= !MapGuide RFC 26 - Stylize Elevation Layer =

This page contains an change request (RFC) for the !MapGuide Open Source project.  
More !MapGuide RFCs can be found on the [wiki:MapGuideRfcs RFCs] page.

== Status == 
 
||RFC Template Version||1.0|| 
||Submission Date||Aug 2, 2007||
||Last Modified||Maggie Yang [[Timestamp]]||
||Author||Maggie Yang||
||RFC Status||draft||
||Implementation Status||under development||
||Proposed Milestone||1.3||
||Assigned PSC guide(s)||(when determined)||
||'''Voting History'''||(vote date)||
||+1||||
||+0||||
||-0||||
||-1||||
 
== Overview ==

The purpose of this RFC is to allow !MapGuide to stylize the elevation data, which configured surface style in its layer definition.

== Motivation ==

!MapGuide cannot stylize the elevation layer, such as DEM and GeoTIFF file, configured by the following kind of layer definition with surface style: 
{{{
<LayerDefinition xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:noNamespaceSchemaLocation="LayerDefinition-1.0.0.xsd" version="1.0.0">
<GridLayerDefinition>  <ResourceId>Library://Publish/Data/Raster_1.FeatureSource</ResourceId> 
  <FeatureName>rasters:davenport</FeatureName> 
  <Geometry>Image</Geometry> 
  <GridScaleRange>
    <SurfaceStyle>
      <Band>1</Band> 
      <DefaultColor>0000FF00</DefaultColor> 
    </SurfaceStyle>
    <ColorStyle>
      <HillShade>
        <Band>1</Band> 
        <Azimuth>45</Azimuth> 
        <Altitude>45</Altitude> 
      </HillShade>
      <ColorRule>
        <LegendLabel>-1.79e+308 to 1.79e+308</LegendLabel> 
        <Filter>(Height(1) > -1.7976931348623158e+308) AND (Height(1) < 1.7976931348623158e+308)</Filter> 
        <Color>
          <ExplicitColor>FF00FF00</ExplicitColor> 
        </Color>
      </ColorRule>
      <ColorRule>
        <LegendLabel>{DEFAULT}</LegendLabel> 
        <Color>
          <ExplicitColor>FF006423</ExplicitColor> 
        </Color>
      </ColorRule>
    </ColorStyle>
    <RebuildFactor>1</RebuildFactor> 
  </GridScaleRange>
</GridLayerDefinition>
}}}
Currently, !MapGuide do not have the stylization mechanism for grid surface data. So, in this release, we will make !MapGuide has the ability to stylize the elevation layer. The user would see the stylized elevation data, like Figure 1 in !MapGuide in the future, not the Figure 2, which is the current status for elevation data in !MapGuide.

||[[Image(After.JPG, align=center)]]|| instead of ||[[Image(Before.JPG, align=center)]]||
||Figure1|| ||Figure2||

== Proposed Solution ==

Modify Stylization project to support the stylization of the elevation data, with surface style. New classes will be introduced to handle that style information, such as color, band, surface, hillshade and etc.

== Implications ==

This RFC does not describe any GUI modifications and does not affect the existed published API. 

== Test Plan ==

Add an elevation layer to !MapGuide, the elevation layer should display with grid surface, like Figure1.

== Funding/Resources ==

Supplied by Autodesk.