MapServer Tutorial——MapServer7.2.1教程学习——第一节用例实践：Example 1.4 Labeling the Map

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <handlers>
            <add name="MapServerFastCgi" path="*" verb="*" type="" modules="FastCgiModule" 
　　　　　　　　　　scriptProcessor="E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\bin\mapserv.exe" 
　　　　　　　　　　resourceType="Unspecified" requireAccess="Script" allowPathInfo="false" preCondition=""  />
        </handlers>
        <caching enabled="true" enableKernelCache="true" />
    </system.webServer>
</configuration>

# The annotated map file (sort of)
# Created by Pericles S. Nacionales for the MapServer tutorial
# 20050408
#
# MapServer map file uses the pound sign (#) to denote the start of a line
# comment--each line that needs to be commented has to be prepended with a "#".
#
# Map files begin with MAP keyword to signify the start of the map object.
# Well, the entire map file is THE map object.  Enclosed between MAP and END
# at the very bottom of this map file, are keyword/value pairs and other
# objects.
MAP
  IMAGETYPE      PNG
  EXTENT         -97.238976 41.619778 -82.122902 49.385620
  SIZE           400 300
  SHAPEPATH      "./data"
  IMAGECOLOR     255 255 255
  FONTSET        "./fonts/fonts.list"

  # Layer objects are defined beneath the map object.  You need at least one
  # layer defined in your map file before you can display a map...  You can
  # define as many layers as you‘d like although a limit is typically hard-coded
  # in map.h in the MapServer source.  The default limit is set at 100.  You‘d
  # have to have a very specialized application to need more than 100 layers in
  # your application.

  # Start of LAYER DEFINITIONS ---------------------------------------------
  LAYER # States polygon layer begins here
    NAME         states_poly
    DATA         states_ugl
    STATUS       OFF
    TYPE         POLYGON

    # CLASSITEM defines the non-spatial attribute that you will be using to
    # separate a layer into classes.  This attribute will be in the DBF file
    # of your shapefile (it will be different for each data format).  In this
    # example the shapefile states_ugl has an associated database
    # (states_ugl.dbf) that contains an attribute called "CLASS".  You will be
    # using two values in the CLASS attribute to separate the classes (also
    # called themes) used in this layer--land and water.  CLASSITEM is used in
    # association with the EXPRESSION parameter in the CLASS object.  See below.
    CLASSITEM    "CLASS"

    # Just like CLASSITEM, LABELITEM defines the database attribute that you
    # will be using to draw labels.  In this case, the values of the attribute
    # "STATE" will be used to label the states polygons.
    LABELITEM    "STATE"

    # The class object is defined within the layer object.  You can define as
    # many classes as you need (well, there are limits as with layers, but it‘s
    # senseless to define more than ten on a "normal" layer.  There are
    # situations, however, where you might have to do it.)
    CLASS
      NAME ‘States‘
      EXPRESSION ‘land‘

      # There are styles in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple styles in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      STYLE
        COLOR      232 232 232
      END

      # There can be labels in a class, just like there are classes in a layer,
      # just like there are layers in a map.  You can define multiple labels in
      # a class just as you can define multiple classes in a layer and multiple
      # layers in a map.
      # MapServer has a very flexible labeling system.  With that flexibility
      # comes complexity, specially when using truetype fonts.  Please read
      # through the LABEL section of the MapServer map file documentation at
      # http://www.mapserver.org/mapfile for more information.
      LABEL
        COLOR 132 31 31
        TYPE TRUETYPE
        FONT arial-bold
        SIZE 12
        ANTIALIAS TRUE
        POSITION CL
        PARTIALS FALSE
        MINDISTANCE 300
        BUFFER 4
        # create a background shadow
        #  Note that the tutorial package has not been updated, so this has
        #  to be done manually!
        #SHADOWCOLOR 218 218 218  # prior to version 6
        #SHADOWSIZE 2 2  # prior to version 6
        STYLE    # since to version 6
          GEOMTRANSFORM ‘labelpoly‘
          COLOR 218 218 218
          OFFSET 2 2
        END # STYLE
      END # end of label
    END

    CLASS
      NAME ‘Water‘
      EXPRESSION ‘water‘

      STYLE
        COLOR      198 198 255
      END
    END
  END # States polygon layer ends here

  LAYER # States line layer begins here
    NAME         states_line
    DATA         states_ugl
    STATUS       OFF
    TYPE         LINE

    CLASSITEM    "CLASS"
    CLASS
      NAME ‘State Boundary‘
      EXPRESSION ‘land‘
      STYLE
        COLOR      64 64 64
      END
    END
  END # States line layer ends here
  # End of LAYER DEFINITIONS -------------------------------

END # All map files must come to an end just as all other things must come to...

