JImage

The JImage object handles in-memory creation of GIF images.

The constructor is defined as follows :

class JImage {
     constructor JImage( [string name] );
     ...
}

Local to current task

var local_image = new JImage();

This image will be deleted when the task ends.

Shared with other tasks

In all tasks needing to update/use the image :

var global_image = new JImage('unique_name');

This image will be deleted when all tasks using the image end.

Class definition

class JImage {
     constructor JImage( [string name] );
     bool setDimensions( width, height );

     bool copyFrom( JImage otherimage );
     bool scrollV(  number_of_lines, background_color );

     bool setPaletteColor( color_index, r, g, b );
     bool setTransparentColor( color_index );
     bool enableTransparency( bool );

     bool drawPixel( x, y, color_index );
     bool drawLine( x0, y0, x1, y1, color_index );

     bool drawRect( x, y, width, height, color_index );
     bool fillRect( x, y, width, height, color_index );

     bool drawRoundRect( x, y, width, height, corner_radius, color_index );
     bool fillRoundRect( x, y, width, height, corner_radius, color_index );

     bool drawCircle( x, y, radius, color_index );
     bool fillCircle( x, y, radius, color_index );

     bool drawQuarterCircle( x, y, radius, corners_mask_bits, color_index );
     bool fillQuarterCircle( x, y, radius, corners_mask_bits, offset_from_center, color_index );

     bool drawTriangle( x0, y0, x1, y1, x2, y2, color_index );
     bool fillTriangle( x0, y0, x1, y1, x2, y2, color_index );

     bool setTextSize( size );
     bool setCursor( x, y );
     bool setTextColor( text_color_index [, text_background_color_index]);
     bool setTextWrap( bool );
     bool print( string );

     bool saveToFile( string );
     Array getData();


}

GIFimage sommand set

.setDimensions

Change the image size. The maximum size is defined so that width*height <= 128 Mpixels

.copyFrom

Set current dimensions and image from another existing JImage.

.scrollV

Scrolls the image vertically (scroll down only) by number_of_lines and fills the added lines with background_color.

.setPaletteColor

Defines one color entry in the 256 color palette. Color is described by the Red, Green, Blue components, each in the [0...255] range.

By default the following palette is set :

• Color 0 : Black
• Color 1...10 : Predefined color tab as follows :
  • TBD
• Color 11...255 : Plasma colormap (see jhere)

.setTransparentColor

Defines which palette entry should be used as the transparent color.

.enableTransparency

Defines if the transparent color entry should be used or not.

.drawPixel

Draws a point (pixel) at (x,y) using the palette color given by color_index.

.drawLine

Draw a line from (x0,y0) to (x1,y1) using the palette color given by color_index.

drawLine( x0, y0, x1, y1, color_index );

.drawRect

Draw an empty rectangle from upper left corner (x,y), using the palette color given by color_index.

drawRect( x, y, width, height, color_index );

.fillRect

Fill a rectangular zone from upper left corner (x,y), using the palette color given by color_index as background.

fillRect( x, y, width, height, color_index );

.drawCircle

Draw a circle centered at (x,y), radius in pixels, using the palette color given by color_index.

img.drawCircle( x, y, radius, color_index );

.fillCircle

Fill a circle using the palette color given by color_index as background.

img.fillCircle( x, y, radius, color_index );

.drawTriangle

Draw a triangle.

drawTriangle( x0, y0, x1, y1, x2, y2, color_index );

.fillTriangle

Draw a colorized triangle, using color_index

fillTriangle( x0, y0, x1, y1, x2, y2, color_index );

.drawRoundRect

Draw a rectangle with round corners

img.drawRoundRect( x, y, width, height, corner_radius, color_index );

.fillRoundRect

Fill a rectangle with round corners.

img.fillRoundRect( x, y, width, height, corner_radius, color_index );

.drawQuarterCircle

Draw a portion of circle

drawQuarterCircle( x, y, radius, corners_mask_bits, color_index );

.fillQuarterCircle

Fill and colorize a portion of circle

fillQuarterCircle( x, y, radius, corners_mask_bits, offset_from_center, color_index );

.setTextSize

Define font size for next text to print.

img.setTextSize( size );

.setCursor

Define the cursor position before printing (display) a text.

img.setCursor( x, y );

.setTextColor

Define font color. Backgroud color is optional.

img.setTextColor( text_color_index [, text_background_color_index]);

.print

Print a text on the GIF image.
You have to define the position (.setCursor), color (.setTextColor), and font size first (.setTextSize).

img.print( 'hello world' );

.saveToFile

img.saveToFile('/tmp/test.gif');