render cat/wolf collars, charged creeper and wither armor energy swirl (additive), fox/dolphin mouth items

src/main/java/eu/mhsl/minecraft/pixelpics/render/entity/EntityCube.java

@@ -13,10 +13,16 @@ public final class EntityCube {
     public final Face[] faces; // by Direction.ordinal()
     public final Affine toWorld;
     public final Affine toLocal; // inverse
+    public final boolean additive; // emissive, added to what lies behind (energy swirl) instead of blended
     public final double[] aabbMin = {Double.MAX_VALUE, Double.MAX_VALUE, Double.MAX_VALUE};
     public final double[] aabbMax = {-Double.MAX_VALUE, -Double.MAX_VALUE, -Double.MAX_VALUE};
 
     public EntityCube(double[] from, double[] to, Face[] faces, Affine toWorld) {
+        this(from, to, faces, toWorld, false);
+    }
+
+    public EntityCube(double[] from, double[] to, Face[] faces, Affine toWorld, boolean additive) {
+        this.additive = additive;
         this.from = from;
         this.to = to;
         this.faces = faces;

src/main/java/eu/mhsl/minecraft/pixelpics/render/entity/EntityIntersector.java

@@ -103,7 +103,7 @@ public final class EntityIntersector {
         Vector normal = new Vector(n[0], n[1], n[2]).normalize();
         // A far/back face is seen from inside: shade it as facing the viewer.
         if (normal.getX() * dx + normal.getY() * dy + normal.getZ() * dz > 0) normal.multiply(-1);
-        return new FaceHit(t, world, normal, color, -1);
+        return new FaceHit(t, world, normal, color, -1, cube.additive);
     }
 
     private static double frac(double v, double lo, double hi) {

src/main/java/eu/mhsl/minecraft/pixelpics/render/entity/EntityState.java

@@ -35,7 +35,10 @@ public record EntityState(
         boolean passenger, // riding something (vanilla sitting pose)
         ItemSpec rightHand, // item in the RIGHT hand (main or off hand, resolved by handedness); null = empty
         ItemSpec leftHand, // item in the LEFT hand; null = empty
-        ItemSpec headItem // non-armor item worn in the head slot (pumpkin, skull, block, …); null = none
+        ItemSpec headItem, // non-armor item worn in the head slot (pumpkin, skull, block, …); null = none
+        int collar, // ARGB dye of a tamed cat's/wolf's collar; 0 = no collar (untamed)
+        boolean powered, // energy-swirl layer: charged creeper, wither below half health
+        ItemSpec mouthItem // item carried in the mouth (fox/dolphin main hand); null = none
         ) {
 
     /** Worn armor (4 slots) of a humanoid wearer; any field may be null. */

src/main/java/eu/mhsl/minecraft/pixelpics/render/entity/cem/CemBaker.java

@@ -110,6 +110,10 @@ public final class CemBaker implements EntityBaker<EntityState> {
             String m = "entity/horse/horse_markings_" + s.markings();
             overlayIfPresent(tex, ch != null && ch.babyModel ? m + "_baby" : m);
         }
+        if (s.collar() != 0 && tex != null && layerModels(base).stream().noneMatch(n -> n.contains("CollarLayer."))) {
+            // Collar drawn on the body model itself (WolfCollarLayer: parent model, same UV) -> composite it.
+            tex = withCollar(tex, base, ch != null && ch.babyModel, s.collar());
+        }
         if (s.typeKey().equals("tropical_fish") && tex != null && s.tint() != 0) {
             tex = TextureOps.deepCopy(tex);
             TextureOps.tint(tex, s.tint()); // white base body tinted with the body colour
@@ -160,15 +164,16 @@ public final class CemBaker implements EntityBaker<EntityState> {
                 : List.of();
 
