NanoVG.Internal

Documentation

newtype FileName

Newtype to avoid accidental use of strings

Constructors

FileName

Fields

unwrapFileName :: Text

newtype Image

Newtype to avoid accidental use of ints

Constructors

Image

Fields

imageHandle :: CInt

Instances

Eq Image

Ord Image

Read Image

Show Image

newtype Font

Newtype to avoid accidental use of ints

Affine matrix

[sx kx tx]
[ky sy ty]
[ 0  0  1]

Constructors

Font

Fields

fontHandle :: CInt

Instances

Eq Font

Ord Font

Read Font

Show Font

newtype Context

Opaque context that needs to be passed around

Constructors

Context (Ptr Context)

newtype Transformation

Constructors

Transformation (M23 CFloat)

Instances

Eq Transformation

Ord Transformation

Read Transformation

Show Transformation

Storable Transformation

newtype Extent

Constructors

Extent (V2 CFloat)

Instances

Eq Extent

Ord Extent

Read Extent

Show Extent

Storable Extent

data Color

rgba

Constructors

Color !CFloat !CFloat !CFloat !CFloat

Instances

Eq Color

Ord Color

Read Color

Show Color

Storable Color

data Paint

Constructors

Paint

Fields

xform :: Transformation

extent :: Extent

radius :: !CFloat

feather :: !CFloat

innerColor :: !Color

outerColor :: !Color

image :: !Image

Instances

Eq Paint

Ord Paint

Read Paint

Show Paint

Storable Paint

newtype Bounds

Constructors

Bounds (V4 CFloat)

Instances

Eq Bounds

Ord Bounds

Read Bounds

Show Bounds

Storable Bounds

data GlyphPosition

Constructors

GlyphPosition

Fields

str :: !(Ptr CChar)

Pointer of the glyph in the input string.

glyphX :: !CFloat

The x-coordinate of the logical glyph position.

glyphPosMinX :: !CFloat

The left bound of the glyph shape.

glyphPosMaxX :: !CFloat

The right bound of the glyph shape.

Instances

Eq GlyphPosition

Ord GlyphPosition

Show GlyphPosition

Storable GlyphPosition

type GlyphPositionPtr = Ptr GlyphPosition

data TextRow

Constructors

TextRow

Fields

start :: !(Ptr CChar)

Pointer to the input text where the row starts.

end :: !(Ptr CChar)

Pointer to the input text where the row ends (one past the last character).

next :: !(Ptr CChar)

Pointer to the beginning of the next row.

width :: !CFloat

Logical width of the row.

textRowMinX :: !CFloat

Actual bounds of the row. Logical with and bounds can differ because of kerning and some parts over extending.

textRowMaxX :: !CFloat

Instances

Eq TextRow

Ord TextRow

Show TextRow

Storable TextRow

type TextRowPtr = Ptr TextRow

data CreateFlags

Constructors

Antialias

StencilStrokes

Debug

Instances

Enum CreateFlags

Eq CreateFlags

Ord CreateFlags

Read CreateFlags

Show CreateFlags

data Solidity

Constructors

Solid

Hole

Instances

Enum Solidity

Eq Solidity

Ord Solidity

Read Solidity

Show Solidity

data LineCap

Constructors

Butt

Round

Square

Bevel

Miter

Instances

Enum LineCap

Eq LineCap

Ord LineCap

Read LineCap

Show LineCap

data Align

Constructors

AlignLeft

AlignCenter

AlignRight

AlignTop

AlignMiddle

AlignBottom

AlignBaseline

Instances

Enum Align

Eq Align

Ord Align

Read Align

Show Align

data Winding

Constructors

CCW

CW

Instances

Enum Winding

Eq Winding

Ord Winding

Read Winding

Show Winding

beginFrame :: Context -> CInt -> CInt -> Float -> IO ()

cancelFrame :: Context -> IO ()

Cancels drawing the current frame.

endFrame :: Context -> IO ()

Ends drawing flushing remaining render state.

