<!doctype HTML PUBLIC "-//IETF//DTD HTML//EN"> <html> <head> <meta http-equiv="Content-Language" content="en-us"> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <title>CD_DGN</title> <link rel="stylesheet" type="text/css" href="../../style.css"> </head> <body> <h2 style="text-align: left">CD_DGN - MicroStation Design File Driver (cddgn.h)</h2> <p>This driver allows generating a MicroStation design file. The file name usually has an extension .DGN. The driver supports only MicroStation version 4.0 or later. The format's copyrights are property of <a href="http://www.bentley.com" target="_top">Bentley Systems</a>.</p> <h3>Use</h3> <p>The file is created and opened by calling function <font face="Courier"> <a href="../func/init.html#cdCreateCanvas"><strong>cdCreateCanvas</strong></a>(CD_DGN, Data)</font>, in which <font face="Courier">Data</font> contains the filename and canvas dimensions. This function opens the file and writes its header. Then, other functions in the CD library can be called as usual. The <font face="Courier">Data</font> parameter string has the following format:</p> <pre><em>"filename [widthxheight] [resolution] [-f] [-sseedfile]" </em>or in C <em>"<strong><tt>%s %gx%g %g %s</tt></strong>"</em></pre> <p>Only the parameter <font face="Courier">filename</font> is required. The filename must be inside double quotes (") if it has spaces.<font face="Courier"> Width</font> and <font face="Courier">height</font> are provided in millimeters (note the lowercase "x" between them), and their default value in pixels is <font face="Courier">INT_MAX</font> for both dimensions. <font face="Courier">Resolution </font>is the number of pixels per millimeter; its default value is "3.78 pixels/mm" (96 DPI). <font face="Courier">Width</font>, <font face="Courier">height</font> and <font face="Courier">resolution</font> are real values. Parameter <font face="Courier">-f</font> modifies the polygon filling's behavior. Just as in MicroStation, you can specify a seed file using parameter <font face="Courier">-s</font>. <font face="Courier">Width</font>, <font face="Courier">height</font> and <font face="Courier">resolution</font> are used only by <a href="../func/coordinates.html#cdGetCanvasSize"> <font face="Courier"><strong>cdCanvasGetSize</strong></font></a><font face="Courier"><strong> </strong></font>and in pixel-millimeter conversion. </p> <p>Any amount of such canvases may exist simultaneously. It is important to note that a call to function <a href="../func/init.html#cdKillCanvas"><font face="Courier"><strong> cdKillCanvas</strong></font></a> is required to close the file properly.</p> <p><b>Images and Colors</b> - The DGN format does not support server images and works with an indexed-color format. Color quality is limited to 256 colors, and the format uses a uniform palette to convert RGB colors into palette indices. If you configure a palette, the color conversion process will become slower.</p> <p><b>Filling</b> - Up to version 5.0, MicroStation presents some limitations for polygon filling. You can disable filling by means of string "<font face="Courier">-f</font>" in the <font face="Courier">Data</font> parameter. Filled polygons can only have around 10,000 vertices; if the value is larger, the polygon style changes to closed lines.</p> <p><b>Seed</b> - In the seed file, several DGN parameters can be defined to be used in the drawing. The library offers a default seed file, called "SEED2D.DGN". The file's location depends on the environment variable <strong>CDDIR</strong>.</p> <h3>Behavior of Functions</h3> <h4>Control</h4> <ul> <li><a href="../func/control.html#cdClear"><font face="Courier"><strong>Clear</strong></font></a>: does nothing.</li> <li><a href="../func/other.html#cdPlay"><font face="Courier"><strong>Play</strong></font></a>: does nothing, returns <font face="Courier">CD_ERROR</font>. </li> </ul> <h4>Coordinate System and Clipping </h4> <ul> <li><a href="../func/clipping.html#cdClip"><font face="Courier"><strong>Clip</strong></font></a>: does nothing (no clipping function is supported), returns <font face="Courier">CD_CLIPOFF</font>.