From 943854b57d12960a19f24dd6741ba4fda8c66ad7 Mon Sep 17 00:00:00 2001
From: Søren Sandmann Pedersen <ssp@redhat.com>
Date: Mon, 27 Sep 2010 08:10:27 -0400
Subject: thresholding

---
 bluenoise.c |  6 ++++--
 gtk-utils.c | 64 ++++++++++++++++++++++++++++++++++++++++++++-----------------
 2 files changed, 50 insertions(+), 20 deletions(-)

diff --git a/bluenoise.c b/bluenoise.c
index 97ea96e..f40f969 100644
--- a/bluenoise.c
+++ b/bluenoise.c
@@ -84,7 +84,7 @@ main ()
 #endif
 		if (f <= 0.5)
 		{
-		    factor = 0.5 * (cos (M_PI * (1 - 2 * (f))) + 1.0);
+		    factor = pow (0.5 * (cos (M_PI * (1 - 2 * (f))) + 1.0), 8);
 		}
 		else
 		{
@@ -94,10 +94,12 @@ main ()
 		noise[i * N_SAMPLES + j].re *= 2.4 * f;
 		noise[i * N_SAMPLES + j].im *= 2.4 * f;
 #endif
+#if 0
 		if (f < 0.2)
 		    factor = 0;
 		else
-		    factor = 5 * (f - 0.2);
+		    factor = 2.5 * (f - 0.2);
+#endif
 
 		noise[i * N_SAMPLES + j].re *= factor;
 		noise[i * N_SAMPLES + j].im *= factor; // 8 * N_SAMPLES * N_SAMPLES * factor;
diff --git a/gtk-utils.c b/gtk-utils.c
index 8d8add6..d499f11 100644
--- a/gtk-utils.c
+++ b/gtk-utils.c
@@ -9,7 +9,10 @@ pixbuf_from_buffer (complex_t *buffer, int n)
 	gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, n, n);
     guint32 *p_bits = (guint32 *)gdk_pixbuf_get_pixels (pixbuf);
     int p_stride = gdk_pixbuf_get_rowstride (pixbuf);
-    int w, h;
+    int w, h, total, set;
+
+    total = 0;
+    set = 0;
 
     for (h = 0; h < n; ++h)
     {
@@ -20,22 +23,45 @@ pixbuf_from_buffer (complex_t *buffer, int n)
 	    double v;
 	    int vi;
 	    int g;
+	    double no;
 
 	    pb += h * p_stride + w * 4;
 
-	    v = c.re * 255.0 + 0.5;
-	    if (v > 255.0)
-		v = 255.0;
-	    if (v < 0)
-		v = 0;
+	    no = c.re;
+	    
+#define THRESHOLD   (0.5)
 
+	    total++;
+	    
+	    if (THRESHOLD + 2 * (no - 0.5) >= 0.5)
+	    {
+		g = 0xff;
+		set++;
+	    }
+	    else if (THRESHOLD + 2 * (no - 0.5) >= -0.5)
+	    {
+		g = 0x80;
+	    }
+	    else if (THRESHOLD + 2 * (no - 0.5) >= -1.5)
+	    {
+		g = 0x00;
+		set--;
+	    }
+	    else
+	    {
+		printf ("asdf\n");
+		g = 100;
+	    }
+	    
 #if 0
 	    vi *= 0x0f;
 #endif
 
 #define SADD(v,a)   (((v) + (a) > 0xff)? 0xff : ((v) + (a) < 0)? 0 : ((v) + (a)))
 	    
+#if 0
 	    g = ((double)w / n) * 255;
+#endif
 
 #if 0
 	    if (vi + g > 0xff)
@@ -43,28 +69,28 @@ pixbuf_from_buffer (complex_t *buffer, int n)
 	    else
 		pb[0] = pb[1] = pb[2] = 0x00;
 #endif
+#if 0
 	    vi = (v - 0x80);
-	    vi >>= 5;
+	    vi >>= 3;
 
 	    int rr, gg, bb;
 
-	    rr = 0;
-	    gg = g * 0.5;
-	    bb = 0;
+	    rr = 0x20 + 0.5 * g;
+	    gg = 0x20 + 0.5 * g;
+	    bb = 0 + 0.3 * g;
 
 	    int x = drand48() > 0.5;
 	    
-	    pb[0] = SADD (rr, vi);
-	    pb[1] = SADD (gg, - (vi));
-	    pb[2] = SADD (bb, vi);
+	    pb[0] = SADD (rr, 0.5 * vi);
+	    pb[1] = SADD (gg, - 0.5 * vi);
+	    pb[2] = SADD (bb, 2 * vi);
 	    pb[3] = 0xff;
+#endif
 
-#if 0
-	    pb[0] = rr;
-	    pb[1] = gg;
-	    pb[2] = bb;
+	    pb[0] = g;
+	    pb[1] = g;
+	    pb[2] = g;
 	    pb[3] = 0xff;
-#endif
 
 #define TRUNC(x, n)							\
 	    x >>= (8 - n);						\
@@ -78,7 +104,9 @@ pixbuf_from_buffer (complex_t *buffer, int n)
 	    TRUNC(pb[2], 5);
 #endif
 	}
+
     }
+    printf ("%d of %d (%f)\n", set, total, (double)set / total);
 
     return pixbuf;
 }
-- 
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