- Got cairo driver mostly working.

  # Only full support for rotated texts is still missing
  # Execute the added tutorial example to see the current result.

1 files changed, 970 insertions, 0 deletions

diff --git a/src/driver/cairo.php b/src/driver/cairo.php
new file mode 100644
index 0000000..94263e9
--- /dev/null
+++ b/src/driver/cairo.php
@@ -0,0 +1,970 @@
+<?php
+/**
+ * File containing the ezcGraphSVGDriver class
+ *
+ * @package Graph
+ * @version //autogentag//
+ * @copyright Copyright (C) 2005-2007 eZ systems as. All rights reserved.
+ * @license http://ez.no/licenses/new_bsd New BSD License
+ */
+/**
+ * Extension of the basic Driver package to utilize the SVGlib.
+ *
+ * This drivers options are defined in the class 
+ * {@link ezcGraphCairoDriverOptions} extending the basic driver options class
+ * {@link ezcGraphDriverOptions}. 
+ *
+ * As this is the default driver you do not need to explicitely set anything to
+ * use it, but may use some of its advanced features.
+ *
+ * <code>
+ *   $graph = new ezcGraphPieChart();
+ *   $graph->background->color = '#FFFFFFFF';
+ *   $graph->title = 'Access statistics';
+ *   $graph->legend = false;
+ *   
+ *   $graph->data['Access statistics'] = new ezcGraphArrayDataSet( array(
+ *       'Mozilla' => 19113,
+ *       'Explorer' => 10917,
+ *       'Opera' => 1464,
+ *       'Safari' => 652,
+ *       'Konqueror' => 474,
+ *   ) );
+ *   
+ *   $graph->renderer = new ezcGraphRenderer3d();
+ *   $graph->renderer->options->pieChartShadowSize = 10;
+ *   $graph->renderer->options->pieChartGleam = .5;
+ *   $graph->renderer->options->dataBorder = false;
+ *   $graph->renderer->options->pieChartHeight = 16;
+ *   $graph->renderer->options->legendSymbolGleam = .5;
+ * 
+ *   // Use cairo driver
+ *   $graph->driver = new ezcGraphCairoDriver();
+ *   
+ *   $graph->render( 400, 200, 'tutorial_driver_cairo.png' );
+ * </code>
+ *
+ * @version //autogentag//
+ * @package Graph
+ * @mainclass
+ */
+class ezcGraphCairoDriver extends ezcGraphDriver
+{
+    /**
+     * Surface for cairo
+     * 
+     * @var resource
+     */
+    protected $surface;
+
+    /**
+     * Current cairo context.
+     * 
+     * @var resource
+     */
+    protected $context;
+
+    /**
+     * List of strings to draw
+     * array ( array(
+     *          'text' => array( 'strings' ),
+     *          'options' => ezcGraphFontOptions,
+     *      )
+     * 
+     * @var array
+     */
+    protected $strings = array();
+
+    /**
+     * Constructor
+     * 
+     * @param array $options Default option array
+     * @return void
+     * @ignore
+     */
+    public function __construct( array $options = array() )
+    {
+        ezcBase::checkDependency( 'Graph', ezcBase::DEP_PHP_EXTENSION, 'cairo_wrapper' );
+        $this->options = new ezcGraphCairoDriverOptions( $options );
+    }
+
+    /**
+     * Initilize cairo surface
+     *
+     * Initilize cairo surface from values provided in the options object, if
+     * is has not been already initlized.
+     * 
+     * @return void
+     */
+    protected function initiliazeSurface()
+    {
+        // Immediatly exit, if surface already exists
+        if ( $this->surface !== null )
+        {
+            return;
+        }
+
+        $this->surface = cairo_image_surface_create( 
+            CAIRO_FORMAT_ARGB32, 
+            $this->options->width, 
+            $this->options->height
+        );
+
+        $this->context = cairo_create( $this->surface );
+        cairo_set_line_width( $this->context, 1 );
+    }
+
+    /**
+     * Get SVG style definition
+     *
+     * Returns a string with SVG style definitions created from color, 
+     * fillstatus and line thickness.
