attempt at adding transparent meshes

src/blocks.lua

@@ -18,14 +18,17 @@ blockTypes = {
       {  1,  0.75, -1 },
       { -1, -1, -1 },
       {  1, -1, -1 },
-    }
+    },
+    alpha = 0.5
   }),
   -- 5: sand
   cube({ { 3, 7 }, { 3, 7 }, { 3, 7 }, { 3, 7 }, { 3, 7 }, { 3, 7 } }),
   -- 6: wood
   cube({ { 14, 13 }, { 15, 13 }, { 14, 13 }, { 15, 13 }, { 14, 13 }, { 14, 13 } }),
   -- 7: leaves
-  cube({ { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 } }, { }),
+  cube({ { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 }, { 1, 17 } }, { 
+    alpha = 0.9
+  }),
 }
 
 return blockTypes

src/camera.lua

@@ -126,6 +126,8 @@ function Camera:drawWorld()
       end
     end
   end
+
+  self.world:draw()
 end
 
 function Camera:drawShadowMap()

src/chunk.lua

@@ -24,14 +24,14 @@ function Chunk:new(x, y, z, world)
   self.dirty = true
 
   self.mesh = nil
+  self.transparentMesh = nil
 
   self.model = Matrix()
   self.model[4] = self.position.x
   self.model[8] = self.position.y
   self.model[12] = self.position.z
 
   self.channel = self:__tostring()
-
 end
 
 function Chunk:__tostring()
@@ -58,6 +58,9 @@ function Chunk:load(thread)
   -- each vertex is currently 36 bytes
   self.verticesData = love.data.newByteData(maxVertices * 36)
 
+  -- FIXME: going on an assumption that the transparent vertices will be less than the opaque ones
+  self.transparentVerticesData = love.data.newByteData(maxVertices * 36 * 0.5)
+
   -- add 1 to the size to include the border
   local blocks = {}
   for i = 0, CHUNK_SIZE + 1 do
@@ -71,7 +74,7 @@ function Chunk:load(thread)
     end
   end
 
-  thread:start(self.position:table(), blocks, self.channel, blockTypes, self.verticesData)
+  thread:start(self.position:table(), blocks, self.channel, blockTypes, self.verticesData, self.transparentVerticesData)
 end
 
 function Chunk:getBlock(x, y, z)
@@ -114,18 +117,38 @@ function Chunk:setBlock(x, y, z, block)
 end
 
 function Chunk:update()
-  local message = love.thread.getChannel(self.channel):pop()
+  for _, suffix in ipairs { "opaque", "transparent" } do
+    local message = love.thread.getChannel(self.channel .. suffix):pop()
+
+    if message then
+      local mesh, data
+
+      if suffix == "opaque" then
+        mesh = self.mesh
+        data = self.verticesData
+      else
+        mesh = self.transparentMesh
+        data = self.transparentVerticesData
+      end
 
-  if message then
-    local numVertices = message
+      local numVertices = message
 
-    if self.mesh then self.mesh:release() end
+      if numVertices == 0 then return end
 
-    self.mesh = love.graphics.newMesh(format, numVertices, "triangles", "static")
-    self.mesh:setTexture(tileset)
-    self.mesh:setVertices(self.verticesData, 1, numVertices)
+      if mesh then mesh:release() end
 
-    self.verticesData:release()
+      mesh = love.graphics.newMesh(format, numVertices, "triangles", "static")
+      mesh:setTexture(tileset)
+      mesh:setVertices(data, 1, numVertices)
+
+      if suffix == "opaque" then
+        self.mesh = mesh
+      else
+        self.transparentMesh = mesh
+      end
+
+      data:release()
+    end
   end
 end
 
