shaders

commit 41fdd8440b27b463b27f2afda901ede873c1f0bd
parent bb966bebb323a2ad4a879789ff1f3c2a0ddf20d9
Author: mpizzzle <m@michaelpercival.xyz>
Date:   Mon,  7 Sep 2020 15:12:32 +0100

following along with book of shaders tutorial. safety commit

Diffstat:
A
miyagi.frag
 | 
28
++++++++++++++++++++++++++++
A
miyagi2.frag
 | 
26
++++++++++++++++++++++++++

2 files changed, 54 insertions(+), 0 deletions(-)
diff --git a/miyagi.frag b/miyagi.frag
@@ -0,0 +1,28 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
+
+// Plot a line on Y using a value between 0.0-1.0
+
+float plot(vec2 st) {
+    return smoothstep(0.02, 0.0, abs(st.y - st.x));
+}
+
+void main() {
+    vec2 st = gl_FragCoord.xy/u_resolution;
+
+    float y = st.x;
+
+    vec3 color = vec3(y);
+
+    // Plot a line
+    float pct = plot(st);
+    color = (1.0-pct)*color+pct*vec3(0.0,1.0,0.0);
+
+    gl_FragColor = vec4(color,1.0);
+}
+
diff --git a/miyagi2.frag b/miyagi2.frag
@@ -0,0 +1,26 @@
+#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 * 1.5)) / 2.0) + 0.5;
+    //float y = abs(sin(st.x * PI / 2.0 + (u_time * 1.5)));
+    //float y = fract(sin(st.x * PI / 2.0 + (u_time * 1.5)));
+    float y = (sin(st.x * PI / 2.0 + (u_time * 1.5)) / 2.0) + 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);
+}
+