It is time to make GDAL a required prerequisite

BUILDING.md

@@ -26,13 +26,13 @@ To build GMT, you have to install:
 - [CMake](https://cmake.org/) (>=2.8.12)
 - [netCDF](https://www.unidata.ucar.edu/software/netcdf/) (>=4.0, netCDF-4/HDF5 support mandatory)
 - [curl](https://curl.haxx.se/)
+- [GDAL](https://www.gdal.org/) (Ability to read and write numerous grid and image formats)
 
 ### Optional dependencies
 
 Optionally install these for more capabilities within GMT:
 
 - [Ghostscript](https://www.ghostscript.com/) (Ability to convert PostScript plots to PDF and rasters)
-- [GDAL](https://www.gdal.org/) (Ability to read and write numerous grid and image formats)
 - [GEOS](https://trac.osgeo.org/geos/) (Ability to buffer lines and polygons)
 - [PCRE](https://www.pcre.org/) or PCRE2 (Regular expression support)
 - [FFTW](http://www.fftw.org/) single-precision (Fast FFTs, >=3.3 [not needed under macOS])

src/CMakeLists.txt

@@ -145,14 +145,9 @@ include_directories (${CURL_INCLUDE_DIRS})
 list (APPEND GMT_OPTIONAL_LIBRARIES ${CURL_LIBRARIES})
 set (CURL_LIBRARY ${CURL_LIBRARIES} CACHE INTERNAL "")
 
-if (NOT DEFINED GMT_EXCLUDE_GDAL)
-	find_package (GDAL)
-endif (NOT DEFINED GMT_EXCLUDE_GDAL)
-if (GDAL_FOUND)
-	set (HAVE_GDAL TRUE CACHE INTERNAL "System has GDAL")
-	include_directories (${GDAL_INCLUDE_DIR})
-	list (APPEND GMT_OPTIONAL_LIBRARIES ${GDAL_LIBRARIES})
-endif (GDAL_FOUND)
+find_package (GDAL REQUIRED)
+include_directories (${GDAL_INCLUDE_DIR})
+list (APPEND GMT_OPTIONAL_LIBRARIES ${GDAL_LIBRARIES})
 
 if (NOT DEFINED GMT_EXCLUDE_GEOS)
 	find_package (GEOS)

src/gmt.c

@@ -326,10 +326,7 @@ int main (int argc, char *argv[]) {
 			fprintf (stderr, "Shared libraries must be in standard system paths or set via environmental parameter %s.\n\n", LIB_PATH);
 		}
 		else {
-			char libraries[GMT_LEN128] = {"netCDF"};	/* Always linked with netCDF */
-#ifdef HAVE_GDAL
-			strcat (libraries, ", GDAL");
-#endif
+			char libraries[GMT_LEN128] = {"netCDF, GDAL"};	/* Always linked with netCDF and GDAL */
 #ifdef HAVE_PCRE
 			strcat (libraries, ", PCRE");
 #endif

src/gmt_api.c

@@ -4504,7 +4504,6 @@ GMT_LOCAL int gmtapi_import_ppm (struct GMT_CTRL *GMT, char *fname, struct GMT_I
 	return GMT_NOERROR;
 }
 
-#ifdef HAVE_GDAL
 GMT_LOCAL bool gmtapi_expand_index_image (struct GMT_CTRL *GMT, struct GMT_IMAGE *I_in, struct GMT_IMAGE **I_out) {
 	/* In most situations we can use an input image given to a module as the dataset to
 	 * plot.  However, if the image is indexed then we must expand it to rgb since we may
@@ -4602,7 +4601,6 @@ void gmtlib_GDALDestroyDriverManager (struct GMTAPI_CTRL *API) {
     /* Cannot close connection to GDAL if calling environment expect it to be open */
 	if (API->external < 2) GDALDestroyDriverManager();
 }
-#endif
 