@@ -134,6 +157,13 @@ function Chunk:draw()
     love.graphics.getShader():send("modelMatrix", self.model)
     love.graphics.draw(self.mesh)
   end
+
+  if self.transparentMesh then
+    self.world.transparentMeshes[#self.world.transparentMeshes + 1] = {
+      mesh = self.transparentMesh,
+      model = self.model
+    }
+  end
 end
 
 return Chunk

src/cube.lua

@@ -71,11 +71,13 @@ return function(textures, config)
         vertices[vertex][3] * 0.5,
         u + uvs[uv][1] * step,
         v + uvs[uv][2] * step,
-        normals[normal],
-        alpha
+        normals[normal]
       }
     end
   end
 
+  cube.alpha = alpha
+  cube.opaque = alpha == 1
+
   return cube
 end

src/mesh.lua

@@ -1,11 +1,16 @@
-local CHUNK_SIZE = 8
-local CHUNK_HEIGHT = 32
+-- to be run on another thread
+local CHUNK_SIZE = 16
+local CHUNK_HEIGHT = 48
+
+local position, blocks, channel, blockTypes, oData, tData = ...
+
+local ffi = require "ffi"
 
 local shading = {
   0.3, 0.4, 0.6, 1,
 }
 
-function sign(value)
+local function sign(value)
   if value > 0 then
     return 1
   elseif value < 0 then
@@ -15,53 +20,104 @@ function sign(value)
   end
 end
 
-function setVertex(index, i, mesh, x, y, z, value, getBlock, outVertex)
+local function getBlock(i, j, k)
+  return blocks[i][j][k]
+end
+
+function setVertex(index, i, mesh, x, y, z, outVertex)
   local block = getBlock(x, y, z)
 
-  if (value == 0 or (value == 4 and block ~= 4)) and mesh then
-    local vertex = mesh[index*6+i]
-    local vx, vy, vz, u, v, normal, alpha = unpack(vertex)
-
-    local dx, dy, dz = sign(vx), sign(vy), sign(vz)
-    local nx, ny, nz = normal[1], normal[2], normal[3]
-    local side1, side2, corner, m
-
-    if nx ~= 0 then
-      side1 = getBlock(x + nx, y + dy, z) == 0 and 0 or 1
-      side2 = getBlock(x + nx, y, z + dz) == 0 and 0 or 1
-      corner = getBlock(x + nx, y + dy, z + dz) == 0 and 0 or 1
-      m = nx == 1 and 0.8 or 0.6
-    elseif ny ~= 0 then
-      side1 = getBlock(x + dx, y + ny, z) == 0 and 0 or 1
-      side2 = getBlock(x, y + ny, z + dz) == 0 and 0 or 1
-      corner = getBlock(x + dx, y + ny, z + dz) == 0 and 0 or 1
-      m = ny == 1 and 1 or 0.4
-    elseif nz ~= 0 then
-      side1 = getBlock(x + dx, y, z + nz) == 0 and 0 or 1
-      side2 = getBlock(x, y + dy, z + nz) == 0 and 0 or 1
-      corner = getBlock(x + dx, y + dy, z + nz) == 0 and 0 or 1
-      m = nz == 1 and 0.6 or 0.8
-    end
+  local vertex = mesh[index*6+i]
+  local vx, vy, vz, u, v, normal = unpack(vertex)
 
-    local state
+  local dx, dy, dz = sign(vx), sign(vy), sign(vz)
+  local nx, ny, nz = normal[1], normal[2], normal[3]
+  local side1, side2, corner, m
 
-    if side1 == 1 and side2 == 1 then
-      state = 1
-    else
-      state = 4 - side1 - side2 - corner
-    end
+  if nx ~= 0 then
+    side1 = getBlock(x + nx, y + dy, z) == 0 and 0 or 1
+    side2 = getBlock(x + nx, y, z + dz) == 0 and 0 or 1
+    corner = getBlock(x + nx, y + dy, z + dz) == 0 and 0 or 1
+    m = nx == 1 and 0.8 or 0.6
+  elseif ny ~= 0 then
+    side1 = getBlock(x + dx, y + ny, z) == 0 and 0 or 1
+    side2 = getBlock(x, y + ny, z + dz) == 0 and 0 or 1
+    corner = getBlock(x + dx, y + ny, z + dz) == 0 and 0 or 1
+    m = ny == 1 and 1 or 0.4
+  elseif nz ~= 0 then
+    side1 = getBlock(x + dx, y, z + nz) == 0 and 0 or 1
+    side2 = getBlock(x, y + dy, z + nz) == 0 and 0 or 1
+    corner = getBlock(x + dx, y + dy, z + nz) == 0 and 0 or 1
+    m = nz == 1 and 0.6 or 0.8
+  end
+
+  local state
+
+  if side1 == 1 and side2 == 1 then
+    state = 1
+  else
+    state = 4 - side1 - side2 - corner
+  end
+
+  s = shading[state] * 255
 
