wrlib: Renamed image format related files for clarity

This patch makes all files appear together when listing files and
it is more clear about their function.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

wrlib/load_ppm.c

@@ -0,0 +1,175 @@
+/* ppm.c - load PPM image from file
+ *
+ * Raster graphics library
+ *
+ * Copyright (c) 1997-2003 Alfredo K. Kojima
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ *  MA 02110-1301, USA.
+ */
+
+#include <config.h>
+
+#include <X11/Xlib.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "wraster.h"
+#include "imgformat.h"
+
+static RImage *load_graymap(FILE *file, int w, int h, int max, int raw)
+{
+	RImage *image;
+	unsigned char *ptr;
+	char *buf;
+	int x, y;
+
+	image = RCreateImage(w, h, 0);
+	if (!image)
+		return NULL;
+
+	if (!raw)
+		return image;
+
+	if (max < 256) {
+		buf = malloc(w + 1);
+		if (!buf)
+			return NULL;
+
+		ptr = image->data;
+		for (y = 0; y < h; y++) {
+			if (!fread(buf, w, 1, file)) {
+				free(buf);
+				RErrorCode = RERR_BADIMAGEFILE;
+				return NULL;
+			}
+
+			for (x = 0; x < w; x++) {
+				*(ptr++) = buf[x];
+				*(ptr++) = buf[x];
+				*(ptr++) = buf[x];
+			}
+		}
+		free(buf);
+	}
+
+	return image;
+}
+
+static RImage *load_pixmap(FILE *file, int w, int h, int max, int raw)
+{
+	RImage *image;
+	int i;
+	char buf[3];
+	unsigned char *ptr;
+
+	image = RCreateImage(w, h, 0);
+	if (!image)
+		return NULL;
+
+	if (!raw)
+		return image;
+
+	ptr = image->data;
+	if (max < 256) {
+		i = 0;
+		while (i < w * h) {
+			if (fread(buf, 1, 3, file) != 3) {
+				RErrorCode = RERR_BADIMAGEFILE;
+				return NULL;
+			}
+
+			*(ptr++) = buf[0];
+			*(ptr++) = buf[1];
+			*(ptr++) = buf[2];
+			i++;
+		}
+	}
+
+	return image;
+}
+
+RImage *RLoadPPM(const char *file_name)
+{
+	FILE *file;
+	RImage *image = NULL;
+	char buffer[256];
+	int w, h, m;
+	int type;
+
+	file = fopen(file_name, "rb");
+	if (!file) {
+		RErrorCode = RERR_OPEN;
+		return NULL;
+	}
+
+	/* get signature */
+	if (!fgets(buffer, 255, file)) {
+		RErrorCode = RERR_BADIMAGEFILE;
+		fclose(file);
+		return NULL;
+	}
+
+	/* only accept raw pixmaps or graymaps */
+	if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
+		RErrorCode = RERR_BADFORMAT;
+		fclose(file);
+		return NULL;
+	}
+
+	type = buffer[1];
+
+	/* skip comments */
+	while (1) {
+		if (!fgets(buffer, 255, file)) {
+			RErrorCode = RERR_BADIMAGEFILE;
+			fclose(file);
+			return NULL;
+		}
+
+		if (buffer[0] != '#')
+			break;
+	}
+
+	/* get size */
+	if (sscanf(buffer, "%i %i", &w, &h) != 2 || w < 1 || h < 1) {
+		/* Short file */
+		RErrorCode = RERR_BADIMAGEFILE;
+		fclose(file);
+		return NULL;
+	}
+
+	if (!fgets(buffer, 255, file)) {
+		RErrorCode = RERR_BADIMAGEFILE;
+		fclose(file);
+		return NULL;
+	}
+
+	if (sscanf(buffer, "%i", &m) != 1 || m < 1) {
+		/* Short file */
+		RErrorCode = RERR_BADIMAGEFILE;
+		fclose(file);
+		return NULL;
+	}
+
+	if (type == '5')
+		image = load_graymap(file, w, h, m, type == '5');
+	else if (type == '6')
+		image = load_pixmap(file, w, h, m, type == '6');
+
+	fclose(file);
+	return image;
+}