Color utils

rgb :: CUChar -> CUChar -> CUChar -> Color

Returns a color value from red, green, blue values. Alpha will be set to 255 (1.0f).

rgbf :: CFloat -> CFloat -> CFloat -> Color

Returns a color value from red, green, blue values. Alpha will be set to 1.0f.

rgba :: CUChar -> CUChar -> CUChar -> CUChar -> Color

Returns a color value from red, green, blue and alpha values.

rgbaf :: CFloat -> CFloat -> CFloat -> CFloat -> Color

Returns a color value from red, green, blue and alpha values.

lerpRGBA :: Color -> Color -> CFloat -> Color

Linearly interpolates from color c0 to c1, and returns resulting color value.

transRGBA :: Color -> CUChar -> Color

Sets transparency of a color value.

transRGBAf :: Color -> CFloat -> Color

Sets transparency of a color value.

hsl :: CFloat -> CFloat -> CFloat -> Color

Returns color value specified by hue, saturation and lightness. HSL values are all in range [0..1], alpha will be set to 255.

hsla :: CFloat -> CFloat -> CFloat -> CUChar -> Color

Returns color value specified by hue, saturation and lightness and alpha. HSL values are all in range [0..1], alpha in range [0..255]

State handling

save :: Context -> IO ()

Pushes and saves the current render state into a state stack. A matching restore must be used to restore the state.

restore :: Context -> IO ()

Pops and restores current render state.

reset :: Context -> IO ()

Resets current render state to default values. Does not affect the render state stack.

Render styles

strokeColor :: Context -> Color -> IO ()

Sets current stroke style to a solid color.

strokePaint :: Context -> Paint -> IO ()

Sets current stroke style to a paint, which can be a one of the gradients or a pattern.

fillColor :: Context -> Color -> IO ()

Sets current fill style to a solid color.

fillPaint :: Context -> Paint -> IO ()

Sets current fill style to a paint, which can be a one of the gradients or a pattern.

miterLimit :: Context -> CFloat -> IO ()

Sets the miter limit of the stroke style. Miter limit controls when a sharp corner is beveled.

strokeWidth :: Context -> CFloat -> IO ()

Sets the stroke width of the stroke style.

lineCap :: Context -> LineCap -> IO ()

Sets how the end of the line (cap) is drawn, Can be one of: Butt (default), Round, Square.

lineJoin :: Context -> LineCap -> IO ()

Sets how sharp path corners are drawn. Can be one of Miter (default), Round, 'Bevel.

globalAlpha :: Context -> CFloat -> IO ()

Sets the transparency applied to all rendered shapes. Already transparent paths will get proportionally more transparent as well.

Transforms

resetTransform :: Context -> IO ()

Resets current transform to a identity matrix.

transform :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Premultiplies current coordinate system by specified matrix. The parameters are interpreted as matrix as follows:

[a c e]
[b d f]
[0 0 1]

translate :: Context -> CFloat -> CFloat -> IO ()

Translates current coordinate system.

rotate :: Context -> CFloat -> IO ()

Rotates current coordinate system. Angle is specified in radians.

skewX :: Context -> CFloat -> IO ()

Skews the current coordinate system along X axis. Angle is specified in radians.

skewY :: Context -> CFloat -> IO ()

Skews the current coordinate system along Y axis. Angle is specified in radians.

scale :: Context -> CFloat -> CFloat -> IO ()

Scales the current coordinate system.

currentTransform :: Context -> IO Transformation

Returns the current transformation matrix.

transformIdentity :: IO Transformation

Sets the transform to identity matrix.

transformTranslate :: CFloat -> CFloat -> IO Transformation

Sets the transform to translation matrix matrix.

transformScale :: CFloat -> CFloat -> IO Transformation

Sets the transform to scale matrix.

transformRotate :: CFloat -> IO Transformation

Sets the transform to rotate matrix. Angle is specified in radians.

transformSkewX :: CFloat -> IO Transformation

Sets the transform to skew-x matrix. Angle is specified in radians.

transformSkewY :: CFloat -> IO Transformation

Sets the transform to skew-y matrix. Angle is specified in radians.

