
+
+
+void AQDG_Placement_LayoutAndStretch(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+                                     int destLength, int borderBegin, int borderEnd, int spacing)
+{
+  if (numElements) {
+    int w;
+    int stretchables;
+
+    w=borderBegin+_getSumOfElementWidths(ptrElements, numElements)+borderEnd+(numElements-1)*spacing;
+    stretchables=_getStretchableElements(ptrElements, numElements);
+    if (stretchables && w<destLength) {
+      int d;
+
+      d=(destLength-w)/stretchables;
+      if (d)
+        _placeAndStretch(ptrElements, numElements, borderBegin, spacing, d);
+      else
+        _place(ptrElements, numElements, borderBegin, spacing);
+    }
+    else
+      _place(ptrElements, numElements, borderBegin, spacing);
+  }
+}
+
+
+
+void AQDG_Placement_LayoutWithEqualLength(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+                                          int destLength,  int borderBegin, int borderEnd, int spacing)
+{
+  if (numElements) {
+    int maxElementWidth;
+    int w;
+    int stretch=0;
+
+    maxElementWidth=_getMaxElementWidth(ptrElements, numElements);
+    w=borderBegin+maxElementWidth+borderEnd+(numElements-1)*spacing;
+    if (w<destLength)
+      stretch=(destLength-w)/numElements;
+    _placeAndStretchWithEqualLength(ptrElements, numElements, borderBegin, spacing, maxElementWidth, (stretch>0)?stretch:0);
+  }
+}
+
+
+
+void AQDG_Placement_LayoutSecondaryAxis(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+                                        int destLength,  int borderBegin, int borderEnd)
+{
+  if (numElements) {
+    int i;
+    int rawLength;
+    AQDG_PLACEMENT_LAYOUT_ELEMENT *ptr;
+
+    rawLength=destLength-borderBegin-borderEnd;
+    ptr=ptrElements;
+    for (i=0; i<numElements; i++) {
+      int pos;
+
+      if (ptr->opts & AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_RIGHT) {
+        pos=destLength-borderEnd-ptr->length;
+      }
+      else if (ptr->opts & AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_CENTER) {
+        pos=borderBegin+(rawLength-ptr->length)/2;
+      }
+      else
+        pos=borderBegin;
+
+      ptr->pos=(pos>borderBegin)?pos:borderBegin;
+      ptr++;
+    }
+  }
+}
+
+
+
+
+
+
+int _getSumOfElementWidths(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements)
+{
+  int i;
+  int w=0;
+
+  for (i=0; i<numElements; i++)
+    w+=(ptrElements++)->length;
+  return w;
+}
+
+
+
+int _getStretchableElements(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements)
+{
+  int i;
+  int n=0;
+
+  for (i=0; i<numElements; i++)
+    if (((ptrElements++)->opts) & AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_STRETCH)
+      n++;
+  return n;
+}
+
+
+
+int _getMaxElementWidth(const AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements)
+{
+  int i;
+  int w=-1;
+
+  for (i=0; i<numElements; i++) {
+    w=(ptrElements->length>w)?(ptrElements->length):w;
+    ptrElements++;
+  }
+  return w;
+}
+
+
+
+void _placeAndStretch(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements, int borderBegin, int spacing, int stretch)
+{
+  int i;
+  int pos=0;
+  AQDG_PLACEMENT_LAYOUT_ELEMENT *ptr;
+
+  pos=borderBegin;
+  ptr=ptrElements;
+  for (i=0; i<numElements; i++) {
+    ptr->pos=pos;
+    if (ptr->opts & AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_STRETCH)
+      ptr->length+=stretch;
+    pos+=ptr->length+spacing;
+    ptr++;
+  }
+}
+
+
+
+void _placeAndStretchWithEqualLength(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+                                     int borderBegin, int spacing, int itemLength, int stretch)
+{
+  int i;
+  int pos=0;
+  AQDG_PLACEMENT_LAYOUT_ELEMENT *ptr;
+
+  pos=borderBegin;
+  ptr=ptrElements;
+  for (i=0; i<numElements; i++) {
+    ptr->pos=pos;
+    ptr->length=itemLength;
+    pos+=itemLength+spacing+stretch;
+    ptr++;
+  }
+}
+
+
+
+void _place(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements, int borderBegin, int spacing)
+{
+  int i;
+  int pos=0;
+  AQDG_PLACEMENT_LAYOUT_ELEMENT *ptr;
+
+  pos=borderBegin;
+  ptr=ptrElements;
+  for (i=0; i<numElements; i++) {
+    ptr->pos=pos;
+    pos+=ptr->length+spacing;
+    ptr++;
+  }
+}
+
+
+
diff --git a/src/lib/aqdiagram/placement/layout.h b/src/lib/aqdiagram/placement/layout.h
new file mode 100644
index 0000000..8fbf64c
--- /dev/null
+++ b/src/lib/aqdiagram/placement/layout.h
@@ -0,0 +1,48 @@
+/****************************************************************************
+ * This file is part of the project AqDiagram.
+ * AqDiagram (c) by 2023 Martin Preuss, all rights reserved.
