ppmload.c

/* load ppm from a file
 *
 * Stephen Chan ... original code
 *
 * 21/11/00 JC
 *	- hacked for VIPS
 *	- reads ppm/pgm/pbm
 *	- mmaps binary pgm/ppm
 *	- reads all ascii formats (slowly!)
 * 22/11/00 JC
 *	- oops, ascii read was broken
 *	- does 16/32 bit ascii now as well
 * 24/5/01
 *	- im_ppm2vips_header() added
 * 28/11/03 JC
 *	- better no-overshoot on tile loop
 * 22/5/04
 *	- does 16/32 bit binary too
 *	- tiny fix for missing file close on read error
 * 19/8/05
 * 	- use im_raw2vips() for binary read
 * 9/9/05
 * 	- tiny cleanups
 * 3/11/07
 * 	- use im_wbuffer() for bg writes
 * 1/5/10
 * 	- add PFM (portable float map) support
 * 19/12/11
 * 	- rework as a set of fns ready to be called from a class
 * 8/11/14
 * 	- add 1 bit write
 * 29/7/19 Kyle-Kyle
 * 	- fix a loop with malformed ppm
 * 13/11/19
 * 	- redone with source/target
 * 	- sequential load, plus mmap for filename sources
 * 	- faster plus lower memory use
 * 02/02/20
 * 	- ban max_vaue < 0
 * 27/6/20
 * 	- add ppmload_source
 * 22/11/20
 * 	- fix msb_first default [ewelot]
 * 26/12/20
 * 	- don't byteswap ascii formats
 * 	- set metadata for map loads
 * 	- byteswap binary loads
 * 9/3/23
 *	- pfm assumes linear 0-1 [NiHoel]
 */

/*

	This file is part of VIPS.

	VIPS is free software; you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	02110-1301  USA

 */

/*

	These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk

 */

/*
#define DEBUG
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <vips/vips.h>
#include <vips/internal.h>

#include "pforeign.h"

#ifdef HAVE_PPM

typedef struct _VipsForeignLoadPpm {
	VipsForeignLoad parent_object;

	/* The source we load from, and the buffered wrapper for it.
	 */
	VipsSource *source;
	VipsSbuf *sbuf;

	/* Properties of this ppm, from the header.
	 */
	int width;
	int height;
	int bands;
	VipsBandFormat format;
	VipsInterpretation interpretation;
	float scale;
	int max_value;
	int index;			/* ppm type .. index in magic_names[] */
	int bits;			/* 1, 8, 16 or 32 */
	gboolean ascii;		/* TRUE for ascii encoding */
	gboolean msb_first; /* TRUE if most sig byte is first */

	gboolean have_read_header;

} VipsForeignLoadPpm;

typedef VipsForeignLoadClass VipsForeignLoadPpmClass;

G_DEFINE_ABSTRACT_TYPE(VipsForeignLoadPpm, vips_foreign_load_ppm,
	VIPS_TYPE_FOREIGN_LOAD);

/* ppm types.
 */
static char *magic_names[] = {
	"P1", /* pbm ... 1 band 1 bit, ascii */
	"P2", /* pgm ... 1 band many bit, ascii */
	"P3", /* ppm ... 3 band many bit, ascii */
	"P4", /* pbm ... 1 band 1 bit, binary */
	"P5", /* pgm ... 1 band 8 bit, binary */
	"P6", /* ppm ... 3 band 8 bit, binary */
	"PF", /* pfm ... 3 band 32 bit, binary */
	"Pf"  /* pfm ... 1 band 32 bit, binary */
};

/* Shared with ppmsave.
 */
const char *vips__ppm_suffs[] = {
	".pbm", ".pgm", ".ppm", ".pfm", ".pnm", NULL
};
const char *vips__save_pbm_suffs[] = { ".pbm", NULL };
const char *vips__save_pgm_suffs[] = { ".pgm", NULL };
const char *vips__save_ppm_suffs[] = { ".ppm", NULL };
const char *vips__save_pfm_suffs[] = { ".pfm", NULL };
const char *vips__save_pnm_suffs[] = { ".pnm", NULL };

static gboolean
vips_foreign_load_ppm_is_a_source(VipsSource *source)
{
	const unsigned char *data;

	if ((data = vips_source_sniff(source, 2))) {
		int i;

		for (i = 0; i < VIPS_NUMBER(magic_names); i++)
			if (vips_isprefix(magic_names[i], (char *) data))
				return TRUE;
	}

	return FALSE;
}

static int
get_int(VipsSbuf *sbuf, int *i)
{
	const char *txt;

	if (vips_sbuf_skip_whitespace(sbuf) ||
		!(txt = vips_sbuf_get_non_whitespace(sbuf)))
		return -1;