transformMultiply :: Transformation -> Transformation -> IO Transformation

Sets the transform to the result of multiplication of two transforms, of A = A*B.

transformPremultiply :: Transformation -> Transformation -> IO Transformation

Sets the transform to the result of multiplication of two transforms, of A = B*A.

transformInverse :: Transformation -> IO Transformation

Sets the destination to inverse of specified transform. Returns 1 if the inverse could be calculated, else 0.

transformPoint :: Transformation -> CFloat -> CFloat -> (CFloat, CFloat)

Transform a point by given transform.

degToRad :: CFloat -> CFloat

Converts degrees to radians.

radToDeg :: CFloat -> CFloat

Converts radians to degrees.

Images

createImage :: Context -> FileName -> CInt -> IO (Maybe Image)

Creates image by loading it from the disk from specified file name.

createImageMem :: Context -> ImageFlags -> ByteString -> IO (Maybe Image)

Creates image by loading it from the specified chunk of memory.

createImageRGBA :: Context -> CInt -> CInt -> ImageFlags -> ByteString -> IO (Maybe Image)

Creates image from specified image data.

updateImage :: Context -> Image -> ByteString -> IO ()

Updates image data specified by image handle.

imageSize :: Context -> Image -> IO (CInt, CInt)

Returns the dimensions of a created image.

deleteImage :: Context -> Image -> IO ()

Deletes created image.

Paints

linearGradient :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> Color -> Color -> IO Paint

Creates and returns a linear gradient. Parameters (sx,sy)-(ex,ey) specify the start and end coordinates of the linear gradient, icol specifies the start color and ocol the end color. The gradient is transformed by the current transform when it is passed to fillPaint or strokePaint.

boxGradient :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> Color -> Color -> IO Paint

Creates and returns a box gradient. Box gradient is a feathered rounded rectangle, it is useful for rendering drop shadows or highlights for boxes. Parameters (x,y) define the top-left corner of the rectangle, (w,h) define the size of the rectangle, r defines the corner radius, and f feather. Feather defines how blurry the border of the rectangle is. Parameter icol specifies the inner color and ocol the outer color of the gradient. The gradient is transformed by the current transform when it is passed to fillPaint or strokePaint.

radialGradient :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> Color -> Color -> IO Paint

Creates and returns a radial gradient. Parameters (cx,cy) specify the center, inr and outr specify the inner and outer radius of the gradient, icol specifies the start color and ocol the end color. The gradient is transformed by the current transform when it is passed to fillPaint or strokePaint.

imagePattern :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> Image -> CFloat -> IO Paint

Creates and returns an image patter. Parameters (ox,oy) specify the left-top location of the image pattern, (ex,ey) the size of one image, angle rotation around the top-left corner, image is handle to the image to render. The gradient is transformed by the current transform when it is passed to fillPaint or strokePaint.

Scissoring

scissor :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Sets the current scissor rectangle. The scissor rectangle is transformed by the current transform.

intersectScissor :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Intersects current scissor rectangle with the specified rectangle. The scissor rectangle is transformed by the current transform. Note: in case the rotation of previous scissor rect differs from the current one, the intersection will be done between the specified rectangle and the previous scissor rectangle transformed in the current transform space. The resulting shape is always rectangle.

resetScissor :: Context -> IO ()

Reset and disables scissoring.

Paths

beginPath :: Context -> IO ()

Clears the current path and sub-paths.

moveTo :: Context -> CFloat -> CFloat -> IO ()

Starts new sub-path with specified point as first point.

lineTo :: Context -> CFloat -> CFloat -> IO ()

Adds line segment from the last point in the path to the specified point.

bezierTo :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Adds cubic bezier segment from last point in the path via two control points to the specified point.

quadTo :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Adds quadratic bezier segment from last point in the path via a control point to the specified point

arcTo :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Adds an arc segment at the corner defined by the last path point, and two specified points.

closePath :: Context -> IO ()

Closes current sub-path with a line segment.

pathWinding :: Context -> CInt -> IO ()

Sets the current sub-path winding, see NVGwinding and NVGsolidity.

arc :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> Winding -> IO ()

