From b8bbcfdb9677130dc0667651df72053ebc788c71 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?= <pobrn@protonmail.com>
Date: Wed, 23 Jul 2025 14:23:00 +0200
Subject: [PATCH] spa: libcamera: source: unify control range logic

If libcamera does not provide a default value, then the average of the
minimum and maximum values is taken. The same logic is duplicated for
`float` and `int32_t`, so move it into a function template.

(cherry picked from commit 8d9e469e09ab2a6bf25a74b756eb7303a3cf2dbb)
---
 spa/plugins/libcamera/libcamera-source.cpp | 37 ++++++++++++----------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/spa/plugins/libcamera/libcamera-source.cpp b/spa/plugins/libcamera/libcamera-source.cpp
index 058d1a159..e61f30a17 100644
--- a/spa/plugins/libcamera/libcamera-source.cpp
+++ b/spa/plugins/libcamera/libcamera-source.cpp
@@ -4,10 +4,12 @@
 /* SPDX-FileCopyrightText: Copyright © 2021 Wim Taymans <wim.taymans@gmail.com> */
 /* SPDX-License-Identifier: MIT */
 
+#include <array>
 #include <cstddef>
 #include <deque>
 #include <limits>
 #include <optional>
+#include <type_traits>
 #include <utility>
 
 #include <sys/mman.h>
@@ -739,6 +741,23 @@ uint32_t prop_id_to_control(uint32_t prop_id)
 	return SPA_ID_INVALID;
 }
 
+template<typename T>
+[[nodiscard]]
+std::array<T, 3> control_info_to_range(const libcamera::ControlInfo& cinfo)
+{
+	static_assert(std::is_arithmetic_v<T>);
+
+	auto min = cinfo.min().get<T>();
+	auto max = cinfo.max().get<T>();
+	spa_assert(min <= max);
+
+	auto def = !cinfo.def().isNone()
+			? cinfo.def().get<T>()
+			: (min + ((max - min) / 2));
+
+	return {{ min, max, def }};
+}
+
 [[nodiscard]]
 spa_pod *control_details_to_pod(spa_pod_builder& b,
 				const libcamera::ControlId& cid, const libcamera::ControlInfo& cinfo)
@@ -773,14 +792,7 @@ spa_pod *control_details_to_pod(spa_pod_builder& b,
 		spa_pod_builder_pop(&b, &f);
 	} break;
 	case ControlTypeFloat: {
-		float min = cinfo.min().get<float>();
-		float max = cinfo.max().get<float>();
-		float def;
-
-		if (cinfo.def().isNone())
-			def = (min + max) / 2;
-		else
-			def = cinfo.def().get<float>();
+		auto [ min, max, def ] = control_info_to_range<float>(cinfo);
 
 		spa_pod_builder_add(&b,
 				SPA_PROP_INFO_type, SPA_POD_CHOICE_RANGE_Float(
@@ -788,14 +800,7 @@ spa_pod *control_details_to_pod(spa_pod_builder& b,
 				0);
 	} break;
 	case ControlTypeInteger32: {
-		int32_t min = cinfo.min().get<int32_t>();
-		int32_t max = cinfo.max().get<int32_t>();
-		int32_t def;
-
-		if (cinfo.def().isNone())
-			def = (min + max) / 2;
-		else
-			def = cinfo.def().get<int32_t>();
+		auto [ min, max, def ] = control_info_to_range<int32_t>(cinfo);
 
 		spa_pod_builder_add(&b,
 				SPA_PROP_INFO_type, SPA_POD_CHOICE_RANGE_Int(