diff --git a/gui_qt/baseform.cpp b/gui_qt/baseform.cpp
index c3122d8..0bf06c9 100644
--- a/gui_qt/baseform.cpp
+++ b/gui_qt/baseform.cpp
@@ -408,9 +408,9 @@ BaseInput* BaseForm::addInputMaterial(QString label, SurfaceMaterial* material)
     return addInput(new InputMaterial(_form, label, material));
 }
 
-BaseInput* BaseForm::addInputHeightMap(QString label, HeightMap* heightmap)
+BaseInput* BaseForm::addInputHeightMap(QString label, HeightMap* heightmap, TerrainCanvas* canvas)
 {
-    return addInput(new InputHeightMap(_form, label, heightmap));
+    return addInput(new InputHeightMap(_form, label, heightmap, canvas));
 }
 
 BaseInput* BaseForm::addInputEnum(QString label, int* value, const QStringList& values)
diff --git a/gui_qt/baseform.h b/gui_qt/baseform.h
index 6e94c3b..a4dc393 100644
--- a/gui_qt/baseform.h
+++ b/gui_qt/baseform.h
@@ -15,6 +15,7 @@
 #include "../lib_paysages/layers.h"
 #include "../lib_paysages/heightmap.h"
 #include "../lib_paysages/pack.h"
+#include "../lib_paysages/terraincanvas.h"
 
 class BaseForm:public QWidget
 {
@@ -57,7 +58,7 @@ protected:
     BaseInput* addInputNoise(QString label, NoiseGenerator* value);
     BaseInput* addInputCurve(QString label, Curve* value, double xmin, double xmax, double ymin, double ymax, QString xlabel, QString ylabel);
     BaseInput* addInputMaterial(QString label, SurfaceMaterial* material);
-    BaseInput* addInputHeightMap(QString label, HeightMap* heightmap);
+    BaseInput* addInputHeightMap(QString label, HeightMap* heightmap, TerrainCanvas* canvas);
     BaseInput* addInputEnum(QString label, int* value, const QStringList& values);
     BaseInput* addInputLayers(QString label, Layers* value, FormLayerBuilder form_builder);
     
diff --git a/gui_qt/dialogcurve.cpp b/gui_qt/dialogcurve.cpp
index 93dcfd3..ba71309 100644
--- a/gui_qt/dialogcurve.cpp
+++ b/gui_qt/dialogcurve.cpp
@@ -83,7 +83,7 @@ bool DialogCurve::getCurve(QWidget* parent, Curve* curve, double xmin, double xm
     return (result != 0) ? true : false;
 }
 
-void DialogCurve::closeEvent(QCloseEvent* e)
+void DialogCurve::closeEvent(QCloseEvent*)
 {
     reject();
 }
diff --git a/gui_qt/dialogheightmap.cpp b/gui_qt/dialogheightmap.cpp
index b16f90f..0ec694f 100644
--- a/gui_qt/dialogheightmap.cpp
+++ b/gui_qt/dialogheightmap.cpp
@@ -6,11 +6,14 @@
 #include <QPushButton>
 #include <QComboBox>
 #include <QSlider>
+#include <QFileDialog>
 #include <math.h>
+#include "../lib_paysages/terrain.h"
+#include "../lib_paysages/scenery.h"
 #include "widgetheightmap.h"
 
 /**************** Dialog form ****************/
-DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : DialogWithPreview(parent)
+DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap, TerrainCanvas* canvas) : DialogWithPreview(parent)
 {
     QWidget* mainarea;
     QWidget* buttons;
@@ -23,6 +26,7 @@ DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : Dialog
     QPushButton* button;
     QComboBox* combobox;
     
+    _canvas = canvas;
     _value_original = heightmap;
     _value_modified = heightmapCreate();
     heightmapCopy(_value_original, &_value_modified);
@@ -62,8 +66,15 @@ DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : Dialog
     viewer_layout->addWidget(slider, 0, 1);
     
