r.geomorphon: separate input from output (#1052)

* r.geomorphon: Use o_forms where it belongs

The for loops that iterate over opt_output[] started from hard-coded 1
(o_forms), which is the first output, but not the first element in the
array. Use the enumeration constant to iterate properly regardless of
the amount of any preceding items in the array. Remove a comment that no
longer applies.

* r.geomorphon: Lose IO.required

All the output rasters were hard-coded as not required regardless of
what was in the array, and the only input raster is a standard option
that is required by default, so just remove the field from the
structure.

* r.geomorphon: Separate input and output rasters

The input raster element did not belong to the array because it used
only two structure fields to store string constants that were excess for
a standard option anyway; it also created a place for an off-by-one
error in every loop over the array. Remove the element from the array,
merge the single-use type into the only declaration that needs it and
constify some fields. Rename io_size to o_size, remove i_dem, UNKNOWN
and a stale comment.

raster/r.geomorphon/main.c

@@ -22,26 +22,13 @@
 #define MAIN
 #include "local_proto.h"
 
-#define UNKNOWN -1
-
 typedef enum
-{ i_dem, o_forms, o_ternary, o_positive, o_negative, o_intensity,
+{ o_forms, o_ternary, o_positive, o_negative, o_intensity,
 	o_exposition,
-    o_range, o_variance, o_elongation, o_azimuth, o_extend, o_width, io_size
+    o_range, o_variance, o_elongation, o_azimuth, o_extend, o_width, o_size
 } outputs;
 
 typedef struct
-{				/* struct is used both for interface and output */
-    char *name;
-    int required;
-    char *description;
-    char *gui;
-    RASTER_MAP_TYPE out_data_type;
-    int fd;
-    void *buffer;
-} IO;
-
-typedef struct
 {
     char name[100];
     int fd;
@@ -50,41 +37,48 @@ typedef struct
 
 int main(int argc, char **argv)
 {
-    IO rasters[] = {		/* rasters stores output buffers */
-	{"elevation", YES, "Name of input elevation raster map", "input", UNKNOWN, -1, NULL},	/* WARNING: this one map is input */
-	{"forms", NO, "Most common geomorphic forms", "Patterns", CELL_TYPE,
+    struct
+    {				/* struct is used both for interface and output */
+	const char *name;
+	const char *description;
+	const char *gui;
+	RASTER_MAP_TYPE out_data_type;
+	int fd;
+	void *buffer;
+    } rasters[] = {		/* rasters stores output buffers */
+	{"forms", "Most common geomorphic forms", "Patterns", CELL_TYPE,
 	 -1, NULL},
-	{"ternary", NO, "Code of ternary patterns", "Patterns", CELL_TYPE, -1,
+	{"ternary", "Code of ternary patterns", "Patterns", CELL_TYPE, -1,
 	 NULL},
-	{"positive", NO, "Code of binary positive patterns", "Patterns",
+	{"positive", "Code of binary positive patterns", "Patterns",
 	 CELL_TYPE, -1, NULL},
-	{"negative", NO, "Code of binary negative patterns", "Patterns",
+	{"negative", "Code of binary negative patterns", "Patterns",
 	 CELL_TYPE, -1, NULL},
-	{"intensity", NO,
+	{"intensity",
 	 "Rasters containing mean relative elevation of the form", "Geometry",
 	 FCELL_TYPE, -1, NULL},
-	{"exposition", NO,
+	{"exposition",
 	 "Rasters containing maximum difference between extend and central cell",
 	 "Geometry", FCELL_TYPE, -1, NULL},
-	{"range", NO,
+	{"range",
 	 "Rasters containing difference between max and min elevation of the form extend",
 	 "Geometry", FCELL_TYPE, -1, NULL},
-	{"variance", NO, "Rasters containing variance of form boundary",
+	{"variance", "Rasters containing variance of form boundary",
 	 "Geometry", FCELL_TYPE, -1, NULL},
-	{"elongation", NO, "Rasters containing local elongation", "Geometry",
+	{"elongation", "Rasters containing local elongation", "Geometry",
 	 FCELL_TYPE, -1, NULL},
-	{"azimuth", NO, "Rasters containing local azimuth of the elongation",
+	{"azimuth", "Rasters containing local azimuth of the elongation",
 	 "Geometry", FCELL_TYPE, -1, NULL},
-	{"extend", NO, "Rasters containing local extend (area) of the form",
+	{"extend", "Rasters containing local extend (area) of the form",
 	 "Geometry", FCELL_TYPE, -1, NULL},
-	{"width", NO, "Rasters containing local width of the form",
+	{"width", "Rasters containing local width of the form",
 	 "Geometry", FCELL_TYPE, -1, NULL}
-    };				/* adding more maps change IOSIZE macro */
+    };
 
