Add fixed in space and moveing example

tracking/main.lua

@@ -1,22 +1,36 @@
-local width = 20
-local height = 20
-local distance = 10
+local width = 7
+local height = 7
+local distance = 5
+local headMatrix
+
+function getHeadsetMatrix()
+    local fx, fy, fz, fangle, fax, fay, faz = lovr.headset.getPose("head")
+    return lovr.math.newMat4(lovr.math.vec3(fx, fy, fz), lovr.math.vec3(1, 1, 1), lovr.math.quat(fangle, fax, fay, faz))
+end
+
+function drawGrid(pass, headMatrix)
 
-function drawGrid(pass)
-	pass:setColor(0, 1, 0)
 	for i=-0.5,0.5,0.05 do
-		pass:line(width*-0.5, height*i, -distance, width*0.5, height*i, -distance)
+		local startVect = headMatrix*lovr.math.newVec3(width*-1, height*i, -distance)
+		local endVect = headMatrix*lovr.math.newVec3(width*1, height*i, -distance)
+		pass:line(startVect, endVect)
 	end
 
 	for i=-0.5,0.5,0.05 do
-		pass:line(width*i, height*-0.5, -distance, width*i, height*0.5, -distance)
+		local startVect = headMatrix*lovr.math.newVec3(width*i, height*-1, -distance)
+		local endVect = headMatrix*lovr.math.newVec3(width*i, height*1, -distance)
+		pass:line(startVect, endVect)
 	end
 end
 
 function lovr.draw(pass)
+	local headMatrix = getHeadsetMatrix()
 
-	drawGrid(pass)
-	pass:circle(0, 0, -distance, 0.05, 0, 0, 0, 1, 'fill')
+	pass:setColor(0, 1, 0)
+	drawGrid(pass, headMatrix)
+
+	local center = headMatrix * lovr.math.newVec3(0.0, 0.0, -distance)
+	pass:circle(center, 0.05, 0, 0, 0, 1, 'fill')
 
 end