	*i = atoi(txt);

	return 0;
}

static int
get_float(VipsSbuf *sbuf, float *f)
{
	const char *txt;

	if (vips_sbuf_skip_whitespace(sbuf) ||
		!(txt = vips_sbuf_get_non_whitespace(sbuf)))
		return -1;

	/* We don't want the locale str -> float conversion.
	 */
	*f = g_ascii_strtod(txt, NULL);

	return 0;
}

static void
vips_foreign_load_ppm_dispose(GObject *gobject)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) gobject;

#ifdef DEBUG
	printf("vips_foreign_load_ppm_dispose: %p\n", ppm);
#endif /*DEBUG*/

	VIPS_UNREF(ppm->sbuf);
	VIPS_UNREF(ppm->source);

	G_OBJECT_CLASS(vips_foreign_load_ppm_parent_class)->dispose(gobject);
}

static int
vips_foreign_load_ppm_build(VipsObject *object)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) object;

	if (ppm->source)
		ppm->sbuf = vips_sbuf_new_from_source(ppm->source);

	if (VIPS_OBJECT_CLASS(vips_foreign_load_ppm_parent_class)->build(object))
		return -1;

	return 0;
}

/* Scan the header into our class.
 */
static int
vips_foreign_load_ppm_parse_header(VipsForeignLoadPpm *ppm)
{
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(ppm);

	int i;
	char buf[2];

	/* Characteristics, indexed by ppm type.
	 */
	static int lookup_bits[] = {
		1, 8, 8, 1, 8, 8, 32, 32
	};
	static int lookup_bands[] = {
		1, 1, 3, 1, 1, 3, 3, 1
	};
	static int lookup_ascii[] = {
		1, 1, 1, 0, 0, 0, 0, 0
	};

	if (vips_source_rewind(ppm->source))
		return -1;

	/* Read in the magic number.
	 */
	buf[0] = VIPS_SBUF_GETC(ppm->sbuf);
	buf[1] = VIPS_SBUF_GETC(ppm->sbuf);

	for (i = 0; i < VIPS_NUMBER(magic_names); i++)
		if (vips_isprefix(magic_names[i], buf))
			break;
	if (i == VIPS_NUMBER(magic_names)) {
		vips_error(class->nickname, "%s", _("bad magic number"));
		return -1;
	}
	ppm->index = i;
	ppm->bits = lookup_bits[i];
	ppm->bands = lookup_bands[i];
	ppm->ascii = lookup_ascii[i];

	/* Default ... can be changed below for PFM images.
	 */
	ppm->msb_first = 1;

	/* Read in size.
	 */
	if (get_int(ppm->sbuf, &ppm->width) ||
		get_int(ppm->sbuf, &ppm->height))
		return -1;

	/* Read in max value / scale for >1 bit images.
	 */
	if (ppm->bits > 1) {
		if (ppm->index == 6 ||
			ppm->index == 7) {
			if (get_float(ppm->sbuf, &ppm->scale))
				return -1;

			/* Scale > 0 means big-endian.
			 */
			ppm->msb_first = ppm->scale > 0;
		}
		else {
			if (get_int(ppm->sbuf, &ppm->max_value))
				return -1;

			/* max_value must be > 0 and <= 65535, according to
			 * the spec, but we allow up to 32 bits per pixel.
			 */
			if (ppm->max_value < 0)
				ppm->max_value = 0;

			if (ppm->max_value > 255)
				ppm->bits = 16;
			if (ppm->max_value > 65535)
				ppm->bits = 32;
		}
	}

	/* Read the end of line character after the scale so we are positioned
	 * exactly at the start of the data. This matters for binary formats.
	 */
	(void) vips_sbuf_get_line(ppm->sbuf);

	/* Choose a VIPS bandfmt.
	 */
	switch (ppm->bits) {
	case 1:
	case 8:
		ppm->format = VIPS_FORMAT_UCHAR;
		break;

	case 16:
		ppm->format = VIPS_FORMAT_USHORT;
		break;

	case 32:
		if (ppm->index == 6 ||
			ppm->index == 7)
			ppm->format = VIPS_FORMAT_FLOAT;
		else
			ppm->format = VIPS_FORMAT_UINT;
		break;

	default:
		g_assert_not_reached();

