fix: use extern "C" and ensure shaders are built before main

CMakeLists.txt

@@ -36,16 +36,20 @@ foreach(SHADER ${SHADERS})
             ${OUTPUT_C}
     DEPENDS ${SHADER} 
             ${CMAKE_SOURCE_DIR}/glsl2c.py
-    COMMENT "Converting shader ${SHADER} to CPP"
+    COMMENT "Converting shader ${NAME_WE}${EXT} to C file"
     VERBATIM
   )
 
   list(APPEND SHADER_C_FILES ${OUTPUT_C})
 endforeach()
 
+add_custom_target(Shaders ALL DEPENDS ${SHADER_C_FILES})
+
 add_executable(main ${CPP_SOURCES} ${SHADER_C_FILES})
 add_definitions(-g)
 
+add_dependencies(main Shaders)
+
 target_include_directories(main PRIVATE
   inc # project
   res/render # ressources (primitive)

res/render/primitives/p_cube.hpp

@@ -1,7 +1,7 @@
 #include "GLFW/glfw3.h"
 
 constexpr GLfloat P_CUBE_VERTICE[] = {
-  // Positions           // _LEN;ales           // texture coordinate
+  // Positions           // normales         // texture coordinate
   // front side
   -0.5f, -0.5f, 0.5f,    0.0f, 0.0f, 1.0f,     0.0f, 0.0f,
    0.5f, -0.5f, 0.5f,    0.0f, 0.0f, 1.0f,     1.0f, 0.0f,
@@ -59,8 +59,7 @@ constexpr unsigned int P_CUBE_INDICE[] = {
   22, 23, 20    // 12
 };  
 
-extern const unsigned char P_CUBE_FRAG[];
-extern const unsigned int P_CUBE_FRAG_LEN;
-
-extern const unsigned char P_CUBE_VERT[];
-extern const unsigned int P_CUBE_VERT_LEN;
+extern "C" const unsigned char P_CUBE_FRAG[];
+extern "C" const unsigned int P_CUBE_FRAG_LEN;
+extern "C" const unsigned char P_CUBE_VERT[];
+extern "C" const unsigned int P_CUBE_VERT_LEN;