Merge branch 'master' into add-canny

ChangeLog

@@ -6,6 +6,9 @@
 - hough_line is 4x faster
 - hough_circle is 2x faster
 
+12/2/18 started 8.6.3
+- use pkg-config to find libjpeg, if we can
+
 5/1/18 started 8.6.2
 - vips_sink_screen() keeps a ref to the input image ... stops a rare race
 - fix a minor accidental ABI break in 8.6.0 -> 8.6.1 [remicollet]

configure.ac

@@ -1034,23 +1034,41 @@ if test x"$with_png" != "xno"; then
   )
 fi
 
-FIND_JPEG(
-  [with_jpeg=yes
-   EXTRA_LIBS_USED="$EXTRA_LIBS_USED -ljpeg"
-  ],
-  [AC_MSG_WARN([libjpeg not found; disabling JPEG support])
-   with_jpeg=no
-  ]
-)
+# look for libjpeg with pkg-config ... fall back to our tester
+AC_ARG_WITH([jpeg], 
+  AS_HELP_STRING([--without-jpeg], [build without libjpeg (default: test)]))
 
-# JPEG extension parameters available in libjpeg-turbo >=1.5.0, mozjpeg >=3.0
+if test x"$with_jpeg" != x"no"; then
+  PKG_CHECK_MODULES(JPEG, libjpeg,
+    [AC_DEFINE(HAVE_JPEG,1,[define if you have libjpeg installed.])
+     with_jpeg="yes (pkg-config)"
+     PACKAGES_USED="$PACKAGES_USED libjpeg"
+    ],
+    [FIND_JPEG(
+       [with_jpeg="yes (found by search)"
+	EXTRA_LIBS_USED="$EXTRA_LIBS_USED -ljpeg"
+       ],
+       [AC_MSG_WARN([libjpeg not found; disabling JPEG support])
+        with_jpeg=no
+       ]
+     )
+    ]
+  )
+fi
+
+# features like trellis quant are exposed as extension parameters ...
+# mozjpeg 3.2 and later have #define JPEG_C_PARAM_SUPPORTED, but we must 
+# work with earlier versions
 if test x"$with_jpeg" != "xno"; then
   save_LIBS="$LIBS"
-  LIBS="$LIBS $JPEG_LIBS"
+  save_CFLAGS="$CFLAGS"
+  LIBS="$JPEG_LIBS $LIBS"
+  CFLAGS="$JPEG_INCLUDES $CFLAGS"
   AC_CHECK_FUNCS(jpeg_c_bool_param_supported,
     AC_DEFINE(HAVE_JPEG_EXT_PARAMS,1,
 	      [define if your libjpeg has extension parameters.]))
   LIBS="$save_LIBS"
+  CFLAGS="$save_CFLAGS"
 fi
 
 # libexif

cplusplus/include/vips/VImage8.h

@@ -474,7 +474,7 @@ public:
 		VipsImage *image;
 
 		if( !(image = vips_image_new_from_image( this->get_image(), 
-			&pixel[0], pixel.size() )) )
+			&pixel[0], static_cast<int>( pixel.size() ) )) )
 			throw( VError() ); 
 
 		return( VImage( image ) ); 

doc/binding.md

@@ -10,18 +10,18 @@
   </refnamediv>
 
 There are full libvips bindings for quite a few environments now: C, C++,
-command-line, Ruby, PHP, Python and JavaScript (node). 
+command-line, Ruby, PHP, Lua, Python and JavaScript (node). 
 
 This chapter runs through the four main styles that have been found to work
 well. If you want to write a new binding, one of these should be close
 to what you need. 
 
-# C API
+# Don't bind the top-level C API
 
-The libvips C API (vips_add() and so on) is very inconvenient to use from other
-languages due to its heavy use of varargs. 
+The libvips C API (vips_add() and so on) is very inconvenient and dangerous
+to use from other languages due to its heavy use of varargs.
 