+     * 
+     * @param ezcGraphColor $color Color
+     * @param mixed $filled Filled
+     * @param float $thickness Line thickness.
+     * @return string Formatstring
+     */
+    protected function getStyle( ezcGraphColor $color, $filled = true, $thickness = 1. )
+    {
+        switch ( true )
+        {
+            case $color instanceof ezcGraphLinearGradient:
+                $pattern = cairo_pattern_create_linear(
+                    $color->startPoint->x, $color->startPoint->y,
+                    $color->endPoint->x, $color->endPoint->y
+                );
+
+                cairo_pattern_add_color_stop_rgba ( 
+                    $pattern,
+                    0,
+                    $color->startColor->red / 255,
+                    $color->startColor->green / 255,
+                    $color->startColor->blue / 255,
+                    1 - $color->startColor->alpha / 255
+                );
+
+                cairo_pattern_add_color_stop_rgba ( 
+                    $pattern, 
+                    1,
+                    $color->endColor->red / 255,
+                    $color->endColor->green / 255,
+                    $color->endColor->blue / 255,
+                    1 - $color->endColor->alpha / 255
+                );
+
+                cairo_set_source( $this->context, $pattern );
+                cairo_fill( $this->context );
+                break;
+
+            case $color instanceof ezcGraphRadialGradient:
+                $pattern = cairo_pattern_create_radial(
+                    0, 0, 0,
+                    0, 0, 1
+                );
+
+                cairo_pattern_add_color_stop_rgba ( 
+                    $pattern,
+                    0,
+                    $color->startColor->red / 255,
+                    $color->startColor->green / 255,
+                    $color->startColor->blue / 255,
+                    1 - $color->startColor->alpha / 255
+                );
+
+                cairo_pattern_add_color_stop_rgba ( 
+                    $pattern, 
+                    1,
+                    $color->endColor->red / 255,
+                    $color->endColor->green / 255,
+                    $color->endColor->blue / 255,
+                    1 - $color->endColor->alpha / 255
+                );
+
+                // Scale pattern, and move it to the correct position
+                $matrix = cairo_matrix_multiply(
+                    $move = cairo_matrix_create_translate( -$color->center->x, -$color->center->y ),
+                    $scale = cairo_matrix_create_scale( 1 / $color->width, 1 / $color->height )
+                );
+                cairo_pattern_set_matrix( $pattern, $matrix );
+
+                cairo_set_source( $this->context, $pattern );
+                cairo_fill( $this->context );
+                break;
+            default:
+                cairo_set_source_rgba( 
+                    $this->context,
+                    $color->red / 255,
+                    $color->green / 255,
+                    $color->blue / 255,
+                    1 - $color->alpha / 255
+                );
+                break;
+        }
+
+        // Set line width
+        cairo_set_line_width( $this->context, $thickness );
+
+        // Set requested fill state for context
+        if ( $filled )
+        {
+            cairo_fill_preserve( $this->context );
+        }
+    }
+
+    /**
+     * Draws a single polygon. 
