Builds on knulli

cmake/targets/knulli.cmake

@@ -1,5 +1,8 @@
 # Find link platform-specific libraries
+set(OpenGL_GL_PREFERENCE LEGACY)
 find_package(SDL2 REQUIRED)
+find_library(EGL_LIB EGL REQUIRED)
+find_library(GL_LIB GL REQUIRED)
 find_package(OpenGL REQUIRED)
 
 # Setup endianess at compile time to optimize.
@@ -16,11 +19,12 @@ else()
 endif()
 
 # Link required libraries.
-target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PUBLIC 
+target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PRIVATE 
   SDL2
   pthread
-  OpenGL::GL
-  GL
+  OpenGL::GLES2
+  ${GL_LIB}
+  ${EGL_LIB}
   m
 )
 
@@ -28,6 +32,7 @@ target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
 target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   DUSK_SDL2
   DUSK_OPENGL
+  DUSK_OPENGL_ES
   DUSK_LINUX
   DUSK_DISPLAY_SIZE_DYNAMIC
   DUSK_DISPLAY_WIDTH_DEFAULT=640