alpha-blend translucent block and entity texels (stained glass, slime skin, text backgrounds)

tools/ObjectTestRender.java

@@ -82,9 +82,10 @@ public class ObjectTestRender {
         objs.add(obj(ObjectState.Kind.TEXT,
             Affine.translation(1.5, 3.0, 0).mul(Affine.rotY(Math.PI)).mul(Affine.scale(0.025)), null, null,
             List.of("Hallo PixelPics!", "Zeile zwei äöü"), 0xFF203040));
-        // Text seen from the BACK (front faces +Z, camera is on -Z) and a shield item.
+        // Text seen from the BACK (front faces +Z, camera is on -Z) on the vanilla default 25% black
+        // background (blended), and a shield item.
         objs.add(obj(ObjectState.Kind.TEXT, Affine.translation(-0.5, 3.0, 0).mul(Affine.scale(0.025)), null, null,
-            List.of("Rueckseite"), 0));
+            List.of("Rueckseite"), 0x40000000));
         objs.add(obj(ObjectState.Kind.ITEM, Affine.translation(4, 1.0, 0.5), null, "shield", List.of(), 0));
         // Dropped item (flat) on the ground.
         objs.add(obj(ObjectState.Kind.ITEM, Affine.translation(-1, 0.3, 0.5).mul(Affine.scale(0.5)), null, "apple", List.of(), 0));

tools/edgecase-plugin/pptest/PPTest.java

@@ -56,6 +56,7 @@ public class PPTest extends JavaPlugin {
         scenes.put("pistondown", new Scene("pistondown", this::piston, -1.6, 2.6, -1.6, 0.5, 1.4, 0.5));
         scenes.put("pistonup", new Scene("pistonup", this::piston, 0.4, 2.6, -1.6, 2.5, 1.4, 0.5));
         scenes.put("vehicles", new Scene("vehicles", this::vehicles, 5, 3, -7, 5, 0.6, 1.5));
+        scenes.put("translucent", new Scene("translucent", this::translucent, 4.5, 2.8, -5.5, 4.5, 0.8, 2));
     }
 
     @Override
@@ -474,4 +475,39 @@ public class PPTest extends JavaPlugin {
         spawn(o, 6, 0, 3, 90, EntityType.CHERRY_CHEST_BOAT);
         spawn(o, 9, 0, 3, 120, EntityType.MANGROVE_BOAT);
     }
+
+    /**
+     * Alpha blending: a stained-glass wall (inner faces culled) and stacked glass colours in front of a striped
+     * wool wall, ice/tinted glass/slime/honey blocks, connected panes, glass under water, a slime and a sulfur
+     * cube (translucent outer skins, one behind glass) and a text display with the default background.
+     */
+    private void translucent(Location o) {
+        java.util.function.BiConsumer<int[], String> put = (p, data) -> o.clone().add(p[0], p[1], p[2]).getBlock()
+                .setBlockData(Bukkit.createBlockData("minecraft:" + data), false);
+        for (int x = -1; x <= 10; x++)
+            for (int y = 0; y <= 4; y++) put.accept(new int[] {x, y, 5}, (x + y) % 2 == 0 ? "white_wool" : "black_wool");
+        for (int x = 0; x <= 2; x++) for (int y = 0; y <= 1; y++) put.accept(new int[] {x, y, 1}, "red_stained_glass");
+        put.accept(new int[] {3, 0, 1}, "blue_stained_glass");
+        put.accept(new int[] {3, 0, 0}, "yellow_stained_glass");
+        put.accept(new int[] {4, 0, 1}, "ice");
+        put.accept(new int[] {4, 1, 1}, "tinted_glass");
+        put.accept(new int[] {5, 0, 1}, "slime_block");
+        put.accept(new int[] {6, 0, 1}, "honey_block");
+        put.accept(new int[] {7, 0, 1}, "lime_stained_glass_pane[east=true]");
+        put.accept(new int[] {8, 0, 1}, "lime_stained_glass_pane[west=true,east=true]");
+        put.accept(new int[] {9, 0, 1}, "lime_stained_glass_pane[west=true]");
+        for (int x = 0; x <= 2; x++) put.accept(new int[] {x, -1, -2}, "water");
+        put.accept(new int[] {1, -2, -2}, "magenta_stained_glass");
+        put.accept(new int[] {0, -2, -2}, "sand");
+        put.accept(new int[] {2, -2, -2}, "sand");
+        Slime slime = spawn(o, 1.5, 0, 3, 200, Slime.class);
+        slime.setSize(2);
+        Slime front = spawn(o, 7.5, 0, -1.5, 160, Slime.class);
+        front.setSize(1);
+        EntityType sulfur = Registry.ENTITY_TYPE.get(NamespacedKey.minecraft("sulfur_cube"));
+        if (sulfur != null) spawn(o, 5.5, 0, -1.5, 200, sulfur);
+        TextDisplay t = spawn(o, 4.5, 2.6, 0, 0, TextDisplay.class);
+        t.text(Component.text("Default background"));
+        t.setBillboard(Display.Billboard.CENTER);
+    }
 }