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Rev | Author | Line No. | Line |
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827 | - | 1 | # Calculate tile characteristics given a bounding box of coordinates and a zoom... |
2 | # Author. John D. Coryat 01/2008... |
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3 | # USNaviguide LLC. |
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4 | # Published under Apache 2.0 license. |
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5 | # Adapted from: Google Maps API Javascript... |
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6 | ## |
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7 | # In order to correctly locate objects of interest on a Custom Map Overlay Google Maps, |
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8 | # the characteristics of each tile to build are required. |
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9 | ## |
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10 | # Google_Tiles # Calculate all tiles for a bounding box and zoom |
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11 | # Google_Tile_Factors # Calculate the factors needed ( Zoom, Tilesize ) |
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12 | # Google_Tile_Calc # Calculate a single tile features from a tile name and zoom |
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13 | # Google_Tile_to_Pix # Calculate tile name to pixel |
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14 | # Google_Coord_to_Pix # Calculate coordinate to Pixel |
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15 | # Google_Pix_to_Tile # Calculate a tile name from a pixel location and zoom |
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16 | # Google_Pix_to_Coordinate # Calculate a coordinate from Pixel |
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17 | |||
18 | require 5.003 ; |
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19 | package libgemaps; |
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20 | use strict ; |
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21 | use Math::Trig ; |
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22 | |||
23 | BEGIN { |
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24 | use Exporter ; |
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25 | use vars qw ( $VERSION @ISA @EXPORT) ; |
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26 | $VERSION = 1.0 ; |
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27 | @ISA = qw ( Exporter ) ; |
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28 | @EXPORT = qw ( |
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29 | Google_Tiles |
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30 | Google_Tile_Factors |
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31 | Google_Tile_Calc |
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32 | Google_Tile_to_Pix |
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33 | Google_Coord_to_Pix |
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34 | Google_Pix_to_Tile |
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35 | Google_Pix_to_Coordinate |
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36 | ) ; |
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37 | } |
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38 | |||
39 | # |
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40 | # Call as: <array of Hashes> = &Google_Tiles(<LatitudeS>, <LongitudeW>, <LatitudeN>, <LongitudeE>, <Zoom>, [<option: tileSize>], [<option: Partial/Whole>]) ; |
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41 | # Partial/Whole option: (Default: Partial) |
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42 | # Partial: Include the edge to create partial tiles |
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43 | # Whole: Include only tiles that are contained by the bounds |
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44 | # |
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45 | # Returned Array Specifications: |
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46 | # Each element is a reference to a Hash: |
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47 | # NAMEY - Tile Name y |
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48 | # NAMEX - Tile Name x |
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49 | # PYS - Pixel South |
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50 | # PXW - Pixel West |
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51 | # PYN - Pixel North |
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52 | # PXE - Pixel East |
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53 | # LATS - South Latitude |
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54 | # LNGW - West Longitude |
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55 | # LATN - North Latitude |
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56 | # LNGE - East Longitude |
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57 | # |
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58 | # Note: X is width, Y is height... |
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59 | # |
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60 | |||
61 | sub Google_Tiles |
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62 | { |
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63 | my $latS = shift ; |
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64 | my $lngW = shift ; |
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65 | my $latN = shift ; |
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66 | my $lngE = shift ; |
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67 | my $zoom = shift ; |
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68 | my $tileSize = shift ; |
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69 | my $parwho = shift ; |
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70 | my $ty = 0 ; |
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71 | my $tx = 0 ; |
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72 | my @ret = ( ) ; |
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73 | my %first = ( ) ; # First Results Hash |
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74 | my %last = ( ) ; # Last Results Hash |
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75 | |||
