-- Init function called from K3dEngine during initialization
-- Warning -- Don't delete this function -- Function must exist
function Init()
	print("Loading map ./maps/test/intr_ray_sphere_map.lua")
	K3d_LoadMap("./maps/test/intr_ray_sphere_map.lua")
	InitScene()
end

-- Update function called from K3dEngine during update scene
-- Warning -- Don't delete this function -- Function must exist
function Update()
	IntrRaySphere()
	if K3d_CheckKeyboardKey("Esc") then
		-- Load new script and delete this script
		-- This function must be called as last function in this script
		-- else engine shut down in next funcion
		-- because next function doesn`t exist in new script
		K3d_LoadNewScript("./scripts/main_menu_script.lua")
	end
end

-- Delete function called from K3dEngine during delete scene
-- Warning -- Don't delete this function -- Function must exist
function Delete()
	print("Delete called")
end

-- Global variables
-- Ray, sphere and camera object indexes
g_iRay = -1
g_iSphere = -1
g_iCamera = -1
-- Draw aiming point
g_iAimingPoint = -1

-- Init scene
function InitScene()
	g_iRay = K3d_GetObject("AimingRay", ObjType.iRayObj)
	print("g_iRay =", g_iRay)
	if g_iRay == -1 then
		print("Ray doesn`t exists.")
		return false
	end
	g_iSphere = K3d_GetObject("BoundSphere", ObjType.iSphereObj)
	print("g_iSphere =", g_iSphere)
	if g_iSphere == -1 then
		print("BoundSphere doesn`t exists.")
		return false
	end
	g_iCamera = K3d_GetObject("MainCamera", ObjType.iCameraObj)
	print("g_iCamera =", g_iCamera)
	if g_iCamera == -1 then
		print("MainCamera doesn`t exists.")
		return false
	end
	CreateAimingPoint()
	return true
end

-- Create aiming point
function CreateAimingPoint()
	local r=255
	local g=0
	local b=0
	local size=5
	g_iAimingPoint = K3d_AddVertex(0.0,0.0,0.0,r,g,b,size)
end

-- Check ray sphere intersection
function IntrRaySphere()
	K3d_Print("K3dEngine 0.1")
	K3d_Print("Ray sphere intersection test")
	-- Get aiming ray
	local aimOrigX, aimOrigY, aimOrigZ, aimDirX, aimDirY, aimDirZ
	aimOrigX, aimOrigY, aimOrigZ, aimDirX, aimDirY, aimDirZ = K3d_GetAimRay()
	-- Set vertex position for visualize aiming point
	K3d_SetVertexPos(g_iAimingPoint, aimDirX, aimDirY, aimDirZ)
	-- Set ray for ray sphere intersection
	K3d_SetRay(g_iRay, aimOrigX, aimOrigY, aimOrigZ, aimDirX, aimDirY, aimDirZ)
	-- Return true if intersect ray the sphere
	local bIsIntr =  K3d_GetIntersection(g_iRay, g_iSphere,ObjType.iRayObj, ObjType.iSphereObj, 0)
	if bIsIntr  then
		K3d_Print("Ray intersect the sphere")
		K3d_SetColor(g_iSphere, ObjType.iSphereObj, 255,0,0)
	else
		K3d_SetColor(g_iSphere, ObjType.iSphereObj, 0,255,0)
	end
end