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  28  <H2><A NAME="11_1">11.1 Introduction</A></H2>
  29  <P> Canvas graph is really not a graph. It a blank sheet of paper which
  30   you can use to draw arbitrary shapes and still have access to some of
  31   the convenient features of JpGraph.</P>
  32  <P> You can work with a canvas in different levels of complexity. You
  33   can for example work directly with the Image class which provides a
  34   large number of primitives for drawing but requires that you use
  35   absolute pixel coordinates.</P>
  36  <P> You can also make life a little bit easier by using a canvas scale.
  37   This lets you define your own scale on the canvas which often makes it
  38   easier by letting you work on a grid you have specified yourself. It
  39   also makes it very easy to re-scale you image automatically by just
  40   changing your scale. For example to half the size of you drawing you
  41   just make the scale twice as large.</P>
  42  <P> To give you some help in working with different canvas you should
  43   include the &quot;jpgraph_canvtools.php&quot; file when working on canvases. This
  44   is not strictly necessary but it will give you some nice abstraction to
  45   help you create your masterpieces.</P>
  46  <P> As another (concrete) example on the use of a canvas the figure
  47   below is a listing of font styles available with JpGraph.<DIV class="example">
  48  <BR> <A href="exframes/frame_listfontsex1.html" target="blank"><IMG border="0"
  49  HEIGHT="450"  src="img/listfontsex1.png" WIDTH="550"></A>
  50  <BR><B>Figure 183:</B> Another example of using a canvas to draw a
  51   number of text boxes <A href="exframes/frame_listfontsex1.html" target="blank">
  52  [src]</A>&nbsp;
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