76 | my $value = &Google_Tile_Factors($zoom, $tileSize) ; # Calculate Tile Factors |
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77 | |||
78 | if (!defined($parwho) or !$parwho) |
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79 | { |
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80 | $parwho = 'Partial' ; |
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81 | } |
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82 | |||
83 | # NW: Convert Coordinates to Pixels... |
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84 | |||
85 | ($first{'NORTH'},$first{'WEST'}) = &Google_Coord_to_Pix( $value, $latN, $lngW ) ; |
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86 | |||
87 | # Convert Pixels to Tile Name... |
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88 | |||
89 | ($first{'NAMEY'},$first{'NAMEX'}) = &PixtoTileName( $value, $first{'NORTH'}, $first{'WEST'}, 'N', 'W', $parwho ) ; |
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90 | |||
91 | # SE: Convert Coordinates to Pixels... |
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92 | |||
93 | ($last{'SOUTH'},$last{'EAST'}) = &Google_Coord_to_Pix( $value, $latS, $lngE ) ; |
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94 | |||
95 | # Convert Pixels to Tile Name... |
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96 | |||
97 | ($last{'NAMEY'},$last{'NAMEX'}) = &PixtoTileName( $value, $last{'SOUTH'}, $last{'EAST'}, 'S', 'E', $parwho ) ; |
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98 | |||
99 | # Calculate tile values for all tiles... |
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100 | |||
101 | if ( $first{'NAMEX'} > $last{'NAMEX'} ) # Across the date line |
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102 | { |
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103 | for ( $ty = $first{'NAMEY'} ; $ty <= $last{'NAMEY'} ; $ty++ ) |
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104 | { |
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105 | for ( $tx = $first{'NAMEX'} ; $tx <= $$value{'max'} ; $tx++ ) |
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106 | { |
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107 | push( @ret, {&Google_Tile_Calc( $value, $ty, $tx)} ) ; |
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108 | } |
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109 | for ( $tx = 0 ; $tx <= $last{'NAMEX'} ; $tx++ ) |
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110 | { |
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111 | push( @ret, {&Google_Tile_Calc( $value, $ty, $tx)} ) ; |
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112 | } |
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113 | } |
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114 | } else |
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115 | { |
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116 | for ( $ty = $first{'NAMEY'} ; $ty <= $last{'NAMEY'} ; $ty++ ) |
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117 | { |
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118 | for ( $tx = $first{'NAMEX'} ; $tx <= $last{'NAMEX'} ; $tx++ ) |
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119 | { |
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120 | push( @ret, {&Google_Tile_Calc( $value, $ty, $tx)} ) ; |
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121 | } |
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122 | } |
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123 | } |
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124 | |||
125 | $ret[0]{'NORTH'} = $first{'NORTH'} ; |
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126 | $ret[0]{'WEST'} = $first{'WEST'} ; |
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127 | |||
128 | $ret[$#ret]{'SOUTH'} = $last{'SOUTH'} ; |
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129 | $ret[$#ret]{'EAST'} = $last{'EAST'} ; |
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130 | |||
131 | return ( @ret ) ; |
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132 | } |
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133 | |||
134 | # Calculate Tile Factors... |
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135 | |||
136 | sub Google_Tile_Factors |
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137 | { |
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138 | my $zoom = shift ; |
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139 | my $tileSize = shift ; |
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140 | my %value = ( ) ; |
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141 | |||
142 | # Validate and correct input parameters... |
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143 | |||
144 | if ( !defined($zoom) or $zoom < 0 ) |
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145 | { |
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146 | $zoom = 0 ; |
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147 | } |
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148 | |||
149 | if ( !defined($tileSize) or !$tileSize ) |
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150 | { |
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151 | $tileSize = 256 ; |
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152 | } |
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153 | |||
154 | # Calculate Values... |
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155 | |||
156 | $value{'zoom'} = $zoom ; |
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157 | $value{'PI'} = 3.1415926536 ; |
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158 | $value{'bc'} = 2 * $value{'PI'} ; |
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159 | $value{'Wa'} = $value{'PI'} / 180 ; |
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160 | $value{'cp'} = 2 ** ($value{'zoom'} + 8) ; |
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161 | $value{'max'} = (2 ** $value{'zoom'}) - 1 ; # Maximum Tile Number |
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162 | $value{'pixLngDeg'}= $value{'cp'} / 360; |
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163 | $value{'pixLngRad'}= $value{'cp'} / $value{'bc'} ; |
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164 | $value{'bmO'} = $value{'cp'} / 2 ; |
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165 | $value{'tileSize'} = $tileSize ; |
