added support for clockwise-ness in shp dumper

git-svn-id: http://svn.osgeo.org/postgis/trunk@207 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/loader/pgsql2shp.c b/loader/pgsql2shp.c
index 028948126f3d72013cf71ec4ff0906222f5ad657..4895d0cbdd43ad67cfb54b7997948b8622548284 100644 (file)
--- a/loader/pgsql2shp.c
+++ b/loader/pgsql2shp.c
@@ -25,8 +25,8 @@ int num_points(char *str);
 int num_lines(char *str);
 char *scan_to_same_level(char *str);
 int points_per_sublist( char *str, int *npoints, long max_lists);
-
-
+int reverse_points(int num_points,double *x,double *y,double *z);
+int is_clockwise(int num_points,double *x,double *y,double *z);
 
 //main
 //USAGE: pgsql2shp [<options>] <database> <table>
@@ -405,14 +405,14 @@ int main(int ARGC, char **ARGV){
 
 
        //get what kind of Geometry type is in the table
-       query= (char *)malloc(strlen(table) + strlen("select distinct (geometrytype()) from where NOT geometrytype(geom) = NULL")+18);
+       query= (char *)malloc(strlen(table) + strlen("select distinct (geometrytype()) from where NOT geometrytype(geom) = NULL")+38);
        strcpy(query, "select distinct (geometrytype(");
        strcat(query, geo_col_name);
        strcat(query, ")) from ") ;
        strcat(query, table);
        strcat(query," where NOT geometrytype(");
        strcat(query,geo_col_name);
-       strcat(query,") = NULL");
+       strcat(query,") IS NULL");
        res3 = PQexec(conn, query);     
        //printf("\n\n-->%s\n\n",query);
 
@@ -1048,15 +1048,15 @@ int create_multipoints(char *str, SHPHandle shp,int dims){
        
        if(dims == 0){
                if(notnull > 0){
-                       obj = SHPCreateSimpleObject(SHPT_MULTIPOINT ,1,x,y,z);
+                       obj = SHPCreateSimpleObject(SHPT_MULTIPOINT ,points,x,y,z);
                }else{
-                       obj = SHPCreateSimpleObject(SHPT_NULL ,1,x,y,z);
+                       obj = SHPCreateSimpleObject(SHPT_NULL ,points,x,y,z);
                }
        }else{
                if(notnull > 0){
-                       obj = SHPCreateSimpleObject(SHPT_MULTIPOINTZ ,1,x,y,z);
+                       obj = SHPCreateSimpleObject(SHPT_MULTIPOINTZ ,points,x,y,z);
                }else{
-                       obj = SHPCreateSimpleObject(SHPT_NULL ,1,x,y,z);
+                       obj = SHPCreateSimpleObject(SHPT_NULL ,points,x,y,z);
                }
        }
 
@@ -1125,17 +1125,30 @@ int create_polygons(char *str,int shape_id, SHPHandle shp,int dims){
                z = (double *)malloc(sizeof(double) * points[i]);
 
                notnull = parse_points(str,points[i],x,y,z);
+
                str = scan_to_same_level(str);
                part_index[i] = index;
+
+               //if this the first ring it should be clockwise, other rings are holes and should be counter-clockwise
+               if(i ==0){
+                       if(is_clockwise(points[i],x,y,z) == 0){
+                               reverse_points(points[i],x,y,z);
+                       }
+               }else{
+                       if(is_clockwise(points[i],x,y,z) == 1){
+                               reverse_points(points[i],x,y,z);
+                       }
+               }
+
                for(j=0;j<points[i];j++){
                        totx[index] = x[j];
                        toty[index] = y[j];
                        totz[index] = z[j];
                        index++;
                }
-               free(x);
-               free(y);
-               free(z);
+//             free(x);
+//             free(y);
+//             free(z);
        }
 
        obj = (SHPObject *)malloc(sizeof(SHPObject));
@@ -1270,6 +1283,18 @@ int create_multipolygons(char *str,int shape_id, SHPHandle shp,int dims){
                        notnull = parse_points(str,points[i],x,y,z);
                        str = scan_to_same_level(str);
                        part_index[i] = index;
+
+                       //if this the first ring it should be clockwise, other rings are holes and should be counter-clockwise
+                       if(i ==0){
+                               if(is_clockwise(points[i],x,y,z) == 0){
+                                       reverse_points(points[i],x,y,z);
+                               }
+                       }else{
+                               if(is_clockwise(points[i],x,y,z) == 1){
+                                       reverse_points(points[i],x,y,z);
+                               }
+                       }
+
                        for(j=0;j<points[i];j++){
                                totx[index] = x[j];
                                toty[index] = y[j];
@@ -1298,7 +1323,7 @@ int create_multipolygons(char *str,int shape_id, SHPHandle shp,int dims){
                free(toty);
                free(totz);
                str -= 1;
-       }//end for (k...
+       }//end for (k < polys... loop
 
 
        obj     = (SHPObject *)malloc(sizeof(SHPObject));
@@ -1329,3 +1354,60 @@ int create_multipolygons(char *str,int shape_id, SHPHandle shp,int dims){
        }
        
 }
+
+
+
+//Reverse the clockwise-ness of the point list...
+int reverse_points(int num_points,double *x,double *y,double *z){
+       
+       int i,j;
+       double temp;
+       j = num_points -1;
+       for(i=0; i <num_points; i++){
+               if(j <= i){
+                       break;
+               }
+               temp = x[j];
+               x[j] = x[i];
+               x[i] = temp;
+
+               temp = y[j];
+               y[j] = y[i];
+               y[i] = temp;
+
+               temp = z[j];
+               z[j] = z[i];
+               z[i] = temp;
+
+               j--;
+       }
+       return 1;
+}
+
+//return 1 if the points are in clockwise order
+int is_clockwise(int  num_points,double *x,double *y,double *z){
+       int i;
+       double x_change,y_change,area;
+       double *x_new, *y_new; //the points, translated to the origin for safer accuracy
+
+       x_new = (double *)malloc(sizeof(double) * num_points);  
+       y_new = (double *)malloc(sizeof(double) * num_points);  
+       area=0.0;
+       x_change = x[0];
+       y_change = z[0];
+
+       for(i=0; i < num_points ; i++){
+               x_new[i] = x[i] - x_change;
+               y_new[i] = y[i] - y_change;
+       }
+
+       for(i=0; i < num_points ; i++){
+               area += (x[i] * y[i+1]) - (y[i] * x[i+1]); //calculate the area 
+       }
+       if(area > 0 ){
+               return 0; //counter-clockwise
+       }else{
+               return 1; //clockwise
+       }
+}
+