Initial revision

wrlib/ppm.c

@@ -0,0 +1,172 @@
+/* ppm.c - load PPM image from file
+ * 
+ *  Raster graphics library
+ * 
+ *  Copyright (c) 1997 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+
+#include <X11/Xlib.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "wraster.h"
+
+
+static RImage*
+load_graymap(char *file_name, FILE *file, int w, int h, int max, int raw)
+{
+    RImage *image;
+    
+    image = RCreateImage(w, h, 0);
+    if (!image) {
+	sprintf(RErrorString, "out of memory");
+	return NULL;
+    }
+    if (!raw) {
+	
+    } else {
+	if (max<256) {
+	    if (!fgets(image->data[0], w*h, file))
+		goto short_file;
+	    memcpy(image->data[0], image->data[1], w*h);
+	    memcpy(image->data[0], image->data[2], w*h);
+	} else {
+	    
+	}
+    }
+    
+    return image;
+    
+  short_file:
+    sprintf(RErrorString, "PPM file \"%s\" seems to be truncated", file_name);
+    return NULL;
+}
+
+
+static RImage*
+load_pixmap(char *file_name, FILE *file, int w, int h, int max, int raw)
+{
+    RImage *image;
+    int i;
+    char buf[3];
+    char *r, *g, *b;
+    
+    image = RCreateImage(w, h, 0);
+    if (!image) {
+	sprintf(RErrorString, "out of memory");
+	return NULL;
+    }
+    r = image->data[0];
+    g = image->data[1];
+    b = image->data[2];
+    if (!raw) {
+	
+    } else {
+	if (max<256) {
+	    i = 0;
+	    while (i < w*h) {
+		if (fread(buf, 1, 3, file)!=3)
+		    goto short_file;
+		*(r++) = buf[0];
+		*(g++) = buf[1];
+		*(b++) = buf[2];
+		i++;
+	    }
+	} else {
+	    
+	}
+    }
+    
+    return image;
+    
+  short_file:
+    sprintf(RErrorString, "PPM file \"%s\" seems to be truncated", file_name);
+    return NULL;
+}
+
+
+RImage*
+RLoadPPM(RContext *context, char *file_name, int index)
+{
+    FILE *file;
+    RImage *image = NULL;
+    char buffer[256];
+    int w, h, m;
+    int type;
+
+#define GETL() if (!fgets(buffer, 255, file)) goto short_file
+    
+    RErrorString[0] = 0;
+
+    file = fopen(file_name, "r");
+    if (!file) {
+	sprintf(RErrorString, "could not open PPM file \"%s\"", file_name);
+	return NULL;
+    }
+    
+    /* get signature */
+    GETL();
+
+    /* only accept raw pixmaps or graymaps */
+    if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
+	sprintf(RErrorString, "unknown PPM format in \"%s\"", file_name);
+	fclose(file);
+	return NULL;
+    }
+    
+    type = buffer[1];
+    
+    /* skip comments */
+    while (1) {
+	GETL();
+	
+	if (buffer[0]!='#')
+	    break;
+    }
+    
+    /* get size */
+    if (sscanf(buffer, "%i %i", &w, &h)!=2)
+	goto bad_file;
+    
+
+    GETL();
+    if (sscanf(buffer, "%i", &m)!=1 || m < 1)
+	goto bad_file;
+
+    if (type=='5')
+	image = load_graymap(file_name, file, w, h, m, type=='5');
+    else if (type=='6')
+	image = load_pixmap(file_name, file, w, h, m, type=='6');
+
+    fclose(file);
+    return image;
+    
+  bad_file:
+    sprintf(RErrorString, "PPM file \"%s\" seems to be corrupted", file_name);
+    fclose(file);
+    return NULL;
+    
+  short_file:
+    sprintf(RErrorString, "PPM file \"%s\" seems to be truncated", file_name);
+    fclose(file);
+    return NULL;
+}
+