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166 | |||
167 | return \%value ; |
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168 | } |
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169 | |||
170 | # Calculate tile values from Name... |
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171 | |||
172 | sub Google_Tile_Calc |
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173 | { |
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174 | my %result = ( ) ; |
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175 | my $value = shift ; |
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176 | $result{'NAMEY'} = shift ; |
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177 | $result{'NAMEX'} = shift ; |
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178 | |||
179 | # Convert Tile Name to Pixels... |
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180 | |||
181 | ($result{'PYN'},$result{'PXW'}) = &Google_Tile_to_Pix( $value, $result{'NAMEY'}, $result{'NAMEX'} ) ; |
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182 | |||
183 | # Convert Pixels to Coordinates (Upper Left Corner)... |
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184 | |||
185 | ($result{'LATN'},$result{'LNGW'}) = &Google_Pix_to_Coordinate( $value, $result{'PYN'}, $result{'PXW'} ) ; |
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186 | |||
187 | $result{'PYS'} = $result{'PYN'} + 255 ; |
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188 | $result{'PXE'} = $result{'PXW'} + 255 ; |
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189 | |||
190 | # Convert Pixels to Coordinates (Lower Right Corner)... |
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191 | |||
192 | ($result{'LATS'},$result{'LNGE'}) = &Google_Pix_to_Coordinate( $value, $result{'PYS'}, $result{'PXE'} ) ; |
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193 | |||
194 | return %result ; |
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195 | } |
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196 | |||
197 | # Calculate a tile name from a pixel location and zoom... |
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198 | |||
199 | sub Google_Pix_to_Tile |
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200 | { |
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201 | my $value = shift ; |
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202 | my $ty = shift ; |
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203 | my $tx = shift ; |
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204 | |||
205 | # Convert Pixels to Tile Name... |
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206 | |||
207 | ($ty,$tx) = &PixtoTileName( $value, $ty, $tx, 'N', 'W', 'Partial' ) ; |
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208 | |||
209 | return ( $ty,$tx ) ; |
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210 | } |
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211 | |||
212 | # Translate a coordinate to a pixel location... |
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213 | |||
214 | sub Google_Coord_to_Pix |
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215 | { |
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216 | my $value = shift ; |
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217 | my $lat = shift ; |
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218 | my $lng = shift ; |
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219 | my @d = ( ) ; |
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220 | my $e = 0 ; |
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221 | |||
222 | $d[1] = sprintf("%0.0f", $$value{'bmO'} + $lng * $$value{'pixLngDeg'} ) ; |
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223 | |||
224 | $e = sin($lat * $$value{'Wa'}) ; |
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225 | |||
226 | if( $e > 0.99999 ) |
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227 | { |
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228 | $e = 0.99999 ; |
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229 | } |
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230 | |||
231 | if( $e < -0.99999 ) |
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232 | { |
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233 | $e = -0.99999 ; |
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234 | } |
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235 | |||
236 | $d[0] = sprintf("%0.0f", $$value{'bmO'} + 0.5 * log((1 + $e) / (1 - $e)) * (-1) * $$value{'pixLngRad'} ) ; |
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237 | |||
238 | return (@d) ; |
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239 | } |
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240 | |||
241 | # Translate a pixel location to a tile name... |
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242 | |||
243 | sub PixtoTileName |
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244 | { |
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245 | my $value = shift ; |
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246 | my $y = shift ; |
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247 | my $x = shift ; |
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248 | my $yd = shift ; # Y Direction: N or S |
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249 | my $xd = shift ; # X Direction: W or E |
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250 | my $parwho = shift ; # Partial / Whole |
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251 | my $yn = 0 ; # Y Name |
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252 | my $xn = 0 ; # X Name |
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253 | |||
254 | $yn = int( $y / $$value{'tileSize'} ) ; # Round Down |
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255 | $xn = int( $x / $$value{'tileSize'} ) ; # Round Down |
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256 | |||
257 | if ( $parwho ne 'Partial' ) |
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258 | { |
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259 | if ( $yd eq 'N' ) |
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260 | { |
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261 | $yn++ ; |
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262 | } else |
