Create Subversion repository

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@1 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 115 insertions, 0 deletions

diff --git a/editor/pnminvert.c b/editor/pnminvert.c
new file mode 100644
index 00000000..40fee9be
--- /dev/null
+++ b/editor/pnminvert.c
@@ -0,0 +1,115 @@
+/* pnminvert.c - read a portable anymap and invert it
+**
+** Copyright (C) 1989 by Jef Poskanzer.
+**
+** Permission to use, copy, modify, and distribute this software and its
+** documentation for any purpose and without fee is hereby granted, provided
+** that the above copyright notice appear in all copies and that both that
+** copyright notice and this permission notice appear in supporting
+** documentation.  This software is provided "as is" without express or
+** implied warranty.
+*/
+
+#include "pnm.h"
+
+#define CHARBITS (sizeof(unsigned char)*8)
+
+
+
+static void
+invertPbm(FILE * const ifP,
+          FILE * const ofP,
+          int    const cols,
+          int    const rows,
+          int    const format) {
+/*----------------------------------------------------------------------------
+   Invert a PBM image.  Use the "packed" PBM functions for speed.
+-----------------------------------------------------------------------------*/
+    /* We could make this faster by inverting whole words at a time,
+       using libnetpbm's wordaccess.h facility.
+    */
+    int const colChars = pbm_packed_bytes(cols);
+
+    unsigned char * bitrow; 
+    unsigned int row;
+    
+    bitrow = pbm_allocrow_packed(cols);
+    
+    for (row = 0; row < rows; ++row) {
+        unsigned int colChar;
+        
+        pbm_readpbmrow_packed(ifP, bitrow, cols, format);
+        for (colChar = 0; colChar < colChars; ++colChar)
+            bitrow[colChar] = ~ bitrow[colChar];
+        
+        /* Clean off remainder of fractional last character */
+        if (cols % CHARBITS > 0) {
+            bitrow[colChars-1] >>= CHARBITS - cols % CHARBITS;
+            bitrow[colChars-1] <<= CHARBITS - cols % CHARBITS;
+        }
+        pbm_writepbmrow_packed(ofP, bitrow, cols, 0);
+    }
+    pbm_freerow_packed(bitrow);
+}
+
+
+
+static void
+invertPnm(FILE * const ifP,
+          FILE * const ofP,
+          int    const cols,
+          int    const rows,
+          xelval const maxval,
+          int    const format) {
+
+    xel * xelrow;
+    unsigned int row;
+    
+    xelrow = pnm_allocrow(cols);
+    
+    for (row = 0; row < rows; ++row) {
+        unsigned int col;
+        pnm_readpnmrow(ifP, xelrow, cols, maxval, format);
+        for (col = 0; col < cols; ++col)
+            pnm_invertxel(&xelrow[col], maxval, format);
+        
+        pnm_writepnmrow(ofP, xelrow, cols, maxval, format, 0);
+    }
+    pnm_freerow(xelrow);
+}
+
+
+
+int
+main(int argc, char * argv[]) {
+    FILE* ifP;
+    xelval maxval;
+    int rows, cols, format;
+
+    pnm_init(&argc, argv);
+
+    if (argc-1 > 1)
+        pm_error("There is at most 1 argument - the input file name.  "
+                 "You specified %d", argc-1);
+    if (argc-1 == 1)
+        ifP = pm_openr(argv[1]);
+    else
+        ifP = stdin;
+
+    pnm_readpnminit(ifP, &cols, &rows, &maxval, &format);
+    pnm_writepnminit(stdout, cols, rows, maxval, format, 0);
+    
+    if (PNM_FORMAT_TYPE(format) == PBM_TYPE)
+        /* Take fast path */
+        invertPbm(ifP, stdout, cols, rows, format);
+    else
+        /* PPM , PGM  (logic also works for PBM) */
+        invertPnm(ifP, stdout, cols, rows, maxval, format);
+
+    pm_close(ifP);
+    pm_close(stdout);
+    
+    return 0;
+}
+
+