"{ Package: 'stx:goodies/libcairo' }"

"{ NameSpace: Smalltalk }"

DeviceGraphicsContext subclass:#CairoGraphicsContext

	instanceVariableNames:'cr'

	classVariableNames:''

	poolDictionaries:'Cairo::FontSlant Cairo::FontWeight Cairo::Format Cairo::Status

		Cairo::Antialias Cairo::Extend'

	category:'Cairo-Compatibility'

!

!CairoGraphicsContext class methodsFor:'instance creation'!

onDeviceGraphicsContext: dGC

    | cGC |

    cGC := self basicNew.

    1 to: DeviceGraphicsContext instSize do:[:i |

        cGC instVarAt: i put: (dGC instVarAt: i).

    ].

    dGC gcId notNil ifTrue:[ 

        cGC initGC.

    ].

    ^ cGC

    "Created: / 15-02-2016 / 21:20:00 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 18-02-2016 / 22:50:51 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!CairoGraphicsContext class methodsFor:'accessing'!

dllPath

    OperatingSystem isMSWINDOWSlike ifTrue:[

        ^ #( 'C:\Windows' 'C:\Windows\System32' "Wild guess, should not harm" )

    ].

    OperatingSystem isUNIXlike ifTrue:[

        OperatingSystem getSystemType == #linux ifTrue:[

            | path |

            path := #( '/lib' '/usr/lib' '/usr/local/lib' ).

            (OperatingSystem getSystemInfo at:#machine) = 'x86_64' ifTrue:[

                "If the machine is 64bit, prepend standard path for 32bit libs.

                 Leave standard paths at the end, as the system might be completely

                 32bit but running on 64bit-capable CPU.

                CAVEAT: This is bit dangerous, as on 64bit OS, if ia32 libs are

                not installed byt 64bit sqlite libs are, then 64bit libs are found

                and when a function is called, segfault will occur!!

                Q: Is there a way how to figure out if the OS itself is 32bit,

                regardles on CPU?"

                path := #( '/lib32' '/usr/lib32' '/usr/local/lib32' ) , path.

            ].

            ^path

        ].

    ].

    self error:'Unsupported operating system'

    "

        SqliteLibrary dllPath

    "

    "Created: / 31-08-2011 / 18:02:17 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

libraryName

    OperatingSystem isUNIXlike ifTrue:[^'libcairo.so.2'].

    OperatingSystem isMSWINDOWSlike ifTrue:[^'cairo.dll'].

    self error:'Library name for host OS is not known'

!

sizeof

    "Returns size of undelaying structure in bytes"

    ^0

! !

!CairoGraphicsContext class methodsFor:'examples'!

rectangleOnTranscript

    "

        Cairo::GraphicsContext rectangleOnTranscript

    "

    | gc |

    gc := Transcript cairo.

    gc paint: Color black.

    gc moveToX: 30 y: 50.

    gc paint: (Color red alpha: 0.5).

    gc rectangleX: 10 y: 15 width: 150 height: 60.

    gc fill.

    gc paint: (Color red alpha: 0.75).

    gc rectangleX: 10 y: 15 width: 150 height: 60.

    gc stroke.

    "Created: / 23-04-2009 / 17:33:57 / Jan Vrany <vranyj1@fel.cvut.cz>"

! !

!CairoGraphicsContext methodsFor:'accessing'!

atX:x y:y

    "return the pixel at the coordinate given by x/y"

    cr notNil ifTrue:[ 

        cr surface flush.

    ].

    ^ device getPixelX:x y:y from:drawableId with:gcId

    "Created: / 16-03-2016 / 18:27:27 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

basicFont:aFont

    (aFont ~~ font) ifTrue:[     

        super basicFont: aFont.

        font notNil ifTrue:[ 

            font := CairoScaledFont fromFontDescription: font onDevice: device.

            cr notNil ifTrue:[ 

                cr font: font scaledFont.

            ].

        ].

    ].

    "Created: / 16-02-2016 / 15:37:44 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 23-02-2016 / 14:46:23 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 21-02-2016 / 15:38:52 / jv"

!

cairo

    "Return a Cairo context for drawing onto this GC" 

    | ncr |

    ncr := Cairo::GraphicsContext onSurface: super cairoSurface.

    ^ ncr.

    "Created: / 31-03-2016 / 00:13:07 / jv"

!

cairoSurface

    cr isNil ifTrue:[ 

        self initCR.

    ].

    cr isNil ifTrue:[ 

        ^ super cairoSurface

    ].

    ^ cr surface

    "Created: / 25-02-2016 / 10:46:31 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

clippingBounds:aRectangleOrNil

    "set the clipping rectangle for drawing (in logical coordinates);

     a nil argument turn off clipping (i.e. whole view is drawable)"    

    super clippingBounds:aRectangleOrNil.

    cr notNil ifTrue:[ 

            cr rectangleX: aRectangleOrNil left

                        y: aRectangleOrNil top

                    width: aRectangleOrNil width

                   height: aRectangleOrNil height.

            cr clip.