 /*! . */
 GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int object_ID, unsigned int mode, struct GMT_IMAGE *image) {
@@ -4617,9 +4615,10 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 	 */
 
 	int item, new_item, new_ID;
-	bool done = true, via = false, must_be_image = true, no_index = false, bc_not_set = true;
+	bool done = true, via = false, must_be_image = true, no_index = false, bc_not_set = true, new = false;
 	uint64_t i0, i1, j0, j1, ij, ij_orig, row, col;
 	unsigned int both_set = (GMT_CONTAINER_ONLY | GMT_DATA_ONLY);
+	size_t size;
 	double dx, dy, d;
 	p_func_uint64_t GMT_2D_to_index = NULL;
 	GMT_getfunction api_get_val = NULL;
@@ -4630,11 +4629,7 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 	struct GMT_GRID_HEADER_HIDDEN *HH = NULL;
 	struct GMTAPI_DATA_OBJECT *S_obj = NULL;
 	struct GMT_CTRL *GMT = API->GMT;
-#ifdef HAVE_GDAL
-	bool new = false;
-	size_t size;
 	struct GMT_IMAGE *Irgb = NULL;
-#endif
 
 	GMT_Report (API, GMT_MSG_DEBUG, "gmtapi_import_image: Passed ID = %d and mode = %d\n", object_ID, mode);
 
@@ -4656,7 +4651,6 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 
 	switch (S_obj->method) {
 		case GMT_IS_FILE:	/* Name of an image file on disk */
-#ifdef HAVE_GDAL
 			if (image == NULL) {	/* Only allocate image struct when not already allocated */
 				if (mode & GMT_DATA_ONLY) return_null (API, GMT_NO_GRDHEADER);		/* For mode & GMT_DATA_ONLY image must already be allocated */
 				I_obj = gmtlib_create_image (GMT);
@@ -4716,9 +4710,6 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 			}
 			IH = gmt_get_I_hidden (I_obj);
 			IH->alloc_mode = GMT_ALLOC_INTERNALLY;
-#else
-			GMT_Report (API, GMT_MSG_ERROR, "GDAL required to read image from file %s\n", S_obj->filename);
-#endif
 			break;
 
 	 	case GMT_IS_DUPLICATE:	/* GMT image and header in a GMT_IMAGE container object. */
@@ -4894,7 +4885,6 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 
 	if (done) S_obj->status = GMT_IS_USED;	/* Mark as read (unless we just got the header) */
 
-#ifdef HAVE_GDAL
 	if (no_index) {   /* true if we have an indexed image and we had to allocate a new one */
 		if (gmtapi_expand_index_image (API->GMT, I_obj, &Irgb)) {   /* true if we have a read-only indexed image and we had to allocate a new one */
 			if (GMT_Destroy_Data (API, &I_obj) != GMT_NOERROR) {
@@ -4906,7 +4896,6 @@ GMT_LOCAL struct GMT_IMAGE *gmtapi_import_image (struct GMTAPI_CTRL *API, int ob
 		if (bc_not_set && gmt_M_err_pass (GMT, gmtlib_image_BC_set (GMT, I_obj), S_obj->filename))
 			return_null (API, GMT_IMAGE_BC_ERROR);	/* Failed to set boundary conditions */
 	}
-#endif
 
 	if (!via) S_obj->resource = I_obj;	/* Retain pointer to the allocated data so we use garbage collection later */
 
@@ -5001,13 +4990,8 @@ GMT_LOCAL int gmtapi_export_image (struct GMTAPI_CTRL *API, int object_ID, unsig
 				GMT_Report (API, GMT_MSG_ERROR, "Unable to export image\n");
 				return (gmtlib_report_error (API, GMT_ERROR_ON_FOPEN));
 			}
-#ifdef HAVE_GDAL
 			else if (gmt_M_err_pass (API->GMT, gmt_export_image (API->GMT, S_obj->filename, I_obj), S_obj->filename))
 				return (gmtlib_report_error (API, GMT_IMAGE_WRITE_ERROR));
-#else
-			else
-				GMT_Report (API, GMT_MSG_ERROR, "GDAL required to write image to file %s\n", S_obj->filename);
-#endif
 			break;
 
