Description: Fix rendering bugs in flam3.c

 Fix smooth interpolation issue (mfeemster)

   https://github.com/scottdraves/flam3/issues/13

 Fix fusing flame iteration (roever)

   https://github.com/scottdraves/flam3/issues/15

 Fix buffer overflows, (ministr too small) 

Author: Peter Blackman <peter@pblackman.plus.com>

Last-Update: 2020-01-20

Index: b/flam3.c

===================================================================

--- a/flam3.c

+++ b/flam3.c

@@ -255,19 +255,25 @@

          fn = xform_distrib[ ((unsigned)irand(rc)) & CHOOSE_XFORM_GRAIN_M1 ];

       if (apply_xform(cp, fn, p, q, rc)>0) {

-         consec ++;

+//	     roever's patch

+         consec =0;

          badvals ++;

-         if (consec<5) {

-            p[0] = q[0];

-            p[1] = q[1];

-            p[2] = q[2];

-            p[3] = q[3];

-            i -= 4;

-            continue;

-         } else

-            consec = 0;

-      } else

-         consec = 0;

+         p[0] = q[0];

+         p[1] = q[1];

+         p[2] = q[2];

+         p[3] = q[3];

+         i -= 4;

+         continue;

+      }

+      else if (consec < fuse) {

+          consec++;

+          p[0] = q[0];

+          p[1] = q[1];

+          p[2] = q[2];

+          p[3] = q[3];

+          i -= 4;

+          continue;

+      }

       /* Store the last used transform */

       lastxf = fn+1;

@@ -753,23 +759,26 @@

        flam3_align(&cpi[0], &cps[i1], 2);

        smoothflag = 0;

-   } else {

+   }

+   else {

+   /* mfeemster's patch */

        if (0 == i1) {

           fprintf(stderr, "error: cannot use smooth interpolation on first segment.\n");

           fprintf(stderr, "reverting to linear interpolation.\n");

           flam3_align(&cpi[0], &cps[i1], 2);

           smoothflag = 0;

        }

-

+	   else

        if (ncps-1 == i2) {

           fprintf(stderr, "error: cannot use smooth interpolation on last segment.\n");

           fprintf(stderr, "reverting to linear interpolation.\n");

           flam3_align(&cpi[0], &cps[i1], 2);

           smoothflag = 0;

        }

-

+	   else {

        flam3_align(&cpi[0], &cps[i1-1], 4);

        smoothflag = 1;

+	   }

    }

    /* Clear the destination cp */

@@ -2659,7 +2668,7 @@

 void flam3_cross(flam3_genome *cp0, flam3_genome *cp1, flam3_genome *out, int cross_mode, randctx *rc, char *action) {

    int i,j, rb;

-   char ministr[10];   

+   char ministr[12];

    if (cross_mode == CROSS_NOT_SPECIFIED) {