| [ << Regression tests ] | [Top][Contents] | [ Programming work >> ] |
| [ < Regtest comparison ] | [ Up : Regression tests ] | [ Finding the cause of a regression > ] |
9.5 Pixel-based regtest comparison
As an alternative to the make test method for regtest checking (which
relies upon .signature files created by a LilyPond run and which describe
the placing of grobs) there is a script which compares the output of two
LilyPond versions pixel-by-pixel. To use this, start by checking out the
version of LilyPond you want to use as a baseline, and run make. Then,
do the following:
cd $LILYPOND_GIT/scripts/auxiliar/ ./make-regtest-pngs.sh -j9 -o
The -j9 option tells the script to use 9 CPUs to create the
images - change this to your own CPU count+1. -o means this is the "old"
version. This will create images of all the regtests in
$LILYPOND_BUILD_DIR/out-png-check/old-regtest-results/
Now checkout the version you want to compare with the baseline. Run
make again to recreate the LilyPond binary. Then, do the following:
cd $LILYPOND_GIT/scripts/auxiliar/ ./make-regtest-pngs.sh -j9 -n
The -n option tells the script to make a "new" version of the
images. They are created in
$LILYPOND_BUILD_DIR/out-png-check/new-regtest-results/
Once the new images have been created, the script compares the old images with the new ones pixel-by-pixel and prints a list of the different images to the terminal, together with a count of how many differences were found. The results of the checks are in
$LILYPOND_BUILD_DIR/out-png-check/regtest-diffs/
To check for differences, browse that directory with an image viewer. Differences are shown in red. Be aware that some images with complex fonts or spacing annotations always display a few minor differences. These can safely be ignored.
| [ << Regression tests ] | [Top][Contents] | [ Programming work >> ] |
| [ < Regtest comparison ] | [ Up : Regression tests ] | [ Finding the cause of a regression > ] |