effect = nil

ctxFBO = nil
ctx = nil

clockTexture = nil

clockText = ""
timer = 0.0

function _create()
    local display0 = Displays[1]
    ctxFBO = FrameBuffer.new(math.floor(display0.z), math.floor(display0.w))

    local att = ColorAttachment.new()
    att.format = TextureFormatType.RGBA8
    att.minFilter = TextureFilter.LinearMipmapLinear
    att.magFilter = TextureFilter.Linear
    att.wrapS = TextureWrap.ClampToEdge
    att.wrapT = TextureWrap.ClampToEdge

    ctxFBO:SetDepthStencilFormat(DepthStencilFormat.Depth24Stencil8) 
    ctxFBO:AddColorAttachment(att)

    clockTexture = ctxFBO:GetColorTexture(0)

    ctx = GraphicsContext.new()
    ctx:CreateFont("font", Resolve("font.otf"))

    local fxSrc = [[uniform sampler2D uTexture;

        const float floorPosition = 0.55;

        float waves(in vec2 uv) {
            float speed = 4.0;

            float topright =	sin(uTime*(speed+1.0)	- sin(length(uv-vec2(1.0,1.0)))*53.0);
            float topleft =		sin(uTime*(speed+1.0)	- sin(length(uv-vec2(0.0,1.0)))*37.0);
            float bottomright =	sin(uTime*(speed)    	- sin(length(uv-vec2(1.0,0.0)))*61.0);
            float bottomleft =	sin(uTime*(speed+2.0)	- sin(length(uv-vec2(0.0,0.0)))*47.0);

            float horizontalWaves = sin(uTime * (speed + 2.0) - sin(uv.y) * 47.0);
            
            float temp = horizontalWaves + bottomleft * 0.4 + bottomright * 0.2 + topleft * 0.6 + topright * 0.3;
            
            float b=smoothstep(-2.5,5.0,temp);
            return b*3.0;
        }

        void main() {
            vec2 uv = vUV;

            for (int i = 0; i < uNumDisplays; i++) {
                vec4 displayNorm = uDisplayNorm[i];

                if (vUV.x >= displayNorm.x && vUV.x <= displayNorm.x + displayNorm.z &&
                    vUV.y >= displayNorm.y && vUV.y <= displayNorm.y + displayNorm.w) {

                    vec2 duv = GetDisplayUV(uTexture, i);

                    // Base
                    FragColor = texture(uTexture, duv);

                    // Reflection
                    if (duv.y > floorPosition) {
                        float reflectY = floorPosition - (duv.y - floorPosition);
                        vec2 reflectUV = vec2(duv.x, reflectY);

                        // deform the reflection based on the height function
                        float wv = waves(vec2(reflectUV.x * 2.0, reflectUV.y * 3.6 - 0.4));
                        float dx = dFdx(wv);
                        float dy = dFdy(wv);
                        reflectUV += vec2(dx, dy) * 0.25; // Adjust deformation

                        float lod = clamp(reflectUV.y * 3.0, 0.0, 3.0); // Adjust LOD based on distance
                        vec4 reflectColor = textureLod(uTexture, reflectUV, lod);

                        // Apply a simple fade based on distance from the floor
                        float fade = 1.0 - smoothstep(floorPosition, floorPosition + 0.1, duv.y);
                        FragColor += reflectColor * fade * 0.5; // Adjust reflection intensity
                    }

                    break;
                }
            }
        }
    ]]
    effect = Effect.new(fxSrc)
    clockText = os.date("%H:%M")
end

function _update(dt)
    timer = timer + dt

    if timer >= 0.5 then
        timer = 0.0
        clockText = os.date("%H:%M")
    end
end

function _render()
    local display0 = Displays[1]

    ctxFBO:Bind()
    gl.Clear(0, 0, 0, 0)
    ctx:BeginFrame(display0.z, display0.w, display0.z / display0.w)

    ctx:FontSize(144)
    ctx:FontFace("font")
    ctx:FillColor(RGBAf(1, 1, 1, 0.75))
    ctx:TextAlign(Align.CENTER | Align.MIDDLE)
    ctx:Text(display0.z / 2, display0.w / 2, clockText)

    ctx:EndFrame()
    ctxFBO:Unbind()

    clockTexture:Bind()
    clockTexture:GenerateMipmaps()

    gl.SetViewport(0, 0, math.floor(DesktopSize.x), math.floor(DesktopSize.y))

    gl.Clear(0, 0, 0, 1.0)
    effect:Use()
    effect:SetTexture("uTexture", clockTexture, 0)
    effect:Render()
end