A new plugin appears: GRIBIO, to read GRIB files (see issue 19). This is still extremely preliminary alpha code (enough warnings?!), but it should (hopefully) quickly evolve. A small naming inconsistency has been fixed in template.cc and all plugins now keep a reference to a Config object instead of a full copy (which means that the only full copy of a Config object should now be in IOManager and all other components should have a reference to it). 

A few more type issues have been fixed. The compilation instructions for Windows have been detailed for compiling PNGIO (not so easy for Visual c++). PNG_INDEXED and PNG_SPEED_OPTIMIZE are not keys exposed to the end user.

The fixed scale values in PNGIO have been changed, hoping to get better, more relevant plots. A few warnings have been removed (found with VC++).

Since the _USE_MATH_DEFINES for Windows was making trouble (it should have enabled using M_PI), the basic math constants have been added to meteolaws/meteoconst.h. Now, please use things like Cst::PI and include meteoconst.h.

Grid namming scheme has been changed: this now uses a slightly modified ISO format: YYYY-MM-DDTHH.MM (because ':' is invalid for filenames under Windows)

The IOManager was only keeping a reference to the Config object given in its constructor. Unfortunately, this means that if the original Config object would go out of scope, the reference would become invalid. Moreover, all internal objects (BufferedIOHandler, Meteo1DInterpolator, etc) were keeping the same reference to this external Config object. However, IOHandler was keeping a copy of the object. This has now been changed: IOManager keeps a copy of the Config object given to its constructor, and all other objects keep a reference to this copy. Therefore, the original Config object can be destroyed without any problem and the internal copy is kept at only one place (within IOManager).

A division by zero (for min=max) has been found and fixed in PGMIO. Moreover, the min and max are written in the metadata (so that the file can be read again and properly rescaled).

The IOManager can now return a copy of its internal Config object. This is convenient for times when one wants to create extra outputs but using a different plugin. A missing const has been added to Config and creating an IOHandler by passing it a config file name is not possible anymore (this was deprecated when we introduced the IOManager). Therefore, the IOHandler now only keeps a reference to a Config object. This means that in the full structure held within IOManager, only one copy of Config is kept, the rest being references.

A small bug has been found and fixed in the Gradient class (when a data range is zero). A few extra output specifications have been added to PNGIO.

PNGIO now compiles with libpng 1.5 (as well as 1.4). Names demangling has been implemented in IOExceptions, making the backtrace much friendlier! (but this only works for gcc)

Oups, fixed a few mistakes in io.ini: PNG should not be enabled by default (since this is an optional plugin) and one PNG key was spelled wrongly...

Fixed a legend labelling issue (the zero was some times appearing as a very small number) and a legend under/over range issue for heat (that was not checking that the data was in [0,1])

Fixed the PNG world file (so that we return the coordinates of the center of the cell) and updated the examples so that they perform correctly with the latest version

Speed improvement for IDW based on the profiling performed by HES-SO's V. Grivel: the stations' positions are saved in two vectors (eastings and northings) before walking the grid. For low number of stations, this makes no visible difference. For large number of stations, this makes a huge difference (as seen on the Graubünden simulation, with 35 stations).

After playing with pngcrush, a new filter has been enabled for the PNG compression. A specific compression strategy for deflate is also now enabled for indexed images. This keeps run time identical but offers a significantly smaller file size (compared to the full color, initially generated PNG of the last benchmarks, it now shows a 40% run time reduction for the whole loading+png output and 87% size reduction).

Indexed gradients are now handled by the Gradient class and used by the PNGIO plugin to generate indexed PNGs (some consts in the code can toggle it back to non-indexed images). This leads to a significant speedup and large file size reduction. On a DEM test case, while reading a 2D ARC grid and writing it back, the following have been measured:

After commit 758, support for indexed PNGs. This leads to major speed and size improvements:

version                  duration                   file size
full color                 0.530                       617k    
reduced to 30        0.460   13%             156k   75%
indexed, 30           0.352   34%               90k   85%
indexed, 30           0.320   40%             123k   80%
(optimized for speed)

The "freeze" color gradient now has a fixed point at zero celsius. A pointer error (related to the FILE pointer) has been fixed in PNGIO by making this pointer a class member. A much improved error message is now generated when a file can not be opened.

