SuperStrict

Import sidesign.minib3d

SetGraphicsDriver GLGraphicsDriver(), GRAPHICS_BACKBUFFER | GRAPHICS_DEPTHBUFFER | GRAPHICS_STENCILBUFFER

Graphics3D 800,600,0,2
Global camera:TCamera=CreateCamera()
CameraZoom Camera, 1.0 / Tan(45.0/2.0)

THardwareInfo.displayinfo()

AmbientLight 128,128,128

Local light:TLight=CreateLight()
LightColor light, 128,128,128

Local cone:TMesh=CreateCone(32)
MoveEntity cone, 0, 1.05, 0
EntityColor cone, 0,200,200

Local cube:TMesh=CreateCube()
MoveEntity cube, 4, 1.1, 0
EntityColor cube, 200,0,0

Local sphere:TMesh=CreateSphere(32)
MoveEntity sphere, -3.5, 1.1, 0
EntityColor sphere, 200,200,64

Local mirror:TMesh = TMirror.createMirror(False,True)
ScaleEntity mirror, 6,0.01,6
EntityColor mirror, 0,0,255
EntityAlpha mirror, 0.5

MoveEntity cube, 0, 0.02, 0
MoveEntity light, 0, 100, 0

Global p:TPivot=CreatePivot()
Global angle:Float = 0

While Not KeyHit(KEY_ESCAPE)
    UpdateWorld

    TMirror.renderMirror(camera)

    ' render everything normal now
    RenderWorld

    Flip
    Delay 1

    TurnEntity cube, 0, 0.75, 0
    TurnEntity cone, 0, 0.75, 0
    TurnEntity sphere, 0, 0.75, 0

    'PositionEntity cone, 0, Cos(angle)*2, 0
    PositionEntity camera, Cos(angle)*20, 4*Cos(angle*2), Sin(angle)*20
    PointEntity camera, p
    angle:+0.5

Wend


Type TMirror
    Global hidden_geometry_list:TList=CreateList()
    Global mirror:TMesh
    Global showMesh%

    Function createMirror:TMesh(infinite%=False, show_Mesh%=False)
           mirror=CreateCube()
        showMesh = show_Mesh
        Return mirror
    End Function

    Function hideMeshes()
        ClearList hidden_geometry_list
        For Local fmesh:TMesh=EachIn TEntity.entity_list
            If fmesh<>mirror And fmesh.parent=Null And fmesh.brush.alpha>0 And fmesh.hidden()=False Then
               HideEntity fmesh
               ListAddLast hidden_geometry_list, fmesh
            End If
        Next
        ShowEntity mirror
    End Function

    Function showMeshes()
        For Local fmesh:TMesh=EachIn hidden_geometry_list
            ShowEntity fmesh
        Next
        HideEntity mirror
    End Function

    Function flipMeshes(sign%=1)
        ' flip every light
        For Local llight:TLight=EachIn TLight.light_list
             PositionEntity llight,llight.px, -llight.py, llight.pz, True
             ScaleEntity llight, llight.sx, -llight.sy, llight.sz, True
        Next

        ' flip every mesh
        For Local fmesh:TMesh=EachIn TEntity.entity_list
          If fmesh.parent=Null Then
             PositionEntity fmesh, fmesh.px, -fmesh.py+(sign*mirror.py), fmesh.pz
             ScaleEntity fmesh, -fmesh.sx, -fmesh.sy, fmesh.sz
          End If
        Next
    End Function

    Function renderMirror(cam:TCamera)
        CameraClsMode cam,True,True

        If EntityY(camera)<mirror.py Then Return

        ' prepare to use the stencil buffer
        glClear(GL_ACCUM_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT)
        glDisable(GL_DEPTH_TEST)
        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE)

        ' Draw into the stencil buffer.
        glEnable(GL_STENCIL_TEST)
        glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE)
        glStencilFunc(GL_ALWAYS, 1, $ffffffff)

        ' draw only the mirror (the actual 'mask' where objects will be drawn)
        hideMeshes()

        RenderWorld

        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
        glEnable(GL_DEPTH_TEST);

        ' Now, only render where stencil is set To 1
        glStencilFunc(GL_EQUAL, 1, $ffffffff)   ' draw If stencil ==1
        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP)

        ' draw everything but the plane
        showMeshes()

        ' invert mesh and light position, to appear reflected
        flipMeshes(1)

        RenderWorld

        ' okay! everything done!
        glDisable(GL_STENCIL_TEST);

        ' shows plane, and re-render everything normally
        CameraClsMode cam,False, False
        If showMesh Then ShowEntity mirror Else HideEntity mirror
        flipMeshes(-1)
    End Function
End Type