a more more work on niftisave

.gitignore

@@ -1,3 +1,4 @@
+.pytest_cache
 compile
 a.out
 *.log

libvips/foreign/niftiload.c

@@ -103,14 +103,7 @@ vips_foreign_load_nifti_dispose( GObject *gobject )
 		dispose( gobject );
 }
 
-/* Map DT_* datatype values to VipsBandFormat.
- */
-typedef struct _DT2Vips {
-	int datatype;
-	VipsBandFormat fmt;
-} DT2Vips;
-
-static DT2Vips vips_DT2Vips[] = {
+VipsForeignDT2Vips vips_foreign_DT2Vips[] = {
 	{ DT_UINT8, VIPS_FORMAT_UCHAR },
 	{ DT_INT8, VIPS_FORMAT_CHAR },
 	{ DT_UINT16, VIPS_FORMAT_USHORT },
@@ -135,15 +128,10 @@ static DT2Vips vips_DT2Vips[] = {
 )
 #endif /*HAVE_CHECKED_MUL*/
 
-/* All the header fields we attach as metadata.
- */
-typedef struct _Field {
-	char *name;
-	GType type;
-	glong offset;
-} Field;
-
-static Field other_fields[] = {
+VipsForeignNiftiFields vips_foreign_nifti_fields[] = {
+	/* The first 8 must be the dims[] fields, see
+	 * vips_foreign_save_nifti_make_nim().
+	 */
 	{ "ndim", G_TYPE_INT, G_STRUCT_OFFSET( nifti_image, ndim ) }, 
 	{ "nx", G_TYPE_INT, G_STRUCT_OFFSET( nifti_image, nx ) }, 
 	{ "ny", G_TYPE_INT, G_STRUCT_OFFSET( nifti_image, ny ) }, 
@@ -401,13 +389,14 @@ vips_foreign_load_nifti_set_header( VipsForeignLoadNifti *nifti,
 			VIPS_INTERPRETATION_B_W : VIPS_INTERPRETATION_sRGB, 
 		xres, yres );
 
-	for( i = 0; i < VIPS_NUMBER( other_fields ); i++ ) {
+	for( i = 0; i < VIPS_NUMBER( vips_foreign_nifti_fields ); i++ ) {
 		GValue value = { 0 };
 
-		g_value_init( &value, other_fields[i].type );
+		g_value_init( &value, vips_foreign_nifti_fields[i].type );
 		vips_gvalue_read( &value, 
-			(gpointer) nim + other_fields[i].offset );
-		vips_snprintf( txt, 256, "nifti-%s", other_fields[i].name );
+			(gpointer) nim + vips_foreign_nifti_fields[i].offset );
+		vips_snprintf( txt, 256, "nifti-%s", 
+			vips_foreign_nifti_fields[i].name );
 		vips_image_set( out, txt, &value );
 		g_value_unset( &value );
 	}

libvips/foreign/niftisave.c

@@ -79,10 +79,50 @@ vips_foreign_save_nifti_dispose( GObject *gobject )
 }
 
 static int
-vips_foreign_save_nifti_make_header( VipsForeignSaveNifti *nifti, 
-	struct nifti_1_header *nhdr )
+vips_foreign_save_nifti_make_nim( VipsForeignSaveNifti *nifti, 
+	VipsImage *image )
 {
+	int dims[8];
+	int datatype;
+	int height;
+	int i;
 
+	/* The first 8 members of vips_foreign_nifti_fields[] are the dims
+	 * fields.
+	 */
+	for( i = 0; i < VIPS_NUMBER( dims ); i++ ) {
+		static char name[256];
+
+		vips_snprintf( name, 256, "nifti-%s", 
+			vips_foreign_nifti_fields[i].name );
+		if( vips_image_get_int( image, name, &dims[i] ) )
+			return( -1 );
+	}
+
+	height = 1;
+	for( i = 2; i < VIPS_NUMBER( dims ) && i < dims[0]; i++ )
+		height *= dims[i];
+	if( images->Xsize != dims[1] ||
+		images->Ysize != height ) {
+		vips_error( class->nickname, 
+			"%s", _( "bad image dimensions" ) );
+		return( -1 );
+	}
+
+	datatype = -1;
+	for( i = 0; i < vips_foreign_DT2Vips; i++ )
+		if( vips_foreign_DT2Vips[i].format == image.format ) {
+			datatype = vips_foreign_DT2Vips[i].datatype;
+			break;
+		}
+	if( datatype == -1 ) {
+		vips_error( class->nickname, 
+			"%s", _( "unsupported libvips image type" ) );
+		return( -1 );
+	}
+
+	if( !(nnifti->nim = nifti_make_new_nim( dims, datatype, FALSE )) )
+		return( -1 );
 
 	return( 0 );
 }
@@ -101,7 +141,7 @@ vips_foreign_save_nifti_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
-	if( vips_foreign_save_nifti_make_header( nifti, &nhdr ) )
+	if( vips_foreign_save_nifti_make_header( nifti, save->ready, &nhdr ) )
 		return( -1 );
 
 	if( !(nifti->nim = nifti_convert_nhdr2nim( nhdr, nifti->filename )) )

libvips/foreign/pforeign.h

@@ -256,6 +256,25 @@ int vips__quantise_image( VipsImage *in,
 	VipsImage **index_out, VipsImage **palette_out,
 	int colours, int Q, double dither );
 
+/* Map DT_* datatype values to VipsBandFormat.
+ */
+typedef struct _VipsForeignDT2Vips {
+	int datatype;
+	VipsBandFormat fmt;
+} VipsForeignDT2Vips 
+
+extern VipsForeignDT2Vips vips_foreign_DT2Vips[];
+
+/* All the header fields we attach as metadata.
+ */
+typedef struct _VipsForeignNiftiFields {
+	char *name;
+	GType type;
+	glong offset;
+} VipsForeignNiftiFields;
+
+VipsForeignNiftiFields vips_foreign_nifti_fields[];
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/