     // Panel layout
-    button = new QPushButton(tr("Reset to terrain height"), panel);
-    connect(button, SIGNAL(clicked()), _3dview, SLOT(resetToTerrain()));
+    if (canvas)
+    {
+        button = new QPushButton(tr("Reset to terrain height"), panel);
+        connect(button, SIGNAL(clicked()), this, SLOT(resetToTerrain()));
+        panel->layout()->addWidget(button);
+    }
+
+    button = new QPushButton(tr("Load from picture file"), panel);
+    connect(button, SIGNAL(clicked()), this, SLOT(loadFromFile()));
     panel->layout()->addWidget(button);
     
     combobox = new QComboBox(panel);
@@ -115,11 +126,11 @@ DialogHeightMap::DialogHeightMap(QWidget* parent, HeightMap* heightmap) : Dialog
     setWindowTitle(tr("Paysages 3D - Height map painting"));
 }
 
-bool DialogHeightMap::editHeightMap(QWidget* parent, HeightMap* heightmap)
+bool DialogHeightMap::editHeightMap(QWidget* parent, HeightMap* heightmap, TerrainCanvas* canvas)
 {
     int result;
 
-    DialogHeightMap* dialog = new DialogHeightMap(parent, heightmap);
+    DialogHeightMap* dialog = new DialogHeightMap(parent, heightmap, canvas);
     result = dialog->exec();
 
     delete dialog;
@@ -168,3 +179,30 @@ void DialogHeightMap::brushStrengthChanged(int value)
 {
     _3dview->setBrushStrength((double)value / 2000.0);
 }
+
+void DialogHeightMap::loadFromFile()
+{
+    QString filepath = QFileDialog::getOpenFileName(this, tr("Paysages 3D - Choose a picture to load"), QString(), tr("Images (*.jpg *.jpeg *.bmp *.png)"));
+    if (!filepath.isNull())
+    {
+        heightmapImportFromPicture(&_value_modified, (char*) filepath.toStdString().c_str());
+        _3dview->revert();
+    }
+}
+
+void DialogHeightMap::resetToTerrain()
+{
+    if (_canvas)
+    {
+        TerrainDefinition terrain;
+
+        terrain = terrainCreateDefinition();
+        sceneryGetTerrain(&terrain);
+
+        heightmapRevertToTerrain(&_value_modified, &terrain, &_canvas->area);
+
+        terrainDeleteDefinition(&terrain);
+        
+        _3dview->revert();
+    }
+}
diff --git a/gui_qt/dialogheightmap.h b/gui_qt/dialogheightmap.h
index b87ac34..e7c0b96 100644
--- a/gui_qt/dialogheightmap.h
+++ b/gui_qt/dialogheightmap.h
@@ -4,13 +4,14 @@
 #include "tools.h"
 #include "widgetheightmap.h"
 #include "../lib_paysages/heightmap.h"
+#include "../lib_paysages/terraincanvas.h"
 
 class DialogHeightMap : public DialogWithPreview
 {
     Q_OBJECT
 public:
-    explicit DialogHeightMap(QWidget* parent, HeightMap* heightmap);
-    static bool editHeightMap(QWidget* parent, HeightMap* heightmap);
+    explicit DialogHeightMap(QWidget* parent, HeightMap* heightmap, TerrainCanvas* canvas);
+    static bool editHeightMap(QWidget* parent, HeightMap* heightmap, TerrainCanvas* canvas);
 
 public slots:
     virtual void accept();
@@ -23,11 +24,14 @@ private slots:
     void brushSizeChanged(int value);
     void brushSmoothingChanged(int value);
     void brushStrengthChanged(int value);
+    void loadFromFile();
+    void resetToTerrain();
 
 private:
     HeightMap* _value_original;
     HeightMap _value_modified;
     WidgetHeightMap* _3dview;
+    TerrainCanvas* _canvas;
 };
 
 #endif
diff --git a/gui_qt/dialoglayers.cpp b/gui_qt/dialoglayers.cpp
index 2954d58..fc5cf3f 100644
--- a/gui_qt/dialoglayers.cpp
+++ b/gui_qt/dialoglayers.cpp
@@ -56,7 +56,7 @@ bool DialogLayers::editLayers(QWidget* parent, Layers* layers, QString title, Fo
     return result != 0;
 }
 
-void DialogLayers::closeEvent(QCloseEvent* e)
+void DialogLayers::closeEvent(QCloseEvent*)
 {
     reject();
 }
diff --git a/gui_qt/formterraincanvas.cpp b/gui_qt/formterraincanvas.cpp
index 047a4e1..3146604 100644
--- a/gui_qt/formterraincanvas.cpp
+++ b/gui_qt/formterraincanvas.cpp
@@ -44,7 +44,7 @@ FormTerrainCanvas::FormTerrainCanvas(QWidget *parent, Layers* layers):
     