-It's much better to use the layer below. This lower layer is structured as:
+It's much better to use the layer below. This lower layer is structured as
 create operator, set parameters, execute, extract results. For example, you can
 execute vips_invert() like this:
 
@@ -113,10 +113,10 @@ main( int argc, char **argv )
 }
 ```
 
-libvips has a couple of extra things to let you fetch the arguments and types
-of an operator. Use vips_lib.vips_argument_map() to loop over all the arguments 
-of an operator, and vips_object_get_argument() to fetch the type and flags 
-of a specific argument. 
+libvips has a couple of extra things to let you examine the arguments and
+types of an operator at runtime. Use vips_lib.vips_argument_map() to loop
+over all the arguments of an operator, and vips_object_get_argument()
+to fetch the type and flags of a specific argument.
 
 Use vips_operation_get_flags() to get general information about an operator. 
 
@@ -124,7 +124,7 @@ Use vips_operation_get_flags() to get general information about an operator.
 
 The C++ binding uses this lower layer to define a function called
 `VImage::call()` which can call any libvips operator with a not-varargs set of
-variable arguments.  
+variable arguments. 
 
 A small Python program walks the set of all libvips operators and generates a
 set of static bindings. For example:
@@ -142,7 +142,7 @@ VImage VImage::invert( VOption *options )
 }
 ```
 
-So from C++ you can call any libvips operator, though without type-safety, with
+So from C++ you can call any libvips operator (though without type-safety) with
 `VImage::call()`, or use the member functions on `VImage` to get type-safe
 calls for at least the required operator arguments.
 
@@ -158,7 +158,7 @@ but use FFI to call into libvips and run operations.
 Since these languages are dynamic, they can add another trick: they intercept
 the method-missing hook and attempt to run any method calls not implemented by
 the `Image` class as libvips operators. This makes these bindings self-writing:
-they only contain a small amount of codeand just expose everything they find in
+they only contain a small amount of code and just expose everything they find in
 the libvips class hierarchy. 
 
 # Dynamic langauge without FFI
@@ -167,7 +167,7 @@ PHP does not have FFI, unfortunately, so for this language a small native
 module implements the general `vips_call()` function for PHP language types,
 and a larger pure PHP layer makes it convenient to use. 
 
-# `gobject-introspection`
+# gobject-introspection
 
 The C source code to libvips has been marked up with special comments
 describing the interface in a standard way. These comments are read by

doc/using-command-line.xml

@@ -44,7 +44,7 @@ where:
 </programlisting>
 
       There's a straightforward relationship with the C API: compare this to 
-      the API docs for vips_rot(), for example.
+      the API docs for vips_rot().
     </para>
   </refsect3>
 
@@ -83,7 +83,7 @@ VipsOperation (operation), operations
     <title>Optional arguments</title>
     <para>
       Many operations take optional arguments. You can supply these as 
-      command-line options, for example:
+      command-line options. For example:
 
 <programlisting>
 $ vips gamma
@@ -120,10 +120,9 @@ $ vips gamma k2.jpg x.jpg --exponent 0.42
   <refsect3 id="using-command-line-array">
     <title>Array arguments</title>
     <para>
-      Some operations take arrays of values as arguments, for example, 
+      Some operations take arrays of values as arguments. For example, 
       vips_affine() needs an array of four numbers for the 
-      2x2 transform matrix. You pass arrays as space-separated lists, for 
-      example:
+      2x2 transform matrix. You pass arrays as space-separated lists:
 
 <programlisting>
 $ vips affine k2.jpg x.jpg "2 0 0 1"
@@ -151,7 +150,7 @@ $ vips bandjoin "k2.jpg k4.jpg" x.tif
 $ vips -l foreign
 </programlisting>
 
-      Then get a list of the options a format supports with, for example:
+      Then get a list of the options a format supports with:
 
 <programlisting>
 $ vips jpegsave
@@ -160,7 +159,7 @@ $ vips jpegsave
 
     <para>
       You can pass options to the implicit load and save operations enclosed 
-      in square brackets after the filename. For example:
+      in square brackets after the filename:
 
 <programlisting>
 vips affine k2.jpg x.jpg[Q=90,strip] "2 0 0 1"