		/* Stop compiler warnings.
		 */
		ppm->format = VIPS_FORMAT_UCHAR;
	}

	if (ppm->bands == 1) {
		if (ppm->format == VIPS_FORMAT_USHORT)
			ppm->interpretation = VIPS_INTERPRETATION_GREY16;
		else
			ppm->interpretation = VIPS_INTERPRETATION_B_W;
	}
	else {
		if (ppm->format == VIPS_FORMAT_USHORT)
			ppm->interpretation = VIPS_INTERPRETATION_RGB16;
		else if (ppm->format == VIPS_FORMAT_FLOAT)
			ppm->interpretation = VIPS_INTERPRETATION_scRGB;
		else
			ppm->interpretation = VIPS_INTERPRETATION_sRGB;
	}

	ppm->have_read_header = TRUE;

#ifdef DEBUG
	printf("vips_foreign_load_ppm_parse_header:\n");
	printf("\twidth = %d\n", ppm->width);
	printf("\theight = %d\n", ppm->height);
	printf("\tbands = %d\n", ppm->bands);
	printf("\tformat = %s\n",
		vips_enum_nick(VIPS_TYPE_BAND_FORMAT, ppm->format));
	printf("\tinterpretation = %s\n",
		vips_enum_nick(VIPS_TYPE_INTERPRETATION, ppm->interpretation));
	printf("\tscale = %g\n", ppm->scale);
	printf("\tmax_value = %d\n", ppm->max_value);
	printf("\tbits = %d\n", ppm->bits);
	printf("\tacsii = %d\n", ppm->ascii);
	printf("\tmsb_first = %d\n", ppm->msb_first);
#endif /*DEBUG*/

	return 0;
}

static VipsForeignFlags
vips_foreign_load_ppm_get_flags(VipsForeignLoad *load)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) load;

	VipsForeignFlags flags;

	flags = 0;

	/* If this source supports fast mmap and this PPM is >=8 bit binary,
	 * then we can mmap the file and support partial load. Otherwise,
	 * it's sequential.
	 */
	if (!ppm->have_read_header &&
		vips_foreign_load_ppm_parse_header(ppm))
		return 0;
	if (vips_source_is_mappable(ppm->source) &&
		!ppm->ascii &&
		ppm->bits >= 8)
		flags |= VIPS_FOREIGN_PARTIAL;
	else
		flags |= VIPS_FOREIGN_SEQUENTIAL;

	return flags;
}

static void
vips_foreign_load_ppm_set_image_metadata(VipsForeignLoadPpm *ppm,
	VipsImage *image)
{
	image->Type = ppm->interpretation;

	if (ppm->index == 6 ||
		ppm->index == 7)
		vips_image_set_double(image,
			"pfm-scale", VIPS_FABS(ppm->scale));
	else
		vips_image_set_double(image,
			"ppm-max-value", VIPS_ABS(ppm->max_value));

	VIPS_SETSTR(image->filename,
		vips_connection_filename(VIPS_CONNECTION(ppm->sbuf->source)));

#ifdef DEBUG
	printf("vips_foreign_load_ppm_set_image: ");
	vips_object_print_summary(VIPS_OBJECT(image));
#endif /*DEBUG*/
}

static void
vips_foreign_load_ppm_set_image(VipsForeignLoadPpm *ppm, VipsImage *image)
{
	vips_image_init_fields(image,
		ppm->width, ppm->height, ppm->bands, ppm->format,
		VIPS_CODING_NONE, ppm->interpretation, 1.0, 1.0);

	(void) vips_image_pipelinev(image, VIPS_DEMAND_STYLE_THINSTRIP, NULL);

	vips_foreign_load_ppm_set_image_metadata(ppm, image);

#ifdef DEBUG
	printf("vips_foreign_load_ppm_set_image: ");
	vips_object_print_summary(VIPS_OBJECT(image));
#endif /*DEBUG*/
}

static int
vips_foreign_load_ppm_header(VipsForeignLoad *load)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) load;

	if (!ppm->have_read_header &&
		vips_foreign_load_ppm_parse_header(ppm))
		return 0;

	vips_foreign_load_ppm_set_image(ppm, load->out);

	vips_source_minimise(ppm->source);

	return 0;
}

/* Read a ppm/pgm file using mmap().
 */
static VipsImage *
vips_foreign_load_ppm_map(VipsForeignLoadPpm *ppm)
{
	gint64 header_offset;
	size_t length;
	const void *data;
	VipsImage *out;