+     * 
+     * @param array $points Point array
+     * @param ezcGraphColor $color Polygon color
+     * @param mixed $filled Filled
+     * @param float $thickness Line thickness
+     * @return void
+     */
+    public function drawPolygon( array $points, ezcGraphColor $color, $filled = true, $thickness = 1. )
+    {
+        $this->initiliazeSurface();
+
+        $path = cairo_new_path( $this->context );
+
+        $lastPoint = end( $points );
+        cairo_move_to( $this->context, $lastPoint->x, $lastPoint->y );
+
+        foreach ( $points as $point )
+        {
+            cairo_line_to( $this->context, $point->x, $point->y );
+        }
+
+        cairo_close_path( $this->context );
+
+        $this->getStyle( $color, $filled, $thickness );
+        cairo_stroke( $this->context );
+
+        return $points;
+    }
+    
+    /**
+     * Draws a line 
+     * 
+     * @param ezcGraphCoordinate $start Start point
+     * @param ezcGraphCoordinate $end End point
+     * @param ezcGraphColor $color Line color
+     * @param float $thickness Line thickness
+     * @return void
+     */
+    public function drawLine( ezcGraphCoordinate $start, ezcGraphCoordinate $end, ezcGraphColor $color, $thickness = 1. )
+    {
+        $this->initiliazeSurface();
+
+        $path = cairo_new_path( $this->context );
+
+        cairo_move_to( $this->context, $start->x, $start->y );
+        cairo_line_to( $this->context, $end->x, $end->y );
+
+        $this->getStyle( $color, false, $thickness );
+        cairo_stroke( $this->context );
+
+        return array( $start, $end );
+    }
+
+    /**
+     * Returns boundings of text depending on the available font extension
+     * 
+     * @param float $size Textsize
+     * @param ezcGraphFontOptions $font Font
+     * @param string $text Text
+     * @return ezcGraphBoundings Boundings of text
+     */
+    protected function getTextBoundings( $size, ezcGraphFontOptions $font, $text )
+    {
+        cairo_select_font_face( $this->context, $font->name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL );
+        cairo_set_font_size( $this->context, $size );
+        $extents = cairo_text_extents( $this->context, $text );
+
+        return new ezcGraphBoundings(
+            0,
+            0,
+            $extents['width'],
+            $extents['height']
+        );
+    }
+
+    /**
+     * Writes text in a box of desired size
+     * 
+     * @param string $string Text
+     * @param ezcGraphCoordinate $position Top left position
+     * @param float $width Width of text box
+     * @param float $height Height of text box
+     * @param int $align Alignement of text
+     * @param ezcGraphRotation $rotation
+     * @return void
+     */
+    public function drawTextBox( $string, ezcGraphCoordinate $position, $width, $height, $align, ezcGraphRotation $rotation = null )
+    {
+        $this->initiliazeSurface();
+
+        $padding = $this->options->font->padding + ( $this->options->font->border !== false ? $this->options->font->borderWidth : 0 );
+
+        $width -= $padding * 2;
+        $height -= $padding * 2;
+        $textPosition = new ezcGraphCoordinate(
+            $position->x + $padding,
+            $position->y + $padding
+        );
+
+        // Try to get a font size for the text to fit into the box
+        $maxSize = min( $height, $this->options->font->maxFontSize );
+        $result = false;
+        for ( $size = $maxSize; $size >= $this->options->font->minFontSize; )
+        {
+            $result = $this->testFitStringInTextBox( $string, $position, $width, $height, $size );
+            if ( is_array( $result ) )
+            {
+                break;
+            }
+            $size = ( ( $newsize = $size * ( $result ) ) >= $size ? $size - 1 : floor( $newsize ) );
+        }
+        
+        if ( !is_array( $result ) )
+        {
+            if ( ( $height >= $this->options->font->minFontSize ) &&
+                 ( $this->options->autoShortenString ) )
+            {
+                $result = $this->tryFitShortenedString( $string, $position, $width, $height, $size = $this->options->font->minFontSize );
+            } 
+            else
+            {
+                throw new ezcGraphFontRenderingException( $string, $this->options->font->minFontSize, $width, $height );
+            }
+        }
+
+        $this->options->font->minimalUsedFont = $size;
+        $this->strings[] = array(
+            'text' => $result,