     // TODO Area
     //addInputDouble(tr("Apply at height"), &_definition->offset_y, -20.0, 20.0, 0.1, 1.0);
-    addInputHeightMap(tr("Height map"), &_definition->height_map);
+    addInputHeightMap(tr("Height map"), &_definition->height_map, _definition);
     //addInputDouble(tr("Canvas height"), &_definition->height_factor, 0.0, 20.0, 0.1, 1.0);
     addInputNoise(tr("Detail noise"), _definition->detail_noise);
     addInputDouble(tr("Detail noise height"), &_definition->detail_height_factor, 0.0, 20.0, 0.1, 1.0);
diff --git a/gui_qt/inputheightmap.cpp b/gui_qt/inputheightmap.cpp
index 036db27..d3c599d 100644
--- a/gui_qt/inputheightmap.cpp
+++ b/gui_qt/inputheightmap.cpp
@@ -45,9 +45,10 @@ public:
     HeightMap* _value;
 };
 
-InputHeightMap::InputHeightMap(QWidget* form, QString label, HeightMap* value) : BaseInput(form, label)
+InputHeightMap::InputHeightMap(QWidget* form, QString label, HeightMap* value, TerrainCanvas* canvas) : BaseInput(form, label)
 {
     _value = value;
+    _canvas = canvas;
     
     _preview = new SmallPreviewHeightMap(form, value);
     _preview->setMinimumSize(100, 100);
@@ -77,7 +78,7 @@ void InputHeightMap::revert()
 
 void InputHeightMap::editHeightMap()
 {
-    if (DialogHeightMap::editHeightMap(_control, _value))
+    if (DialogHeightMap::editHeightMap(_control, _value, _canvas))
     {
         applyValue();
     }
diff --git a/gui_qt/inputheightmap.h b/gui_qt/inputheightmap.h
index 2cd25cd..f25189d 100644
--- a/gui_qt/inputheightmap.h
+++ b/gui_qt/inputheightmap.h
@@ -5,13 +5,14 @@
 #include "baseinput.h"
 
 #include "../lib_paysages/heightmap.h"
+#include "../lib_paysages/terraincanvas.h"
 
 class InputHeightMap:public BaseInput
 {
     Q_OBJECT
 
 public:
-    InputHeightMap(QWidget* form, QString label, HeightMap* value);
+    InputHeightMap(QWidget* form, QString label, HeightMap* value, TerrainCanvas* canvas);
 
 public slots:
     virtual void updatePreview();
@@ -23,6 +24,7 @@ private slots:
 
 private:
     HeightMap* _value;
+    TerrainCanvas* _canvas;
 };
 
 #endif
diff --git a/gui_qt/widgetheightmap.cpp b/gui_qt/widgetheightmap.cpp
index b2fad69..5e2f263 100644
--- a/gui_qt/widgetheightmap.cpp
+++ b/gui_qt/widgetheightmap.cpp
@@ -5,8 +5,6 @@
 #include <math.h>
 #include <GL/glu.h>
 #include "tools.h"
-#include "../lib_paysages/terrain.h"
-#include "../lib_paysages/scenery.h"
 
 WidgetHeightMap::WidgetHeightMap(QWidget *parent, HeightMap* heightmap):
     QGLWidget(parent)
@@ -18,7 +16,7 @@ WidgetHeightMap::WidgetHeightMap(QWidget *parent, HeightMap* heightmap):
     startTimer(100);
 
     _heightmap = heightmap;
-    _vertexes = new _VertexInfo[heightmap->resolution_x * heightmap->resolution_z];
+    _vertices = new _VertexInfo[heightmap->resolution_x * heightmap->resolution_z];
     
     _dirty = true;
     
@@ -47,7 +45,7 @@ WidgetHeightMap::WidgetHeightMap(QWidget *parent, HeightMap* heightmap):
 WidgetHeightMap::~WidgetHeightMap()
 {
     noiseDeleteGenerator(_brush_noise);
-    delete[] _vertexes;
+    delete[] _vertices;
 }
 
 void WidgetHeightMap::setHorizontalViewAngle(double angle_h)
@@ -100,28 +98,6 @@ void WidgetHeightMap::revert()
     updateGL();
 }
 