 	 	case GMT_IS_DUPLICATE:	/* Duplicate GMT image to a new GMT_IMAGE container object */
@@ -13528,13 +13512,7 @@ int GMT_Get_Default (void *V_API, const char *keyword, char *value) {
 	else if (!strncmp (keyword, "API_CORES", 9U))	/* Report number of cores */
 		sprintf (value, "%d", API->n_cores);
 	else if (!strncmp (keyword, "API_IMAGE_LAYOUT", 16U)) {	/* Report image/band layout */
-#ifdef HAVE_GDAL
 		gmt_M_memcpy (value, API->GMT->current.gdal_read_in.O.mem_layout, 4, char);
-#else
-		GMT_Report (API, GMT_MSG_ERROR, "API_IMAGE_LAYOUT only available when GMT is linked with GDAL; request ignored");
-		value[0] = '\0';
-		error = GMT_NOT_A_VALID_ARG;
-#endif
 	}
 	else if (!strncmp (keyword, "API_GRID_LAYOUT", 15U)) {	/* Report grid layout */
 		if (API->shape == GMT_IS_COL_FORMAT)
@@ -13577,7 +13555,6 @@ int GMT_Set_Default (void *V_API, const char *keyword, const char *txt_val) {
 			API->pad = pad;
 		}
 	}
-#ifdef HAVE_GDAL
 	else if (!strncmp (keyword, "API_IMAGE_LAYOUT", 16U)) {	/* Change image/band layout */
 		if (strlen (value) != 4U) {
 			error = 1;
@@ -13586,7 +13563,6 @@ int GMT_Set_Default (void *V_API, const char *keyword, const char *txt_val) {
 		else
 			gmt_M_memcpy (API->GMT->current.gdal_read_in.O.mem_layout, value, 4, char);
 	}
-#endif
 	else if (!strncmp (keyword, "API_GRID_LAYOUT", 15U)) {	/* Change grid layout */
 		if (!strncmp (value, "columns", 7U) || (strlen(value) >= 2 && value[1] == 'C'))		/* Accept also TC, though ignore 1st and 3-end chars. Accept this to be consistent with the "API_IMAGE_LAYOUT" case */
 			API->shape = GMT_IS_COL_FORMAT;	/* Switch to column-major format */

src/gmt_customio.c

@@ -1623,13 +1623,8 @@ int gmt_srf_write_grd (struct GMT_CTRL *GMT, struct GMT_GRID_HEADER *header, gmt
 	struct GMT_GRID_HEADER_HIDDEN *HH = gmt_get_H_hidden (header);
 
 	if (GMT->session.grdformat[header->type][1] == 'd') {
-#ifdef HAVE_GDAL
 		GMT_Report(GMT->parent, GMT_MSG_INFORMATION,
 			"Surfer 7 format in GMT is read-only but you can do it via GDAL by appending '=gd:GS7BG' to the file name\n");
-#else
-		GMT_Report(GMT->parent, GMT_MSG_INFORMATION,
-			"As mentioned in the manual, Surfer 7 format in GMT is read-only\n");
-#endif
 		return (GMT_NOERROR);
 	}
 
@@ -1719,7 +1714,6 @@ int gmt_srf_write_grd (struct GMT_CTRL *GMT, struct GMT_GRID_HEADER *header, gmt
 	return (GMT_NOERROR);
 }
 
-#ifdef HAVE_GDAL
 #include "gmt_gdalread.c"
 #include "gmt_gdalwrite.c"
 #include "gmt_ogrproj.c"		/* For coordinate conversions but can "enter" here too */
@@ -2173,8 +2167,6 @@ int gmt_gdal_write_grd (struct GMT_CTRL *GMT, struct GMT_GRID_HEADER *header, gm
 	return (GMT_NOERROR);
 }
 