         List<CemGeometry.Baked> baked = new ArrayList<>();
+        List<CemGeometry.Baked> glow = new ArrayList<>(); // additive energy-swirl layers
         if (!invisible) {
             baked.addAll(body);
-            if (vanilla) addVanillaLayers(s, ch, pose, show, tex, baked);
+            if (vanilla) addVanillaLayers(s, ch, pose, show, tex, baked, glow);
         }
         // Humanoid armor / elytra: drawn even when invisible (vanilla "floating armor").
         if (vanilla && s.equipment() != null) addArmorLayers(s, ch, pose, baked);
         List<EntityCube> itemCubes = new ArrayList<>();
         if (vanilla && items != null) addItems(s, frames, isIllager(info), itemCubes);
-        if (baked.isEmpty() && itemCubes.isEmpty()) return invisible ? null : fallbackBox(s, tex);
+        if (baked.isEmpty() && glow.isEmpty() && itemCubes.isEmpty()) return invisible ? null : fallbackBox(s, tex);
 
         // Legacy CEM models: snap the lowest point to the ground (their rest geometry has no reliable origin).
         if (place == null) {
@@ -182,6 +187,9 @@ public final class CemBaker implements EntityBaker<EntityState> {
 
         List<EntityCube> cubes = new ArrayList<>(baked.size());
         for (CemGeometry.Baked b : baked) cubes.add(new EntityCube(b.from(), b.to(), b.faces(), place.mul(b.world())));
+        for (CemGeometry.Baked b : glow) {
+            cubes.add(new EntityCube(b.from(), b.to(), b.faces(), place.mul(b.world()), true));
+        }
         for (EntityCube c : itemCubes) cubes.add(new EntityCube(c.from, c.to, c.faces, place.mul(c.toWorld)));
         return RenderedEntity.of(cubes);
     }
@@ -260,6 +268,7 @@ public final class CemBaker implements EntityBaker<EntityState> {
                 items.bake(item, "ground", false, x, out);
             }
         }
+        addMouthItem(s, frames, out);
         ItemSpec head = s.headItem();
         Affine h = frames.get("head");
         if (head != null && h != null) {
@@ -280,6 +289,27 @@ public final class CemBaker implements EntityBaker<EntityState> {
         }
     }
 
+    /**
+     * Item carried in the mouth, rendered in the "ground" context like vanilla (HoldingEntityRenderState).
+     * Fox (FoxHeldItemLayer, awake): head pivot · [baby: S(0.75)] · head rotation · T(0.06, 0.27 [baby 0.26],
+     * -0.5) · rotX(90) — the head frame carries exactly that pivot + rotation. Dolphin (DolphinCarryingItemLayer)
+     * at the model root · T(0, 1, -1) (its xRot-dependent shift is 0: PixelPics dolphins aren't pitched).
+     */
+    private void addMouthItem(EntityState s, Map<String, Affine> frames, List<EntityCube> out) {
+        ItemSpec item = s.mouthItem();
+        if (item == null) return;
+        boolean baby = s.baby();
+        Affine x = null;
+        if (s.typeKey().equals("fox") && frames.containsKey("head")) {
+            x = frames.get("head").mul(CemGeometry.JAVA_LOCAL);
+            if (baby) x = x.mul(Affine.scale(0.75));
+            x = x.mul(Affine.translation(0.06, baby ? 0.26 : 0.27, -0.5)).mul(Affine.rotX(Math.PI / 2));
+        } else if (s.typeKey().equals("dolphin") && frames.containsKey("root")) {
+            x = frames.get("root").mul(CemGeometry.JAVA_LOCAL).mul(Affine.translation(0, 1, -1));
+        }
+        if (x != null) items.bake(item, "ground", false, x, out);
+    }
+
     private static boolean isIllager(CemModelLoader.EntityInfo info) {
         return info != null && info.poses().keySet().stream().anyMatch(k -> k.startsWith("arms_"));
     }
@@ -373,7 +403,13 @@ public final class CemBaker implements EntityBaker<EntityState> {
     // --- vanilla render layers -----------------------------------------------------------------------
 