+            'position' => $textPosition,
+            'width' => $width,
+            'height' => $height,
+            'align' => $align,
+            'font' => $this->options->font,
+            'rotation' => $rotation,
+        );
+
+        return array(
+            clone $position,
+            new ezcGraphCoordinate( $position->x + $width, $position->y ),
+            new ezcGraphCoordinate( $position->x + $width, $position->y + $height ),
+            new ezcGraphCoordinate( $position->x, $position->y + $height ),
+        );
+    }
+    
+    /**
+     * Render text depending of font type and available font extensions
+     * 
+     * @param string $id 
+     * @param string $text 
+     * @param string $font 
+     * @param ezcGraphColor $color 
+     * @param ezcGraphCoordinate $position 
+     * @param float $size 
+     * @param float $rotation 
+     * @return void
+     */
+    protected function renderText( $text, $font, ezcGraphColor $color, ezcGraphCoordinate $position, $size, $rotation = null )
+    {
+        cairo_select_font_face( $this->context, $font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL );
+        cairo_set_font_size( $this->context, $size );
+        
+        // Store current state of context
+        cairo_save( $this->context );
+
+
+        if ( $rotation !== null )
+        {
+            cairo_rotate( $this->context, deg2rad( $rotation->getRotation() ) );
+            cairo_move_to( $this->context,
+                $position->x + $rotation->get( 0, 1 ), 
+                $position->y + $rotation->get( 0, 2 ) - $size * .15
+            );
+        } else {
+            cairo_move_to( $this->context,
+                $position->x,
+                $position->y - $size * .15
+            );
+        }
+
+        $this->getStyle( $color, true );
+        cairo_show_text( $this->context, $text );
+
+        // Restore state of context
+        cairo_restore( $this->context );
+    }
+
+    /**
+     * Draw all collected texts
+     *
+     * The texts are collected and their maximum possible font size is 
+     * calculated. This function finally draws the texts on the image, this
+     * delayed drawing has two reasons:
+     *
+     * 1) This way the text strings are always on top of the image, what 
+     *    results in better readable texts
+     * 2) The maximum possible font size can be calculated for a set of texts
+     *    with the same font configuration. Strings belonging to one chart 
+     *    element normally have the same font configuration, so that all texts
+     *    belonging to one element will have the same font size.
+     * 
+     * @access protected
+     * @return void
+     */
+    protected function drawAllTexts()
+    {
+        foreach ( $this->strings as $text )
+        {
+            $size = $text['font']->minimalUsedFont;
+
+            $completeHeight = count( $text['text'] ) * $size + ( count( $text['text'] ) - 1 ) * $this->options->lineSpacing;
+
+            // Calculate y offset for vertical alignement
+            switch ( true )
+            {
+                case ( $text['align'] & ezcGraph::BOTTOM ):
+                    $yOffset = $text['height'] - $completeHeight;
+                    break;
+                case ( $text['align'] & ezcGraph::MIDDLE ):
+                    $yOffset = ( $text['height'] - $completeHeight ) / 2;
+                    break;
+                case ( $text['align'] & ezcGraph::TOP ):
+                default:
+                    $yOffset = 0;
+                    break;
+            }
+
+            $padding = $text['font']->padding + $text['font']->borderWidth / 2;
+            if ( $this->options->font->minimizeBorder === true )
+            {
+                // Calculate maximum width of text rows
+                $width = false;
+                foreach ( $text['text'] as $line )
+                {
+                    $string = implode( ' ', $line );
+                    $boundings = $this->getTextBoundings( $size, $text['font'], $string );
+                    if ( ( $width === false) || ( $boundings->width > $width ) )
+                    {
+                        $width = $boundings->width;
+                    }
+                }
+
+                switch ( true )
+                {
+                    case ( $text['align'] & ezcGraph::LEFT ):
+                        $xOffset = 0;
+                        break;
+                    case ( $text['align'] & ezcGraph::CENTER ):
