1 files changed, 105 insertions, 0 deletions
diff --git a/editor/specialty/ppmtv.c b/editor/specialty/ppmtv.c
new file mode 100644
index 00000000..da25102a
--- /dev/null
+++ b/editor/specialty/ppmtv.c
@@ -0,0 +1,105 @@
+
+/*********************************************************************/
+/* ppmtv -  make a 'look-alike ntsc' picture from a PPM file       */
+/* Frank Neumann, October 1993                                       */
+/* V1.1 16.11.1993                                                   */
+/*                                                                   */
+/* version history:                                                  */
+/* V1.0 12.10.1993    first version                                  */
+/* V1.1 16.11.1993    Rewritten to be NetPBM.programming conforming  */
+/*********************************************************************/
+
+#include "ppm.h"
+
+/**************************/
+/* start of main function */
+/**************************/
+int main(argc, argv)
+int argc;
+char *argv[];
+{
+	FILE* ifp;
+	int argn, rows, cols, format, i = 0, j = 0;
+	pixel *srcrow, *destrow;
+	pixel *pP = NULL, *pP2 = NULL;
+	pixval maxval;
+	double dimfactor;
+	long longfactor;
+	const char * const usage = "dimfactor [ppmfile]\n        dimfactor: 0.0 = total blackness, 1.0 = original picture\n";
+
+	/* parse in 'default' parameters */
+	ppm_init(&argc, argv);
+
+	argn = 1;
+
+	/* parse in dim factor */
+	if (argn == argc)
+		pm_usage(usage);
+	if (sscanf(argv[argn], "%lf", &dimfactor) != 1)
+		pm_usage(usage);
+	if (dimfactor < 0.0 || dimfactor > 1.0)
+		pm_error("dim factor must be in the range from 0.0 to 1.0 ");
+	++argn;
+
+	/* parse in filename (if present, stdin otherwise) */
+	if (argn != argc)
+	{
+		ifp = pm_openr(argv[argn]);
+		++argn;
+	}
+	else
+		ifp = stdin;
+
+	if (argn != argc)
+		pm_usage(usage);
+
+	/* read first data from file */
+	ppm_readppminit(ifp, &cols, &rows, &maxval, &format);
+
+	/* no error checking required here, ppmlib does it all for us */
+	srcrow = ppm_allocrow(cols);
+
+	longfactor = (long)(dimfactor * 65536);
+
+	/* allocate a row of pixel data for the new pixels */
+	destrow = ppm_allocrow(cols);
+
+	ppm_writeppminit(stdout, cols, rows, maxval, 0);
+
+	/** now do the ntsc'ing (actually very similar to ppmdim) **/
+	for (i = 0; i < rows; i++)
+	{
+		ppm_readppmrow(ifp, srcrow, cols, maxval, format);
+
+		pP = srcrow;
+		pP2 = destrow;
+
+		for (j = 0; j < cols; j++)
+		{
+			/* every alternating row is left in unchanged condition */
+			if (i & 1)
+			{
+				PPM_ASSIGN(*pP2, PPM_GETR(*pP), PPM_GETG(*pP), PPM_GETB(*pP));
+			}
+			/* and the other lines are dimmed to the specified factor */
+			else
+			{
+				PPM_ASSIGN(*pP2, (PPM_GETR(*pP) * longfactor) >> 16,
+								 (PPM_GETG(*pP) * longfactor) >> 16,
+								 (PPM_GETB(*pP) * longfactor) >> 16);
+			}
+			pP++;
+			pP2++;
+		}
+
+		/* write out one line of graphic data */
+		ppm_writeppmrow(stdout, destrow, cols, maxval, 0);
+	}
+
+	pm_close(ifp);
+	ppm_freerow(srcrow);
+	ppm_freerow(destrow);
+
+	exit(0);
+}
+