Makes potion icons fade over time.

src/main/java/markil3/immersive_hud/EventBus.java

@@ -140,6 +140,24 @@ public class EventBus
                 resetAlpha();
             }
             break;
+        case POTION_ICONS:
+            if (event instanceof RenderGameOverlayEvent.Pre)
+            {
+                TimerUtils.updatePotions(mc.player);
+                event.setCanceled(true);
+                RenderUtils.renderPotionIcons(mc,
+                        mc.ingameGUI,
+                        event.getMatrixStack());
+                resetAlpha();
+            }
+            /*
+             * Reset the transparency.
+             */
+            else if (event instanceof RenderGameOverlayEvent.Post)
+            {
+                resetAlpha();
+            }
+            break;
         case HOTBAR:
             if (event instanceof RenderGameOverlayEvent.Pre)
             {

src/main/java/markil3/immersive_hud/RenderUtils.java

@@ -1,32 +1,36 @@
 /**
  * Copyright (C) 2009-2021 Mojang Studios
- *
+ * <p>
- * Players are free to create, build, and mod within Minecraft if the
+ * Players are free to create, build, and mod within Minecraft if the branding
- * branding usage guidelines are followed. Fan art, logos, videos, and screen
+ * usage guidelines are followed. Fan art, logos, videos, and screen shots are
- * shots are acceptable as long as they are not used to falsely represent
+ * acceptable as long as they are not used to falsely represent Mojang Minecraft
- * Mojang Minecraft assets.  If you intend to use any portion of the name in
+ * assets.  If you intend to use any portion of the name in relation to
- * relation to services, products, or distribution, you must adhere to the
+ * services, products, or distribution, you must adhere to the following
- * following requirements.
+ * requirements.
- *
+ * <p>
- * Mojang's terms of service and brand guidelines are designed to let you
+ * Mojang's terms of service and brand guidelines are designed to let you know
- * know in plain terms what you can and cannot do with your game, the Mojang
+ * in plain terms what you can and cannot do with your game, the Mojang brand or
- * brand or Mojang assets.
+ * Mojang assets. https://account.mojang.com/documents/minecraft_eula
- * https://account.mojang.com/documents/minecraft_eula
  */
 package markil3.immersive_hud;
 
+import com.google.common.collect.Lists;
+import com.google.common.collect.Ordering;
 import com.mojang.blaze3d.matrix.MatrixStack;
 import com.mojang.blaze3d.systems.RenderSystem;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.AbstractGui;
 import net.minecraft.client.gui.IngameGui;
+import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.client.renderer.IRenderTypeBuffer;
 import net.minecraft.client.renderer.RenderHelper;
 import net.minecraft.client.renderer.model.IBakedModel;
 import net.minecraft.client.renderer.model.ItemCameraTransforms;
 import net.minecraft.client.renderer.texture.AtlasTexture;
 import net.minecraft.client.renderer.texture.OverlayTexture;
+import net.minecraft.client.renderer.texture.PotionSpriteUploader;
+import net.minecraft.client.renderer.texture.TextureAtlasSprite;
 import net.minecraft.client.renderer.texture.TextureManager;
 import net.minecraft.client.settings.AttackIndicatorStatus;
 import net.minecraft.crash.CrashReport;
@@ -35,10 +39,16 @@ import net.minecraft.crash.ReportedException;
 import net.minecraft.entity.LivingEntity;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
+import net.minecraft.potion.Effect;
+import net.minecraft.potion.EffectInstance;
 import net.minecraft.util.HandSide;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.math.MathHelper;
 import net.minecraft.world.World;
 
