From ec7032809d0c985b629d10f0f59fdef92ddc16c9 Mon Sep 17 00:00:00 2001
From: Søren Sandmann Pedersen <ssp@redhat.com>
Date: Tue, 13 Nov 2012 23:52:45 -0500
Subject: box

---
 jinc.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 46 insertions(+), 10 deletions(-)

diff --git a/jinc.c b/jinc.c
index a0f53d3..eabfdec 100644
--- a/jinc.c
+++ b/jinc.c
@@ -17,7 +17,7 @@ static const double J1_roots[] =
 };
 
 #define MAIN_LOBE       (J1_roots[0] / M_PI)
-#define LOBES           (J1_roots[2] / M_PI)
+#define LOBES           (J1_roots[4] / M_PI)
 #define AT_ZERO         (M_PI / 4)
 
 static double
@@ -44,7 +44,7 @@ jinc_jinc (double x, double y)
     return rf;
 }
 
-#define SIZE 512
+#define SIZE 1024
 
 static complex_image_t *
 make_jinc_image (void)
@@ -70,7 +70,7 @@ make_jinc_image (void)
 	    
 	    r->re = g->re = b->re = 0.0;
 	    r->re = v;
-	    b->re = 1 - v;
+	    b->re = 0;
 
 	    r->im = g->im = b->im = 0.0;
 	}
@@ -186,16 +186,51 @@ make_jnw_image (void)
 	    double step = (2 * LOBES) / (double)SIZE;
 	    double x = - LOBES + step / 2 + i * step;
 	    double y = - LOBES + step / 2 + j * step;
-	    double v;
+	    double vj, vs;
 
-	    v = jinc (sqrt (8 * x * 8 * x + 8 * y * 8 * y));
+	    vj = (jinc (sqrt (8 * x * 8 * x + 8 * y * 8 * y)));
+            vs = (sinc (8 * x) * sinc (8 * y));
 
-	    v = 0.5 * (v + 1);
-	    
+	    r->re = g->re = b->re = 0.0;
+	    r->re = 0.5 * (vj + 1);
+	    g->re = 0.0; // 0.5 * (vs + 1);
+            b->re = 0.0;
+
+	    r->im = g->im = b->im = 0.0;
+	}
+    }
+
+    return result;
+}
+
+static complex_image_t *
+make_box_image (void)
+{
+    complex_image_t *result = complex_image_new (SIZE, SIZE);
+    int i, j;
+
+    for (j = 0; j < SIZE; ++j)
+    {
+	for (i = 0; i < SIZE; ++i)
+	{
+	    complex_t *r = &(result->red[j * SIZE + i]);
+	    complex_t *g = &(result->green[j * SIZE + i]);
+	    complex_t *b = &(result->blue[j * SIZE + i]);
+	    double step = (2 * 0.5) / (double)SIZE;
+	    double x = - 0.5 + step / 2 + i * step;
+	    double y = - 0.5 + step / 2 + j * step;
+	    double v;
+
+            if (fabs (8 * x) < 0.5 && fabs (8 * y) < 0.5)
+                v = 1;
+            else
+                v = 0;
+                
+            
 	    r->re = g->re = b->re = 0.0;
 	    b->re = v;
-	    g->re = 1 - v;
-            r->re = v;
+	    g->re = 0.0; // 0.5 * (vs + 1);
+            r->re = 0.0;
 
 	    r->im = g->im = b->im = 0.0;
 	}
@@ -204,6 +239,7 @@ make_jnw_image (void)
     return result;
 }
 
+
 static complex_t
 filter (complex_t c, double dist)
 {
@@ -246,7 +282,7 @@ main (int argc, char **argv)
     
     g_type_init ();
     
-    image = make_jnw_image ();
+    image = make_lanczos_image ();
     
     g_print ("width, height %d %d\n", image->width, image->height);
     
-- 
cgit v1.2.3