        ].

    ].

    "Created: / 15-02-2016 / 21:38:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 25-03-2016 / 06:58:26 / jv"

!

deviceClippingBounds:aRectangleOrNil

    "set the clipping rectangle for drawing (in device coordinates);

     a nil argument turns off clipping (i.e. whole view is drawable - incl. margins)"

    super deviceClippingBounds: aRectangleOrNil.

    self deviceCoordinatesDo:[

        cr notNil ifTrue:[ 

            aRectangleOrNil isNil ifTrue:[ 

                cr clipReset

            ] ifFalse:[ 

                cr rectangleX: aRectangleOrNil left

                            y: aRectangleOrNil top

                        width: aRectangleOrNil width

                       height: aRectangleOrNil height.

                cr clip.

            ].

        ].

    ].

    "Created: / 27-03-2016 / 00:09:19 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

function:aFunctionSymbol

    "set the drawing function"

    #todo.

    ^ super function:aFunctionSymbol

    "Modified: / 27-02-2016 / 15:21:01 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

lineWidth: w

    super lineWidth: w. 

    cr notNil ifTrue:[

        cr lineWidth: (w == 0 ifTrue:[ 1 ] ifFalse:[ w ]).

    ].

    "Created: / 17-06-2012 / 21:55:05 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 23-02-2016 / 11:29:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

mask:aForm

    "set the drawing mask"

    super mask: aForm.

    cr notNil ifTrue:[ 

        self maskSet.

    ].

    "Modified (format): / 08-03-2016 / 21:22:25 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

maskOrigin:aPoint

    "set the origin of the mask-pattern"

    super maskOrigin: aPoint.

    gcId notNil ifTrue:[

        mask notNil ifTrue:[   

            self maskSet.

        ].

    ].

    "Created: / 08-03-2016 / 21:23:15 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

paint: aColor

    super paint: aColor.

    cr notNil ifTrue:[

        cr source: paint.

    ].

    "Created: / 10-07-2008 / 11:18:13 / Jan Vrany <vranyj1@fel.cvut.cz>"

    "Modified: / 23-04-2009 / 17:31:33 / Jan Vrany <vranyj1@fel.cvut.cz>"

    "Modified: / 18-02-2016 / 22:56:37 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

paint:fgColor on:bgColor

    "Set the paint and background-paint color.

     The bg-paint is used in opaque-draw operations"

    super paint: fgColor on: bgColor.

    cr notNil ifTrue:[ 

        cr source: paint.        

    ].

    "Created: / 05-03-2016 / 16:35:23 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

width: width height: height

    device isX11Platform ifTrue:[ 

        cr surface width: width height: height 

    ] ifFalse:[ 

        self destroyCR.

    ].

    "Created: / 02-04-2016 / 15:37:49 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 02-04-2016 / 15:55:29 / jv"

! !

!CairoGraphicsContext methodsFor:'accessing-transformation'!

transformation:aTransformation 

    "set the transformation"

    super transformation: aTransformation.

    cr notNil ifTrue:[

        cr matrixReset.

        transformation notNil ifTrue:[ 

            cr

                scale: transformation scale;

                translate: transformation translation.

        ]

    ]

    "Created: / 01-01-2015 / 12:07:07 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 16-03-2016 / 22:26:43 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!CairoGraphicsContext methodsFor:'basic drawing'!

displayArcX:x y:y width:w height:h from:start angle:angle

    | angle1 angle2 |

    cr isNil ifTrue:[ 

        self initCR.

    ]. 

    cr save.  

    [

        w ~~ h ifTrue:[

            self notYetImplemented

        ].

        angle1 := (360 - start) .

        angle2 := (360 - (start + angle)) \\ 360.

        (angle2 < angle1) ifTrue:[

            cr arcNegativeX: (x + (w / 2)) y: (y + (h / 2)) radius: w / 2 from: angle1 * (Float pi / 180) to: angle2 * (Float pi / 180).

        ] ifFalse:[ 

            cr arcNegativeX: (x + (w / 2)) y: (y + (h / 2)) radius: w / 2 from: angle2 * (Float pi / 180) to: angle1 * (Float pi / 180).

        ].

        cr stroke.

        w ~~ h ifTrue:[

            self notYetImplemented

        ].

    ] ensure:[ 

        cr restore.

    ]

    "Modified: / 13-02-2016 / 20:05:32 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 21-02-2016 / 15:34:08 / jv"

!

displayLineFromX:x0 y:y0 toX:x1 y:y1

    "draw a line from x0/y0 to x1/y1"

    cr isNil ifTrue:[ 

        self initCR.

    ].

    x0 = x1 ifTrue:[

        cr moveToX: x0 + 0.5 y: y0.

        cr lineToX: x1 + 0.5 y: y1.

