Wumpus.Basic.Kernel.Base.QueryDC

Querying the Drawing Context.

** WARNING ** - parts of this module especially the mono-space glyph metrics need a re-think and will change or be dropped.

Documentation

textAttr :: DrawingCtxM m => m (RGBi, FontAttr)

withTextAttr :: DrawingCtxM m => (RGBi -> FontAttr -> a) -> m a

Because textAttr is so commonly used here is a functional version that avoids tupling.

strokeAttr :: DrawingCtxM m => m (RGBi, StrokeAttr)

withStrokeAttr :: DrawingCtxM m => (RGBi -> StrokeAttr -> a) -> m a

fillAttr :: DrawingCtxM m => m RGBi

withFillAttr :: DrawingCtxM m => (RGBi -> a) -> m a

borderedAttr :: DrawingCtxM m => m (RGBi, StrokeAttr, RGBi)

withBorderedAttr :: DrawingCtxM m => (RGBi -> StrokeAttr -> RGBi -> a) -> m a

getRoundCornerSize :: (DrawingCtxM m, Fractional u, FromPtSize u) => m u

Size of the round corner factor.

getTextMargin :: (DrawingCtxM m, Fractional u, FromPtSize u) => m (u, u)

Get the (x,y) margin around text.

Note - not all text operations in Wumpus are drawn with text margin.

getLineWidth :: DrawingCtxM m => m Double

getFontAttr :: DrawingCtxM m => m FontAttr

getFontSize :: DrawingCtxM m => m Int

getFontFace :: DrawingCtxM m => m FontFace

markHeight :: (DrawingCtxM m, FromPtSize u) => m u

The mark height is the height of a lowercase letter in the current font.

Arrowheads, dots etc. should generally be drawn at the mark height.

markHalfHeight :: (DrawingCtxM m, Fractional u, FromPtSize u) => m u

baselineSpacing :: (DrawingCtxM m, Fractional u) => m u

Vertical distance between baselines of consecutive text lines.

Glyph metrics

glyphBoundingBox :: (FromPtSize u, DrawingCtxM m) => m (BoundingBox u)

Get the font bounding box - this is the maximum boundary of the glyphs in the font. The span of the height is expected to be bigger than the cap_height plus descender depth.

glyphCapHeight :: (FromPtSize u, DrawingCtxM m) => m u

glyphDescender :: (FromPtSize u, DrawingCtxM m) => m u

Note - descender is expected to be negative.

glyphVerticalSpan :: (FromPtSize u, DrawingCtxM m) => m u

This is the distance from cap_height to descender.

cwLookupTable :: (FromPtSize u, DrawingCtxM m) => m (CharWidthTable u)

Default monospace metrics

monoFontPointSize :: (DrawingCtxM m, FromPtSize u) => m u

monoCharWidth :: (DrawingCtxM m, FromPtSize u) => m u

monoTextWidth :: (DrawingCtxM m, FromPtSize u) => Int -> m u

monoTextLength :: (DrawingCtxM m, FromPtSize u) => String -> m u

monoCapHeight :: (DrawingCtxM m, FromPtSize u) => m u

monoLowerxHeight :: (DrawingCtxM m, FromPtSize u) => m u

Height of a lower case 'x' in Courier.

'x' has no ascenders or descenders.

monoDescenderDepth :: (DrawingCtxM m, FromPtSize u) => m u

monoAscenderHeight :: (DrawingCtxM m, FromPtSize u) => m u

monoTextDimensions :: (DrawingCtxM m, Num u, Ord u, FromPtSize u) => String -> m (u, u)

Query the dimensions of the text using the current font size but using metrics derived from Courier.

Note - the width will generally be a over-estimate for non-monospaced fonts.

monoMultiLineHeight :: (DrawingCtxM m, Fractional u, FromPtSize u) => Int -> m u

The heigth of n lines of text, which is n lines + n-1 line spacers

monoDefaultPadding :: (DrawingCtxM m, Fractional u, FromPtSize u) => m u

The default padding is half of the char width.

monoVecToCenter :: (DrawingCtxM m, Fractional u, Ord u, FromPtSize u) => String -> m (Vec2 u)

Vector from baseline left to center