1 files changed, 38 insertions, 0 deletions
diff --git a/src/main/resources/assets/notenoughupdates/shaders/make_gold.frag b/src/main/resources/assets/notenoughupdates/shaders/make_gold.frag
new file mode 100644
index 00000000..e771f2c2
--- /dev/null
+++ b/src/main/resources/assets/notenoughupdates/shaders/make_gold.frag
@@ -0,0 +1,38 @@
+#version 120
+
+varying vec4 passColour;
+varying vec3 passPosition;
+uniform sampler2D textureIn;
+
+uniform float amount;
+
+//Algorithm by sam hocevar
+vec3 rgb2hsv(vec3 c) {
+    vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+    vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
+    vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
+
+    float d = q.x - min(q.w, q.y);
+    float e = 1.0e-10;
+    return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+}
+
+//Algorithm by hughsk
+vec3 hsv2rgb(vec3 c) {
+  vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+  vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+  return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
+void main() {
+    vec4 texture = texture2D(textureIn, gl_TexCoord[0].st);
+
+    vec3 hsv = rgb2hsv(texture.rgb);
+
+    float hue = mod(hsv.x + amount + passPosition.x*4.0f, 1.0f);
+    float sat = hsv.y*0.7f;
+    float val = hsv.z;
+    vec3 fade = hsv2rgb(vec3(hue, sat, val));
+
+    gl_FragColor = vec4(fade.rgb, texture.a);
+}