    ] ifFalse:[ 

        y0 = y1 ifTrue:[ 

            cr moveToX: x0 y: y0 + 0.5.

            cr lineToX: x1 y: y1 + 0.5.

        ] ifFalse:[ 

            cr moveToX: x0 y: y0.

            cr lineToX: x1 y: y1.

        ].

    ].

    cr stroke.

    "Modified: / 21-02-2016 / 15:24:52 / jv"

    "Modified: / 16-03-2016 / 22:40:35 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

displayPolygon:points

    "draw a polygon

     - this could be recoded to draw using displayLine"

    cr isNil ifTrue:[ 

        self initCR.

    ]. 

    cr moveToX: points first x asFloat y: points first y asFloat.

    2 to: points size do:[:i |  

        cr lineToX: (points at: i) x asFloat  y: (points at: i) y asFloat

    ].

    cr closePath.

    cr stroke.

    "Modified: / 13-02-2016 / 20:04:45 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 21-02-2016 / 15:34:19 / jv"

!

displayRectangleX:x y:y width:w height:h

    "draw a rectangle

     - this could be recoded to draw using displayLine"

    cr isNil ifTrue:[ 

        self initCR.

    ]. 

    (w > 0 and:[h > 0]) ifTrue:[

        cr rectangleX: x + 0.5 y: y + 0.5 width: w - 0.5 height: h - 0.5.

        cr stroke.

    ]

    "Modified: / 21-02-2016 / 15:34:34 / jv"

    "Modified: / 16-03-2016 / 22:42:13 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

displayString:string from:index1 to:index2 x:x y:y opaque:opaqueArg maxWidth:maxWidth

    "draw a substring at the coordinate x/y - draw foreground pixels in

     paint-color and (if opaque is true), background pixels in bgPaint-color.

     If the transformation involves scaling, the font's point-size is scaled as appropriate.

     Assuming that device can only draw in device colors, we have to handle

     the case where paint and/or bgPaint are dithered colors.

     maxWidth is the maximum width of the string in pixels or nil if unknown."    

    | opaque |

    "

     if backgroundPaint color is nil, we assume

     this is a non-opaque draw

    "

    opaque := opaqueArg ? false.

    bgPaint isNil ifTrue:[

        opaque := false.

    ].

    cr isNil ifTrue:[

        self initGC

    ]. 

    (string isString not or:[string isText]) ifTrue:[

        "

         hook for non-strings (i.e. attributed text)

         that 'thing' should know how to display itself ...

        "

        string displayOn:self x:x y:y from:index1 to:index2 opaque:opaque.

        ^ self

    ].   

    font class == CairoScaledFont ifTrue:[ 

        font displayString:string from:index1 to:index2 x:x y:y cr:cr fg: paint bg: bgPaint opaque:opaque

    ] ifFalse:[ 

        Logger warning:'Drawing text using non-Cairo font (%1 )on CairoGraphicsContext' with: font class name.

        cr surface flush.

        super displayString:string from:index1 to:index2 x:x y:y opaque:opaqueArg maxWidth:maxWidth.

        cr surface markDirty.

    ].

    "Created: / 16-02-2016 / 10:51:24 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 19-02-2016 / 21:04:49 / jv"

    "Modified: / 24-02-2016 / 17:14:20 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!CairoGraphicsContext methodsFor:'basic filling'!

fillArcX:x y:y width:w height:h from:start angle:angle

    | angle1 angle2 |

    cr isNil ifTrue:[ 

        self initCR.

    ].

    cr save. 

    [

        w ~~ h ifTrue:[

            self notYetImplemented

        ].

        angle1 := (360 - start) .

        angle2 := (360 - (start + angle)) \\ 360.

        cr moveToX: (x + (w / 2)) y: (y + (h / 2)).

        (angle2 < angle1) ifTrue:[

            cr arcNegativeX: (x + (w / 2)) y: (y + (h / 2)) radius: w / 2 from: angle1 * (Float pi / 180) to: angle2 * (Float pi / 180).

        ] ifFalse:[ 

            cr arcNegativeX: (x + (w / 2)) y: (y + (h / 2)) radius: w / 2 from: angle2 * (Float pi / 180) to: angle1 * (Float pi / 180).

        ].

        cr closePath.

        cr strokeAndPreserve.

        cr fill.

        w ~~ h ifTrue:[

            self notYetImplemented        

        ].

    ] ensure:[ 

        cr restore.

    ]

    "Modified: / 13-02-2016 / 20:03:39 / Jan Vrany <jan.vrany@fit.cvut.cz>"

    "Modified: / 21-02-2016 / 15:34:47 / jv"

!

fillPolygon:points

    "fill a polygon with current paint color"

    cr isNil ifTrue:[ 

        self initCR.

    ].

    cr moveToX: points first x asFloat y: points first y asFloat.

    2 to: points size do:[:i |