module Graphics.LambdaCube.Common where

{-| Comparison functions used for the depth/stencil buffer operations and 
	others. -}
data CompareFunction
    = CMPF_ALWAYS_FAIL
    | CMPF_ALWAYS_PASS
    | CMPF_LESS
    | CMPF_LESS_EQUAL
    | CMPF_EQUAL
    | CMPF_NOT_EQUAL
    | CMPF_GREATER_EQUAL
    | CMPF_GREATER
    deriving Eq

{-| High-level filtering options providing shortcuts to settings the
    minification, magnification and mip filters. -}
data TextureFilterOptions
    = TFO_NONE        -- ^ Equal to: min=FO_POINT, mag=FO_POINT, mip=FO_NONE
    | TFO_BILINEAR    -- ^ Equal to: min=FO_LINEAR, mag=FO_LINEAR, mip=FO_POINT
    | TFO_TRILINEAR   -- ^ Equal to: min=FO_LINEAR, mag=FO_LINEAR, mip=FO_LINEAR
    | TFO_ANISOTROPIC -- ^ Equal to: min=FO_ANISOTROPIC, max=FO_ANISOTROPIC, mip=FO_LINEAR
    deriving Eq

data FilterType
    = FT_MIN -- ^ The filter used when shrinking a texture
    | FT_MAG -- ^ The filter used when magnifying a texture
    | FT_MIP -- ^ The filter used when determining the mipmap
    deriving Eq
    
-- | Filtering options for textures / mipmaps.
data FilterOptions
    = FO_NONE        -- ^ No filtering, used for FILT_MIP to turn off mipmapping
    | FO_POINT       -- ^ Use the closest pixel
    | FO_LINEAR      -- ^ Average of a 2x2 pixel area, denotes bilinear for MIN and MAG, trilinear for MIP
    | FO_ANISOTROPIC -- ^ Similar to FO_LINEAR, but compensates for the angle of the texture plane
    deriving Eq
    
-- | Light shading modes.
data ShadeOptions
    = SO_FLAT
    | SO_GOURAUD
    | SO_PHONG
    deriving Eq

-- | Fog modes.
data FogMode
    = FOG_NONE      -- ^ No fog. Duh.
    | FOG_EXP       -- ^ Fog density increases  exponentially from the camera (fog = 1/e^(distance * density))
    | FOG_EXP2      -- ^ Fog density increases at the square of FOG_EXP, i.e. even quicker (fog = 1/e^(distance * density)^2)
    | FOG_LINEAR    -- ^ Fog density increases linearly between the start and end distances
    deriving Eq

{-| Hardware culling modes based on vertex winding.
    This setting applies to how the hardware API culls triangles it is sent. -}
data CullingMode
    = CULL_NONE             -- ^ Hardware never culls triangles and renders everything it receives.
    | CULL_CLOCKWISE        -- ^ Hardware culls triangles whose vertices are listed clockwise in the view (default).
    | CULL_ANTICLOCKWISE    -- ^ Hardware culls triangles whose vertices are listed anticlockwise in the view.
    deriving Eq

{-| Manual culling modes based on vertex normals.
    This setting applies to how the software culls triangles before sending them to the 
	hardware API. This culling mode is used by scene managers which choose to implement it -
	normally those which deal with large amounts of fixed world geometry which is often 
	planar (software culling movable variable geometry is expensive). -}
data ManualCullingMode
    = MANUAL_CULL_NONE  -- ^ No culling so everything is sent to the hardware.
    | MANUAL_CULL_BACK  -- ^ Cull triangles whose normal is pointing away from the camera (default).
    | MANUAL_CULL_FRONT -- ^ Cull triangles whose normal is pointing towards the camera.
    deriving Eq

-- | Enumerates the wave types usable with the Ogre engine.
data WaveformType
    = WFT_SINE             -- ^ Standard sine wave which smoothly changes from low to high and back again.
    | WFT_TRIANGLE         -- ^ An angular wave with a constant increase / decrease speed with pointed peaks.
    | WFT_SQUARE           -- ^ Half of the time is spent at the min, half at the max with instant transition between.
    | WFT_SAWTOOTH         -- ^ Gradual steady increase from min to max over the period with an instant return to min at the end.
    | WFT_INVERSE_SAWTOOTH -- ^ Gradual steady decrease from max to min over the period, with an instant return to max at the end.
    | WFT_PWM              -- ^ Pulse Width Modulation. Works like WFT_SQUARE, except the high to low transition is controlled by duty cycle. 
                           -- ^  With a duty cycle of 50% (0.5) will give the same output as WFT_SQUARE.
    deriving Eq

-- | The polygon mode to use when rasterising.
data PolygonMode
    = PM_POINTS     -- ^ Only points are rendered.
    | PM_WIREFRAME  -- ^ Wireframe models are rendered.
    | PM_SOLID      -- ^ Solid polygons are rendered.
    deriving Eq

-- | An enumeration describing which material properties should track the vertex colours 
data TrackVertexColourType
    = TrackVertexColourType
    { tvcAmbient  :: Bool
    , tvcDiffuse  :: Bool
    , tvcSpecular :: Bool
    , tvcEmissive :: Bool
    }
    deriving Eq

-- | Sort mode for billboard-set and particle-system
data SortMode
    = SM_DIRECTION -- ^ Sort by direction of the camera
    | SM_DISTANCE  -- ^ Sort by distance from the camera
    deriving Eq

-- | Defines the frame buffer types.
data FrameBufferType
    = FrameBufferType
    { fbtColour  :: Bool
    , fbtDepth   :: Bool
    , fbtStencil :: Bool
    }
    deriving Eq