+ *
+ * The license for this file can be found in the file COPYING which you
+ * should have received along with this file.
+ ****************************************************************************/
+
+#ifndef AQDG_PLACEMENT_LAYOUT_H
+#define AQDG_PLACEMENT_LAYOUT_H
+
+#include <aqdiagram/aqdg_api.h>
+
+#include <inttypes.h>
+
+
+
+#define AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_STRETCH 0x0001
+#define AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_CENTER  0x0002
+#define AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_RIGHT   0x0004
+
+
+
+
+typedef struct AQDG_PLACEMENT_LAYOUT_ELEMENT AQDG_PLACEMENT_LAYOUT_ELEMENT;
+struct AQDG_PLACEMENT_LAYOUT_ELEMENT {
+  int pos;
+  int length;
+  uint32_t opts;
+};
+
+
+
+
+AQDG_API void AQDG_Placement_LayoutAndStretch(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+					      int destLength, int borderBegin, int borderEnd, int spacing);
+
+AQDG_API void AQDG_Placement_LayoutWithEqualLength(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+						   int destLength, int borderBegin, int borderEnd, int spacing);
+
+AQDG_API void AQDG_Placement_LayoutSecondaryAxis(AQDG_PLACEMENT_LAYOUT_ELEMENT *ptrElements, int numElements,
+						 int destLength,  int borderBegin, int borderEnd);
+
+
+
+#endif
+
+
diff --git a/src/lib/aqdiagram/placement/o_hlayout.h b/src/lib/aqdiagram/placement/o_hlayout.h
index a23ff71..50a5399 100644
--- a/src/lib/aqdiagram/placement/o_hlayout.h
+++ b/src/lib/aqdiagram/placement/o_hlayout.h
@@ -6,8 +6,8 @@
  * should have received along with this file.
  ****************************************************************************/
 
-#ifndef AQDG_PLACEMENT_O_LAYOUT_H
-#define AQDG_PLACEMENT_O_LAYOUT_H
+#ifndef AQDG_PLACEMENT_O_HLAYOUT_H
+#define AQDG_PLACEMENT_O_HLAYOUT_H
 
 #include <aqdiagram/aqdg_api.h>
 
diff --git a/src/lib/aqdiagram/placement/o_layout.c b/src/lib/aqdiagram/placement/o_layout.c
new file mode 100644
index 0000000..958b51f
--- /dev/null
+++ b/src/lib/aqdiagram/placement/o_layout.c
@@ -0,0 +1,189 @@
+/****************************************************************************
+ * This file is part of the project AqDiagram.
+ * AqDiagram (c) by 2023 Martin Preuss, all rights reserved.
+ *
+ * The license for this file can be found in the file COPYING which you
+ * should have received along with this file.
+ ****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "o_layout.h"
+
+
+
+/* ------------------------------------------------------------------------------------------------
+ * forward declarations
+ * ------------------------------------------------------------------------------------------------
+ */
+
+static void _setElementFromObjectX(AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr, const AQDG_OBJECT *object);
+static void _setElementFromObjectY(AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr, const AQDG_OBJECT *object);
+static void _setObjectFromElementX(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr);
+static void _setObjectFromElementY(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr);
+
+
+
+/* ------------------------------------------------------------------------------------------------
+ * implementations
+ * ------------------------------------------------------------------------------------------------
+ */
+
+
+int AQDG_LayoutObject_CountDirectChildren(const AQDG_OBJECT *object)
+{
+  int c=0;
+  const AQDG_OBJECT *child;
+
+  child=AQDG_Object_Tree2_GetFirstChild(object);
+  while(child) {
+    c++;
+    child=AQDG_Object_Tree2_GetNext(child);
+  }
+
+  return c;
+}
+
+
+
+AQDG_PLACEMENT_LAYOUT_ELEMENT *AQDG_LayoutObject_Children2ElementsX(const AQDG_OBJECT *object, int num)
+{
+  if (num) {
+    AQDG_PLACEMENT_LAYOUT_ELEMENT *elements;
+
+    elements=(AQDG_PLACEMENT_LAYOUT_ELEMENT*) malloc(num*sizeof(AQDG_PLACEMENT_LAYOUT_ELEMENT));
+    if (elements) {
+      const AQDG_OBJECT *child;
+      AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr;
+
+      eptr=elements;
+      child=AQDG_Object_Tree2_GetFirstChild(object);
+      while(child && num) {
+        _setElementFromObjectX(eptr, object);
+        child=AQDG_Object_Tree2_GetNext(child);
+        eptr++;
+        num--;
+      }
+      return elements;
+    }
+  }
+
+  return NULL;
+}
+
+
+
+AQDG_PLACEMENT_LAYOUT_ELEMENT *AQDG_LayoutObject_Children2ElementsY(const AQDG_OBJECT *object, int num)
+{
+  if (num) {
+    AQDG_PLACEMENT_LAYOUT_ELEMENT *elements;
