Overlaps and anisotropic filtering

demo/demo-font.cc

@@ -154,7 +154,7 @@ encode_ft_glyph (demo_font_t      *font,
 
   assert (glyphy_arc_accumulator_get_error (font->acc) <= tolerance);
 
-#if 0
+#if 1
   /* Technically speaking, we want the following code,
    * however, crappy fonts have crappy flags.  So we just
    * fixup unconditionally... */

demo/demo-fshader.glsl

@@ -58,12 +58,27 @@ main()
   /* isotropic antialiasing */
   vec2 dpdx = dFdx (p);
   vec2 dpdy = dFdy (p);
-  float m = length (vec2 (length (dpdx), length (dpdy))) * SQRT2_2;
-  float w = abs (normalize (dpdx).x) + abs (normalize (dpdy).x);
-
-  vec4 color = vec4 (0,0,0,1);
+
+  float det = dpdx.x * dpdy.y - dpdx.y * dpdy.x;
+  mat2 P_inv = mat2(dpdy.y, -dpdx.y, -dpdy.x, dpdx.x) * (1. / det);
+  vec2 sdf_vector;
+
+  /* gdist is signed distance to nearest contour; sdf_vector is the shortest vector version. */
+  float gsdist = glyphy_sdf (p, gi.nominal_size, sdf_vector GLYPHY_DEMO_EXTRA_ARGS);
+
+
+
+
+  if (glyphy_iszero (det)) {
+    gl_FragColor = vec4(1,0,0,1);
+    return;
+  }
+
+  float m = 1.;//SQRT2;//length (vec2 (length (dpdx), length (dpdy))); //1.0;
+  gsdist = sign (gsdist) * length (P_inv * sdf_vector);
 
-  float gsdist = glyphy_sdf (p, gi.nominal_size GLYPHY_DEMO_EXTRA_ARGS);
+  float w = abs (normalize (dpdx).x) + abs (normalize (dpdy).x);
+  vec4 color = vec4 (0,0,0,1);  
   float sdist = gsdist / m * u_contrast;
 
   if (!u_debug) {
@@ -84,19 +99,32 @@ main()
 
     float udist = abs (sdist);
     float gudist = abs (gsdist);
-    // Color the outline red
+    float pdist = glyphy_point_dist (p, gi.nominal_size GLYPHY_DEMO_EXTRA_ARGS);
+/*    // Color the outline red
     color += vec4 (1,0,0,1) * smoothstep (2., 1., udist);
     // Color the distance field in green
     if (!glyphy_isinf (udist))
       color += vec4 (0,.3,0,(1. + sin (sdist)) * abs(1. - gsdist * 3.) / 3.);
 
-    float pdist = glyphy_point_dist (p, gi.nominal_size GLYPHY_DEMO_EXTRA_ARGS);
+
     // Color points green
     color = mix (vec4 (0,1,0,.5), color, smoothstep (.05, .06, pdist));
 
     glyphy_arc_list_t arc_list = glyphy_arc_list (p, gi.nominal_size GLYPHY_DEMO_EXTRA_ARGS);
     // Color the number of endpoints per cell blue
     color += vec4 (0,0,1,.1) * float(arc_list.num_endpoints) * 32./255.;
+*/    
+    if (glyphy_isinf (sdf_vector.x) || glyphy_isinf (sdf_vector.y))
+      color = vec4 (0, 0, 0, 1);
+
+    else
+      color = vec4 (0.5*(sdf_vector.x)+0.5, 0.5*(sdf_vector.y)+0.5, 0.4, 1);
+
+
+    color += vec4 (1,1,1,1) * smoothstep (1.6, 1.4, udist);
+    color = mix (vec4 (0,0.2,0.2,.5), color, smoothstep (.04, .06, pdist));
+  //  else
+  //    color = vec4 (0,0,0,1);
   }
 
   gl_FragColor = color;

demo/jabberwocky.h

@@ -5,7 +5,7 @@ static const char *jabberwocky =
 "  And the mome raths outgrabe.\n"
 "\n"
 "\"Beware the Jabberwock, my son!\n"
-"  The jaws that bite, the claws that catch!\n"
+"  The jaws ţhąt bite, thę çląwş that ©atch!\n"
 "Beware the Jubjub bird, and shun\n"
 "  The frumious Bandersnatch!\"\n"
 "He took his vorpal sword in hand:\n"