     private void addVanillaLayers(
-            EntityState s, Choice ch, Pose pose, Set<String> show, int[][] bodyTex, List<CemGeometry.Baked> baked) {
+            EntityState s,
+            Choice ch,
+            Pose pose,
+            Set<String> show,
+            int[][] bodyTex,
+            List<CemGeometry.Baked> baked,
+            List<CemGeometry.Baked> glow) {
         String base = ch.base;
         boolean baby = ch.babyModel;
         for (String n : layerModels(base)) {
@@ -392,6 +428,21 @@ public final class CemBaker implements EntityBaker<EntityState> {
                     baked.addAll(pose.bake(lm, t, show));
                 }
                 case "TropicalFishPatternLayer" -> addTropicalPattern(s, n, lm, pose, baked);
+                case "CatCollarLayer" -> {
+                    // Own collar model (inflated by 0.01), collar texture tinted with the collar's dye colour.
+                    if (s.collar() == 0 || lm.texture() == null) continue;
+                    int[][] t = texture(lm.texture());
+                    if (t == null) continue;
+                    t = TextureOps.deepCopy(t);
+                    TextureOps.tint(t, s.collar());
+                    baked.addAll(pose.bake(lm, t, show));
+                }
+                case "CreeperPowerLayer", "WitherArmorLayer" -> {
+                    // EnergySwirlLayer: charged creeper / wither below half health; drawn additively.
+                    if (!s.powered() || lm.texture() == null) continue;
+                    int[][] t = energySwirl(lm.texture(), layerClass.equals("WitherArmorLayer"));
+                    if (t != null) glow.addAll(pose.bake(lm, t, show));
+                }
                 case "SlimeOuterLayer" -> {
                     // Translucent outer cube on the body texture (alpha < 255 there; blended by the tracer).
                     int[][] t = lm.texture() != null ? texture(lm.texture()) : bodyTex;
@@ -475,6 +526,49 @@ public final class CemBaker implements EntityBaker<EntityState> {
         return out;
     }
 
+    // --- energy swirl & collars ----------------------------------------------------------------------
+
+    // A photo has no time: the swirl's scrolling texture is frozen at this age (ticks). Chosen so the sparse
+    // wither_armor pattern covers every wither part (at e.g. 42 the side heads land on empty rows).
+    private static final float SWIRL_AGE = 59f;
+
+    /**
+     * Energy-swirl texture (vanilla EnergySwirlLayer / RenderTypes.energySwirl): the texture matrix shifts the UV
+     * by ({@code xOffset(age) % 1}, {@code age·0.01 % 1}) on a repeating texture — baked here as a wrapped copy
+     * of the texture rolled by that offset — and the vertex colour 0xFF808080 halves the RGB. The result is
+     * drawn additively (BlendFunction.ADDITIVE), so alpha only cuts out (shader ALPHA_CUTOUT 0.1).
+     * xOffset: creeper {@code age·0.01}, wither {@code cos(age·0.02)·3}.
+     */
+    private int[][] energySwirl(String path, boolean wither) {
+        int[][] src = texture(path);
+        if (src == null) return null;
+        double u = wither ? Math.cos(SWIRL_AGE * 0.02) * 3 : SWIRL_AGE * 0.01;
+        double v = SWIRL_AGE * 0.01;
+        int h = src.length, w = src[0].length;
+        int du = Math.floorMod((int) Math.round((u % 1) * w), w);
+        int dv = Math.floorMod((int) Math.round((v % 1) * h), h);
+        int[][] out = new int[h][w];
+        for (int y = 0; y < h; y++) {
+            for (int x = 0; x < w; x++) {
+                int p = src[(y + dv) % h][(x + du) % w];
+                out[y][x] = (p & 0xFF000000) | ((p >>> 1) & 0x7F7F7F);
+            }
+        }
+        return out;
+    }
+
+    /** Body texture with the dye-tinted {@code entity/<base>/<base>_collar[_baby]} composited over it. */
+    private int[][] withCollar(int[][] tex, String base, boolean baby, int dye) {
+        String path = "entity/" + base + "/" + base + "_collar" + (baby ? "_baby" : "");
+        int[][] collar = texture(path);
+        if (collar == null || collar.length != tex.length || collar[0].length != tex[0].length) return tex;
+        int[][] tinted = TextureOps.deepCopy(collar);
+        TextureOps.tint(tinted, dye);
+        int[][] out = TextureOps.deepCopy(tex);
+        TextureOps.overlay(out, tinted);
+        return out;
+    }
+
     // --- texture resolution --------------------------------------------------------------------------
 
     private int[][] texture(String path) {
@@ -501,6 +595,12 @@ public final class CemBaker implements EntityBaker<EntityState> {
                     Math.min(adult.size(), EntityModels.specificCandidateCount(s.typeKey(), s.variant())),
                     info.texture());
         }
+        if (s.collar() != 0) {
+            // Tamed: vanilla switches to the "_tame" texture where the variant has one (wolves).
+            List<String> tame = new ArrayList<>();
+            for (String a : adult) tame.add(a + "_tame");
+            adult.addAll(0, tame);
+        }
         List<String> order = new ArrayList<>();
         if (ch != null && ch.babyModel) {
             for (String a : adult) order.add(a + "_baby");

src/main/java/eu/mhsl/minecraft/pixelpics/render/raytrace/ElementIntersector.java

