ezGDAL

@@ -375,6 +375,36 @@ EZGDAL_LAYER*  ezgdal_create_layer(char *fname,

   return o;

 }

+void  ezgdal_read_buffer_with_shift(EZGDAL_LAYER *layer, int row) {

+  int i;

+  double d = 0.0;

+  double *p;

+  row += layer->shift_rows;

+  if(row<0 || row>=layer->rows) {

+    if(layer->is_no_data) d = layer->no_data;

+    p = layer->buffer;

+    for(i=0; i<layer->cols; i++)

+      *(p++) = d;

+  } else if(layer->shift_cols==0)

+    i=GDALRasterIO(layer->band_h, GF_Read, 0, row, layer->cols, 1,

+                 layer->buffer, layer->cols, 1, GDT_Float64, 0, 0);

+  else if(layer->shift_cols>0) {

+    i=GDALRasterIO(layer->band_h, GF_Read, layer->shift_cols, row, layer->cols, 1,

+                 layer->buffer, layer->cols - layer->shift_cols, 1, GDT_Float64, 0, 0);

+    if(layer->is_no_data) d = layer->no_data;

+    p = layer->buffer;

+    for(i=0; i<layer->shift_cols; i++)

+      *(p++) = d;

+  } else {

+    i=GDALRasterIO(layer->band_h, GF_Read, 0, row, layer->cols+layer->shift_cols, 1,

+                 layer->buffer, layer->cols + layer->shift_cols, 1, GDT_Float64, 0, 0);

+    if(layer->is_no_data) d = layer->no_data;

+    p = layer->buffer - (layer->cols + layer->shift_cols);

+    for(i=0; i<layer->shift_cols; i++)

+      *(p++) = d;

+  }

+}

+

 void  ezgdal_read_buffer(EZGDAL_LAYER *layer, int row) {

   int i;

   double d = 0.0;

@@ -428,6 +458,10 @@ void  ezgdal_set_null(EZGDAL_LAYER *layer, double *v) {

     *v = layer->no_data;

 }

+void  ezgdal_shift_layer(EZGDAL_LAYER *layer, int shift_rows, int shift_cols) {

+  layer->shift_rows = shift_rows;

+  layer->shift_cols = shift_cols;

+}

 /*==========================================*/

@@ -89,6 +89,8 @@ struct EZGDAL_LAYER {

   GDALRasterBandH band_h;

   int rows;

   int cols;

+  int shift_rows;

+  int shift_cols;

   int is_no_data;

   double no_data;

   double *buffer;

@@ -134,9 +136,11 @@ EZGDAL_DLL_API EZGDAL_LAYER*  ezgdal_open_layer_band(char *fname, int band);

 EZGDAL_DLL_API EZGDAL_LAYER*  ezgdal_open_layer_rw(char *fname);

 EZGDAL_DLL_API void  ezgdal_close_layer(EZGDAL_LAYER *layer);

+EZGDAL_DLL_API void  ezgdal_shift_layer(EZGDAL_LAYER *layer, int shift_rows, int shift_cols);

 EZGDAL_DLL_API void  ezgdal_set_palette255(EZGDAL_LAYER *layer, double palette[][5], int n);

 EZGDAL_DLL_API void  ezgdal_read_buffer(EZGDAL_LAYER *layer, int row);

+EZGDAL_DLL_API void  ezgdal_read_buffer_with_shift(EZGDAL_LAYER *layer, int row);

 EZGDAL_DLL_API void  ezgdal_write_buffer(EZGDAL_LAYER *layer, int row);

 EZGDAL_DLL_API void  ezgdal_read_all_layer(EZGDAL_LAYER *layer, double* buffer);