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eZ Components 2008.2.1

Graph: ezcGraphGdDriver

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Class: ezcGraphGdDriver

Driver using PHPs ext/gd to draw images. The GD extension is available on nearly all PHP installations, but slow and produces slightly incorrect results. [source]
The driver can make use of the different font extensions available with ext/gd. It is possible to use Free Type 2, native TTF and PostScript Type 1 fonts.
The options of this driver are configured in ezcGraphGdDriverOptions extending the basic driver options class ezcGraphDriverOptions.
 1.    $graph = new ezcGraphPieChart();
 2.    $graph->palette = new ezcGraphPaletteEzGreen();
 3.    $graph->title = 'Access statistics';
 4.    $graph->legend = false;
 5.  
 6.    $graph->driver = new ezcGraphGdDriver();
 7.    $graph->options->font = 'tutorial_font.ttf';
 8.  
 9.    // Generate a Jpeg with lower quality. The default settings result in a image
10.    // with better quality.
11.    //
12.    // The reduction of the supersampling to 1 will result in no anti aliasing of
13.    // the image. JPEG is not the optimal format for grapics, PNG is far better for
14.    // this kind of images.
15.       $graph->driver->options->supersampling = 1;
16.    $graph->driver->options->jpegQuality = 100;
17.    $graph->driver->options->imageFormat = IMG_JPEG;
18.  
19.    $graph->data['Access statistics'] = new ezcGraphArrayDataSet( array(
20.        'Mozilla' => 19113,
21.        'Explorer' => 10917,
22.        'Opera' => 1464,
23.        'Safari' => 652,
24.        'Konqueror' => 474,
25.    ) );
26.  
27.    $graph->render( 400, 200, 'tutorial_dirver_gd.jpg' );

Parents

ezcGraphDriver
   |
   --ezcGraphGdDriver

Member Variables

protected resource $image
Image resource
protected array $preProcessImages = array()
Array with image files to draw
protected array $psFontResources = array()
Contains resources for already loaded ps fonts.

array( path => resource )
protected array $strings = array()
List of strings to draw

array ( array( 'text' => array( 'strings' ), 'options' => ezcGraphFontOptions, )

Inherited Member Variables

From ezcGraphDriver:
protected  ezcGraphDriver::$options

Method Summary

protected resource addImages( $image )
Draw all images to image resource handler
protected int allocate( $color )
Allocates a color
protected void drawAllTexts( )
Draw all collected texts
public void drawCircle( $center, $width, $height, $color, [$filled = true] )
Draw circle
public void drawCircleSector( $center, $width, $height, $startAngle, $endAngle, $color, [$filled = true] )
Draws a sector of cirlce
public void drawCircularArc( $center, $width, $height, $size, $startAngle, $endAngle, $color, [$filled = true] )
Draws a circular arc
protected void drawCircularArcStep( $center, $width, $height, $size, $startAngle, $endAngle, $color )
Draws a single element of a circular arc
public void drawImage( $file, $position, $width, $height )
Draw an image
public void drawLine( $start, $end, $color, [$thickness = 1.] )
Draws a line
public void drawPolygon( $points, $color, [$filled = true], [$thickness = 1.] )
Draws a single polygon.
public void drawTextBox( $string, $position, $width, $height, $align, [$rotation = null] )
Writes text in a box of desired size
protected resource getImage( )
Returns the image resource to draw on.
public string getMimeType( )
Return mime type for current image format
public resource getResource( )
Get resource of rendered result
protected ezcGraphBoundings getTextBoundings( $size, $font, $text )
Returns boundings of text depending on the available font extension
protected resource imageCreateFrom( $file )
Creates an image resource from an image file
public void render( $file )
Finally save image
protected void renderText( $image, $text, $type, $path, $color, $position, $size, [$rotation = null], $rotation )
Render text depending of font type and available font extensions
public void renderToOutput( )
Render image directly to output
protected float supersample( $value )
Supersamples a single coordinate value.