@@ -81,7 +81,7 @@ public final class ElementIntersector {
 
             Vector world = new Vector(bx + ox + dx * c.t, by + oy + dy * c.t, bz + oz + dz * c.t);
             Vector normal = new Vector(c.normal[0], c.normal[1], c.normal[2]);
-            return new FaceHit(c.t, world, normal, color, face.tintIndex);
+            return new FaceHit(c.t, world, normal, color, face.tintIndex, false);
         }
         return null;
     }

src/main/java/eu/mhsl/minecraft/pixelpics/render/raytrace/FaceHit.java

@@ -4,6 +4,7 @@ import org.bukkit.util.Vector;
 
 /**
  * The result of intersecting a ray with a block's geometry: the world-space hit point and normal,
- * the sampled ARGB color (before shading/tinting) and the face's tint index ({@code -1} = none).
+ * the sampled ARGB color (before shading/tinting), the face's tint index ({@code -1} = none) and whether the
+ * surface is drawn additively (emissive energy-swirl layers: its colour is added to what lies behind).
  */
-public record FaceHit(double t, Vector point, Vector normal, int color, int tintIndex) {}
+public record FaceHit(double t, Vector point, Vector normal, int color, int tintIndex, boolean additive) {}

src/main/java/eu/mhsl/minecraft/pixelpics/render/raytrace/SnapshotRaytracer.java

@@ -42,6 +42,8 @@ public final class SnapshotRaytracer {
     private static final int MAX_TRANSLUCENT_LAYERS = 6;
     private static final double MIN_TRANSMITTANCE = 0.03;
     private static final double LAYER_EPS = 1e-5;
+    // layerAlpha marker of an additive (emissive) layer: its colour is added to what lies behind.
+    private static final double ADDITIVE = -1;
 
     private final BlockModelRegistry registry;
     private final BiomeTintProvider tintProvider;
@@ -78,7 +80,8 @@ public final class SnapshotRaytracer {
         BlockCursor blocks = new BlockCursor(snapshot, origin, direction, sky, scene, depth);
         boolean entities = scene != null && !scene.isEmpty();
 
-        // Translucent surfaces in front of the final one, front to back (shaded colour, alpha 0..1, ray t).
+        // Translucent surfaces in front of the final one, front to back (shaded colour, alpha 0..1 or ADDITIVE,
+        // ray t).
         int[] layerColor = null;
         double[] layerAlpha = null, layerT = null;
         int layers = 0;
@@ -97,8 +100,11 @@ public final class SnapshotRaytracer {
             FaceHit eh = entities ? scene.nearestHit(ox, oy, oz, dx, dy, dz, minT, limit) : null;
             int color;
             double t;
+            boolean additive = false;
             if (eh != null) {
-                color = ColorUtil.shade(eh.color(), shadeFactor(eh.normal()));
+                // Emissive additive surfaces (energy swirl) are unshaded: vanilla NO_CARDINAL_LIGHTING + EMISSIVE.
+                additive = eh.additive();
+                color = additive ? eh.color() : ColorUtil.shade(eh.color(), shadeFactor(eh.normal()));
                 t = eh.t();
             } else if (pending != null) {
                 color = pending.color;
@@ -109,7 +115,14 @@ public final class SnapshotRaytracer {
             }
             int alpha = ColorUtil.alpha(color);
             double a = alpha / 255.0;
-            if (alpha >= OPAQUE_ALPHA
+            if (additive) {
+                // Additive light never hides what lies behind it: it neither ends the ray nor dims it. Beyond the
+                // layer budget it is dropped.
+                if (layers == MAX_TRANSLUCENT_LAYERS) {
+                    minT = t + LAYER_EPS;
+                    continue;
+                }
+            } else if (alpha >= OPAQUE_ALPHA
                     || layers == MAX_TRANSLUCENT_LAYERS
                     || transmittance * (1 - a) < MIN_TRANSMITTANCE) {
                 // Opaque, or what lies behind would contribute next to nothing: this surface ends the ray.
@@ -123,10 +136,10 @@ public final class SnapshotRaytracer {
                 layerT = new double[MAX_TRANSLUCENT_LAYERS];
             }
             layerColor[layers] = color;
-            layerAlpha[layers] = a;
+            layerAlpha[layers] = additive ? ADDITIVE : a;
             layerT[layers] = t;
             layers++;
-            transmittance *= 1 - a;
+            if (!additive) transmittance *= 1 - a;
             minT = t + LAYER_EPS;
         }
 
