-- conf.lua
function lovr.conf(cfg)
    cfg.headset.overlay = true
end

-- main.lua
local mat4 = lovr.math.mat4
local vec3 = lovr.math.vec3
local quat = lovr.math.quat

local xr_layer

function lovr.load()
    xr_layer = lovr.headset.newLayer(256, 256)
    xr_layer:setDimensions(1.0, 1.0)
    lovr.headset.setLayers({xr_layer})
end

function lovr.draw(pass)
    local pose_mat = mat4(lovr.headset.getPose("head"))

    pass:push()
    pass:transform(pose_mat:translate(0.5, 0.0, -1.0))
    pass:setColor(0.5, 0.0, 0.0, 1.0)
    pass:plane(0.0, 0.0, 0.0, 0.5, 0.5)
    pass:setColor(1.0, 1.0, 1.0, 1.0)
    pass:text("Draw Pass", 0, 0, 0.01, 0.1)
    pass:pop()

    local xr_pass = xr_layer:getPass()
    xr_pass:setProjection(1, mat4():orthographic(0, 256, 0, 256, -10, 10))
    xr_pass:setViewport(0, 0, 256, 256)
    xr_pass:setViewPose(1, vec3(), quat())
    xr_pass:setDepthTest("none")
    xr_pass:setDepthWrite(false)
    xr_pass:setColor(0.0, 0.0, 0.5, 1.0)
    xr_pass:fill()
    xr_pass:setColor(1.0, 1.0, 1.0, 1.0)
    xr_pass:text("XR Quad Layer", 128, 128, 0, 36)
    lovr.graphics.submit(xr_pass)

    xr_layer:setPose(pose_mat:translate(-0.5, 0.0, -1.0):getPose())
end