adding kynd examples of DF

examples/07/1454255754461.frag

@@ -0,0 +1,97 @@
+// Author @kynd - 2016
+// http://www.kynd.info
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+float smoothedge(float v) {
+    return smoothstep(0.0, 1.0 / u_resolution.x, v);
+}
+
+float circle(vec2 p, float radius) {
+  return length(p) - radius;
+}
+
+float rect(vec2 p, vec2 size) {  
+  vec2 d = abs(p) - size;
+  return min(max(d.x, d.y), 0.0) + length(max(d,0.0));
+}
+
+float roundRect(vec2 p, vec2 size, float radius) {
+  vec2 d = abs(p) - size;
+  return min(max(d.x, d.y), 0.0) + length(max(d,0.0))- radius;
+}
+
+float ring(vec2 p, float radius, float width) {
+  return abs(length(p) - radius) - width;
+}
+
+float hexagon(vec2 p, float radius) {
+    vec2 q = abs(p);
+    return max(abs(q.y), q.x * 0.866025 + q.y * 0.5) - radius;
+}
+
+float triangle(vec2 p, float size) {
+    vec2 q = abs(p);
+    return max(q.x * 0.866025 + p.y * 0.5, -p.y * 0.5) - size * 0.5;
+}
+
+float ellipse(vec2 p, vec2 r, float s) {
+    return (length(p / r) - s);
+}
+
+float capsule(vec2 p, vec2 a, vec2 b, float r) {
+    vec2 pa = p - a, ba = b - a;
+    float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );
+    return length( pa - ba*h ) - r;
+}
+
+//http://thndl.com/square-shaped-shaders.html
+float polygon(vec2 p, int vertices, float size) {
+    float a = atan(p.x, p.y) + 0.2;
+    float b = 6.28319 / float(vertices);
+    return cos(floor(0.5 + a / b) * b - a) * length(p) - size;
+}
+
+float getShape(vec2 st, int i) {
+    if (i == 0) {
+        return circle(st, 0.4);
+    } else if (i == 1) {
+        return ring(st, 0.36, 0.08);
+    } else if (i == 2) {
+        return roundRect(st, vec2(0.32, 0.24), 0.08);
+    } else if (i == 3) {
+        return rect(st, vec2(0.4, 0.32));
+    } else if (i == 4) {
+        return capsule(st, vec2(-0.25, -0.25), vec2(0.25, 0.25), 0.2);
+    } else if (i == 5) {
+        return ellipse(st, vec2(0.9, 1.2), 0.4);
+    } else if (i == 6) {
+        return triangle(st, 0.4);
+    } else if (i == 7) {
+        return polygon(st, 5, 0.4);
+    } else {
+        return hexagon(st, 0.4);
+    }
+}
+
+
+void main() {
+    vec2 st = gl_FragCoord.xy/u_resolution.xy;
+	
+    float t0 = mod(u_time * 2.0, 9.0);
+    float t1 = mod(u_time * 2.0 + 1.0, 9.0);
+    int i0 = int(floor(t0));
+    int i1 = int(floor(t1));
+    float f = fract(t0);
+    
+    st -= vec2(0.5, 0.5);
+    vec3 color = vec3(smoothedge(mix(getShape(st, i0), getShape(st, i1), f)));
+    
+    gl_FragColor = vec4(color, 1.0);
+}

examples/07/1454255757379.frag

@@ -0,0 +1,75 @@
+// Author @kynd - 2016
+// http://www.kynd.info
+
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+float smoothedge(float v) {
+    return smoothstep(0.0, 1.0 / u_resolution.x, v);
+}
+
+float circle(vec2 p, float radius) {
+  return length(p) - radius;
+}
+
+float rect(vec2 p, vec2 size) {  
+  vec2 d = abs(p) - size;
+  return min(max(d.x, d.y), 0.0) + length(max(d,0.0));
+}
+
+float roundRect(vec2 p, vec2 size, float radius) {
+  vec2 d = abs(p) - size;
+  return min(max(d.x, d.y), 0.0) + length(max(d,0.0))- radius;
+}
+
+float ring(vec2 p, float radius, float width) {
+  return abs(length(p) - radius * 0.5) - width;
+}
+
+float hexagon(vec2 p, float radius) {
+    vec2 q = abs(p);
+    return max(abs(q.y), q.x * 0.866025 + q.y * 0.5) - radius;
+}
+
+float triangle(vec2 p, float size) {
+    vec2 q = abs(p);
+    return max(q.x * 0.866025 + p.y * 0.5, -p.y * 0.5) - size * 0.5;
+}
+
+float ellipse(vec2 p, vec2 r, float s) {
+    return (length(p / r) - s);
+}
+
+float capsule(vec2 p, vec2 a, vec2 b, float r) {
+    vec2 pa = p - a, ba = b - a;
+    float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );
+    return length( pa - ba*h ) - r;
+}
+
+//http://thndl.com/square-shaped-shaders.html
+float polygon(vec2 p, int vertices, float size) {
+    float a = atan(p.x, p.y) + 0.2;
+    float b = 6.28319 / float(vertices);
+    return cos(floor(0.5 + a / b) * b - a) * length(p) - size;
+}
+
+void main() {
+    vec2 st = gl_FragCoord.xy/u_resolution.xy;
+
+    float d = circle(st - vec2(0.2), 0.1);
+    d = min(d, rect(st - vec2(0.5, 0.2), vec2(0.1, 0.08)));
+    d = min(d, roundRect(st - vec2(0.8, 0.2), vec2(0.08, 0.06), 0.02));
+    d = min(d, ring(st - vec2(0.2, 0.5), 0.18, 0.02));
+    d = min(d, hexagon(st - vec2(0.5, 0.5), 0.1));
+    d = min(d, triangle(st - vec2(0.8, 0.5), 0.1));
+    d = min(d, ellipse(st - vec2(0.2, 0.8), vec2(0.9, 1.2), 0.1));
+    d = min(d, capsule(st - vec2(0.5, 0.8), vec2(-0.05, -0.05), vec2(0.05, 0.05), 0.05));
+    d = min(d, polygon(st - vec2(0.8, 0.8), 5, 0.1));
+    vec3 color = vec3(smoothedge(d));
+    gl_FragColor = vec4(color, 1.0);
+}

examples/README.md

@@ -44,6 +44,7 @@ The following is a list of examples present in this book.
         - [Polar shapes](../edit.html#07/polar.frag)
         - [Polar Poligons](../edit.html#07/shapes.frag)
         - Composition: [Arrow](../edit.html#07/arrow.frag)
+				- More Distance field by [Kynd](https://twitter.com/kyndinfo): [0](../edit.html#07/examples/160131053729.frag), [1](../edit.html#07/examples/160131053646.frag)
 
     * [Matrix](../08/)
         - [cross](../edit.html#08/cross.frag)