[cairo] [PATCH v2 2/7] test: Add script to check for redundant reference images

[Bryce W. Harrington]

This script requires the perceptualdiff program, which can be built as
follows:

  cd test/pdiff && make perceptualdiff

The script's output provides a list of target-specific or
format-specific images that are identical to their more generic
reference files, and thus are redundant and can be safely removed from
the archive without altering any test behaviors.

Signed-off-by: Bryce Harrington <b.harrington at samsung.com>
---
 test/Makefile.am   |    1 +
 test/check_refs.sh |   60 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100755 test/check_refs.sh

diff --git a/test/Makefile.am b/test/Makefile.am
index d5c726a..a097409 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -72,6 +72,7 @@ endif
 test_sources += $(test)
 
 noinst_PROGRAMS = cairo-test-suite$(EXEEXT) # always build
+noinst_SCRIPTS += check_refs.sh
 
 TESTS += cairo-test-suite$(EXEEXT)
 
diff --git a/test/check_refs.sh b/test/check_refs.sh
new file mode 100755
index 0000000..649d509
--- /dev/null
+++ b/test/check_refs.sh
@@ -0,0 +1,60 @@
+#!/bin/bash
+
+current_dir=$(pwd)
+
+# Move to the reference directory as needed
+if [ $(basename $current_dir) != 'test' ]; then
+    if [ -d test ]; then
+        cd test || exit 1
+    fi
+fi
+if [ $(basename $current_dir) != 'reference' ]; then
+    if [ -d reference ]; then
+        cd reference || exit 2
+    fi
+fi
+
+pdiff=../pdiff/perceptualdiff
+if [ ! -e "${pdiff}" ]; then
+    echo "Error:  requires ${pdiff} executable"
+    exit 3
+fi
+
+for file in *.ref.png; do
+    test=$(echo $file | cut -d'.' -f1)
+    target=$(echo $file | cut -d'.' -f2)
+    format=$(echo $file | cut -d'.' -f3)
+    notes=""
+    ref=""
+    result=""
+
+    if [ $target = 'base' ]; then
+        # Ignore the base images for this script's purposes
+        continue
+    elif [ $target = 'ref' ]; then
+        # This is actually the baseline reference image 
+        continue
+    elif [ $format = 'ref' ]; then
+        # This is either a format-specific reference, or a target-specific/format-generic image
+        # In either case, compare it against the generic reference image
+        ref="$test.ref.png"
+    else
+        # Prefer the target-specific/format-generic reference image, if available
+	ref="$test.$target.ref.png"
+	if [ ! -e $ref ]; then
+            ref="$test.$format.ref.png"
+	fi
+    fi
+
+    if [ -e $ref ]; then
+        # Run perceptualdiff with minimum threshold
+        pdiff_output=$($pdiff $ref $file -threshold 1)
+        result=${pdiff_output%:*}
+        notes=$(echo "${pdiff_output#*: }" | tail -n 1)
+        if [ "$result" = "PASS" ] && [ "$notes" = "Images are binary identical" ]; then
+	    printf "redundant: %s is binary identical to %s\n" $file $ref
+            notes=""
+        fi
+    fi
+
+done
-- 
1.7.9.5

--
Bryce Harrington
Senior Open Source Developer  -  b.harrington at samsung.com
Open Source Group             -  Samsung Research America