Initial commit

extracted/assets/minecraft/shaders/core/arc.fsh

@@ -0,0 +1,37 @@
+#version 150
+
+uniform vec4 color1;
+uniform vec4 color2;
+uniform float radius;
+uniform float thickness;
+uniform float start;
+uniform float end;
+uniform vec2 size;
+uniform vec2 location;
+
+out vec4 fragColor;
+
+#define PI 3.141592653589793
+#define RAD 0.0174533
+
+void main() {
+    float startAngle = start * RAD;
+    float endAngle = startAngle + min(end * RAD, PI * 2);
+
+    float smoothThresh = 6.0 * (1.0 / length(size));
+    vec2 centerPos = ((gl_FragCoord.xy - location) / size.xy) * 2.0 - 1.0;
+
+    float dist = length(centerPos);
+    float bandAlpha = smoothstep(radius, radius + smoothThresh, dist) * smoothstep(radius + thickness, (radius + thickness) - smoothThresh, dist);
+    float angle = (atan(centerPos.y, centerPos.x) + PI);
+    float angleAlpha = smoothstep(angle, angle - smoothThresh, startAngle - 0.1) * smoothstep(angle, angle + smoothThresh, endAngle + 0.1);
+
+    float angle2 = (angle / PI * 180.);
+    angle2 = angle2 - 360. * floor(angle2 / 360.);
+    if (angle2 >= 180.) {
+        angle2 = (360. - angle2) * 2.;
+    } else {
+        angle2 = angle2 * 2.;
+    }
+    fragColor = mix(color1, color2, angle2 / 360.) * bandAlpha * angleAlpha;
+}