1Imager::API(3) User Contributed Perl Documentation Imager::API(3)
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6 Imager::API - Imager's C API - introduction.
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9 #include "imext.h"
10 #include "imperl.h"
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12 DEFINE_IMAGER_CALLBACKS;
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14 MODULE = Your::Module PACKAGE = Your::Module
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16 ...
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18 BOOT:
19 PERL_INITIALIZE_IMAGER_CALLBACKS;
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22 The API allows you to access Imager functions at the C level from XS
23 and from Inline::C.
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25 The intent is to allow users to:
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27 · write C code that does Imager operations the user might do from
28 Perl, but faster, for example, the Imager::CountColor example.
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30 · write C code that implements an application specific version of
31 some core Imager object, for example, Imager::SDL.
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33 · write C code that hooks into Imager's existing methods, such as
34 filter or file format handlers.
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36 See Imager::Inline for information on using Imager's Inline::C support.
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39 · don't return an object you received as a parameter - this will
40 cause the object to be freed twice.
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43 The API makes the following types visible:
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45 · i_img - used to represent an image
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47 · i_color - used to represent a color with up to 8 bits per sample.
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49 · i_fcolor - used to represent a color with a double per sample.
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51 · i_fill_t - an abstract fill
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53 At this point there is no consolidated font object type, and hence the
54 font functions are not visible through Imager's API.
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56 i_img - images
57 This contains the dimensions of the image ("xsize", "ysize",
58 "channels"), image metadata ("ch_mask", "bits", "type", "virtual"),
59 potentially image data ("idata") and the a function table, with
60 pointers to functions to perform various low level image operations.
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62 The only time you should directly write to any value in this type is if
63 you're implementing your own image type.
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65 The typemap includes type names Imager and Imager::ImgRaw as typedefs
66 for "i_img *".
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68 For incoming parameters the typemap will accept either Imager or
69 Imager::ImgRaw objects.
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71 For return values the typemap will produce a full Imager object for an
72 Imager return type and a raw image object for an Imager::ImgRaw return
73 type.
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75 "i_color" - 8-bit color
76 Represents an 8-bit per sample color. This is a union containing
77 several different structs for access to components of a color:
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79 · "gray" - single member "gray_color".
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81 · "rgb" - "r", "g", "b" members.
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83 · "rgba" - "r", "g", "b", "a" members.
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85 · "channels" - array of channels.
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87 Use Imager::Color for parameter and return value types.
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89 "i_fcolor" - floating point color
90 Similar to "i_color" except that each component is a double instead of
91 an unsigned char.
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93 Use Imager::Color::Float for parameter and return value types.
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95 "i_fill_t" - fill objects
96 Abstract type containing pointers called to perform low level fill
97 operations.
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99 Unless you're defining your own fill objects you should treat this as
100 an opaque type.
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102 Use Imager::FillHandle for parameter and return value types. At the
103 Perl level this is stored in the "fill" member of the Perl level
104 Imager::Fill object.
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107 Foo.pm
108 Load Imager:
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110 use Imager 0.48;
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112 and bootstrap your XS code - see XSLoader or DynaLoader.
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114 "Foo.xs"
115 You'll need the following in your XS source:
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117 · include the Imager external API header, and the perl interface
118 header:
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120 #include "imext.h"
121 #include "imperl.h"
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123 · create the variables used to hold the callback table:
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125 DEFINE_IMAGER_CALLBACKS;
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127 · initialize the callback table in your "BOOT" code:
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129 BOOT:
130 PERL_INITIALIZE_IMAGER_CALLBACKS;
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132 foo.c
133 In any other source files where you want to access the Imager API,
134 you'll need to:
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136 · include the Imager external API header:
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138 #include "imext.h"
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140 "Makefile.PL"
141 If you're creating an XS module that depends on Imager's API your
142 "Makefile.PL" will need to do the following:
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144 · "use Imager::ExtUtils;"
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146 · include Imager's include directory in INC:
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148 INC => Imager::ExtUtils->includes
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150 · use Imager's typemap:
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152 TYPEMAPS => [ Imager::ExtUtils->typemap ]
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154 · include Imager 0.48 as a PREREQ_PM:
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156 PREREQ_PM =>
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158 Imager => 0.48,
159 },
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161 · Since you use Imager::ExtUtils in "Makefile.PL" (or "Build.PL") you
162 should include Imager in your configure_requires:
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164 META_MERGE =>
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166 configure_requires => { Imager => "0.48" }
167 },
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170 Tony Cook <tonyc@cpan.org>
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173 Imager, Imager::ExtUtils, Imager::APIRef, Imager::Inline
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177perl v5.12.3 2011-06-06 Imager::API(3)