#ifdef DEBUG
	printf("vips_foreign_load_ppm_map:\n");
#endif /*DEBUG*/

	vips_sbuf_unbuffer(ppm->sbuf);
	header_offset = vips_source_seek(ppm->source, 0, SEEK_CUR);
	data = vips_source_map(ppm->source, &length);
	if (header_offset < 0 ||
		!data)
		return NULL;
	data = (char *) data + header_offset;
	length -= header_offset;

	if (!(out = vips_image_new_from_memory(data, length,
			  ppm->width, ppm->height, ppm->bands, ppm->format)))
		return NULL;

	vips_foreign_load_ppm_set_image_metadata(ppm, out);

	return out;
}

static int
vips_foreign_load_ppm_generate_binary(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRect *r = &out_region->valid;
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) a;
	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS(ppm);
	VipsImage *image = out_region->im;
	size_t sizeof_line = VIPS_IMAGE_SIZEOF_LINE(image);

	int y;

	for (y = 0; y < r->height; y++) {
		VipsPel *q = VIPS_REGION_ADDR(out_region, 0, r->top + y);

		size_t n_bytes;

		n_bytes = sizeof_line;
		while (n_bytes > 0) {
			gint64 bytes_read;

			bytes_read =
				vips_source_read(ppm->source, q, n_bytes);
			if (bytes_read < 0)
				return -1;
			if (bytes_read == 0) {
				vips_error(class->nickname,
					"%s", _("file truncated"));
				return -1;
			}

			q += bytes_read;
			n_bytes -= bytes_read;
		}
	}

	return 0;
}

static int
vips_foreign_load_ppm_generate_1bit_ascii(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRect *r = &out_region->valid;
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) a;
	VipsImage *image = out_region->im;

	int x, y;

	for (y = 0; y < r->height; y++) {
		VipsPel *q = VIPS_REGION_ADDR(out_region, 0, r->top + y);

		for (x = 0; x < image->Xsize; x++) {
			int val;

			if (get_int(ppm->sbuf, &val))
				return -1;

			if (val)
				q[x] = 0;
			else
				q[x] = 255;
		}
	}

	return 0;
}

static int
vips_foreign_load_ppm_generate_1bit_binary(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRect *r = &out_region->valid;
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) a;
	VipsImage *image = out_region->im;

	int x, y;

	for (y = 0; y < r->height; y++) {
		VipsPel *q = VIPS_REGION_ADDR(out_region, 0, r->top + y);

		int bits;

		/* Not needed, but stop a compiler warning.
		 */
		bits = 0;

		for (x = 0; x < image->Xsize; x++) {
			if ((x & 7) == 0)
				bits = VIPS_SBUF_GETC(ppm->sbuf);
			q[x] = (bits & 128) ? 0 : 255;
			bits = VIPS_LSHIFT_INT(bits, 1);
		}
	}

	return 0;
}

static int
vips_foreign_load_ppm_generate_ascii_int(VipsRegion *out_region,
	void *seq, void *a, void *b, gboolean *stop)
{
	VipsRect *r = &out_region->valid;
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) a;
	VipsImage *image = out_region->im;
	int n_elements = image->Xsize * image->Bands;

	int i, y;

	for (y = 0; y < r->height; y++) {
		VipsPel *q = VIPS_REGION_ADDR(out_region, r->left, r->top + y);

		for (i = 0; i < n_elements; i++) {
			int val;

			if (get_int(ppm->sbuf, &val))
				return -1;

			switch (image->BandFmt) {
			case VIPS_FORMAT_UCHAR:
				q[i] = VIPS_CLIP(0, val, 255);
				break;

			case VIPS_FORMAT_USHORT:
				((unsigned short *) q)[i] =
					VIPS_CLIP(0, val, 65535);
				break;

			case VIPS_FORMAT_UINT:
				((unsigned int *) q)[i] = val;
				break;

			default:
				g_assert_not_reached();
			}
		}
	}

	return 0;
}

static VipsImage *
vips_foreign_load_ppm_scan(VipsForeignLoadPpm *ppm)
{
	VipsImage **t = (VipsImage **)
		vips_object_local_array(VIPS_OBJECT(ppm), 2);