+
+    elements=(AQDG_PLACEMENT_LAYOUT_ELEMENT*) malloc(num*sizeof(AQDG_PLACEMENT_LAYOUT_ELEMENT));
+    if (elements) {
+      const AQDG_OBJECT *child;
+      AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr;
+
+      eptr=elements;
+      child=AQDG_Object_Tree2_GetFirstChild(object);
+      while(child && num) {
+        _setElementFromObjectY(eptr, object);
+        child=AQDG_Object_Tree2_GetNext(child);
+        eptr++;
+        num--;
+      }
+      return elements;
+    }
+  }
+
+  return NULL;
+}
+
+
+
+void AQDG_LayoutObject_ChildrenFromElementsX(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *elements, int num)
+{
+  if (num && elements) {
+    AQDG_OBJECT *child;
+    const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr;
+
+    eptr=elements;
+    child=AQDG_Object_Tree2_GetFirstChild(object);
+    while(child && num) {
+      _setObjectFromElementX(child, eptr);
+      eptr++;
+      num--;
+      child=AQDG_Object_Tree2_GetNext(child);
+    }
+  }
+}
+
+
+
+void AQDG_LayoutObject_ChildrenFromElementsY(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *elements, int num)
+{
+  if (num && elements) {
+    AQDG_OBJECT *child;
+    const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr;
+
+    eptr=elements;
+    child=AQDG_Object_Tree2_GetFirstChild(object);
+    while(child && num) {
+      _setObjectFromElementY(child, eptr);
+      eptr++;
+      num--;
+      child=AQDG_Object_Tree2_GetNext(child);
+    }
+  }
+}
+
+
+
+void _setElementFromObjectX(AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr, const AQDG_OBJECT *object)
+{
+  uint32_t opts;
+
+  opts=AQDG_Object_GetOptions(object);
+  eptr->pos=0;
+  eptr->length=AQDG_Object_GetWidth(object);
+  eptr->opts=(opts & AQDG_OBJECT_OPTIONS_STRETCHX)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_STRETCH:0;
+  eptr->opts|=(opts  & AQDG_OBJECT_OPTIONS_HALIGNCENTER)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_CENTER:0;
+  eptr->opts|=(opts  & AQDG_OBJECT_OPTIONS_HALIGNRIGHT)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_RIGHT:0;
+}
+
+
+
+void _setElementFromObjectY(AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr, const AQDG_OBJECT *object)
+{
+  uint32_t opts;
+
+  opts=AQDG_Object_GetOptions(object);
+  eptr->pos=0;
+  eptr->length=AQDG_Object_GetHeight(object);
+  eptr->opts=(opts & AQDG_OBJECT_OPTIONS_STRETCHY)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_STRETCH:0;
+  eptr->opts|=(opts  & AQDG_OBJECT_OPTIONS_VALIGNCENTER)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_CENTER:0;
+  eptr->opts|=(opts  & AQDG_OBJECT_OPTIONS_VALIGNBOTTOM)?AQDG_PLACEMENT_LAYOUT_ELEMENT_OPTS_RIGHT:0;
+}
+
+
+
+void _setObjectFromElementX(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr)
+{
+  AQDG_Object_SetRelativeX(object, eptr->pos);
+  AQDG_Object_SetWidth(object, eptr->length);
+}
+
+
+
+void _setObjectFromElementY(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *eptr)
+{
+  AQDG_Object_SetRelativeY(object, eptr->pos);
+  AQDG_Object_SetHeight(object, eptr->length);
+}
+
+
+
+
+
+
diff --git a/src/lib/aqdiagram/placement/o_layout.h b/src/lib/aqdiagram/placement/o_layout.h
new file mode 100644
index 0000000..fac4325
--- /dev/null
+++ b/src/lib/aqdiagram/placement/o_layout.h
@@ -0,0 +1,32 @@
+/****************************************************************************
+ * This file is part of the project AqDiagram.
+ * AqDiagram (c) by 2023 Martin Preuss, all rights reserved.
+ *
+ * The license for this file can be found in the file COPYING which you
+ * should have received along with this file.
+ ****************************************************************************/
+
+#ifndef AQDG_PLACEMENT_O_LAYOUT_H
+#define AQDG_PLACEMENT_O_LAYOUT_H
+
+#include <aqdiagram/aqdg_api.h>
+
+#include <aqdiagram/placement/object.h>
+#include <aqdiagram/placement/layout.h>
+
+
+
+AQDG_API int AQDG_LayoutObject_CountDirectChildren(const AQDG_OBJECT *object);
+
+AQDG_API AQDG_PLACEMENT_LAYOUT_ELEMENT *AQDG_LayoutObject_Children2ElementsX(const AQDG_OBJECT *object, int num);
+AQDG_API AQDG_PLACEMENT_LAYOUT_ELEMENT *AQDG_LayoutObject_Children2ElementsY(const AQDG_OBJECT *object, int num);
+AQDG_API void AQDG_LayoutObject_ChildrenFromElementsX(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *elements, int num);
+AQDG_API void AQDG_LayoutObject_ChildrenFromElementsY(AQDG_OBJECT *object, const AQDG_PLACEMENT_LAYOUT_ELEMENT *elements, int num);
+
+
+
+
+
+
+#endif
+