Spring RTS Engine

Code: Select all

function widget:GetInfo()
  return {
	name	  = "Dynamic Blob Shadows",
	desc	  = "Creates shadow projections from the sun position that wrap around the unit size",
	author	= "user, speedups by Argh",
	date	  = "March 3, 2008",
	license   = "GNU GPL, v2",
	layer	 = -1,
	enabled   = true  
  }
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
local side = 0
local xmul = 0
local zmu = 0
local ShadowList = {}
local sunx,suny,sunz = gl.GetSun()
local shadowdens = gl.GetSun("shadowdensity","unit")
local SR, SG, SB = gl.GetSun("ambient","unit")
local noshadow = 0 
local shadowsareon = 0 
local sundist = 0
local realdist = 0
local greater  = 0
local sunscale = 0   
local sunangle = 0  
local cangle = 0
									  
local ShadowsOn			= Spring.HaveShadows 
local list	
local UnitIDList
local height, diff, fx, fy, x, y, z, cx, cy, cz, id
local ShadowTex = 'LuaUI/Images/shadow.tga'


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- sun calculations,for projection----------------------------------------------
--------------------------------------------------------------------------------
sunangle = Spring.GetHeadingFromVector(sunx,sunz)/182.0444445 --exact number to convert a short integer to a 0 to 360 number.  
sunangle = sunangle + (360+90)								--when it is 65536, divide it by 182,0444445 you get 360.  
if (sunangle > 360) then
   sunangle = sunangle - 360
end
if (suny < 0 )then
   noshadow = 1
else
   sunscale = math.abs(suny + 0.1)* 200
   sunscale = math.abs(sunscale - 200) * 100
end
sundist = math.pow(sunx,2) + math.pow(sunz,2)
sundist = math.sqrt(sundist)
realdist = sundist * 50
sunscale = sunscale / 1876

local glTexture = gl.Texture
local glDepthMask = gl.DepthMask
local glDepthTest = gl.DepthTest
local glColor = gl.Color
local SpringGetUnitDefID = Spring.GetUnitDefID
local SpringGetUnitViewPosition = Spring.GetUnitViewPosition
local SpringGetGroundHeight = Spring.GetGroundHeight
local glPushMatrix = gl.PushMatrix
local glDrawListAtUnit = gl.DrawListAtUnit
local glPopMatrix = gl.PopMatrix
local glCreateList = gl.CreateList
local  glBeginEnd =  gl.BeginEnd
local GLQUAD_STRIP = GL.QUAD_STRIP
local glTexCoord = gl.TexCoord
local glVertex = gl.Vertex
local SpringGetCameraPosition = Spring.GetCameraPosition
local SpringGetVisibleUnits = Spring.GetVisibleUnits
local cx,cy,cz = 0,0,0

if SR > 1.0 then SR = 0.5 end
if SG > 1.0 then SG = 0.5 end
if SB > 1.0 then SB = 0.5 end
if shadowdens == nil or shadowdens > 1.0 then shadowdens = 0.5 end

function widget:DrawWorldPreUnit()
	cx,cy,cz = SpringGetCameraPosition()

	glTexture(ShadowTex)
	glDepthMask(false)
	glDepthTest(false)
	glColor(SR,SG,SB,shadowdens)

	unitIDList = SpringGetVisibleUnits(-1,3000,false)

	if unitIDList[1] == nil then 
		return false 
	else
		if (ShadowsOn()) then
			return false
		else
			if cy < 25 or cy > 4000 then 
				return false 
			else			
				for _,unitID in ipairs(unitIDList) do
					id = SpringGetUnitDefID(unitID) 
					x,y,z = SpringGetUnitViewPosition(unitID)
					height = SpringGetGroundHeight(x,z)
					diff = height-y+5
					if ShadowList[id] then
						fx = UnitDefs[id].xsize
						fy = UnitDefs[id].zsize
						glPushMatrix()
						glDrawListAtUnit(unitID,list,false,fx,1.0,fy,sunangle,0,1.0,0)
						glPopMatrix()
					end																																																		
				end
			end
		end
	end
	glDepthMask(true)
	glDepthTest(true)
	glColor(1,1,1,1)	
end

function widget:Initialize()

	for ud,_ in pairs(UnitDefs) do
		if UnitDefs[ud].customParams.draw_shadow == 'yes' then
			table.insert(ShadowList,ud,1)
		end
	end

list = glCreateList(function() 
	 glBeginEnd(GLQUAD_STRIP,function()  
	   --point1
	   glTexCoord(0,0)
	   glVertex(-4,0,-4)
	   --point2								 
	   glTexCoord(0,1)						   
	   glVertex(4*sunscale,0,-4)				   
	   --point3
	   glTexCoord(1,0)
	   glVertex(-4,0,4)
	   --point4
	   glTexCoord(1,1)
	   glVertex(4*sunscale,0,4)
	 end)
   end)
end   
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------