	VipsImage *out;
	VipsGenerateFn generate;

	/* What sort of read are we doing?
	 */
	if (!ppm->ascii && ppm->bits >= 8) {
#ifdef DEBUG
		printf("vips_foreign_load_ppm_source: >1 bit binary load\n");
#endif /*DEBUG*/

		generate = vips_foreign_load_ppm_generate_binary;

		/* The binary loader does not use the buffered IO
		 * object.
		 */
		vips_sbuf_unbuffer(ppm->sbuf);
	}
	else if (!ppm->ascii && ppm->bits == 1) {
#ifdef DEBUG
		printf("vips_foreign_load_ppm_source: 1-bit binary load\n");
#endif /*DEBUG*/

		generate = vips_foreign_load_ppm_generate_1bit_binary;
	}
	else if (ppm->ascii && ppm->bits == 1) {
#ifdef DEBUG
		printf("vips_foreign_load_ppm_source: 1-bit ascii load\n");
#endif /*DEBUG*/

		generate = vips_foreign_load_ppm_generate_1bit_ascii;
	}
	else {
#ifdef DEBUG
		printf("vips_foreign_load_ppm_source: >1-bit ascii load\n");
#endif /*DEBUG*/

		generate = vips_foreign_load_ppm_generate_ascii_int;
	}

	t[0] = vips_image_new();
	vips_foreign_load_ppm_set_image(ppm, t[0]);
	if (vips_image_generate(t[0], NULL, generate, NULL, ppm, NULL) ||
		vips_sequential(t[0], &out, NULL))
		return NULL;

	return out;
}

static int
vips_foreign_load_ppm_load(VipsForeignLoad *load)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) load;
	VipsImage **t = (VipsImage **)
		vips_object_local_array((VipsObject *) load, 2);

	if (!ppm->have_read_header &&
		vips_foreign_load_ppm_parse_header(ppm))
		return 0;

	/* If the source is mappable and this is a binary file, we can map it.
	 */
	if (vips_source_is_mappable(ppm->source) &&
		!ppm->ascii &&
		ppm->bits >= 8) {
		if (!(t[0] = vips_foreign_load_ppm_map(ppm)))
			return -1;
	}
	else {
		if (!(t[0] = vips_foreign_load_ppm_scan(ppm)))
			return -1;
	}

#ifdef DEBUG
	printf("vips_foreign_load_ppm: byteswap = %d\n",
		vips_amiMSBfirst() != ppm->msb_first);
#endif /*DEBUG*/

	/* Don't byteswap the ascii formats.
	 */
	if (vips__byteswap_bool(t[0], &t[1],
			!ppm->ascii &&
				vips_amiMSBfirst() != ppm->msb_first) ||
		vips_image_write(t[1], load->real))
		return -1;

	if (vips_source_decode(ppm->source))
		return -1;

	return 0;
}

static void
vips_foreign_load_ppm_class_init(VipsForeignLoadPpmClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS(class);
	VipsForeignClass *foreign_class = (VipsForeignClass *) class;
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->dispose = vips_foreign_load_ppm_dispose;
	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "ppmload_base";
	object_class->description = _("load ppm base class");
	object_class->build = vips_foreign_load_ppm_build;

	/* You're unlikely to want to use this on untrusted files.
	 */
	operation_class->flags |= VIPS_OPERATION_UNTRUSTED;

	foreign_class->suffs = vips__ppm_suffs;

	/* We are fast at is_a(), so high priority.
	 */
	foreign_class->priority = 200;

	load_class->get_flags = vips_foreign_load_ppm_get_flags;
	load_class->header = vips_foreign_load_ppm_header;
	load_class->load = vips_foreign_load_ppm_load;
}

static void
vips_foreign_load_ppm_init(VipsForeignLoadPpm *ppm)
{
	ppm->scale = 1.0;
}

typedef struct _VipsForeignLoadPpmFile {
	VipsForeignLoadPpm parent_object;

	char *filename;

} VipsForeignLoadPpmFile;

typedef VipsForeignLoadPpmClass VipsForeignLoadPpmFileClass;