Creates new circle arc shaped sub-path. The arc center is at cx,cy, the arc radius is r, and the arc is drawn from angle a0 to a1, and swept in direction dir (NVG_CCW, or NVG_CW). Angles are specified in radians.

rect :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Creates new rectangle shaped sub-path.

roundedRect :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Creates new rounded rectangle shaped sub-path.

ellipse :: Context -> CFloat -> CFloat -> CFloat -> CFloat -> IO ()

Creates new ellipse shaped sub-path.

circle :: Context -> CFloat -> CFloat -> CFloat -> IO ()

Creates new circle shaped sub-path.

fill :: Context -> IO ()

Fills the current path with current fill style.

stroke :: Context -> IO ()

Fills the current path with current stroke style.

Text

createFont :: Context -> Text -> FileName -> IO (Maybe Font)

Creates font by loading it from the disk from specified file name. Returns handle to the font.

createFontMem :: Context -> Text -> ByteString -> IO (Maybe Font)

Creates image by loading it from the specified memory chunk. Returns handle to the font.

findFont :: Context -> Text -> IO (Maybe Font)

Finds a loaded font of specified name, and returns handle to it, or -1 if the font is not found.

fontSize :: Context -> CFloat -> IO ()

Sets the font size of current text style.

fontBlur :: Context -> CFloat -> IO ()

Sets the blur of current text style.

textLetterSpacing :: Context -> CFloat -> IO ()

Sets the letter spacing of current text style.

textLineHeight :: Context -> CFloat -> IO ()

Sets the proportional line height of current text style. The line height is specified as multiple of font size.

textAlign :: Context -> Set Align -> IO ()

Sets the text align of current text style, see NVGalign for options.

fontFaceId :: Context -> Font -> IO ()

Sets the font face based on specified id of current text style.

fontFace :: Context -> Text -> IO ()

Sets the font face based on specified name of current text styl

text :: Context -> CFloat -> CFloat -> Ptr CChar -> Ptr CChar -> IO ()

Draws text string at specified location. If end is specified only the sub-string up to the end is drawn.

textBox :: Context -> CFloat -> CFloat -> CFloat -> Text -> IO ()

Draws multi-line text string at specified location wrapped at the specified width. If end is specified only the sub-string up to the end is drawn. | White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered. | Words longer than the max width are slit at nearest character (i.e. no hyphenation).

textBounds :: Context -> CFloat -> CFloat -> Text -> IO Bounds

Measures the specified text string. Parameter bounds should be a pointer to float[4], if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax] Returns the horizontal advance of the measured text (i.e. where the next character should drawn). Measured values are returned in local coordinate space.

textBoxBounds :: Context -> CFloat -> CFloat -> CFloat -> Text -> IO Bounds

Measures the specified multi-text string. Parameter bounds should be a pointer to float[4], if the bounding box of the text should be returned. The bounds value are [xmin,ymin, xmax,ymax] Measured values are returned in local coordinate space.

textGlyphPositions :: Context -> CFloat -> CFloat -> Ptr CChar -> Ptr CChar -> GlyphPositionPtr -> CInt -> IO CInt

Calculates the glyph x positions of the specified text. If end is specified only the sub-string will be used. Measured values are returned in local coordinate space.

textMetrics :: Context -> IO (CFloat, CFloat, CFloat)

Returns the vertical metrics based on the current text style. Measured values are returned in local coordinate space.

textBreakLines :: Context -> Ptr CChar -> Ptr CChar -> CFloat -> TextRowPtr -> CInt -> IO CInt

Breaks the specified text into lines. If end is specified only the sub-string will be used. White space is stripped at the beginning of the rows, the text is split at word boundaries or when new-line characters are encountered. Words longer than the max width are slit at nearest character (i.e. no hyphenation).

GL

createGL3 :: Set CreateFlags -> IO Context

deleteGL3 :: Context -> IO ()

createImageFromHandleGL3 :: Context -> GLuint -> CInt -> CInt -> CreateFlags -> IO Image

imageHandleGL3 :: Context -> Image -> IO GLuint