     struct GModule *module;
     struct Option
 	*opt_input,
-	*opt_output[io_size],
+	*opt_output[o_size],
 	*par_search_radius,
 	*par_skip_radius,
 	*par_flat_threshold,
@@ -118,11 +112,8 @@ int main(int argc, char **argv)
 	G_add_keyword(_("machine vision geomorphometry"));
 
 	opt_input = G_define_standard_option(G_OPT_R_ELEV);
-	opt_input->key = rasters[0].name;
-	opt_input->required = rasters[0].required;
-	opt_input->description = _(rasters[0].description);
 
-	for (i = 1; i < io_size; ++i) {	/* WARNING: loop starts from one, zero is for input */
+	for (i = o_forms; i < o_size; ++i) {
 	    opt_output[i] = G_define_standard_option(G_OPT_R_OUTPUT);
 	    opt_output[i]->key = rasters[i].name;
 	    opt_output[i]->required = NO;
@@ -201,7 +192,7 @@ int main(int argc, char **argv)
 	double ns_resolution;
 
 	multires = (par_multi_prefix->answer) ? 1 : 0;
-	for (i = 1; i < io_size; ++i)	/* check for outputs */
+	for (i = o_forms; i < o_size; ++i)	/* check for outputs */
 	    if (opt_output[i]->answer) {
 		if (G_legal_filename(opt_output[i]->answer) < 0)
 		    G_fatal_error(_("<%s> is an illegal file name"),
@@ -330,7 +321,7 @@ int main(int argc, char **argv)
 
 	cell_step = 1;
 	/* prepare outputs */
-	for (i = 1; i < io_size; ++i)
+	for (i = o_forms; i < o_size; ++i)
 	    if (opt_output[i]->answer) {
 		rasters[i].fd =
 		    Rast_open_new(opt_output[i]->answer,
@@ -359,7 +350,7 @@ int main(int argc, char **argv)
 		    col > ncols - (skip_cells + 2) ||
 		    Rast_is_f_null_value(&elevation.elev[cur_row][col])) {
 		    /* set outputs to NULL and do nothing if source value is null   or border */
-		    for (i = 1; i < io_size; ++i)
+		    for (i = o_forms; i < o_size; ++i)
 			if (opt_output[i]->answer) {
 			    pointer_buf = rasters[i].buffer;
 			    switch (rasters[i].out_data_type) {
@@ -472,7 +463,7 @@ int main(int argc, char **argv)
 	    }			/* end for col */
 
 	    /* write existing outputs */
-	    for (i = 1; i < io_size; ++i)
+	    for (i = o_forms; i < o_size; ++i)
 		if (opt_output[i]->answer)
 		    Rast_put_row(rasters[i].fd, rasters[i].buffer,
 				 rasters[i].out_data_type);
@@ -481,7 +472,7 @@ int main(int argc, char **argv)
 
 	/* finish and close */
 	free_map(elevation.elev, row_buffer_size + 1);
-	for (i = 1; i < io_size; ++i)
+	for (i = o_forms; i < o_size; ++i)
 	    if (opt_output[i]->answer) {
 		G_free(rasters[i].buffer);
 		Rast_close(rasters[i].fd);