-void WidgetHeightMap::resetToTerrain()
-{
-    TerrainDefinition terrain;
-    
-    terrain = terrainCreateDefinition();
-    sceneryGetTerrain(&terrain);
-    
-    // TODO Apply geoarea
-    int rx = _heightmap->resolution_x;
-    int rz = _heightmap->resolution_z;
-    for (int x = 0; x < rx; x++)
-    {
-        for (int z = 0; z < rz; z++)
-        {
-            _heightmap->data[z * rx + x] = terrainGetHeight(&terrain, 80.0 * (double)x / (double)(rx - 1) - 40.0, 80.0 * (double)z / (double)(rz - 1) - 40.0);
-        }
-    }
-
-    terrainDeleteDefinition(&terrain);
-    revert();
-}
-
 void WidgetHeightMap::mousePressEvent(QMouseEvent* event)
 {
     _last_mouse_x = event->x();
@@ -312,7 +288,7 @@ void WidgetHeightMap::paintGL()
         glBegin(GL_QUAD_STRIP);
         for (int z = 0; z < rz; z++)
         {
-            _VertexInfo* vertex = _vertexes + z * rx + x;
+            _VertexInfo* vertex = _vertices + z * rx + x;
             double diff_x, diff_z, diff;
             
             diff_x = (vertex + 1)->point.x - _brush_x;
@@ -371,13 +347,17 @@ void WidgetHeightMap::updateVertexInfo()
 {
     int rx = _heightmap->resolution_x;
     int rz = _heightmap->resolution_z;
+
+    _VertexInfo* old_vertices = _vertices;
+    _vertices = new _VertexInfo[rx * rz];
+    delete[] old_vertices;
     
     // Update positions
     for (int x = 0; x < rx; x++)
     {
         for (int z = 0; z < rz; z++)
         {
-            _VertexInfo* vertex = _vertexes + z * rx + x;
+            _VertexInfo* vertex = _vertices + z * rx + x;
             
             vertex->point.x = 80.0 * (double)x / (double)(rx - 1) - 40.0;
             vertex->point.y = _heightmap->data[z * rx + x];
@@ -390,7 +370,7 @@ void WidgetHeightMap::updateVertexInfo()
     {
         for (int z = 0; z < rz; z++)
         {
-            _VertexInfo* vertex = _vertexes + z * rx + x;
+            _VertexInfo* vertex = _vertices + z * rx + x;
             
             if (x == rx - 1)
             {
diff --git a/gui_qt/widgetheightmap.h b/gui_qt/widgetheightmap.h
index a954eae..b48e95b 100644
--- a/gui_qt/widgetheightmap.h
+++ b/gui_qt/widgetheightmap.h
@@ -34,7 +34,6 @@ public:
     
 public slots:
     void revert();
-    void resetToTerrain();
 
 protected:
     void mousePressEvent(QMouseEvent* event);
@@ -52,7 +51,7 @@ private:
 
 private:
     HeightMap* _heightmap;
-    _VertexInfo* _vertexes;
+    _VertexInfo* _vertices;
     
     bool _dirty;
     