                             MAP
 (states_poly) LAYER----------|---------LAYER (states_line)
(land) CLASS-----|-CLASS (water)         |-CLASS
  STYLE-|-LABEL     |-STYLE                 |-STYLE</pre>

# This be the fonts list
arial                           Vera.ttf
arial-bold                      VeraBd.ttf
arial-italic                    VeraIt.ttf
arial-bold-italic               VeraBI.ttf
times                           VeraSe.ttf
times-bold                      VeraSeBd.ttf
andale-mono                     VeraMono.ttf
vera_sans                       Vera.ttf
vera_sans-bold                  VeraBd.ttf
vera_sans-italic                VeraIt.ttf
vera_sans-bold-italic           VeraBI.ttf
vera_sans_mono                  VeraMono.ttf
vera_sans_mono-bold             VeraMoBd.ttf
vera_sans_mono-italic           VeraMoIt.ttf
vera_sans_mono-bold-italic      VeraMoBI.ttf
vera_serif                      VeraSe.ttf
vera_serif-bold                 VeraSeBd.ttf

# This be the fonts list
arial                           E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\Vera.ttf
arial-bold                      E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraBd.ttf
arial-italic                    E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraIt.ttf
arial-bold-italic               E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraBI.ttf
times                           E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraSe.ttf
times-bold                      E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraSeBd.ttf
andale-mono                     E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraMono.ttf
vera_sans                       E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\Vera.ttf
vera_sans-bold                  E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraBd.ttf
vera_sans-italic                E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraIt.ttf
vera_sans-bold-italic           E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraBI.ttf
vera_sans_mono                  E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraMono.ttf
vera_sans_mono-bold             E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraMoBd.ttf
vera_sans_mono-italic           E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraMoIt.ttf
vera_sans_mono-bold-italic      E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraMoBI.ttf
vera_serif                      E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraSe.ttf
vera_serif-bold                 E:\SvnWorkspace\LY_WEB_GIS\branches\Documents\ms4w-mapserver-for-wimdows\release-1911-x64-gdal-2-3-3-mapserver-7-2-1\apps\Example1.4\fonts\VeraSeBd.ttf

The following simple geometry transformations are available at the LABEL STYLE level: #在LABEL标签的STYLE标签中，使用GEOMTRANSFORM有两种类型，分别为：labelpnt 和 labelpoly

labelpnt
labelpoly

These are used for label styling (background colour, background shadow, background frame). #他们是为label的背景颜色，背景阴影，背景框架做样式设置的。

Note The result of using labelpnt is affected by the LAYER LABELCACHE setting. If LABELCACHE is ON (the default), the label will be shifted when a non-zero sized symbol is added using labelpnt.

labelpnt and labelpoly

• GEOMTRANSFORM labelpnt produces the geographic position the label is attached to. This corresponds to the center of the label text only if the label is in position CC.

　　　　GEOMTRANSFORM “labelpnt”

• GEOMTRANSFORM labelpoly produces a polygon that covers the label plus a 1 pixel padding.

　　　　GEOMTRANSFORM “labelpoly”

Note Only available for STYLE in the LABEL context.

These transformations can be used to make background rectangles for labels and add symbols to the label points.

Class definitions for the example:

CLASS
  STYLE
    OUTLINECOLOR 255 255 204
  END # STYLE
  LABEL
    SIZE giant
    POSITION UC
　　　#好了，第一个的疑问就在此处，同样 LABEL 中 GEOMTRANSFORM 的值均为"labelpoly"，是如何判断当前 设置的为：阴影、背景颜色、还是边线呢？
　　　#设置shadow难道是因为style标签中有 OFFSET 标签吗？
　　　#设置 backgground 是因为只有COLOR，没有其他标签吗？
　　　#设置outline是因为有OUTLINECOLOR标签，和WIDTH标签吗？
　　  #我实在是有点费解。

    STYLE # shadow
      GEOMTRANSFORM "labelpoly"
      COLOR 153 153 153
      OFFSET 3 3
    END # Style
    STYLE # background
      GEOMTRANSFORM "labelpoly"
      COLOR 204 255 204
    END # Style
    STYLE # outline
      GEOMTRANSFORM "labelpoly"
      OUTLINECOLOR 0 0 255
      WIDTH 1
    END # Style
    STYLE
      GEOMTRANSFORM "labelpnt"
      SYMBOL ‘circlef‘ #此处是自定义符号，设置红色圆点的。
      COLOR 255 0 0
      SIZE 15
    END # Style
  END # Label
END # Class

 Symbol definition for the circlef symbol:

SYMBOL
  NAME "circlef"
  TYPE ellipse
  FILLED true
  POINTS
    1 1
  END # POINTS
END # SYMBOL

GEOMTRANSFORM [bbox|centroid|end|labelpnt|labelpoly|start|vertices|<expression>] 
　　Used to indicate that the current feature will be transformed before the actual style is applied. Introduced in version 5.4.