</li> <li><a href="../func/coordinates.html#cdUpdateYAxis"><font face="Courier"> <strong>UpdateYAxis</strong></font></a>: does nothing. The axis orientation is the same as the CD library.</li> <li><strong>Transformation Matrix</strong>: not supported.</li> </ul> <h4>Primitives</h4> <ul> <li><a href="../func/lines.html#cdBegin"><font face="Courier"><strong>Begin</strong></font></a>: if parameter <strong><tt>CD_CLIP</tt></strong> or <strong><tt>CD_BEZIER</tt></strong> are specified, does nothing.</li> <li><strong><font face="Courier"><a href="../func/filled.html#cdChord">cdChord</a></font></strong>: does nothing.</li> </ul> <h4>Attributes </h4> <ul> <li><a href="../func/filled.html#cdBackOpacity"><font face="Courier"><strong> BackOpacity</strong></font></a>: does nothing, returns <font face="Courier">CD_OPAQUE</font>.</li> <li><a href="../func/attributes.html#cdWriteMode"><font face="Courier"> <strong> WriteMode</strong></font></a>: does nothing, returns <font face="Courier">CD_REPLACE</font>.</li> <li><a href="../func/filled.html#cdInteriorStyle"><font face="Courier"> <strong> InteriorStyle</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdFillMode"><font face="Courier"><strong> FillMode</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdLineCap"><font face="Courier"><strong> LineCap</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdLineJoin"><font face="Courier"><strong> LineJoin</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdHatch"><font face="Courier"><strong>Hatch</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdStipple"><font face="Courier"><strong> Stipple</strong></font></a>: does nothing.</li> <li><a href="../func/filled.html#cdPattern"><font face="Courier"><strong> Pattern</strong></font></a>: does nothing.</li> <li><a href="../func/text.html#cdTextSize"><font face="Courier"><strong> TextSize</strong></font></a>: returns a bounding box which is usually larger than the text (the computation is based on the widest character).</li> <li><a href="../func/text.html#cdTextAlignment"><font face="Courier"><strong> TextAlignment</strong></font></a>: uses <font face="Courier"><strong>cdTextSize</strong></font>, therefore is not precise.</li> <li><a href="../func/text.html#cdFont"><font face="Courier"><strong>Font</strong></font></a>: See the font mapping table for the equivalence used to map CD fonts into MicroStation fonts. Styles are not supported.</li> </ul> <div align="center"> <center> <table border="1" cellpadding="5"> <caption valign="top"><font size="4">Font Mapping</font></caption> <tr> <th>CD Fonts</th> <th>MicroStation Font Index</th> </tr> <tr> <td><font face="Courier">CD_SYSTEM</font></td> <td><font face="Courier">0</font></td> </tr> <tr> <td><font face="Courier">CD_COURIER</font> </td> <td><font face="Courier">1</font></td> </tr> <tr> <td><font face="Courier">CD_TIMES_ROMAN</font></td> <td><font face="Courier">2</font></td> </tr> <tr> <td><font face="Courier">CD_HELVETICA</font></td> <td><font face="Courier">3</font></td> </tr> </table> </center> </div> <h4>Colors </h4> <ul> <li><a href="../func/color.html#cdGetColorPlanes"><font face="Courier"> <strong> GetColorPlanes</strong></font></a>: returns 8 (MicroStation uses a palette with 256 values).</li> <li><a href="../func/attributes.html#cdBackground"><font face="Courier"> <strong> Background</strong></font></a>: always returns <code><font face="Times New Roman">CD_WHITE</font></code>.</li> </ul> <h4>Client Images </h4> <ul> <li><a href="../func/client.html#cdGetImageRGB"><font face="Courier"><strong> GetImageRGB</strong></font></a>: does nothing.</li> <li><a href="../func/client.html#cdPutImageRGB"><font face="Courier"><strong> PutImageRGB</strong></font></a>: considering that the format supports only 256 colors, image quality is quite poor.</li> <li><a href="../func/client.html#cdPutImageRGBA"><font face="Courier"><strong> PutImageRGBA</strong></font></a>: alpha is ignored.</li> <li><a href="../func/client.html#cdPutImageMap"><font face="Courier"><strong> PutImageMap</strong></font></a>: considering that the format supports only 256 colors, image quality is quite poor.</li> </ul> <h4>Server Images </h4> <ul> <li>All functions do nothing.</li> </ul> </body> </html>