diff --git a/lib_paysages/geoarea.c b/lib_paysages/geoarea.c
new file mode 100644
index 0000000..9571b05
--- /dev/null
+++ b/lib_paysages/geoarea.c
@@ -0,0 +1,53 @@
+#include "geoarea.h"
+
+#include "tools.h"
+
+GeoArea geoareaCreate()
+{
+    GeoArea result;
+    
+    result.location_x = -40.0;
+    result.location_z = -40.0;
+    result.size_x = 80.0;
+    result.size_z = 80.0;
+    
+    return result;
+}
+
+void geoareaDelete(GeoArea* geoarea)
+{
+    UNUSED(geoarea);
+}
+
+void geoareaCopy(GeoArea* source, GeoArea* destination)
+{
+    *destination = *source;
+}
+
+void geoareaValidate(GeoArea* geoarea)
+{
+    if (geoarea->size_x < 0.000000001)
+    {
+        geoarea->size_x = 0.000000001;
+    }
+    if (geoarea->size_z < 0.000000001)
+    {
+        geoarea->size_z = 0.000000001;
+    }
+}
+
+void geoareaSave(PackStream* stream, GeoArea* geoarea)
+{
+    packWriteDouble(stream, &geoarea->location_x);
+    packWriteDouble(stream, &geoarea->location_z);
+    packWriteDouble(stream, &geoarea->size_x);
+    packWriteDouble(stream, &geoarea->size_z);
+}
+
+void geoareaLoad(PackStream* stream, GeoArea* geoarea)
+{
+    packReadDouble(stream, &geoarea->location_x);
+    packReadDouble(stream, &geoarea->location_z);
+    packReadDouble(stream, &geoarea->size_x);
+    packReadDouble(stream, &geoarea->size_z);
+}
diff --git a/lib_paysages/geoarea.h b/lib_paysages/geoarea.h
new file mode 100644
index 0000000..e18f1e2
--- /dev/null
+++ b/lib_paysages/geoarea.h
@@ -0,0 +1,32 @@
+#ifndef _PAYSAGES_GEOAREA_H_
+#define _PAYSAGES_GEOAREA_H_
+
+/* Geographic area definition */
+
+#include "pack.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct
+{
+    double location_x;
+    double location_z;
+    double size_x;
+    double size_z;
+} GeoArea;
+
+GeoArea geoareaCreate();
+void geoareaDelete(GeoArea* geoarea);
+void geoareaCopy(GeoArea* source, GeoArea* destination);
+void geoareaValidate(GeoArea* geoarea);
+
+void geoareaSave(PackStream* stream, GeoArea* geoarea);
+void geoareaLoad(PackStream* stream, GeoArea* geoarea);
+    
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/lib_paysages/heightmap.c b/lib_paysages/heightmap.c
index d5a9016..adc16de 100644
--- a/lib_paysages/heightmap.c
+++ b/lib_paysages/heightmap.c
@@ -1,12 +1,12 @@
 #include "heightmap.h"
-#include "tools.h"
-#include "system.h"
-#include "noise.h"
 
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 #include <assert.h>
+#include "tools.h"
+#include "system.h"
+#include "noise.h"
 
 HeightMap heightmapCreate()
 {
@@ -34,6 +34,7 @@ void heightmapCopy(HeightMap* source, HeightMap* destination)
 
 void heightmapValidate(HeightMap* heightmap)
 {
+    UNUSED(heightmap);
 }
 
 void heightmapSave(PackStream* stream, HeightMap* heightmap)
@@ -69,25 +70,6 @@ static void _loadFromFilePixel(HeightMap* heightmap, int x, int y, Color col)
     heightmap->data[y * heightmap->resolution_x + x] = (col.r + col.g + col.b) / 3.0;
 }
 
-void heightmapImportFromPicture(HeightMap* heightmap, const char* picturepath)
-{
-    systemLoadPictureFile(picturepath, (PictureCallbackLoadStarted)heightmapChangeResolution, (PictureCallbackLoadPixel)_loadFromFilePixel, heightmap);
-}
-
-void heightmapChangeResolution(HeightMap* heightmap, int resolution_x, int resolution_z)
-{
-    int i;
-    
-    heightmap->resolution_x = resolution_x;
-    heightmap->resolution_z = resolution_z;
-    heightmap->data = realloc(heightmap->data, sizeof(double) * heightmap->resolution_x * heightmap->resolution_z);
-    
-    for (i = 0; i < heightmap->resolution_x * heightmap->resolution_z; i++)
-    {
-        heightmap->data[i] = 0.0;
-    }
-}
-
 void heightmapGetLimits(HeightMap* heightmap, double* ymin, double* ymax)
 {
     double y;
@@ -161,6 +143,44 @@ double heightmapGetValue(HeightMap* heightmap, double x, double z)
     return toolsBicubicInterpolate(stencil, x * xmax - (double)xlow, z * zmax - (double)zlow);
 }
 