• bbox: produces the bounding box of the current feature geometry.
• centroid: produces the centroid of the current feature geometry.
• end: produces the last point of the current feature geometry. When used with ANGLE AUTO, it can for instance be used to render arrowheads on line segments.
• labelpnt: used for LABEL styles. Draws a marker on the geographic position the label is attached to. This corresponds to the center of the label text only if the label is in position CC.
• labelpoly: used for LABEL styles. Produces a polygon that covers the label plus a 1 pixel padding.
• start: produces the first point of the current feature geometry. When used with ANGLE AUTO, it can for instance be used to render arrow tails on line segments.
• vertices: produces all the intermediate vertices (points) of the current feature geometry (the start and end are excluded). When used with ANGLE AUTO, the marker is oriented by the half angle formed by the two adjacent line segments.
• <expression>: Applies the given expression to the geometry. Supported expressions:
  • (buffer([shape],dist)): Buffer the geometry ([shape]) using dist pixels as buffer distance. For polygons, a negative dist will produce a setback.
  • (generalize([shape],tolerance)): simplifies a geometry ([shape]) in way comparable to FME’s ThinNoPoint algorithm. See http://trac.osgeo.org/gdal/ticket/966 for more information.

　　　　Note Depends on GEOS.

• • (simplify([shape],tolerance)): simplifies a geometry ([shape]) using the standard Douglas-Peucker algorithm.
  • (simplifypt([shape],tolerance)): simplifies a geometry ([shape]), ensuring that the result is a valid geometry having the same dimension and number of components as the input. tolerance must be non-negative.
  • (smoothsia([shape], smoothing_size, smoothing_iteration, preprocessing)): will smooth a geometry ([shape]) using the SIA algorithm

　　　　Example (polygon data set) - draw a two pixel wide line 5 pixels inside the boundary of the polygon:

STYLE
  OUTLINECOLOR 255 0 0
  WIDTH 2
  GEOMTRANSFORM (buffer([shape],-5))
END

 　　There is a difference between STYLE and LAYER GEOMTRANSFORM. LAYER-level will receive ground coordinates (meters, degrees, etc) and STYLE-level will receive pixel coordinates. The argument to methods such as simplify() must be in the same units as the coordinates of the shapes at that point of the rendering workflow, i.e. pixels at the STYLE-level and in ground units at the LAYER-level.

LAYER NAME "my_layer"
    TYPE LINE
    STATUS DEFAULT
    DATA "lines.shp"
    GEOMTRANSFORM (simplify([shape], 10))  ## 10 ground units
    CLASS
        STYLE
            GEOMTRANSFORM (buffer([shape], 5)  ## 5 pixels
            WIDTH 2
            COLOR 255 0 0
        END
    END
END

　　See also GEOMTRANSFORM - Geometry Transformations

STYLE

　　The start of a STYLE object.
　　Label specific mechanisms of the STYLE object are the GEOMTRANSFORM options: #此处也说明了，在STYLE对象中使用 GEOMTRANSFORM ，当然，前提是基于 LABEL 的使用 STYLE
　　　　GEOMTRANSFORM [labelpnt|labelpoly]
　　　　Creates a geometry that can be used for styling the label. Does not apply to ANGLE FOLLOW labels.

• • labelpnt draws a marker on the geographic position the label is attached to. This corresponds to the center of the label text only if the label is in position CC.
  • labelpoly generates the bounding rectangle for the text, with 1 pixel of padding added in all directions.

　　　　The resulting geometries can be styled using the mechanisms available in the STYLE object.

　　　　　　Example - draw a red background rectangle for the labels (i.e. billboard) with a “shadow” in gray:

STYLE
  GEOMTRANSFORM ‘labelpoly‘
  COLOR 153 153 153
  OFFSET 3 2
END # STYLE
STYLE
  GEOMTRANSFORM ‘labelpoly‘
  COLOR 255 0 0
END # STYLE

　　New in version 6.0.