+ line shifter and bla

Fonderie/glitches.c

@@ -7,6 +7,7 @@
 
 #include  <stdio.h>
 #include  <stdlib.h>
+#include  <string.h>
 #include  <math.h>
 
 #include  "../floatimg.h"
@@ -188,4 +189,48 @@ for (y=BB; y<h-BB; y++) {
 return 0;
 }
 /*   --------------------------------------------------------------   */
+static void shifter(float *fs, float *fd, int w, int nbr)
+{
+int	krkr;
+
+for (krkr=0; krkr<nbr; krkr++) {
+	fd[krkr] = fs[(krkr+w)%nbr];
+	}
+/* take your sixpack, film at 11 */
+}
+
+int multilines_shift_0(FloatImg *picz, int step, int nombre)
+{
+float		*buffline, *sptr;
+int		idx, ypos;
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %p %d %d )\n", __func__, picz, step, nombre);
+#endif
+
+buffline = alloca(picz->width * sizeof(float));
+if (NULL==buffline) {
+	fprintf(stderr, "%s: memory panic\n", __func__);
+	abort();
+	}
+
+for (idx=0; idx<nombre; idx++) {
+	ypos = rand() % picz->height;
+
+	sptr = picz->R + (ypos * picz->width);
+	shifter(sptr, buffline, step, picz->width);
+	memcpy(sptr, buffline, picz->width*sizeof(float));
+
+	sptr = picz->G + (ypos * picz->width);
+	shifter(sptr, buffline, step, picz->width);
+	memcpy(sptr, buffline, picz->width*sizeof(float));
+
+	sptr = picz->B + (ypos * picz->width);
+	shifter(sptr, buffline, step, picz->width);
+	memcpy(sptr, buffline, picz->width*sizeof(float));
+	}
+
+return 0;
+}
+/*   --------------------------------------------------------------   */