They seem to have changed the build system for opencsg.  I've been
running OpenSCAD with this for a while, as they bumped it.

https://opencsg.org/news.html

(I'm pretty sure I checked that it was just a minor bump, but it has
been a while so now I'm less positive)

Comments, tests, OK?

Index: Makefile
===================================================================
RCS file: /cvs/ports/graphics/opencsg/Makefile,v
diff -u -p -r1.18 Makefile
--- Makefile	26 Sep 2023 11:39:08 -0000	1.18
+++ Makefile	24 Jun 2026 00:46:10 -0000
@@ -1,11 +1,9 @@
 COMMENT =		constructive solid geometry rendering library
 
-V =			1.4.2
-DISTNAME =		OpenCSG-${V}
-PKGNAME =		opencsg-${V}
-REVISION =		2
+DISTNAME =		OpenCSG-1.8.2
+PKGNAME =		${DISTNAME:L}
 
-SHARED_LIBS =		opencsg		1.0
+SHARED_LIBS =		opencsg		1.1
 
 CATEGORIES =		graphics
 
@@ -14,29 +12,12 @@ HOMEPAGE =		http://www.opencsg.org/
 # GPLv2 with CGAL exception
 PERMIT_PACKAGE =	Yes
 
-WANTLIB += ${COMPILER_LIBCXX} GL GLEW m
+WANTLIB += ${COMPILER_LIBCXX} m
 
 SITES =			http://www.opencsg.org/
 
-MODULES =		devel/qmake \
-			x11/qt5
+MODULES =		devel/cmake
 
-MODQT_DEPS = No
-
-SEPARATE_BUILD =	No
-
-BUILD_DEPENDS = 	x11/qt5/qttools,-main
-
-LIB_DEPENDS =		graphics/glew
-
-WRKSRC =		${WRKDIST}/src
-
-pre-configure:
-	${SUBST_CMD} ${WRKSRC}/src.pro
-
-do-install:
-	${INSTALL_DATA} ${WRKDIST}/lib/libopencsg.so.${LIBopencsg_VERSION} \
-		${PREFIX}/lib
-	${INSTALL_DATA} ${WRKDIST}/include/opencsg.h ${PREFIX}/include
+CONFIGURE_ARGS +=       -DBUILD_EXAMPLE=OFF
 
 .include <bsd.port.mk>
Index: distinfo
===================================================================
RCS file: /cvs/ports/graphics/opencsg/distinfo,v
diff -u -p -r1.3 distinfo
--- distinfo	4 Feb 2020 06:09:04 -0000	1.3
+++ distinfo	24 Jun 2026 00:46:10 -0000
@@ -1,2 +1,2 @@
-SHA256 (OpenCSG-1.4.2.tar.gz) = 2VLsXTouRqMAGcIQlj/N3/ZoE+/JwpYDty+VU63/Svs=
-SIZE (OpenCSG-1.4.2.tar.gz) = 933135
+SHA256 (OpenCSG-1.8.2.tar.gz) = WsXfc7GtM0DdZwX/kOAJ8alGu5U2whwiY6b5dCZWZMA=
+SIZE (OpenCSG-1.8.2.tar.gz) = 306362
Index: patches/patch-example_CMakeLists_txt
===================================================================
RCS file: patches/patch-example_CMakeLists_txt
diff -N patches/patch-example_CMakeLists_txt
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-example_CMakeLists_txt	24 Jun 2026 00:46:10 -0000
@@ -0,0 +1,12 @@
+Index: example/CMakeLists.txt
+--- example/CMakeLists.txt.orig
++++ example/CMakeLists.txt
+@@ -9,6 +9,8 @@ find_package(GLUT REQUIRED)
+ 
+ target_include_directories(opencsgexample PRIVATE
+     "${CMAKE_SOURCE_DIR}/include"
++    "${OPENGL_INCLUDE_DIRS}"
++    "${GLUT_INCLUDE_DIRS}"
+ )
+ 
+ target_link_libraries(opencsgexample PRIVATE
Index: patches/patch-src_CMakeLists_txt
===================================================================
RCS file: patches/patch-src_CMakeLists_txt
diff -N patches/patch-src_CMakeLists_txt
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_CMakeLists_txt	24 Jun 2026 00:46:10 -0000
@@ -0,0 +1,17 @@
+Index: src/CMakeLists.txt
+--- src/CMakeLists.txt.orig
++++ src/CMakeLists.txt
+@@ -25,11 +25,11 @@ add_library(opencsg
+ 
+ target_include_directories(opencsg PUBLIC
+     "${CMAKE_SOURCE_DIR}/include"
+ )
+ 
+ set_target_properties(opencsg PROPERTIES
+-    VERSION ${PROJECT_VERSION}
+-    SOVERSION ${PROJECT_VERSION_MAJOR}
++    VERSION ${LIBopencsg_VERSION}
++    SOVERSION ${LIBopencsg_VERSION}
+     PUBLIC_HEADER "${CMAKE_SOURCE_DIR}/include/opencsg.h" 
+ )
+ 
Index: patches/patch-src_src_pro
===================================================================
RCS file: patches/patch-src_src_pro
diff -N patches/patch-src_src_pro
--- patches/patch-src_src_pro	11 Mar 2022 19:22:56 -0000	1.4
+++ /dev/null	1 Jan 1970 00:00:00 -0000
@@ -1,11 +0,0 @@
-Index: src/src.pro
---- src/src.pro.orig
-+++ src/src.pro
-@@ -1,6 +1,6 @@
- TEMPLATE = lib
- TARGET = opencsg
--VERSION = 1.4.2
-+VERSION = ${LIBopencsg_VERSION}
- 
- isEmpty(INSTALLDIR) {
-   INSTALLDIR = /usr/local