+                        $xOffset = ( $text['width'] - $width ) / 2;
+                        break;
+                    case ( $text['align'] & ezcGraph::RIGHT ):
+                        $xOffset = $text['width'] - $width;
+                        break;
+                }
+
+                $borderPolygonArray = array(
+                    new ezcGraphCoordinate(
+                        $text['position']->x - $padding + $xOffset,
+                        $text['position']->y - $padding + $yOffset
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x + $padding * 2 + $xOffset + $width,
+                        $text['position']->y - $padding + $yOffset
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x + $padding * 2 + $xOffset + $width,
+                        $text['position']->y + $padding * 2 + $yOffset + $completeHeight
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x - $padding + $xOffset,
+                        $text['position']->y + $padding * 2 + $yOffset + $completeHeight
+                    ),
+                );
+            }
+            else
+            {
+                $borderPolygonArray = array(
+                    new ezcGraphCoordinate(
+                        $text['position']->x - $padding,
+                        $text['position']->y - $padding
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x + $padding * 2 + $text['width'],
+                        $text['position']->y - $padding
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x + $padding * 2 + $text['width'],
+                        $text['position']->y + $padding * 2 + $text['height']
+                    ),
+                    new ezcGraphCoordinate(
+                        $text['position']->x - $padding,
+                        $text['position']->y + $padding * 2 + $text['height']
+                    ),
+                );
+            }
+
+            if ( $text['rotation'] !==  null )
+            {
+                foreach ( $borderPolygonArray as $nr => $point )
+                {
+                    $borderPolygonArray[$nr] = $text['rotation']->transformCoordinate( $point );
+                }
+            }
+
+            if ( $text['font']->background !== false )
+            {
+                $this->drawPolygon( 
+                    $borderPolygonArray, 
+                    $text['font']->background,
+                    true
+                );
+            }
+
+            if ( $text['font']->border !== false )
+            {
+                $this->drawPolygon( 
+                    $borderPolygonArray, 
+                    $text['font']->border,
+                    false,
+                    $text['font']->borderWidth
+                );
+            }
+
+            // Render text with evaluated font size
+            $completeString = '';
+            foreach ( $text['text'] as $line )
+            {
+                $string = implode( ' ', $line );
+                $completeString .= $string;
+                $boundings = $this->getTextBoundings( $size, $text['font'], $string );
+                $text['position']->y += $size;
+
+                switch ( true )
+                {
+                    case ( $text['align'] & ezcGraph::LEFT ):
+                        $position = new ezcGraphCoordinate( 
+                            $text['position']->x, 
+                            $text['position']->y + $yOffset
+                        );
+                        break;
+                    case ( $text['align'] & ezcGraph::RIGHT ):
+                        $position = new ezcGraphCoordinate( 
+                            $text['position']->x + ( $text['width'] - $boundings->width ), 
+                            $text['position']->y + $yOffset
+                        );
+                        break;
+                    case ( $text['align'] & ezcGraph::CENTER ):
+                        $position = new ezcGraphCoordinate( 
+                            $text['position']->x + ( ( $text['width'] - $boundings->width ) / 2 ), 
+                            $text['position']->y + $yOffset
+                        );
+                        break;
+                }
+
+                // Optionally draw text shadow
+                if ( $text['font']->textShadow === true )
+                {
+                    $this->renderText( 
+                        $string,
+                        $text['font']->name, 