Inherited Methods

From ezcGraphDriver :
public abstract void ezcGraphDriver::drawCircle()
Draw circle
public abstract void ezcGraphDriver::drawCircleSector()
Draws a sector of cirlce
public abstract void ezcGraphDriver::drawCircularArc()
Draws a circular arc
public abstract void ezcGraphDriver::drawImage()
Draw an image
public abstract void ezcGraphDriver::drawLine()
Draws a line
public abstract void ezcGraphDriver::drawPolygon()
Draws a single polygon.
public abstract void ezcGraphDriver::drawTextBox()
Writes text in a box of desired size
public abstract string ezcGraphDriver::getMimeType()
Return mime type for current image format
protected abstract ezcGraphBoundings ezcGraphDriver::getTextBoundings()
Returns boundings of text depending on the available font extension
protected array ezcGraphDriver::reduceEllipseSize()
Reduce the size of an ellipse
protected array( ezcGraphDriver::reducePolygonSize()
Reduces the size of a polygon
public abstract void ezcGraphDriver::render()
Finally save image
public void ezcGraphDriver::renderToOutput()
Render image directly to output
protected mixed ezcGraphDriver::testFitStringInTextBox()
Test if string fits in a box with given font size
protected void ezcGraphDriver::tryFitShortenedString()
If it is allow to shortened the string, this method tries to extract as many chars as possible to display a decent amount of characters.

Methods

addImages

resource addImages( resource $image )
Draw all images to image resource handler

Parameters

Name Type Description
$image resource Image to draw on

allocate

int allocate( ezcGraphColor $color )
Allocates a color
This function tries to allocate the requested color. If the color already exists in the imaga it will be reused.

Parameters

Name Type Description
$color ezcGraphColor  

drawAllTexts

void drawAllTexts( )
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.

drawCircle

void drawCircle( ezcGraphCoordinate $center, mixed $width, mixed $height, ezcGraphColor $color, [mixed $filled = true] )
Draw circle

Parameters

Name Type Description
$center ezcGraphCoordinate Center of ellipse
$width mixed Width of ellipse
$height mixed height of ellipse
$color ezcGraphColor Color
$filled mixed Filled

Redefinition of

Method Description
ezcGraphDriver::drawCircle() Draw circle

drawCircleSector

void drawCircleSector( ezcGraphCoordinate $center, mixed $width, mixed $height, mixed $startAngle, mixed $endAngle, ezcGraphColor $color, [mixed $filled = true] )
Draws a sector of cirlce

Parameters

Name Type Description
$center ezcGraphCoordinate Center of circle
$width mixed Width
$height mixed Height
$startAngle mixed Start angle of circle sector
$endAngle mixed End angle of circle sector
$color ezcGraphColor Color
$filled mixed Filled

Redefinition of

Method Description
ezcGraphDriver::drawCircleSector() Draws a sector of cirlce

drawCircularArc

void drawCircularArc( ezcGraphCoordinate $center, integer $width, integer $height, integer $size, float $startAngle, float $endAngle, ezcGraphColor $color, [bool $filled = true] )
Draws a circular arc

Parameters

Name Type Description
$center ezcGraphCoordinate Center of ellipse
$width integer Width of ellipse
$height integer Height of ellipse
$size integer Height of border
$startAngle float Starting angle of circle sector
$endAngle float Ending angle of circle sector
$color ezcGraphColor Color of Border
$filled bool  

Redefinition of

Method Description
ezcGraphDriver::drawCircularArc() Draws a circular arc

drawCircularArcStep

void drawCircularArcStep( ezcGraphCoordinate $center, integer $width, integer $height, integer $size, float $startAngle, float $endAngle, ezcGraphColor $color )
Draws a single element of a circular arc
ext/gd itself does not support something like circular arcs, so that this functions draws rectangular polygons as a part of circular arcs to interpolate them. This way it is possible to apply a linear gradient to the circular arc, because we draw single steps anyway.