-#endif
-
 /* Add custom code here */
 
 /* 12: NOAA NGDC MGG Format */
@@ -2432,21 +2424,12 @@ void gmtlib_grdio_init (struct GMT_CTRL *GMT) {
 	/* FORMAT: Import via the GDAL interface */
 
 	id                        = GMT_GRID_IS_GD;
-#ifdef HAVE_GDAL
 	GMT->session.grdformat[id]  = "gd = Import/export through GDAL";
 	GMT->session.readinfo[id]   = &gmt_gdal_read_grd_info;
 	GMT->session.updateinfo[id] = &gmt_gdal_write_grd_info;
 	GMT->session.writeinfo[id]  = &gmt_gdal_write_grd_info;
 	GMT->session.readgrd[id]    = &gmt_gdal_read_grd;
 	GMT->session.writegrd[id]   = &gmt_gdal_write_grd;
-#else
-	GMT->session.grdformat[id]  = "gd = Import/export through GDAL (not supported)";
-	GMT->session.readinfo[id]   = &gmt_dummy_grd_info;
-	GMT->session.updateinfo[id] = &gmt_dummy_grd_info;
-	GMT->session.writeinfo[id]  = &gmt_dummy_grd_info;
-	GMT->session.readgrd[id]    = &gmt_dummy_grd_read;
-	GMT->session.writegrd[id]   = &gmt_dummy_grd_read;
-#endif
 
 	/* ----------------------------------------------
 	 * ADD CUSTOM FORMATS BELOW AS THEY ARE NEEDED */

src/gmt_dev.h

@@ -145,9 +145,7 @@ struct GMT_CTRL; /* forward declaration of GMT_CTRL */
 #include "gmt_psl.h"            /* Declarations of structure for GMT PostScript settings */
 #include "gmt_hash.h"           /* Declarations of structure for GMT hashing */
 
-#ifdef HAVE_GDAL
-#	include "gmt_gdalread.h"      /* GDAL support */
-#endif
+#include "gmt_gdalread.h"      /* GDAL support */
 
 #include "gmt_common.h"         /* For holding the GMT common option settings */
 #include "gmt_fft.h"            /* Structures and enums used by programs needing FFTs */

src/gmt_gdalcall.c

@@ -18,7 +18,7 @@
 #include "gmt_dev.h"
 #include "gmt_internals.h"
 
-#if defined(HAVE_GDAL) && ((GDAL_VERSION_MAJOR >= 2) && (GDAL_VERSION_MINOR >= 1)) || (GDAL_VERSION_MAJOR >= 3)
+#if ((GDAL_VERSION_MAJOR >= 2) && (GDAL_VERSION_MINOR >= 1)) || (GDAL_VERSION_MAJOR >= 3)
 
 #include <gdal_utils.h>
 

src/gmt_grdio.c

@@ -1131,14 +1131,12 @@ int gmt_grd_get_format (struct GMT_CTRL *GMT, char *file, struct GMT_GRID_HEADER
 	else if (magic) {	/* Reading: determine file format automatically based on grid content */
 		int choice = 0;
 		sscanf (HH->name, "%[^?]?%s", tmp, HH->varname);    /* Strip off variable name */
-#ifdef HAVE_GDAL
 		/* Check if file is an URL */
 		if (gmtlib_found_url_for_gdal(HH->name)) {
 			/* Then check for GDAL grid */
 			if (gmtlib_is_gdal_grid (GMT, header) == GMT_NOERROR)
 				return (GMT_NOERROR);
 		}
-#endif
 		if (!gmt_getdatapath (GMT, tmp, HH->name, R_OK))
 			return (GMT_GRDIO_FILE_NOT_FOUND);	/* Possibly prepended a path from GMT_[GRID|DATA|IMG]DIR */
 		/* First check if we have a netCDF grid. This MUST be first, because ?var needs to be stripped off. */
@@ -1171,11 +1169,9 @@ int gmt_grd_get_format (struct GMT_CTRL *GMT, char *file, struct GMT_GRID_HEADER
 		ext = gmt_get_ext (file);
 		if (ext && (!strcmp (ext, "txt") || !strcmp (ext, "lis")))
 			return (GMT_GRDIO_UNKNOWN_FORMAT);
-#ifdef HAVE_GDAL
 		/* Then check for GDAL grid */
 		if (gmtlib_is_gdal_grid (GMT, header) == GMT_NOERROR)
 			return (GMT_NOERROR);
-#endif
 		return (GMT_GRDIO_UNKNOWN_FORMAT);	/* No supported format found */
 	}
 	else {			/* Writing: get format type, scale, offset and missing value from GMT->current.setting.io_gridfile_format */
@@ -3630,7 +3626,6 @@ uint64_t gmt_get_active_layers (struct GMT_CTRL *GMT, struct GMT_CUBE *U, double
 	return (n_layers_used);
 }
 