+
+void heightmapImportFromPicture(HeightMap* heightmap, const char* picturepath)
+{
+    systemLoadPictureFile(picturepath, (PictureCallbackLoadStarted)heightmapChangeResolution, (PictureCallbackLoadPixel)_loadFromFilePixel, heightmap);
+}
+
+void heightmapChangeResolution(HeightMap* heightmap, int resolution_x, int resolution_z)
+{
+    int i;
+    
+    heightmap->resolution_x = resolution_x;
+    heightmap->resolution_z = resolution_z;
+    heightmap->data = realloc(heightmap->data, sizeof(double) * heightmap->resolution_x * heightmap->resolution_z);
+    
+    for (i = 0; i < heightmap->resolution_x * heightmap->resolution_z; i++)
+    {
+        heightmap->data[i] = 0.0;
+    }
+}
+
+void heightmapRevertToTerrain(HeightMap* heightmap, TerrainDefinition* terrain, GeoArea* area)
+{
+    int rx, rz;
+    int x, z;
+    
+    rx = heightmap->resolution_x;
+    rz = heightmap->resolution_z;
+    for (x = 0; x < rx; x++)
+    {
+        for (z = 0; z < rz; z++)
+        {
+            /* FIXME Apply geoarea */
+            heightmap->data[z * rx + x] = terrainGetHeight(terrain, 80.0 * (double)x / (double)(rx - 1) - 40.0, 80.0 * (double)z / (double)(rz - 1) - 40.0);
+        }
+    }
+}
+
+
 static inline void _getBrushBoundaries(HeightMapBrush* brush, int rx, int rz, int* x1, int* x2, int* z1, int* z2)
 {
     double cx = brush->relative_x * rx;
@@ -211,10 +231,9 @@ typedef double (*BrushCallback)(HeightMap* heightmap, HeightMapBrush* brush, dou
 static inline void _applyBrush(HeightMap* heightmap, HeightMapBrush* brush, double force, void* data, BrushCallback callback)
 {
     int x, x1, x2, z, z1, z2;
-    double dx, dz, distance, influence, brush_size;
+    double dx, dz, distance, influence;
     
     _getBrushBoundaries(brush, heightmap->resolution_x - 1, heightmap->resolution_z - 1, &x1, &x2, &z1, &z2);
-    brush_size = brush->hard_radius + brush->smoothed_size;
     
     for (x = x1; x <= x2; x++)
     {
diff --git a/lib_paysages/heightmap.h b/lib_paysages/heightmap.h
index 23e070a..2b06c83 100644
--- a/lib_paysages/heightmap.h
+++ b/lib_paysages/heightmap.h
@@ -5,6 +5,8 @@
 
 #include "pack.h"
 #include "noise.h"
+#include "geoarea.h"
+#include "terrain.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -40,6 +42,7 @@ double heightmapGetValue(HeightMap* heightmap, double x, double z);
 
 void heightmapChangeResolution(HeightMap* heightmap, int resolution_x, int resolution_z);
 void heightmapImportFromPicture(HeightMap* heightmap, const char* picturepath);
+void heightmapRevertToTerrain(HeightMap* heightmap, TerrainDefinition* terrain, GeoArea* area);
 
 void heightmapBrushElevation(HeightMap* heightmap, HeightMapBrush* brush, double value);
 void heightmapBrushSmooth(HeightMap* heightmap, HeightMapBrush* brush, double value);
diff --git a/lib_paysages/terraincanvas.c b/lib_paysages/terraincanvas.c
index 7f82edf..3bb0aaa 100644
--- a/lib_paysages/terraincanvas.c
+++ b/lib_paysages/terraincanvas.c
@@ -1,4 +1,5 @@
 #include "terraincanvas.h"
+#include "scenery.h"
 
 #include <stdlib.h>
 #include <string.h>
@@ -8,11 +9,7 @@ TerrainCanvas* terrainCanvasCreate()
 {
     TerrainCanvas* result = malloc(sizeof(TerrainCanvas));
     
-    result->area.bounded = 1;
-    result->area.location_x = -40.0;
-    result->area.location_z = -40.0;
-    result->area.size_x = 80.0;
-    result->area.size_z = 80.0;
+    result->area = geoareaCreate();
     result->offset_y = 0.0;
     result->height_map = heightmapCreate();
     heightmapChangeResolution(&result->height_map, 256, 256);
@@ -24,10 +21,7 @@ TerrainCanvas* terrainCanvasCreate()
     result->detail_scaling = 0.4;
     result->mask.mode = INTEGRATIONMASK_MODE_CIRCLE;
     result->mask.smoothing = 0.1;
-
-    /* DEBUG */
-    /*heightmapImportFromPicture(&result->height_map, "output/height.png");*/
-        
+    
     return result;
 }
 