-    s = shading[state] * 255
+  outVertex.x, outVertex.y, outVertex.z = vx + x, vy + y, vz + z
+  outVertex.u, outVertex.v = u, v
+  outVertex.nx, outVertex.ny, outVertex.nz = nx, ny, nz
+  outVertex.r, outVertex.g, outVertex.b, outVertex.a = s, s, s, mesh.alpha * 255
 
-    outVertex.x, outVertex.y, outVertex.z = vx + x, vy + y, vz + z
-    outVertex.u, outVertex.v = u, v
-    outVertex.nx, outVertex.ny, outVertex.nz = nx, ny, nz
-    outVertex.r, outVertex.g, outVertex.b, outVertex.a = s, s, s, alpha * 255
+  return true
+end
+
+ffi.cdef [[
+typedef struct {
+  float x, y, z;
+  float u, v;
+  float nx, ny, nz;
+  unsigned char r, g, b, a;
+} ck_vertex;
+]]
+
+
+function getMesh(opaque, data)
+  local pointer = ffi.cast('ck_vertex*', data:getFFIPointer())
+
+  local vi = 0
+
+  function setFace(index, mesh, x, y, z, value)
+    for i = 1, 6 do
+      local vertex = pointer[vi]
+      local prev = blockTypes[value]
 
-    return true
+      if (value == 0 or prev.opaque ~= opaque) and mesh.opaque == opaque then
+        setVertex(index, i, mesh, x, y, z, vertex)
+        vi = vi + 1
+      end
+    end
+  end
+
+  for k = 1, CHUNK_SIZE do
+    for j = 1, CHUNK_HEIGHT do
+      for i = 1, CHUNK_SIZE do
+        local block = blocks[i][j][k]
+        local mesh = blockTypes[block]
+
+        if mesh then
+          setFace(0, mesh, i, j, k, getBlock(i, j, k + 1))
+          setFace(1, mesh, i, j, k, getBlock(i, j + 1, k))
+          setFace(2, mesh, i, j, k, getBlock(i, j, k - 1))
+          setFace(3, mesh, i, j, k, getBlock(i, j - 1, k))
+          setFace(4, mesh, i, j, k, getBlock(i + 1, j, k))
+          setFace(5, mesh, i, j, k, getBlock(i - 1, j, k))
+        end
+      end
+    end
   end
 
-  return false
+  local channelSuffix = opaque and "opaque" or "transparent"
+
+  love.thread.getChannel(channel .. channelSuffix):supply(vi)
 end
 
-return setVertex
+getMesh(true, oData)
+getMesh(false, tData)

src/world.lua

@@ -14,11 +14,13 @@ function World:new()
   self.threads = {}
 
   for i = 1, 4 do
-    self.threads[i] = love.thread.newThread("src/load_mesh.lua")
+    self.threads[i] = love.thread.newThread("src/mesh.lua")
   end
 
   self:loadChunk(0, 0)
 
+  self.transparentMeshes = {}
+
   return self
 end
 
@@ -140,11 +142,12 @@ function World:update(dt)
 end
 
 function World:draw()
-  for i, v in pairs(self.chunks) do
-    for j, chunk in pairs(v) do
-      chunk:draw()
-    end
+  for i, data in pairs(self.transparentMeshes) do
+    love.graphics.getShader():send("modelMatrix", data.model)
+    love.graphics.draw(data.mesh)
   end
+
+  self.transparentMeshes = {}
 end
 
 return World