-#ifdef HAVE_GDAL
 GMT_LOCAL void gmtgrdio_gdal_free_from (struct GMT_CTRL *GMT, struct GMT_GDALREAD_OUT_CTRL *from_gdalread) {
 	int i;
 	if (from_gdalread->band_field_names) {
@@ -3838,4 +3833,3 @@ int gmtlib_read_image (struct GMT_CTRL *GMT, char *file, struct GMT_IMAGE *I, do
 
 	return (GMT_NOERROR);
 }
-#endif

src/gmt_init.c

@@ -15741,14 +15741,12 @@ void gmt_end_module (struct GMT_CTRL *GMT, struct GMT_CTRL *Ccopy) {
 
 	gmt_M_memcpy (spacing, GMT->current.plot.gridline_spacing, 2U, double);	/* Remember these so they can survive the end of the module */
 
-#ifdef HAVE_GDAL
 	/* If that's the case, clean up anu GDAL CT object */
 	if (GMT->current.gdal_read_in.hCT_fwd)
 		OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_fwd);
 	if (GMT->current.gdal_read_in.hCT_inv)
 		OCTDestroyCoordinateTransformation(GMT->current.gdal_read_in.hCT_inv);
 	GMT->current.gdal_read_in.hCT_fwd = GMT->current.gdal_read_in.hCT_inv = NULL;
-#endif
 
 	if (GMT->hidden.func_level == GMT_TOP_MODULE && GMT->current.ps.oneliner && GMT->current.ps.active) {
 		char *setting = getenv ("GMT_END_SHOW");
@@ -15893,12 +15891,10 @@ void gmt_end_module (struct GMT_CTRL *GMT, struct GMT_CTRL *Ccopy) {
 	*/
 	GMT->current.setting.io_lonlat_toggle[GMT_IN] = GMT->current.setting.io_lonlat_toggle[GMT_OUT] = false;
 
-#ifdef HAVE_GDAL
 	/* Reset these GDAL in/out stuff */
 	gmt_M_memset (&GMT->current.gdal_read_in,  1, struct GMT_GDALREAD_IN_CTRL);
 	gmt_M_memset (&GMT->current.gdal_read_out, 1, struct GMT_GDALREAD_OUT_CTRL);
 	gmt_M_memset (&GMT->current.gdal_write,    1, struct GMT_GDALWRITE_CTRL);
-#endif
 
 	GMT->parent->cache = false;		/* Otherwise gdalread from externals on Windows would mingle CACHEDIR in fnames */
 
@@ -17406,7 +17402,6 @@ unsigned int gmt_parse_inc_option (struct GMT_CTRL *GMT, char option, char *item
 	return GMT_NOERROR;
 }
 
