From df1be775ae630e15a7d159d88d061f28fa464d17 Mon Sep 17 00:00:00 2001
From: David Vierra <codewarrior@hawaii.rr.com>
Date: Fri, 13 Nov 2015 17:02:33 -1000
Subject: [PATCH] Add chunk renderer for positions that can spawn mobs

---
 .../rendering/chunkmeshes/mobspawns.py        | 86 +++++++++++++++++++
 src/mcedit2/rendering/chunkupdate.py          |  2 +
 src/mcedit2/rendering/layers.py               |  4 +-
 3 files changed, 91 insertions(+), 1 deletion(-)
 create mode 100644 src/mcedit2/rendering/chunkmeshes/mobspawns.py

diff --git a/src/mcedit2/rendering/chunkmeshes/mobspawns.py b/src/mcedit2/rendering/chunkmeshes/mobspawns.py
new file mode 100644
index 0000000..3994aec
--- /dev/null
+++ b/src/mcedit2/rendering/chunkmeshes/mobspawns.py
@@ -0,0 +1,86 @@
+"""
+    mobspawns
+"""
+from __future__ import absolute_import, division, print_function, unicode_literals
+import logging
+
+from mcedit2.rendering import renderstates
+from mcedit2.rendering.blockmeshes import ChunkMeshBase, standardCubeTemplates
+from mcedit2.rendering.layers import Layer
+from mcedit2.rendering.scenegraph.vertex_array import VertexNode
+from mcedit2.rendering.vertexarraybuffer import QuadVertexArrayBuffer
+from mceditlib import faces
+
+log = logging.getLogger(__name__)
+
+
+class MobSpawnsBlockMesh(ChunkMeshBase):
+    renderstate = renderstates.RenderstateHeightLevel
+    layer = Layer.MobSpawns
+
+    def makeChunkVertices(self, chunk, limitBox):
+        """
+
+        :param chunk:
+        :type chunk: WorldEditorChunk
+        :param limitBox:
+        :return: :raise:
+        """
+
+        vertexes = []
+
+        for cy in chunk.sectionPositions():
+            section = chunk.getSection(cy)
+            if section is None:
+                continue
+
+            blockLight = section.BlockLight
+            skyLight = section.SkyLight
+            blocks = section.Blocks
+
+            # A block can spawn monsters if it is air, and the block above it is air,
+            # and the block below it is solid, and the light level is < 8.
+            # blocks with blockLight < 8 AND skyLight < 8 will always spawn monsters
+            # blocks with blockLight < 8 AND skyLight >= 8 will only spawn monsters at night
+
+            lowBlockLight = blockLight < 8
+            lowNightLight = lowBlockLight & (skyLight < 8)
+            lowDayLight = lowBlockLight & (skyLight >= 8)
+
+            validBlocks = blocks == 0                  # block is air
+            validBlocks[:-1] &= blocks[1:] == 0   # block above is air
+            validBlocks[1:] &= blocks[:-1] != 0   # block below is not air
+
+            belowSection = chunk.getSection(cy-1)
+            if belowSection:
+                validBlocks[:1] &= belowSection.Blocks[-1:] != 0
+            else:
+                validBlocks[:1] = 0
+            aboveSection = chunk.getSection(cy+1)
+
+            if aboveSection:
+                validBlocks[-1:] &= aboveSection.Blocks[:1] == 0
+
+            def getVertexes(mask, color):
+                y, z, x = mask.nonzero()
+                vertexBuffer = QuadVertexArrayBuffer(len(x), textures=False, lights=False)
+                vertexBuffer.vertex[..., 0] = x[:, None]
+                vertexBuffer.vertex[..., 1] = y[:, None]
+                vertexBuffer.vertex[..., 2] = z[:, None]
+
+                vertexBuffer.vertex[:] += (0, (cy << 4), 0)
+
+                vertexBuffer.vertex[:] += standardCubeTemplates[faces.FaceYDecreasing, ..., :3]
+
+                vertexBuffer.rgba[:] = color
+                return vertexBuffer
+
+            nightVertexes = getVertexes(lowNightLight & validBlocks, (0xff, 0x00, 0x00, 0x3f))
+            dayVertexes = getVertexes(lowDayLight & validBlocks, (0xff, 0xFF, 0x00, 0x3f))
+
+            vertexes.append(dayVertexes)
+            vertexes.append(nightVertexes)
+
+        self.sceneNode = VertexNode(vertexes)
+
+        yield
diff --git a/src/mcedit2/rendering/chunkupdate.py b/src/mcedit2/rendering/chunkupdate.py
index f14d350..808c273 100644
--- a/src/mcedit2/rendering/chunkupdate.py
+++ b/src/mcedit2/rendering/chunkupdate.py
@@ -14,6 +14,7 @@ from mcedit2.rendering.chunkmeshes.entitymesh import TileEntityLocationMesh, Mon
     TileEntityModelRenderer
 from mcedit2.rendering.chunkmeshes.heightlevel import HeightLevelBlockMesh
 from mcedit2.rendering.chunkmeshes.lowdetail import LowDetailBlockMesh, OverheadBlockMesh
+from mcedit2.rendering.chunkmeshes.mobspawns import MobSpawnsBlockMesh
 from mcedit2.rendering.chunkmeshes.terrainpop import TerrainPopulatedRenderer
 from mcedit2.rendering.chunkmeshes.tileticks import TileTicksRenderer
 from mcedit2.util import profiler
@@ -138,6 +139,7 @@ class ChunkUpdate(object):
         LowDetailBlockMesh,
         OverheadBlockMesh,
         HeightLevelBlockMesh,
+        MobSpawnsBlockMesh,
     ]
 
     @profiler.iterator("ChunkUpdate")
diff --git a/src/mcedit2/rendering/layers.py b/src/mcedit2/rendering/layers.py
index 00cc81f..70f7b6c 100644
--- a/src/mcedit2/rendering/layers.py
+++ b/src/mcedit2/rendering/layers.py
@@ -19,9 +19,11 @@ class Layer:
     TileTicks = "TileTicks"
     TerrainPopulated = "TerrainPopulated"
     HeightMap = "HeightMap"
+    MobSpawns = "Places Where Creepers Can Spawn"
     ChunkSections = "ChunkSections"
     AllLayers = (Blocks, MonsterLocations, Items,
                  TileEntities, TileEntityLocations,
                  CommandBlockColors, CommandBlockLocations,
-                 ItemFrames, TileTicks, ChunkSections, HeightMap)
+                 ItemFrames, TileTicks, ChunkSections, HeightMap,
+                 MobSpawns)
     DefaultVisibleLayers = (Blocks, Items, TileEntities, CommandBlockColors, ItemFrames)