@@ -138,7 +151,12 @@ public final class SnapshotRaytracer {
                 color = blocks.applyLiquid(color, finalT, skyColor);
                 liquidPending = false;
             }
-            color = ColorUtil.mix(fog(layerColor[i], layerT[i], skyColor), color, layerAlpha[i], 1 - layerAlpha[i]);
+            if (layerAlpha[i] == ADDITIVE) {
+                // Added light fades with distance like the surface it would otherwise be.
+                color = ColorUtil.add(color, ColorUtil.shade(layerColor[i], 1 - fogFactor(layerT[i])));
+            } else {
+                color = ColorUtil.mix(fog(layerColor[i], layerT[i], skyColor), color, layerAlpha[i], 1 - layerAlpha[i]);
+            }
         }
         if (liquidPending) color = blocks.applyLiquid(color, finalT, skyColor);
         return color & 0xFFFFFF;

src/main/java/eu/mhsl/minecraft/pixelpics/render/snapshot/EntitySnapshotBuilder.java

@@ -19,6 +19,8 @@ import java.util.function.DoubleSupplier;
 import org.bukkit.Keyed;
 import org.bukkit.Location;
 import org.bukkit.Material;
+import org.bukkit.attribute.Attribute;
+import org.bukkit.attribute.AttributeInstance;
 import org.bukkit.entity.AbstractArrow;
 import org.bukkit.entity.AbstractHorse;
 import org.bukkit.entity.Ageable;
@@ -28,6 +30,7 @@ import org.bukkit.entity.Cat;
 import org.bukkit.entity.ChestedHorse;
 import org.bukkit.entity.Chicken;
 import org.bukkit.entity.Cow;
+import org.bukkit.entity.Creeper;
 import org.bukkit.entity.Entity;
 import org.bukkit.entity.Fox;
 import org.bukkit.entity.Frog;
@@ -51,6 +54,7 @@ import org.bukkit.entity.TraderLlama;
 import org.bukkit.entity.Trident;
 import org.bukkit.entity.TropicalFish;
 import org.bukkit.entity.Villager;
+import org.bukkit.entity.Wither;
 import org.bukkit.entity.Wolf;
 import org.bukkit.entity.ZombieVillager;
 import org.bukkit.inventory.EntityEquipment;
@@ -114,6 +118,9 @@ public final class EntitySnapshotBuilder {
             "piglin",
             "piglin_brute");
 