-#ifdef HAVE_GDAL
 GMT_LOCAL int gmtinit_parse_proj4 (struct GMT_CTRL *GMT, char *item, char *dest) {
 	/* Deal with proj.4 or EPSGs passed in -J option */
 	char  *item_t1 = NULL, *item_t2 = NULL, wktext[32] = {""}, *pch;
@@ -17565,7 +17560,6 @@ GMT_LOCAL int gmtinit_parse_proj4 (struct GMT_CTRL *GMT, char *item, char *dest)
 
 	return error;
 }
-#endif
 
 /*! gmt_parse_common_options interprets the command line for the common, unique options
  * -B, -J, -K, -O, -P, -R, -U, -V, -X, -Y, -a, -b, -c, -d, -e, -f, -g, -h, -i, -j, -l, -n, -o, -p, -q, -r, -s, -t, -w, -:, -- and -^.
@@ -17636,7 +17630,6 @@ int gmt_parse_common_options (struct GMT_CTRL *GMT, char *list, char option, cha
 				GMT->common.J.zactive = true;
 			}
 			else if (item && (item[0] == '+' || isdigit(item[0]) || !strncmp(item, "EPSG:", 5) || !strncmp(item, "epsg:", 5))) {
-#ifdef HAVE_GDAL
 				char   source[GMT_LEN1024] = {""}, dest[GMT_LEN1024] = {""}, *pch;
 				bool two = false;
 
@@ -17692,11 +17685,6 @@ int gmt_parse_common_options (struct GMT_CTRL *GMT, char *list, char option, cha
 				if (GMT->current.gdal_read_in.hCT_fwd == NULL || GMT->current.gdal_read_in.hCT_inv == NULL)
 					error = 1;
 			}
-#else
-				GMT_Report (GMT->parent, GMT_MSG_ERROR, "PROJ.4 can only be used with GDAL linked GMT.\n");
-				error = 1;
-			}
-#endif
 			else {	/* Horizontal map projection */
 				error += (gmt_M_check_condition (GMT, GMT->common.J.active, "Option -J given more than once\n") ||
 				                                 gmtinit_parse_J_option (GMT, item));
@@ -18151,7 +18139,7 @@ struct GMT_CTRL *gmt_begin (struct GMTAPI_CTRL *API, const char *session, unsign
 
 	struct GMT_CTRL *GMT = NULL;
 	char version[GMT_LEN8] = {""};
-#if defined(HAVE_GDAL) && (GDAL_VERSION_MAJOR >= 3)
+#if (GDAL_VERSION_MAJOR >= 3)
 	char *path1 = NULL, *path2 = NULL, *paths[2] = {NULL, NULL};
 	int  local_count = 0;
 #endif
@@ -18208,7 +18196,7 @@ struct GMT_CTRL *gmt_begin (struct GMTAPI_CTRL *API, const char *session, unsign
 
 	API->GMT = GMT;
 
-#if defined(HAVE_GDAL) && (GDAL_VERSION_MAJOR >= 3)
+#if (GDAL_VERSION_MAJOR >= 3)
 	/* Here we allow users to declare a different location for the GDAL's GDAL_DATA and
 	   PROJ4 PROJ_LIB directories. The later may be particularly useful in these days of
 	   transition to GDAL3.0, which imply PROJ4 V6 but many (different) PROJ_LIB from PROJ4 < 6

src/gmt_internals.h

@@ -291,13 +291,11 @@ EXTERN_MSC const char *gmtlib_module_group (void *API, struct GMT_MODULEINFO M[]
 
 EXTERN_MSC int gmtlib_ind2rgb (struct GMT_CTRL *GMT, struct GMT_IMAGE **I_in);
 
-#ifdef HAVE_GDAL
 EXTERN_MSC int gmtlib_read_image (struct GMT_CTRL *GMT, char *file, struct GMT_IMAGE *I, double *wesn,
 			unsigned int *pad, unsigned int complex_mode);		/* Function to read true images via GDAL */
 int gmtlib_read_image_info (struct GMT_CTRL *GMT, char *file, bool must_be_image, struct GMT_IMAGE *I);
 EXTERN_MSC int gmtlib_is_gdal_grid (struct GMT_CTRL *GMT, struct GMT_GRID_HEADER *header);
 EXTERN_MSC void gmtlib_GDALDestroyDriverManager (struct GMTAPI_CTRL *API);
-#endif
 
 /* LOCAL MACROS USED BY GMT_*.C ONLY - NOT PART OF GMT_DEV.H DISTRIBUTION */