From 7ee50de85404a2310f1fd3fd653b3bafaa4d91af Mon Sep 17 00:00:00 2001
From: Bastian Dehn <hhaalo@arcor.de>
Date: Tue, 7 Oct 2025 18:04:30 +0200
Subject: [PATCH] add convert from pixel to tenth inch

---
 src/CMakeLists.txt                       |  3 ++-
 src/kds_s2000w_pixel_converter.c         |  8 ++++++++
 src/kds_s2000w_pixel_converter.h         |  7 +++++++
 tests/CMakeLists.txt                     | 11 ++++++++++-
 tests/kds_s2000w_pixel_converter_tests.c | 25 ++++++++++++++++++++++++
 5 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 src/kds_s2000w_pixel_converter.c
 create mode 100644 src/kds_s2000w_pixel_converter.h
 create mode 100644 tests/kds_s2000w_pixel_converter_tests.c

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 305874e..de90320 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -85,7 +85,8 @@ SET(SOURCES
 	"kds_s2000w_debug.c"
 	"kds_s2000w_config.c"
 	"kds_s2000w_heartbeat.c"
-	"kds_s2000w_image_type_check.c")
+	"kds_s2000w_image_type_check.c"
+	"kds_s2000w_pixel_converter.c")
 
 IF(IMAGEMAGICK)
 	LIST(APPEND SOURCES "kds_s2000w_image_converter_magick.c")
diff --git a/src/kds_s2000w_pixel_converter.c b/src/kds_s2000w_pixel_converter.c
new file mode 100644
index 0000000..1cc3c52
--- /dev/null
+++ b/src/kds_s2000w_pixel_converter.c
@@ -0,0 +1,8 @@
+#include "kds_s2000w_pixel_converter.h"
+
+#define TENTH 10
+
+uint32_t kds_s2000w_pixel_converter_pixel_to_tenth_of_inch(uint32_t dpi, uint32_t pixel)
+{
+	return pixel * TENTH / dpi;
+}
\ No newline at end of file
diff --git a/src/kds_s2000w_pixel_converter.h b/src/kds_s2000w_pixel_converter.h
new file mode 100644
index 0000000..33e6c04
--- /dev/null
+++ b/src/kds_s2000w_pixel_converter.h
@@ -0,0 +1,7 @@
+#ifndef KDS_S2000W_PIXEL_CONVERTER_H
+#define KDS_S2000W_PIXEL_CONVERTER_H
+#include <stdint.h>
+
+uint32_t kds_s2000w_pixel_converter_pixel_to_tenth_of_inch(uint32_t dpi, uint32_t pixel);
+
+#endif
\ No newline at end of file
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index a68dbd3..2c9795a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -59,6 +59,13 @@ TARGET_LINK_LIBRARIES("kds_s2000w_image_type_check_tests"
 	${CMOCKA_LIBRARY}
 	sane-kds_s2000w_net-static)
 
+ADD_EXECUTABLE("kds_s2000w_pixel_converter_tests"
+	"kds_s2000w_pixel_converter_tests.c")
+ADD_DEPENDENCIES("kds_s2000w_pixel_converter_tests" sane-kds_s2000w_net-static)
+TARGET_LINK_LIBRARIES("kds_s2000w_pixel_converter_tests"
+	${CMOCKA_LIBRARY}
+	sane-kds_s2000w_net-static)
+
 ADD_CUSTOM_TARGET("runningtests"
 	ALL ./kds_s2000w_read_config_tests
 	COMMAND ./kds_s2000w_option_descriptor_tests
@@ -67,6 +74,7 @@ ADD_CUSTOM_TARGET("runningtests"
 	COMMAND ./kds_s2000w_net_read_tests
 	COMMAND ./kds_s2000w_image_type_check_tests
 	COMMAND ./kds_s2000w_image_converter_tests
+	COMMAND ./kds_s2000w_pixel_converter_tests
 	WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
 	DEPENDS "kds_s2000w_read_config_tests"
 	"kds_s2000w_option_descriptor_tests"
@@ -74,7 +82,8 @@ ADD_CUSTOM_TARGET("runningtests"
 	"kds_s2000w_net_tests"
 	"kds_s2000w_net_read_tests"
 	"kds_s2000w_image_type_check_tests"
-	"kds_s2000w_image_converter_tests")
+	"kds_s2000w_image_converter_tests"
+	"kds_s2000w_pixel_converter_tests")
 
 ADD_CUSTOM_TARGET("generate_gcov_coverage"
 	ALL gcov ${CMAKE_BINARY_DIR}/src/CMakeFiles/sane-kds_s2000w_net-static.dir/*.c.o
diff --git a/tests/kds_s2000w_pixel_converter_tests.c b/tests/kds_s2000w_pixel_converter_tests.c
new file mode 100644
index 0000000..54adc4f
--- /dev/null
+++ b/tests/kds_s2000w_pixel_converter_tests.c
@@ -0,0 +1,25 @@
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <cmocka.h>
+#include "../src/kds_s2000w_pixel_converter.h"
+
+void kds_s2000w_max_tl_x_pixel_to_tenth_inch_test()
+{
+	uint32_t dpi = 300;
+	uint32_t pixel = 2250;
+
+	uint32_t tenth_inch = kds_s2000w_pixel_converter_pixel_to_tenth_of_inch(dpi, pixel);
+
+	assert_int_equal(tenth_inch, 75);
+}
+
+int main()
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(kds_s2000w_max_tl_x_pixel_to_tenth_inch_test)
+	};
+
+	return cmocka_run_group_tests(tests, NULL, NULL);
+}
\ No newline at end of file
-- 
2.47.3