+    // Mobs whose main-hand item is drawn in the mouth (FoxHeldItemLayer, DolphinCarryingItemLayer).
+    private static final Set<String> MOUTH_CARRIERS = Set.of("fox", "dolphin");
+
     /** {@code nearby}: {@link FrustumBounds#nearbyEntities} of this photo. */
     public static List<EntityState> build(Collection<Entity> nearby, UUID shooter) {
         List<EntityState> states = new ArrayList<>();
@@ -169,6 +176,8 @@ public final class EntitySnapshotBuilder {
         String bodyEquip = null;
         int bodyDye = 0;
         int tint2 = 0;
+        int collar = 0;
+        boolean powered = false;
         try {
             // Slime & magma cube (MagmaCube extends Slime) scale their model by size (1/2/4).
             if (e instanceof Slime sl) sizeScale = sl.getSize();
@@ -187,8 +196,16 @@ public final class EntitySnapshotBuilder {
                     default -> "big";};
             } else if (e instanceof Cat c) {
                 variant = keyOf(c.getCatType());
+                if (c.isTamed()) collar = ColorUtil.dyeArgb(c.getCollarColor(), 0);
             } else if (e instanceof Wolf w) {
                 variant = keyOf(w.getVariant());
+                if (w.isTamed()) collar = ColorUtil.dyeArgb(w.getCollarColor(), 0);
+            } else if (e instanceof Creeper cr) {
+                powered = cr.isPowered();
+            } else if (e instanceof Wither wi) {
+                // WitherBoss.isPowered(): health <= max health / 2 (wither armor layer).
+                AttributeInstance max = wi.getAttribute(Attribute.MAX_HEALTH);
+                powered = max != null && wi.getHealth() <= max.getValue() / 2;
             } else if (e instanceof Axolotl a) {
                 variant = keyOf(a.getVariant());
             } else if (e instanceof Parrot p) {
@@ -245,7 +262,7 @@ public final class EntitySnapshotBuilder {
         // Equipment slots: saddle + BODY equipment (horse armor, llama carpet, harness, wolf/nautilus armor, …)
         // for every mount — including ones added in newer versions — plus held items (by hand side, like
         // vanilla: a left-handed mob holds its main-hand item left) and a non-armor head item.
-        ItemSpec rightHand = null, leftHand = null, headItem = null;
+        ItemSpec rightHand = null, leftHand = null, headItem = null, mouthItem = null;
         EntityEquipment eq = e instanceof LivingEntity le ? le.getEquipment() : null;
         if (eq != null) {
             try {
@@ -263,8 +280,12 @@ public final class EntitySnapshotBuilder {
                         || (e instanceof HumanEntity he && he.getMainHand() == MainHand.LEFT);
                 ItemSpec main = ItemSpecs.of(eq.getItemInMainHand());
                 ItemSpec off = ItemSpecs.of(eq.getItemInOffHand());
-                rightHand = leftHanded ? off : main;
-                leftHand = leftHanded ? main : off;
+                if (MOUTH_CARRIERS.contains(type)) {
+                    mouthItem = main; // fox/dolphin carry their main-hand item in the mouth, not in a hand
+                } else {
+                    rightHand = leftHanded ? off : main;
+                    leftHand = leftHanded ? main : off;
+                }
                 ItemStack helmet = eq.getHelmet();
                 if (helmet != null && !helmet.getType().isAir() && armorAsset(helmet.getType()) == null) {
                     headItem = ItemSpecs.of(helmet);
@@ -312,7 +333,10 @@ public final class EntitySnapshotBuilder {
                 e.isInsideVehicle(),
                 rightHand,
                 leftHand,
-                headItem);
+                headItem,
+                collar,
+                powered,
+                mouthItem);
     }
 
     /** Worn armor (4 slots) from a humanoid wearer; null when nothing is equipped. */

src/main/java/eu/mhsl/minecraft/pixelpics/render/util/ColorUtil.java

@@ -92,7 +92,6 @@ public final class ColorUtil {
         return argb(a, r, g, b);
     }
 
-    /** Scales the RGB channels by {@code factor} (0..1), keeping alpha. Used for directional face shading. */
     /** Texels with alpha at or below this are holes (alpha cutout) for every intersector and the extrusion. */
     public static final int ALPHA_CUTOUT = 16;
 
@@ -101,6 +100,7 @@ public final class ColorUtil {
         return alpha(argb) > ALPHA_CUTOUT;
     }
 
+    /** Scales the RGB channels by {@code factor} (0..1), keeping alpha. Used for directional face shading. */
     public static int shade(int argb, double factor) {
         int a = alpha(argb);
         int r = clamp((int) (red(argb) * factor));
@@ -109,6 +109,13 @@ public final class ColorUtil {
         return argb(a, r, g, b);
     }
 
+    /** Additive blend (vanilla BlendFunction.ADDITIVE, ONE/ONE): RGB of {@code src} added to {@code dst}, clamped. */
+    public static int add(int dst, int src) {
+        return (clamp(red(dst) + red(src)) << 16)
+                | (clamp(green(dst) + green(src)) << 8)
+                | clamp(blue(dst) + blue(src));
+    }
+
     private static int clamp(int v) {
         return v < 0 ? 0 : Math.min(v, 255);
     }