@@ -40,7 +34,7 @@ void terrainCanvasDelete(TerrainCanvas* canvas)
 
 void terrainCanvasCopy(TerrainCanvas* source, TerrainCanvas* destination)
 {
-    destination->area = source->area;
+    geoareaCopy(&source->area, &destination->area);
     destination->offset_y = source->offset_y;
     destination->height_factor = source->height_factor;
     heightmapCopy(&source->height_map, &destination->height_map);
@@ -56,6 +50,7 @@ void terrainCanvasValidate(TerrainCanvas* canvas)
     {
         canvas->detail_scaling = 0.00001;
     }
+    geoareaValidate(&canvas->area);
     heightmapValidate(&canvas->height_map);
     noiseValidate(canvas->detail_noise);
 }
@@ -76,11 +71,7 @@ LayerType terrainCanvasGetLayerType()
 
 void terrainCanvasSave(PackStream* stream, TerrainCanvas* canvas)
 {
-    packWriteInt(stream, &canvas->area.bounded);
-    packWriteDouble(stream, &canvas->area.location_x);
-    packWriteDouble(stream, &canvas->area.location_z);
-    packWriteDouble(stream, &canvas->area.size_x);
-    packWriteDouble(stream, &canvas->area.size_z);
+    geoareaSave(stream, &canvas->area);
     packWriteDouble(stream, &canvas->offset_y);
     heightmapSave(stream, &canvas->height_map);
     packWriteDouble(stream, &canvas->height_factor);
@@ -93,11 +84,7 @@ void terrainCanvasSave(PackStream* stream, TerrainCanvas* canvas)
 
 void terrainCanvasLoad(PackStream* stream, TerrainCanvas* canvas)
 {
-    packReadInt(stream, &canvas->area.bounded);
-    packReadDouble(stream, &canvas->area.location_x);
-    packReadDouble(stream, &canvas->area.location_z);
-    packReadDouble(stream, &canvas->area.size_x);
-    packReadDouble(stream, &canvas->area.size_z);
+    geoareaLoad(stream, &canvas->area);
     packReadDouble(stream, &canvas->offset_y);
     heightmapLoad(stream, &canvas->height_map);
     packReadDouble(stream, &canvas->height_factor);
@@ -116,8 +103,16 @@ void terrainCanvasGetLimits(TerrainCanvas* canvas, double* ymin, double* ymax)
     *ymax += noise_max;
 }
 
-void terrainCanvasRevertToTerrain(TerrainCanvas* canvas, TerrainDefinition* terrain, int only_masked)
+void terrainCanvasRevertToTerrain(TerrainCanvas* canvas)
 {
+    TerrainDefinition terrain;
+    
+    terrain = terrainCreateDefinition();
+    sceneryGetTerrain(&terrain);
+    
+    heightmapRevertToTerrain(&canvas->height_map, &terrain, &canvas->area);
+    
+    terrainDeleteDefinition(&terrain);
 }
 
 Vector3 terrainCanvasApply(TerrainCanvas* canvas, Vector3 location)
diff --git a/lib_paysages/terraincanvas.h b/lib_paysages/terraincanvas.h
index 835160e..e61c8d2 100644
--- a/lib_paysages/terraincanvas.h
+++ b/lib_paysages/terraincanvas.h
@@ -8,20 +8,12 @@
 #include "terrain.h"
 #include "layers.h"
 #include "heightmap.h"
+#include "geoarea.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct
-{
-    int bounded;
-    double location_x;
-    double location_z;
-    double size_x;
-    double size_z;
-} GeoArea;
-
 typedef struct
 {
     int mode;
@@ -53,7 +45,7 @@ void terrainCanvasSave(PackStream* stream, TerrainCanvas* canvas);
 void terrainCanvasLoad(PackStream* stream, TerrainCanvas* canvas);
 
 void terrainCanvasGetLimits(TerrainCanvas* canvas, double* ymin, double* ymax);
-void terrainCanvasRevertToTerrain(TerrainCanvas* canvas, TerrainDefinition* terrain, int only_masked);
+void terrainCanvasRevertToTerrain(TerrainCanvas* canvas);
 Vector3 terrainCanvasApply(TerrainCanvas* canvas, Vector3 location);
     
 #ifdef __cplusplus
diff --git a/lib_paysages/tools.h b/lib_paysages/tools.h
index 012192e..80daa4d 100644
--- a/lib_paysages/tools.h
+++ b/lib_paysages/tools.h
@@ -7,6 +7,8 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+    
+#define UNUSED(_x_) ((void)(_x_))
 
 double toolsRandom();
 double toolsBicubicInterpolate(double stencil[16], double x, double y);