+                        $text['font']->textShadowColor,
+                        new ezcGraphCoordinate(
+                            $position->x + $text['font']->textShadowOffset,
+                            $position->y + $text['font']->textShadowOffset
+                        ),
+                        $size,
+                        $text['rotation']
+                    );
+                }
+                
+                // Finally draw text
+                $this->renderText( 
+                    $string,
+                    $text['font']->name, 
+                    $text['font']->color, 
+                    $position,
+                    $size,
+                    $text['rotation']
+                );
+
+                $text['position']->y += $size * $this->options->lineSpacing;
+            }
+        }
+    }
+
+    /**
+     * Draws a sector of cirlce
+     * 
+     * @param ezcGraphCoordinate $center Center of circle
+     * @param mixed $width Width
+     * @param mixed $height Height
+     * @param mixed $startAngle Start angle of circle sector
+     * @param mixed $endAngle End angle of circle sector
+     * @param ezcGraphColor $color Color
+     * @param mixed $filled Filled;
+     * @return void
+     */
+    public function drawCircleSector( ezcGraphCoordinate $center, $width, $height, $startAngle, $endAngle, ezcGraphColor $color, $filled = true )
+    {
+        $this->initiliazeSurface();
+
+        // Normalize angles
+        if ( $startAngle > $endAngle )
+        {
+            $tmp = $startAngle;
+            $startAngle = $endAngle;
+            $endAngle = $tmp;
+        }
+        
+        cairo_save( $this->context );
+        
+        // Draw circular arc path
+        $path = cairo_new_path( $this->context );
+        cairo_translate( $this->context, 
+            $center->x,
+            $center->y
+        );
+        cairo_scale( $this->context, 
+            1, $height / $width
+        );
+
+        cairo_move_to( $this->context, 0, 0 );
+        cairo_arc( $this->context, 
+            0., 0., 
+            $width / 2, 
+            deg2rad( $startAngle ),
+            deg2rad( $endAngle )
+        );
+        cairo_line_to( $this->context, 0, 0 );
+
+        cairo_restore( $this->context );
+        $this->getStyle( $color, $filled );
+        cairo_stroke( $this->context );
+
+        // Create polygon array to return
+        $polygonArray = array( $center );
+        for ( $angle = $startAngle; $angle < $endAngle; $angle += $this->options->imageMapResolution )
+        {
+            $polygonArray[] = new ezcGraphCoordinate(
+                $center->x + 
+                    ( ( cos( deg2rad( $angle ) ) * $width ) / 2 ),
+                $center->y + 
+                    ( ( sin( deg2rad( $angle ) ) * $height ) / 2 )
+            );
+        }
+        $polygonArray[] = new ezcGraphCoordinate(
+            $center->x + 
+                ( ( cos( deg2rad( $endAngle ) ) * $width ) / 2 ),
+            $center->y + 
+                ( ( sin( deg2rad( $endAngle ) ) * $height ) / 2 )
+        );
+
+        return $polygonArray;
+    }
+
+    /**
+     * Draws a circular arc consisting of several minor steps on the bounding 
+     * lines.
+     * 
+     * @param ezcGraphCoordinate $center 
+     * @param mixed $width 
+     * @param mixed $height 
+     * @param mixed $size 
+     * @param mixed $startAngle 
+     * @param mixed $endAngle 
+     * @param ezcGraphColor $color 
+     * @param bool $filled 
+     * @return string Element id
+     */
+    protected function simulateCircularArc( ezcGraphCoordinate $center, $width, $height, $size, $startAngle, $endAngle, ezcGraphColor $color, $filled )
+    {
+        for ( 
+            $tmpAngle = min( ceil ( $startAngle / 180 ) * 180, $endAngle ); 
+            $tmpAngle <= $endAngle; 
+            $tmpAngle = min( ceil ( $startAngle / 180 + 1 ) * 180, $endAngle ) )
+        {
+            $path = cairo_new_path( $this->context );
+            cairo_move_to( $this->context,
+                $center->x + cos( deg2rad( $startAngle ) ) * $width / 2, 
+                $center->y + sin( deg2rad( $startAngle ) ) * $height / 2
+            );
+
+            // @TODO: Use cairo_curve_to()
+            for(
+                $angle = $startAngle;
+                $angle <= $tmpAngle;
+                $angle = min( $angle + $this->options->circleResolution, $tmpAngle ) )
+            {
