From d8fbddac62eea524daff6d1e1f9787864bfe4edd Mon Sep 17 00:00:00 2001
From: EReckase <e.reckase@gmail.com>
Date: Sat, 11 Apr 2015 17:44:36 -0600
Subject: [PATCH] still need to change interp mode to hsv_circular

---
 flam3.c         |  2 +-
 interpolation.c | 58 ++++++++++++++++++++++++++++---------------------
 2 files changed, 34 insertions(+), 26 deletions(-)

diff --git a/flam3.c b/flam3.c
index e0e6aa5..370d14a 100644
--- a/flam3.c
+++ b/flam3.c
@@ -480,7 +480,7 @@ flam3_genome *sheep_edge(flam3_genome *cp, double blend, int seqflag, double sta
       flam3_rotate(&spun[0], blend*360.0, spun[0].interpolation_type);
       flam3_rotate(&spun[1], blend*360.0, spun[0].interpolation_type);
 
-      fprintf(stderr, "xyzzy %d %d\n", spun[0].palette_interpolation, spun[1].palette_interpolation);
+      //fprintf(stderr, "xyzzy %d %d\n", spun[0].palette_interpolation, spun[1].palette_interpolation);
 
       /* Now call the interpolation */
       if (argi("unsmoother",0) == 0)
diff --git a/interpolation.c b/interpolation.c
index 0cfe668..80da2be 100644
--- a/interpolation.c
+++ b/interpolation.c
@@ -172,13 +172,15 @@ void interpolate_cmap(flam3_palette cmap, double blend,
       t[4] = p1[i].index;
 
       /* take the shorter way around the hue circle */
-      if (0 == i) {
-	fprintf(stderr, "xxx interpolating between hues, %g %g\n", s[0], t[0]);
-      }
-      if ((s[0] - t[0]) > 3.0)
+//      if (0 == i) {
+//	fprintf(stderr, "xxx interpolating between hues, %g %g\n", s[0], t[0]);
+ //     }
+      
+      /* Correct the first hue to go the short way around */
+      if ((s[0] - t[0]) > 3.0)  /* first hue much bigger than second hue */
+        s[0] -= 6.0
+      if ((s[0] - t[0]) < -3.0)  /* first hue much smaller than second hue */
 	s[0] += 6.0;
-      if ((t[0] - s[0]) > 3.0)
-	t[0] += 6.0;
     
       for (j = 0; j < 5; j++)
          t[j] = ((1.0-blend) * s[j]) + (blend * t[j]);
@@ -372,7 +374,7 @@ void flam3_interpolate_n(flam3_genome *result, int ncp,
           flam3_genome *cpi, double *c, double stagger) {
    int i, j, k, numstd;
 
-   fprintf(stderr, "xxx pi=%d\n", cpi[0].palette_interpolation);
+//   fprintf(stderr, "xxx pi=%d\n", cpi[0].palette_interpolation);
 
    if (flam3_palette_interpolation_sweep != cpi[0].palette_interpolation) {
    
@@ -384,8 +386,8 @@ void flam3_interpolate_n(flam3_genome *result, int ncp,
 
          for (k = 0; k < ncp; k++) {
 	    if (i == 0) {
-	       fprintf(stderr, "ncp=%d, k=%d\n", ncp, k);
-	       fprintf(stderr, "rgb=%g %g %g\n", cpi[k].palette[i].color[0], cpi[k].palette[i].color[1], cpi[k].palette[i].color[2]);
+//	       fprintf(stderr, "ncp=%d, k=%d\n", ncp, k);
+//	       fprintf(stderr, "rgb=%g %g %g\n", cpi[k].palette[i].color[0], cpi[k].palette[i].color[1], cpi[k].palette[i].color[2]);
             }
 	    if (flam3_palette_interpolation_rgb != cpi[0].palette_interpolation)
                rgb2hsv(cpi[k].palette[i].color, t);
@@ -394,19 +396,25 @@ void flam3_interpolate_n(flam3_genome *result, int ncp,
 	      for (l = 0; l < 3; l++)
 		t[l] = cpi[k].palette[i].color[l];
             }
-	    if (i == 0) {
-	      fprintf(stderr, "hsv=%g %g %g\n", t[0], t[1], t[2]);
-            }
+//	    if (i == 0) {
+//	      fprintf(stderr, "hsv=%g %g %g\n", t[0], t[1], t[2]);
+//            }
 
-	    if (2 == ncp && cpi[0].palette_interpolation == flam3_palette_interpolation_hsv2) {
+	    if (2 == ncp && k == 0 &&cpi[0].palette_interpolation == flam3_palette_interpolation_hsv2) {
 	      /* should also support blending between rgb and hsv,
 		 and change the color of the cut, so we can keep
 		 a dominant color but control what it is. */
-	      double z[3];
-	      rgb2hsv(cpi[1-k].palette[i].color, z);
-	      if ((z[0] - t[0]) > 3.0) t[0] += 6.0;
-	      if (i == 0)
-		fprintf(stderr, "adjusted %g %g\n", z[0], t[0]);
+		 
+	      /* only adjust the first coordinate based on the other control point's hue */
+	      double second_color[3];
+	      rgb2hsv(cpi[1].palette[i].color, second_color);
+
+	      /* Adjust the hue so that we go the shorter direction around the circle */
+	      if ((second_color[0] - t[0]) > 3.0) {
+	          t[0] += 6.0;
+	      } else if ((second_color[0] - t[0]) < -3.0) {
+	          t[0] -= 6.0;	          
+	      }
 	    }
 
             for (j = 0; j < 3; j++)
@@ -422,8 +430,8 @@ void flam3_interpolate_n(flam3_genome *result, int ncp,
          if (alpha1 == 1)
             s[3] = 1.0;
 
-	 if (i == 0)
-	   fprintf(stderr, "s0=%g\n", s[0]);
+//	 if (i == 0)
+//	   fprintf(stderr, "s0=%g\n", s[0]);
        
 	 if (flam3_palette_interpolation_rgb != cpi[0].palette_interpolation)
             hsv2rgb(s, result->palette[i].color);
@@ -435,11 +443,11 @@ void flam3_interpolate_n(flam3_genome *result, int ncp,
          result->palette[i].color[3] = s[3];
          result->palette[i].index = s[4];
 
-	 if (i == 0)
-	   fprintf(stderr, "result rgb=%g %g %g\n",
-		   result->palette[0].color[0],
-		   result->palette[0].color[1],
-		   result->palette[0].color[2]);
+//	 if (i == 0)
+//	   fprintf(stderr, "result rgb=%g %g %g\n",
+//		   result->palette[0].color[0],
+//		   result->palette[0].color[1],
+//		   result->palette[0].color[2]);
        
          for (j = 0; j < 4; j++) {
             if (result->palette[i].color[j] < 0.0)