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263 | { |
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264 | $yn-- ; |
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265 | } |
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266 | if ( $xd eq 'W' ) |
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267 | { |
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268 | $xn++ ; |
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269 | } else |
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270 | { |
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271 | $xn-- ; |
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272 | } |
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273 | } |
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274 | |||
275 | # Make sure tile numbers are sane... |
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276 | |||
277 | if ( $yn > $$value{'max'} ) |
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278 | { |
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279 | $yn = $$value{'max'} ; |
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280 | } elsif ( $yn < 0 ) |
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281 | { |
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282 | $yn = 0 ; |
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283 | } |
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284 | |||
285 | if ( $xn > $$value{'max'} ) |
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286 | { |
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287 | $xn = $$value{'max'} ; |
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288 | } elsif ( $xn < 0 ) |
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289 | { |
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290 | $xn = 0 ; |
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291 | } |
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292 | |||
293 | return( $yn, $xn ) ; |
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294 | } |
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295 | |||
296 | # Translate a tile name to a pixel location... |
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297 | |||
298 | sub Google_Tile_to_Pix |
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299 | { |
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300 | my $value = shift ; |
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301 | my $y = shift ; |
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302 | my $x = shift ; |
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303 | return( (sprintf("%0.0f", $y * $$value{'tileSize'} ), sprintf("%0.0f", $x * $$value{'tileSize'} )) ) ; |
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304 | } |
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305 | |||
306 | # Translate a pixel location to a coordinate... |
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307 | |||
308 | sub Google_Pix_to_Coordinate |
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309 | { |
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310 | my $value = shift ; |
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311 | my $y = shift ; |
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312 | my $x = shift ; |
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313 | my @d = ( ) ; |
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314 | my $e = (($y - $$value{'bmO'}) / $$value{'pixLngRad'}) * (-1) ; |
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315 | |||
316 | $d[1] = sprintf("%0.6f",($x - $$value{'bmO'}) / $$value{'pixLngDeg'}) ; |
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317 | |||
318 | $d[0] = sprintf("%0.6f", (2 * atan(exp($e)) - $$value{'PI'} / 2) / $$value{'Wa'}) ; |
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319 | return (@d); |
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320 | } |
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321 | |||
322 | 1; |
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323 | |||
324 | __END__ |
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325 | |||
326 | =head1 SYNOPSIS |
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327 | |||
328 | #!/usr/bin/perl -w |
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329 | # Test Program: |
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330 | |||
331 | # Google Tile Calculator Test Program... |
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332 | # Author. John D. Coryat 01/2008 USNaviguide LLC |
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333 | |||
334 | use strict; |
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335 | use USNaviguide_Google_Tiles ; |
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336 | |||
337 | my $latS = 34.177442 ; |
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338 | my $lngW = -91.318359 ; |
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339 | my $latN = 35.797300 ; |
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340 | my $lngE = -88.681641 ; |
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341 | my $zoom = 8 ; |
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342 | my $x = '' ; |
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343 | my %tile = ( ) ; |
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344 | my $i = 0 ; |
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345 | |||
346 | my @d = &Google_Tiles($latS, $lngW, $latN, $lngE, $zoom,0,'Whole'); |
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347 | |||
348 | print "Total: " . scalar(@d) . "\n" ; |
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349 | |||
350 | for ( $i = 0; $i <= $#d; $i++ ) |
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351 | { |
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352 | print "Tile # $i Y: $d[$i]{'NAMEY'} X: $d[$i]{'NAMEX'}\n" ; |
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353 | |||
354 | %tile = %{$d[$i]} ; |
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355 | |||
356 | foreach $x (sort keys %tile) |
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357 | { |
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358 | print "\t$x: $tile{$x}\n" ; |
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359 | } |
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360 | } |
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361 | |||
362 | =cut |