shaders

commit e0e2a8ba8fac3fd35ed446a0db17d439c8fa050d
parent 6487ca220d0eff32b0cde7aa024bdb75b4b36012
Author: mpizzzle <m@michaelpercival.xyz>
Date:   Mon,  7 Sep 2020 16:51:07 +0100

added bezier curve, whippy thing

Diffstat:
A
bezier.frag
 | 
38
++++++++++++++++++++++++++++++++++++++
A
miyagi3.frag
 | 
23
+++++++++++++++++++++++

2 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/bezier.frag b/bezier.frag
@@ -0,0 +1,38 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.14159265359
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+float quadraticBezier(float x, vec2 ab) {
+  float epsilon = 0.00001;
+  float a = max(0.0, min(1.0, ab.x)); 
+  float b = max(0.0, min(1.0, ab.y)); 
+
+  if (a == 0.5) {
+    a += epsilon;
+  }
+  
+  // solve t from x (an inverse operation)
+  float om2a = 1.0 - 2.0 * a;
+  float t = (sqrt(a * a + om2a * x) - a) / om2a;
+  return (1.0 - 2.0 * b) * (t * t) + (2.0 * b) * t;
+}
+
+void main() {
+    vec2 st = gl_FragCoord.xy / u_resolution;
+
+    float y = quadraticBezier(st.x, u_mouse / u_resolution);
+    vec3 color = vec3(y);
+
+    float plot = smoothstep(y - 0.02, y, st.y) - smoothstep(y, y + 0.02, st.y);
+
+    color = (1.0 - plot) * color + plot * vec3(1.0, 0.0, 1.0);
+
+    gl_FragColor = vec4(color, 1.0);
+}
+
diff --git a/miyagi3.frag b/miyagi3.frag
@@ -0,0 +1,23 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.14159265359
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+void main() {
+    vec2 st = gl_FragCoord.xy / u_resolution;
+
+    float y = (sin(st.x * PI / 2.0 + (u_time * 3.)) / st.x / 8.0) + 0.5;
+    vec3 color = vec3(y);
+
+    float pct = smoothstep(y - 0.02, y, st.y) - smoothstep(y, y + 0.02, st.y);
+
+    color = (1.0 - pct) * color + pct * vec3(1.0, 0.0, 1.0);
+
+    gl_FragColor = vec4(color, 1.0);
+}
+