+                cairo_line_to( $this->context,
+                    $center->x + cos( deg2rad( $angle ) ) * $width / 2, 
+                    $center->y + sin( deg2rad( $angle ) ) * $height / 2 + $size
+                );
+
+                if ( $angle === $tmpAngle )
+                {
+                    break;
+                }
+            }
+
+            for(
+                $angle = $tmpAngle;
+                $angle >= $startAngle;
+                $angle = max( $angle - $this->options->circleResolution, $startAngle ) )
+            {
+                cairo_line_to(  $this->context,
+                    $center->x + cos( deg2rad( $angle ) ) * $width / 2, 
+                    $center->y + sin( deg2rad( $angle ) ) * $height / 2
+                );
+
+                if ( $angle === $startAngle )
+                {
+                    break;
+                }
+            }
+
+            cairo_close_path( $this->context );
+            $this->getStyle( $color, $filled );
+            cairo_stroke( $this->context );
+
+            $startAngle = $tmpAngle;
+            if ( $tmpAngle === $endAngle ) 
+            {
+                break;
+            }
+        }
+    }
+
+    /**
+     * Draws a circular arc
+     * 
+     * @param ezcGraphCoordinate $center Center of ellipse
+     * @param integer $width Width of ellipse
+     * @param integer $height Height of ellipse
+     * @param integer $size Height of border
+     * @param float $startAngle Starting angle of circle sector
+     * @param float $endAngle Ending angle of circle sector
+     * @param ezcGraphColor $color Color of Border
+     * @param bool $filled
+     * @return void
+     */
+    public function drawCircularArc( ezcGraphCoordinate $center, $width, $height, $size, $startAngle, $endAngle, ezcGraphColor $color, $filled = true )
+    {
+        $this->initiliazeSurface();
+
+        // Normalize angles
+        if ( $startAngle > $endAngle )
+        {
+            $tmp = $startAngle;
+            $startAngle = $endAngle;
+            $endAngle = $tmp;
+        }
+
+        $this->simulateCircularArc( $center, $width, $height, $size, $startAngle, $endAngle, $color, $filled );
+
+        if ( ( $this->options->shadeCircularArc !== false ) &&
+             $filled )
+        {
+            $gradient = new ezcGraphLinearGradient(
+                new ezcGraphCoordinate(
+                    $center->x - $width,
+                    $center->y
+                ),
+                new ezcGraphCoordinate(
+                    $center->x + $width,
+                    $center->y
+                ),
+                ezcGraphColor::fromHex( '#FFFFFF' )->transparent( $this->options->shadeCircularArc * 1.5 ),
+                ezcGraphColor::fromHex( '#000000' )->transparent( $this->options->shadeCircularArc * 1.5 )
+            );
+        
+            $this->simulateCircularArc( $center, $width, $height, $size, $startAngle, $endAngle, $gradient, $filled );
+        }
+
+        // Create polygon array to return
+        $polygonArray = array();
+        for ( $angle = $startAngle; $angle < $endAngle; $angle += $this->options->imageMapResolution )
+        {
+            $polygonArray[] = new ezcGraphCoordinate(
+                $center->x + 
+                    ( ( cos( deg2rad( $angle ) ) * $width ) / 2 ),
+                $center->y + 
+                    ( ( sin( deg2rad( $angle ) ) * $height ) / 2 )
+            );
+        }
+        $polygonArray[] = new ezcGraphCoordinate(
+            $center->x + 
+                ( ( cos( deg2rad( $endAngle ) ) * $width ) / 2 ),
+            $center->y + 
+                ( ( sin( deg2rad( $endAngle ) ) * $height ) / 2 )
+        );
+
+        for ( $angle = $endAngle; $angle > $startAngle; $angle -= $this->options->imageMapResolution )
+        {
+            $polygonArray[] = new ezcGraphCoordinate(
+                $center->x + 
+                    ( ( cos( deg2rad( $angle ) ) * $width ) / 2 ) + $size,
+                $center->y + 
+                    ( ( sin( deg2rad( $angle ) ) * $height ) / 2 )
+            );
+        }
+        $polygonArray[] = new ezcGraphCoordinate(
+            $center->x + 
+                ( ( cos( deg2rad( $startAngle ) ) * $width ) / 2 ) + $size,
+            $center->y + 
+                ( ( sin( deg2rad( $startAngle ) ) * $height ) / 2 )
+        );
+
+        return $polygonArray;
+    }
+
+    /**
+     * Draw circle 
+     * 
