Add glslwrite tool and some examples

1 files changed, 42 insertions, 0 deletions

diff --git a/examples/squares.frag b/examples/squares.frag
new file mode 100644
index 0000000..fd5dc94
--- /dev/null
+++ b/examples/squares.frag
@@ -0,0 +1,42 @@
+#version 330
+
+out vec4 fragColor;
+
+uniform vec2 res;
+uniform float time;
+
+const float sharpness = 500;
+
+mat2 rot(float a) {
+        return mat2(
+                cos(a), -sin(a),
+                sin(a), cos(a)
+        );
+}
+
+float square(vec2 m, float a, float r, vec2 p) {
+        vec2 diff = abs((m - p) * rot(r));
+        float d = max(diff.x, diff.y);
+
+        return clamp((a - d)*sharpness, 0.0, 1.0);
+}
+
+void main(void) {
+        vec2 m = res/2;
+        float s = min(m.x, m.y);
+        vec2 p = (gl_FragCoord.xy - m) / s;
+
+        float a = atan(p.x, p.y);
+
+        float x = mod(p.x, 0.1);
+        float y = mod(p.y, 0.1);
+
+        float scene = 0;
+
+        for (int i = 1; i <= 50; i++) {
+                float c = square(vec2(0.5, 0) * rot(time/500/i), 0.1 + 0.005*i, time/500/i + time/(100*i), p);
+                scene = abs(scene - c);
+        }
+
+        fragColor = vec4(vec3(1, 1, 1) * scene, 1);
+}