Rewrite large parts of the mod

Blur is now more alive than ever, as I've been working on a new update: Blur+ 🪩
The mod's goal now is to improve upon the vanilla blur effect, adding smooth & configurable animations, the ability to apply it to containers (such as the inventory, chests, etc.), as well as customizable gradient backgrounds. 🌈

src/main/java/eu/midnightdust/blur/Blur.java

@@ -0,0 +1,74 @@
+package eu.midnightdust.blur;
+
+import eu.midnightdust.blur.config.BlurConfig;
+import eu.midnightdust.lib.util.MidnightColorUtil;
+import net.fabricmc.api.ClientModInitializer;
+
+public class Blur implements ClientModInitializer {
+
+    public static long start;
+    public static float progress;
+
+    public static boolean prevScreenHasBlur;
+    public static boolean screenHasBlur;
+
+    public static boolean prevScreenHasBackground;
+    public static boolean screenHasBackground;
+
+    public static boolean doTest = true;
+    public static boolean screenChanged = true;
+    public static long lastScreenChange = System.currentTimeMillis();
+
+    @Override
+    public void onInitializeClient() {
+        BlurConfig.init("blur", BlurConfig.class);
+    }
+
+    public static boolean doFade = false;
+
+    public static void onScreenChange() {
+        if (screenHasBlur) {
+            if (doFade) {
+                start = System.currentTimeMillis();
+                doFade = false;
+            }
+        } else if (prevScreenHasBlur && BlurConfig.fadeOutTimeMillis > 0) {
+            start = System.currentTimeMillis();
+            doFade = true;
+        } else {
+            start = -1;
+            doFade = true;
+        }
+    }
+
+    public static void updateProgress(boolean fadeIn) {
+        float x;
+        if (fadeIn) {
+            x = Math.min((System.currentTimeMillis() - start) / (float) BlurConfig.fadeTimeMillis, 1);
+            if (BlurConfig.animationCurve.equals(BlurConfig.AnimationCurve.EASE)) x *= (2 - x);  // easeInCubic
+        }
+        else {
+            x = Math.max(1 + (start - System.currentTimeMillis()) / (float) BlurConfig.fadeOutTimeMillis, 0);
+            if (BlurConfig.animationCurve.equals(BlurConfig.AnimationCurve.EASE)) x *= (2 - x);  // easeOutCubic
+            if (x <= 0) {
+                start = -1;
+                x = 0;
+            }
+        }
+        Blur.progress = x;
+    }
+
+    public static int getBackgroundColor(boolean second) {
+        int a = second ? BlurConfig.gradientEndAlpha : BlurConfig.gradientStartAlpha;
+        var col = MidnightColorUtil.hex2Rgb(second ? BlurConfig.gradientEnd : BlurConfig.gradientStart);
+        int r = (col.getRGB() >> 16) & 0xFF;
+        int b = (col.getRGB() >> 8) & 0xFF;
+        int g = col.getRGB() & 0xFF;
+        float prog = progress;
+        a *= prog;
+        r *= prog;
+        g *= prog;
+        b *= prog;
+        return a << 24 | r << 16 | b << 8 | g;
+    }
+}