G_DEFINE_TYPE(VipsForeignLoadPpmFile, vips_foreign_load_ppm_file,
	vips_foreign_load_ppm_get_type());

static gboolean
vips_foreign_load_ppm_file_is_a(const char *filename)
{
	VipsSource *source;
	gboolean result;

	if (!(source = vips_source_new_from_file(filename)))
		return FALSE;
	result = vips_foreign_load_ppm_is_a_source(source);
	VIPS_UNREF(source);

	return result;
}

static int
vips_foreign_load_ppm_file_build(VipsObject *object)
{
	VipsForeignLoadPpmFile *file = (VipsForeignLoadPpmFile *) object;
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) object;

	if (file->filename &&
		!(ppm->source = vips_source_new_from_file(file->filename)))
		return -1;

	if (VIPS_OBJECT_CLASS(vips_foreign_load_ppm_file_parent_class)->build(object))
		return -1;

	return 0;
}

static void
vips_foreign_load_ppm_file_class_init(VipsForeignLoadPpmClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "ppmload";
	object_class->description = _("load ppm from file");
	object_class->build = vips_foreign_load_ppm_file_build;

	load_class->is_a = vips_foreign_load_ppm_file_is_a;

	VIPS_ARG_STRING(class, "filename", 1,
		_("Filename"),
		_("Filename to load from"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsForeignLoadPpmFile, filename),
		NULL);
}

static void
vips_foreign_load_ppm_file_init(VipsForeignLoadPpmFile *file)
{
}

typedef struct _VipsForeignLoadPpmSource {
	VipsForeignLoadPpm parent_object;

	VipsSource *source;

} VipsForeignLoadPpmSource;

typedef VipsForeignLoadPpmClass VipsForeignLoadPpmSourceClass;

G_DEFINE_TYPE(VipsForeignLoadPpmSource, vips_foreign_load_ppm_source,
	vips_foreign_load_ppm_get_type());

static int
vips_foreign_load_ppm_source_build(VipsObject *object)
{
	VipsForeignLoadPpm *ppm = (VipsForeignLoadPpm *) object;
	VipsForeignLoadPpmSource *source = (VipsForeignLoadPpmSource *) object;

	if (source->source) {
		ppm->source = source->source;
		g_object_ref(ppm->source);
	}

	if (VIPS_OBJECT_CLASS(vips_foreign_load_ppm_source_parent_class)
			->build(object))
		return -1;

	return 0;
}

static void
vips_foreign_load_ppm_source_class_init(VipsForeignLoadPpmFileClass *class)
{
	GObjectClass *gobject_class = G_OBJECT_CLASS(class);
	VipsObjectClass *object_class = (VipsObjectClass *) class;
	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS(class);
	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "ppmload_source";
	object_class->build = vips_foreign_load_ppm_source_build;

	operation_class->flags |= VIPS_OPERATION_NOCACHE;

	load_class->is_a_source = vips_foreign_load_ppm_is_a_source;

	VIPS_ARG_OBJECT(class, "source", 1,
		_("Source"),
		_("Source to load from"),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET(VipsForeignLoadPpmSource, source),
		VIPS_TYPE_SOURCE);
}

static void
vips_foreign_load_ppm_source_init(VipsForeignLoadPpmSource *source)
{
}

#endif /*HAVE_PPM*/

/**
 * vips_ppmload:
 * @filename: file to load
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Read a PPM/PBM/PGM/PFM file into a VIPS image.
 *
 * It can read 1, 8, 16 and 32 bit images, colour or monochrome,
 * stored in binary or in ASCII. One bit images become 8 bit VIPS images,
 * with 0 and 255 for 0 and 1.
 *
 * See also: vips_image_new_from_file().
 *
 * Returns: 0 on success, -1 on error.
 */
int
vips_ppmload(const char *filename, VipsImage **out, ...)
{
	va_list ap;
	int result;

	va_start(ap, out);
	result = vips_call_split("ppmload", ap, filename, out);
	va_end(ap);

	return result;
}

/**
 * vips_ppmload_source:
 * @source: source to load
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Exactly as vips_ppmload(), but read from a source.
 *
 * See also: vips_ppmload().
 *
 * Returns: 0 on success, -1 on error.
 */
int
vips_ppmload_source(VipsSource *source, VipsImage **out, ...)
{
	va_list ap;
	int result;

	va_start(ap, out);
	result = vips_call_split("ppmload_source", ap, source, out);
	va_end(ap);

	return result;
}