Fix linux ci build error

Author: wysaid

examples/desktop.cmake

@@ -12,10 +12,8 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
         find_package(glfw3 QUIET)
 
         if(glfw3_FOUND)
-            find_package(OpenGL REQUIRED)
             set(GLFW_AVAILABLE TRUE)
             set(GLFW_TARGET glfw)
-            message(STATUS "ccap: Using system-installed GLFW via CMake")
         endif()
     endif()
 
@@ -56,32 +54,22 @@ foreach(EXAMPLE ${EXAMPLE_SOURCE})
         )
     endif()
 
-    # If NAME contains glfw, link glfw3 and OpenGL, etc.
+    # If NAME contains glfw, link glfw3 and optionally OpenGL
     if(${EXAMPLE_NAME} MATCHES "glfw")
-        target_link_libraries(${EXAMPLE_NAME} PRIVATE
-            ${GLFW_TARGET}
-        )
+        target_link_libraries(${EXAMPLE_NAME} PRIVATE ${GLFW_TARGET})
 
-        if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-            # On Linux, link OpenGL libraries
-            target_link_libraries(${EXAMPLE_NAME} PRIVATE
-                OpenGL::GL
-            )
-        else()
+        # On Linux, OpenGL functions are loaded dynamically via GLAD
+        # GLAD uses function pointers provided by GLFW (glfwGetProcAddress)
+        # No additional libraries needed for dynamic loading
+        if(NOT CMAKE_SYSTEM_NAME STREQUAL "Linux")
             if(APPLE)
-                target_link_libraries(${EXAMPLE_NAME} PRIVATE
-                    "-framework OpenGL"
-                )
+                target_link_libraries(${EXAMPLE_NAME} PRIVATE "-framework OpenGL")
             endif()
 
-            target_include_directories(${EXAMPLE_NAME} PUBLIC
-                ${DESKTOP_EXAMPLES_DIR}/glfw/include
-            )
+            target_include_directories(${EXAMPLE_NAME} PUBLIC ${DESKTOP_EXAMPLES_DIR}/glfw/include)
         endif()
 
-        target_include_directories(${EXAMPLE_NAME} PUBLIC
-            ${DESKTOP_EXAMPLES_DIR}
-        )
+        target_include_directories(${EXAMPLE_NAME} PUBLIC ${DESKTOP_EXAMPLES_DIR})
 
         message(STATUS "ccap: Add example: ${EXAMPLE_NAME} with GLFW")
     else()