[postgis-devel] WKTRaster Scale and Skew

[Pierre Racine]

>  Width is computed based on scale & skew?

In 99% of the cases there is no rotation and pixel width & height ARE synonyms for scale X and scale Y. Is it worth changing their names? Adding confusion? How does GDAL name it?

>We don't call it scaleX and scaleY, but cell_width_x and cell_height_y
>We don't call it skewX and skewY, but cell_width_y and cell_height_x

In rt_api.c? Why not...

>We separate the accessors for the pixel width and the georeference component that is now used as the width.

You mean creating a "truepixelwidth" function? Same reluctance since it is not really a width when the pixel shape is a diamond. But you could say "this happen only 0.001 of the time"... Does that mean removing or renaming the ST_PixelSizeX and ST_PixelSizeY function?

>Tests assume the upper left coordinate is SMALLER in the X and GREATER in the Y for all other coordinates in the raster -- this would require adjusting our tests to handle the coordinate space uniformly.

Ok.

My main concern is to not confuse users with scale, skew and width. Most people know only pixelsize.

Pierre