+import java.util.Collection;
+import java.util.List;
+
 /**
  * Contains methods for rendering various HUD elements. Most of these methods
  * come from {@link IngameGui} and
@@ -50,6 +60,102 @@ import net.minecraft.world.World;
  */
 public class RenderUtils
 {
+    public static void renderPotionIcons(Minecraft mc,
+                                     IngameGui gui,
+                                     MatrixStack matrixStack)
+    {
+        int scaledWidth = mc.getMainWindow().getScaledWidth();
+        int scaledHeight = mc.getMainWindow().getScaledHeight();
+
+        Collection<EffectInstance> collection =
+                mc.player.getActivePotionEffects();
+        if (!collection.isEmpty())
+        {
+            RenderSystem.enableBlend();
+            int i = 0;
+            int j = 0;
+            PotionSpriteUploader potionspriteuploader =
+                    mc.getPotionSpriteUploader();
+            List<Runnable> list =
+                    Lists.newArrayListWithExpectedSize(collection.size());
+            mc.getTextureManager()
+                    .bindTexture(ContainerScreen.INVENTORY_BACKGROUND);
+
+            for (EffectInstance effectinstance : Ordering.natural()
+                    .reverse()
+                    .sortedCopy(collection))
+            {
+                Effect effect = effectinstance.getPotion();
+                float effectAlpha = TimerUtils.getPotionAlpha(mc.player, effectinstance);
+                if (!effectinstance.shouldRenderHUD() || effectAlpha < 0.01F)
+                {
+                    continue;
+                }
+                // Rebind in case previous renderHUDEffect changed texture
+                mc.getTextureManager()
+                        .bindTexture(ContainerScreen.INVENTORY_BACKGROUND);
+                if (effectinstance.isShowIcon())
+                {
+                    int k = scaledWidth;
+                    int l = 1;
+                    if (mc.isDemo())
+                    {
+                        l += 15;
+                    }
+
+                    if (effect.isBeneficial())
+                    {
+                        ++i;
+                        k = k - 25 * i;
+                    }
+                    else
+                    {
+                        ++j;
+                        k = k - 25 * j;
+                        l += 26;
+                    }
+
+                    RenderSystem.color4f(1.0F, 1.0F, 1.0F, effectAlpha);
+                    if (effectinstance.isAmbient())
+                    {
+                        gui.blit(matrixStack, k, l, 165, 166, 24, 24);
+                    }
+                    else
+                    {
+                        gui.blit(matrixStack, k, l, 141, 166, 24, 24);
+                    }
+
+                    TextureAtlasSprite textureatlassprite =
+                            potionspriteuploader.getSprite(effect);
+                    int j1 = k;
+                    int k1 = l;
+                    float f1 = effectAlpha;
+                    list.add(() -> {
+                        mc.getTextureManager()
+                                .bindTexture(textureatlassprite.getAtlasTexture()
+                                        .getTextureLocation());
+                        RenderSystem.color4f(1.0F, 1.0F, 1.0F, f1);
+                        gui.blit(matrixStack,
+                                j1 + 3,
+                                k1 + 3,
+                                gui.getBlitOffset(),
+                                18,
+                                18,
+                                textureatlassprite);
+                    });
+                    effectinstance.renderHUDEffect(gui,
+                            matrixStack,
+                            k,
+                            l,
+                            gui.getBlitOffset(),
+                            effectAlpha);
+                }
+            }
+
+            list.forEach(Runnable::run);
+        }
+    }
+
     /**
      * Renders the horse jump bar.
      *

src/main/java/markil3/immersive_hud/TimerUtils.java

@@ -4,6 +4,7 @@ import com.mojang.blaze3d.matrix.MatrixStack;
 import com.mojang.blaze3d.systems.RenderSystem;
 
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.entity.player.ClientPlayerEntity;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
 import net.minecraft.item.BowItem;
@@ -19,10 +20,16 @@ import net.minecraft.item.ShootableItem;
 import net.minecraft.item.SnowballItem;
 import net.minecraft.item.ThrowablePotionItem;
 import net.minecraft.item.TridentItem;
+import net.minecraft.potion.Effect;
+import net.minecraft.potion.EffectInstance;
 import net.minecraft.potion.Effects;
 import net.minecraft.util.Hand;
+import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.RayTraceResult;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Optional;
 
 public class TimerUtils
@@ -66,6 +73,8 @@ public class TimerUtils
      */
     private static int mapLock;
 
+    private static HashMap<Effect, Integer> effectTime = new HashMap<>();
+
     /**
      * How many more ticks the hotbar will be onscreen. Every tick is 1/20th of
      * a second.
@@ -310,6 +319,63 @@ public class TimerUtils
         return canceled;
     }
 
+    /**
+     * Updates the timings of some of the potions currently affecting the
+     * player.
+     *
+     * @param player - The player being affected.
+     */
+    public static void updatePotions(ClientPlayerEntity player)
+    {
+        for (Effect effect : Collections.checkedSet(effectTime.keySet(),
+                Effect.class))
+        {
+            if (!player.isPotionActive(effect))
+            {
+                effectTime.remove(effect);
+            }
+        }
+    }
+
+    /**
+     * Obtains how transparent
+     *
+     * @param player
+     * @param effectinstance
+     *
+     * @return
+     */
+    public static float getPotionAlpha(ClientPlayerEntity player,
+                                       EffectInstance effectinstance)
+    {
+        final int BLINK_TIME = 200;
+        float effectAlpha = 0.0F;
+        Integer time = effectTime.get(effectinstance.getPotion());
+        if (time == null)
+        {
+            effectTime.put(effectinstance.getPotion(), (time = VISUAL_TIME));
+        }
+        else
+        {
+            effectTime.put(effectinstance.getPotion(), (time -= 1));
+        }
+        if (effectinstance.getDuration() <= BLINK_TIME)
+        {
+            effectAlpha =
+                    MathHelper.sin(7000F / (effectinstance.getDuration() + 16F * (float) Math.PI)) * 50F / (effectinstance
+                            .getDuration() + 100F) + 0.5F;
+        }
+        else if (effectinstance.getDuration() <= BLINK_TIME + 10)
+        {
+            effectAlpha = -(effectinstance.getDuration() - 200) / 22F + 0.454F;
+        }
+        else
+        {
+            effectAlpha = Main.getAlpha(time);
+        }
+        return effectAlpha;
+    }
+
     /**
      * Updates several fields relating to what items are being held by the
      * player.