+     * @param ezcGraphCoordinate $center Center of ellipse
+     * @param mixed $width Width of ellipse
+     * @param mixed $height height of ellipse
+     * @param ezcGraphColor $color Color
+     * @param mixed $filled Filled
+     * @return void
+     */
+    public function drawCircle( ezcGraphCoordinate $center, $width, $height, ezcGraphColor $color, $filled = true )
+    {
+        $this->initiliazeSurface();
+        
+        cairo_save( $this->context );
+        
+        // Draw circular arc path
+        $path = cairo_new_path( $this->context );
+        cairo_translate( $this->context, 
+            $center->x,
+            $center->y
+        );
+        cairo_scale( $this->context, 
+            1, $height / $width
+        );
+
+        cairo_arc( $this->context, 
+            0., 0., 
+            $width / 2, 
+            0, 2 * M_PI
+        );
+
+        cairo_restore( $this->context );
+        $this->getStyle( $color, $filled );
+        cairo_stroke( $this->context );
+
+        // Create polygon array to return
+        $polygonArray = array();
+        for ( $angle = 0; $angle < ( 2 * M_PI ); $angle += deg2rad( $this->options->imageMapResolution ) )
+        {
+            $polygonArray[] = new ezcGraphCoordinate(
+                $center->x + 
+                    ( ( cos( $angle ) * $width ) / 2 ),
+                $center->y + 
+                    ( ( sin( $angle ) * $height ) / 2 )
+            );
+        }
+
+        return $polygonArray;
+    }
+
+    /**
+     * Draw an image 
+     *
+     * The image will be inlined in the SVG document using data URL scheme. For
+     * this the mime type and base64 encoded file content will be merged to 
+     * URL.
+     * 
+     * @param mixed $file Image file
+     * @param ezcGraphCoordinate $position Top left position
+     * @param mixed $width Width of image in destination image
+     * @param mixed $height Height of image in destination image
+     * @return void
+     */
+    public function drawImage( $file, ezcGraphCoordinate $position, $width, $height )
+    {
+        $this->initiliazeSurface();
+
+        // Ensure given bitmap is a PNG image
+        $data = getimagesize( $file );
+        if ( $data[2] !== IMAGETYPE_PNG )
+        {
+            throw new Exception( 'Cairo only has support for PNGs.' );
+        }
+
+        // Create new surface from given bitmap
+        $imageSurface = cairo_image_surface_create_from_png( $file );
+
+        // Create pattern from source image to be able to transform it
+        $pattern = cairo_pattern_create_for_surface( $imageSurface );
+
+        // Scale pattern to defined dimensions and move it to its destination position
+        $matrix = cairo_matrix_multiply(
+            $move = cairo_matrix_create_translate( -$position->x, -$position->y ),
+            $scale = cairo_matrix_create_scale( $data[0] / $width, $data[1] / $height )
+        );
+        cairo_pattern_set_matrix( $pattern, $matrix );
+
+        // Merge surfaces
+        cairo_set_source( $this->context, $pattern );
+        cairo_rectangle( $this->context, $position->x, $position->y, $width, $height );
+        cairo_fill( $this->context );
+    }
+
+    /**
+     * Return mime type for current image format
+     * 
+     * @return string
+     */
+    public function getMimeType()
+    {
+        return 'image/png';
+    }
+
+    /**
+     * Render image directly to output
+     *
+     * The method renders the image directly to the standard output. You 
+     * normally do not want to use this function, because it makes it harder 
+     * to proper cache the generated graphs.
+     * 
+     * @return void
+     */
+    public function renderToOutput()
+    {
+        $this->drawAllTexts();
+
+        header( 'Content-Type: ' . $this->getMimeType() );
+
+        // Write to tmp file, echo and remove tmp file again.
+        $fileName = tempnam( '/tmp', 'ezc' );
+
+        // cairo_surface_write_to_png( $this->surface, $file );
+        cairo_surface_write_to_png( $this->surface, $fileName );
+        $contents = file_get_contents( $fileName );
+        unlink( $fileName );
+
+        // Directly echo contents
+        echo $contents;
+    }
+
+    /**
+     * Finally save image
+     * 
+     * @param string $file Destination filename
+     * @return void
+     */
+    public function render ( $file )
+    {
+        $this->drawAllTexts();
+        cairo_surface_write_to_png( $this->surface, $file );
+    }
+}
+
+?>