adding float and double as types with name and size tests (#51)

add translate to type cases

replace float compare by Nextafter and Nextafter32

add parser for floats and doubles

add float and double parsers

add support for doubles and floats in FormatFrom functions

add ReadFloats and ReadDoubles for context

add float32 and double encoder

merging

merge

add float and double parsers

add ReadFloats and ReadDoubles for context

add float32 and double encoder

removing log alias from parser

removing log alias from parser_test

removing log alias from type

removing log alias from type_test

removing log alias from value_context

removing aliases from value_contex_test

removing log alias from value_encoder

removing log alias from value_encoder_test

update parser slices from floats and doubles

merge

update values for tests

raise exception when parsing with different expected size

Revert "move tags to bottom part of IFD and add description with source"

This reverts commit 9d79f79757.

Revert "adding Geotiff tags ModelTransformationTag, ModelTiepointTag and ModelPixelScaleTag"

This reverts commit 60653d5647.

adding tags with required formatation

v2/tags_data.go

@@ -909,25 +909,6 @@ IFD:
 - id: 0xc74e
   name: OpcodeList3
   type_name: UNDEFINED
-# This tag may be used to specify the size of raster pixel spacing in the model space units, when the raster space can be embedded in the model space coordinate system without rotation, and consists of the following 3 values:
-#    ModelPixelScaleTag = (ScaleX, ScaleY, ScaleZ)
-# where ScaleX and ScaleY give the horizontal and vertical spacing of raster pixels. The ScaleZ is primarily used to map the pixel value of a digital elevation model into the correct Z-scale, and so for most other purposes this value should be zero (since most model spaces are 2-D, with Z=0).
-# Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
-- id: 0x830e
-  name: ModelPixelScaleTag
-  type_name: RATIONAL
-# This tag stores raster->model tiepoint pairs in the order
-#	ModelTiepointTag = (...,I,J,K, X,Y,Z...),
-# where (I,J,K) is the point at location (I,J) in raster space with pixel-value K, and (X,Y,Z) is a vector in model space. In most cases the model space is only two-dimensional, in which case both K and Z should be set to zero; this third dimension is provided in anticipation of future support for 3D digital elevation models and vertical coordinate systems.
-# Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
-- id: 0x8482
-  name: ModelTiepointTag
-  type_name: RATIONAL
-# This tag may be used to specify the transformation matrix between the raster space (and its dependent pixel-value space) and the (possibly 3D) model space.
-# Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
-- id: 0x85d8
-  name: ModelTransformationTag
-  type_name: RATIONAL
 IFD/Exif/Iop:
 - id: 0x0001
   name: InteroperabilityIndex

v3/common/value_encoder_test.go

@@ -7,7 +7,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/dsoprea/go-logging"
+	log "github.com/dsoprea/go-logging"
 )
 
 func TestValueEncoder_encodeBytes__Cycle(t *testing.T) {

v3/tags_data.go

@@ -909,25 +909,36 @@ IFD:
 - id: 0xc74e
   name: OpcodeList3
   type_name: UNDEFINED
-# This tag may be used to specify the size of raster pixel spacing in the model space units, when the raster space can be embedded in the model space coordinate system without rotation, and consists of the following 3 values:
+# This tag may be used to specify the size of raster pixel spacing in the 
+# model space units, when the raster space can be embedded in the model space 
+# coordinate system without rotation, and consists of the following 3 values:
 #    ModelPixelScaleTag = (ScaleX, ScaleY, ScaleZ)
-# where ScaleX and ScaleY give the horizontal and vertical spacing of raster pixels. The ScaleZ is primarily used to map the pixel value of a digital elevation model into the correct Z-scale, and so for most other purposes this value should be zero (since most model spaces are 2-D, with Z=0).
+# where ScaleX and ScaleY give the horizontal and vertical spacing of raster 
+# pixels. The ScaleZ is primarily used to map the pixel value of a digital 
+# elevation model into the correct Z-scale, and so for most other purposes 
+# this value should be zero (since most model spaces are 2-D, with Z=0).
 # Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
 - id: 0x830e
   name: ModelPixelScaleTag
-  type_name: RATIONAL
+  type_name: DOUBLE
 # This tag stores raster->model tiepoint pairs in the order
 #	ModelTiepointTag = (...,I,J,K, X,Y,Z...),
-# where (I,J,K) is the point at location (I,J) in raster space with pixel-value K, and (X,Y,Z) is a vector in model space. In most cases the model space is only two-dimensional, in which case both K and Z should be set to zero; this third dimension is provided in anticipation of future support for 3D digital elevation models and vertical coordinate systems.
+# where (I,J,K) is the point at location (I,J) in raster space with 
+# pixel-value K, and (X,Y,Z) is a vector in model space. In most cases the 
+# model space is only two-dimensional, in which case both K and Z should be 
+# set to zero; this third dimension is provided in anticipation of future 
+# support for 3D digital elevation models and vertical coordinate systems.
 # Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
 - id: 0x8482
   name: ModelTiepointTag
-  type_name: RATIONAL
-# This tag may be used to specify the transformation matrix between the raster space (and its dependent pixel-value space) and the (possibly 3D) model space.
+  type_name: DOUBLE
+# This tag may be used to specify the transformation matrix between the 
+# raster space (and its dependent pixel-value space) and the (possibly 3D) 
+# model space.
 # Source: http://geotiff.maptools.org/spec/geotiff2.6.html#2.6.1
 - id: 0x85d8
   name: ModelTransformationTag
-  type_name: RATIONAL
+  type_name: DOUBLE
 IFD/Exif/Iop:
 - id: 0x0001
   name: InteroperabilityIndex