1 files changed, 77 insertions, 0 deletions
diff --git a/testfiles/utils/functions.sh b/testfiles/utils/functions.sh
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+++ b/testfiles/utils/functions.sh
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+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Bash functions useful for fuzzy bitmap comparisons. This file is a part of Inkscape.
+#
+# Authors:
+#   Rafael Siejakowski <rs@rs-math.net>
+#
+# Copyright (C) 2023 Authors
+#
+# Released under GNU GPL v2+, read the file 'COPYING' for more information.
+#
+
+ensure_command()
+{
+    command -v $1 >/dev/null 2>&1 || { echo >&2 "Required command '$1' not found. Aborting."; exit 1; }
+}
+
+export LANG=C # Needed to force . as the decimal separator
+ensure_command "bc"
+
+# Parse out the relative difference between two images from the command line output
+# of an ImageMagick compare command. In case of error, crash out of the script to ensure the test fails.
+#
+# Arguments:
+# $1 - commandline output from a compare command with RMSE metric.
+#
+# Output:
+# The parsed relative error, as a floating point number.
+#
+get_compare_result()
+{
+    local COMPARE_OUTPUT="$1"
+    RELATIVE_ERROR=${COMPARE_OUTPUT#*(}
+    RELATIVE_ERROR=${RELATIVE_ERROR%)*}
+    if [[ "x$RELATIVE_ERROR" == "x" ]]
+    then
+        echo "Warning: Could not parse out the relative error from ImageMagick output." >&2
+        exit 42
+    fi
+    echo "$RELATIVE_ERROR"
+}
+
+# Check whether a floating point number is less than or equal to a percentage value.
+# In case of error, crash out of the script.
+#
+# Arguments:
+# $1 - a floating pointing number between 0.0 and 1.0
+# $2 - a number between 0.0 and 100.0 representing a percentage. Scientific notation not allowed.
+#
+# Output:
+# 1 if and only if $1 * 100 <= $2 else 0.
+#
+is_relative_error_within_tolerance()
+{
+    local CONDITION=$(printf "%.12f * 100 <= $2" "$1")
+    WITHIN_TOLERANCE=$(echo "${CONDITION}" | bc)
+    if [[ $? -ne 0 || ( $WITHIN_TOLERANCE -ne 0 && $WITHIN_TOLERANCE -ne 1 ) ]]
+    then
+        echo "Warning: An error occurred running 'bc'." >&2
+        exit 42
+    fi
+    echo "$WITHIN_TOLERANCE"
+}
+
+# Multiply a floating point number by 100.
+#
+# Arguments:
+# $1 - a floating point number.
+#
+# Output:
+# The result of multiplying the passed number by 100, rounded to 1 digit after the decimal point.
+fraction_to_percentage()
+{
+    local FORMULA=$(printf "%.4f * 100" "$1")
+    echo "$FORMULA" | bc
+}
+