Introducing smart legends: this tries to find a meanigful range and steps within that range. The choice of rounding the lower and upper bounds (thus not guaranteeing that the whole data fits in the legend) has been made as it could lead to more suitable legends.

Changing the case of A3D_VIEW in ARCIO, fixed an image corruption issue in PNGIO (libpng just *forgets* to flush the file buffer...). Added a missing include in MeteoIO.h

A new key has been added that was missing: GRID2DPATH that can be in intput and output. This key is now properly handled by the appropriate plugins. A new color reduction strategy has been implemented in the gradients and the PNG plugin: instead of reducing the colors coming out of the gradient, the values coming in are discretized. This leads to much more effective size reduction for the same output quality, with 5% speed increase compared to the original code not doing this reduction (test: reading and writing back a grid). The file size is now 1/3 of the full color file.

A few hard coded parameters have been declared as static const (color depth per channel, max color per channel) in order to make the code cleaner. A new method has been introduced in the Gradient class: setNrOfColors. This allows to specify a reduced number of unique colors (even if still coded on 8 bits per channel). By using this call in PNGIO (with 8000 unique colors), the output remains visibly almost the same (only some very slow varying parts see a flat color instead of a slow gradient) while the run time is reduced by up to 5% and the file size more than halved.

The gradients now don't provide a transparency value (since it had to be either fully opaque or fully transparent) but only a boolean. PNGIO now uses a transparent color to encode transparency instead of a true alpha channel, leading to improved run times and smaller file size. The drawback is that pure white is now the transparent color.

A new gradient type has been added (blue-green isomorphic) and some small things improved thanks to valgrind (one potential out of bounds read and with callgrind some small speed improvements)

New methods "moveByXY" and "moveByBearing" have been added to Coords, addressing issue 39. Code cleanup and extensive documenting have been performed on Graphics and PNGIO, that now supports creating world file (optionnally). A new option has also been added to ARCIO, "A3D_view", to generate file names compatible with the Alpine3D's grid viewer (false by default). A new function to remove the extension from a file name has been implemented in IOUtils.

Better handling of "autoscale": the min and max are almost always taken into account (this is usefull to set fixed points, like the snow line, the sea level, etc) and the autoscale bool is used to tweak a given gradient for better display in autoscale (ie: removing the snow line in autoscale). The client is then responsible for provided the relevant min and max that he wants to use (constant -> no autoscale or variable -> autoscale).

Now, the plots are fitted/optimized depending on the meteo parameter (if available). The proper metadata is written into the file (again, if available). More gradients have been implemented.

Now the color gradient can be chosen (given as an argument in the Gradient constructor). This is not yet really used by PNGIO, but this will come!

The legend class is now free of hard-coded values in the middle of the code (all depends on the static consts).

The NearestNeighbour 2D resampling algorithm has been reshaped in order to offer the same interface as BiLinear. A typo in its name has been fixed. But NearestNeighbour does not work properly (bug not found yet)

A better way of submitting metadata to libpng has been implemented (ie: two vectors of strings that are then converted to char* to be given to libpng). The plugin basic options have been implemented, including size specifications. 

Some fonts improvements.

The purely graphical parts of PNGIO have been isolated in a new file, Graphics, that contain the Legend class, a Color namespace and a Gradient class. The gradient code is not so clean yet, but the PNGIO plugin is now much cleaner. The color gradients will actially need some serious re-actoring and design in order to be both flexible and efficient (the odds are, it would be based on a object factory and several derived classes like for libFit1D).

The 2D_interpolations example has been updated to reflect recent changes (see previous commit). Improvements in the legend for PNGIO.

This addresses the 2D part of issue 168: the ability to specify which meteo parameter and time step to read/write from/to a 2D grid. This should be the prefered reading method in the future, since it leaves to the plugin the task of building the file name, extension, database table, etc This also provides added metadata and more control over the writing process.

The legend text has now its own color and the legend background can also have its own color (or remain transparent).

Much improved legends: the font size is twice as big, the verticals are bold, the exponent is half-height. And spacing is more pleasant.

The png plugin can now generate a legend. This is still very primitive, the code is not so nice, but it compiles cleanly and works. Looking forward for the next version!