Parameters

Name Type Description
$center ezcGraphCoordinate Center of ellipse
$width integer Width of ellipse
$height integer Height of ellipse
$size integer Height of border
$startAngle float Starting angle of circle sector
$endAngle float Ending angle of circle sector
$color ezcGraphColor Color of Border

drawImage

void drawImage( mixed $file, ezcGraphCoordinate $position, mixed $width, mixed $height )
Draw an image
The actual drawing of the image is delayed, to not apply supersampling to the image. The image will normally be resized using the gd function imagecopyresampled, which provides nice antialiased scaling, so that additional supersampling would make the image look blurred. The delayed images will be pre-processed, so that they are draw in the back of everything else.

Parameters

Name Type Description
$file mixed Image file
$position ezcGraphCoordinate Top left position
$width mixed Width of image in destination image
$height mixed Height of image in destination image

Redefinition of

Method Description
ezcGraphDriver::drawImage() Draw an image

drawLine

void drawLine( ezcGraphCoordinate $start, ezcGraphCoordinate $end, ezcGraphColor $color, [float $thickness = 1.] )
Draws a line

Parameters

Name Type Description
$start ezcGraphCoordinate Start point
$end ezcGraphCoordinate End point
$color ezcGraphColor Line color
$thickness float Line thickness

Redefinition of

Method Description
ezcGraphDriver::drawLine() Draws a line

drawPolygon

void drawPolygon( $points, ezcGraphColor $color, [mixed $filled = true], [float $thickness = 1.] )
Draws a single polygon.

Parameters

Name Type Description
$points array Point array
$color ezcGraphColor Polygon color
$filled mixed Filled
$thickness float Line thickness

Redefinition of

Method Description
ezcGraphDriver::drawPolygon() Draws a single polygon.

drawTextBox

void drawTextBox( string $string, ezcGraphCoordinate $position, float $width, float $height, int $align, [ $rotation = null] )
Writes text in a box of desired size

Parameters

Name Type Description
$string string Text
$position ezcGraphCoordinate Top left position
$width float Width of text box
$height float Height of text box
$align int Alignement of text
$rotation ezcGraphRotation  

Redefinition of

Method Description
ezcGraphDriver::drawTextBox() Writes text in a box of desired size

getImage

resource getImage( )
Returns the image resource to draw on.
If no resource exists the image will be created. The size of the returned image depends on the supersampling factor and the size of the chart.

getMimeType

string getMimeType( )
Return mime type for current image format

Redefinition of

Method Description
ezcGraphDriver::getMimeType() Return mime type for current image format

getResource

resource getResource( )
Get resource of rendered result
Return the resource of the rendered result. You should not use this method before you called either renderToOutput() or render(), as the image may not be completely rendered until then.

getTextBoundings

ezcGraphBoundings getTextBoundings( float $size, ezcGraphFontOptions $font, string $text )
Returns boundings of text depending on the available font extension

Parameters

Name Type Description
$size float Textsize
$font ezcGraphFontOptions Font
$text string Text

Redefinition of

Method Description
ezcGraphDriver::getTextBoundings() Returns boundings of text depending on the available font extension

imageCreateFrom

resource imageCreateFrom( string $file )
Creates an image resource from an image file

Parameters

Name Type Description
$file string Filename

render

void render( string $file )
Finally save image

Parameters

Name Type Description
$file string Destination filename

Redefinition of

Method Description
ezcGraphDriver::render() Finally save image

renderText

void renderText( resource $image, string $text, int $type, string $path, ezcGraphColor $color, ezcGraphCoordinate $position, float $size, [ $rotation = null], ezcGraphRotation $rotation )
Render text depending of font type and available font extensions

Parameters

Name Type Description
$image resource Image resource
$text string Text
$type int Font type
$path string Font path
$color ezcGraphColor Font color
$position ezcGraphCoordinate Position
$size float Textsize
$rotation ezcGraphRotation  
$rotation ezcGraphRotation  

renderToOutput

void renderToOutput( )
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.

Redefinition of

Method Description
ezcGraphDriver::renderToOutput() Render image directly to output

supersample

float supersample( float $value )
Supersamples a single coordinate value.
Applies supersampling to a single coordinate value.

Parameters

Name Type Description
$value float Coordinate value

Last updated: Mon, 09 Feb 2009