cmake_minimum_required(VERSION 3.0.0)
project(monkvg VERSION 0.1.0)

## configuration
# Set CMP0077 policy to NEW
cmake_policy(SET CMP0077 NEW)
option(MKVG_DO_VULKAN_BACKEND "Use Vulkan as the rendering backend.  NOT IMPLEMENTED" OFF) # Not Implemented Yet
option(MKVG_DO_OPENGLES_BACKEND "Use OpenGL ES as the rendering backend. NOT IMPLEMENTED" OFF)
option(MKVG_DO_OPENGL_BACKEND "Use OpenGL as the rendering backend." ON)
option(MKVG_DO_GLU_TESSELATION "Use GLU tesselator" ON)
option(MKVG_DO_EXAMPLES "Build examples in the ./examples directory" ON)
option(MKVG_DO_PYTHON_BINDINGS "Build Python Bindings" OFF)

# if (MKVG_DO_VULKAN_BACKEND)
#     message(WARNING "Vulkan Backend Not Fully Implemented Yet")
# endif()

if (MKVG_DO_OPENGLES_BACKEND)
    message(FATAL_ERROR "OpenGL ES Backend Not Implemented Yet")
endif()

if (MKVG_DO_OPENGLES_BACKEND AND MKVG_DO_OPENGL_BACKEND)
    message(FATAL_ERROR "Cannot build both OpenGL and OpenGL ES backends MKVG_DO_OPENGLES_BACKEND: ${MKVG_DO_OPENGLES_BACKEND} MKVG_DO_OPENGL_BACKEND: ${MKVG_DO_OPENGL_BACKEND}" )
endif()

# C++ 20
set(CMAKE_CXX_STANDARD 20)

# require PkgConfig
find_package(PkgConfig REQUIRED)


## GLU Tesselation
if(MKVG_DO_GLU_TESSELATION)
    
    add_subdirectory(thirdparty/glu)
    set(GLU_LIBRARIES glu_tess glu_util)
    set(GLU_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/thirdparty/glu/include)

    set(BACKEND_SOURCE ${BACKEND_SOURCE} ./src/glu-tessellator/gluTessellator.cpp)
    set(MNKVG_COMPILE_DEFS ${MNKVG_COMPILE_DEFS} MNKVG_GLU_TESSELATION)

    message(STATUS "GLU Tesselation Enabled")
    message(STATUS "GLU_INCLUDE_DIRS: ${GLU_INCLUDE_DIRS}")
    message(STATUS "GLU_LIBRARIES: ${GLU_LIBRARIES}")
endif()


## OpenGL Backend
if(MKVG_DO_OPENGL_BACKEND)
    if (${CMAKE_SYSTEM_NAME} MATCHES Linux)
        # use vendor version of OpenGL if available
        set(OpenGL_GL_PREFERENCE "GLVND")
    endif()

    find_package(OpenGL REQUIRED)
    add_subdirectory(thirdparty/glm)

    set(BACKEND_SOURCE ${BACKEND_SOURCE}
        ./src/opengl/glBatch.cpp
        ./src/opengl/glContext.cpp
        ./src/opengl/glFont.cpp
        ./src/opengl/glImage.cpp
        ./src/opengl/glPaint.cpp
        ./src/opengl/glPath.cpp
        ./src/opengl/glShader.cpp)
    set(BACKEND_INCLUDE ${BACKEND_INCLUDE}
        ${GLU_INCLUDE_DIRS})

    set(MNKVG_COMPILE_DEFS ${MNKVG_COMPILE_DEFS} MNKVG_GL_BACKEND)
    set(MNKVG_LIBRARIES ${MNKVG_LIBRARIES} glm::glm)

    message(STATUS "OpenGL Include: ${OPENGL_INCLUDE_DIR}")
    message(STATUS "OpenGL Libraries: ${OPENGL_LIBRARIES}")

endif()

## Vulkan Backend
if(MKVG_DO_VULKAN_BACKEND)
    find_package(Vulkan REQUIRED)

    ## thirdparty dependencies
    add_subdirectory(thirdparty/glm)
    add_subdirectory(thirdparty/vma)

   
    set(BACKEND_SOURCE ${BACKEND_SOURCE}
        ./src/vulkan/vkVmaUsage.cpp
        ./src/vulkan/vkBatch.cpp
        ./src/vulkan/vkContext.cpp
        ./src/vulkan/vkFont.cpp
        ./src/vulkan/vkImage.cpp
        ./src/vulkan/vkPaint.cpp
        ./src/vulkan/vkPath.cpp        
        ./src/vulkan/vkColorPipeline.cpp
        ./src/vulkan/vkTexturePipeline.cpp)
    set(BACKEND_INCLUDE ${BACKEND_INCLUDE}
        ${GLU_INCLUDE_DIRS})

    set(MNKVG_COMPILE_DEFS ${MNKVG_COMPILE_DEFS} MNKVG_VULKAN_BACKEND)
    set(MNKVG_LIBRARIES ${MNKVG_LIBRARIES} glm::glm GPUOpen::VulkanMemoryAllocator Vulkan::Vulkan)


    # make sure there is a vulkan glslc executable
    if(EXISTS ${Vulkan_GLSLC_EXECUTABLE})
        ### Build Vulkan Shaders ###
        # See: https://stackoverflow.com/questions/57478571/why-wont-cmake-build-my-vulkan-spirv-shaders
        set(SHADER_DIR ${CMAKE_CURRENT_SOURCE_DIR}/src/vulkan/shaders)
        file(GLOB SHADERS 
            ${SHADER_DIR}/*.vert 
            ${SHADER_DIR}/*.frag)

        message(STATUS "Vulkan Shader Compiler: ${Vulkan_GLSLC_EXECUTABLE}")

        # make spv header files for glsl shaders
        foreach(SHADER IN LISTS SHADERS)
            message(STATUS "SHADER: ${SHADER}")
            get_filename_component(FILENAME ${SHADER} NAME)
            add_custom_command(      
                COMMAND ${Vulkan_GLSLC_EXECUTABLE} -mfmt=c ${SHADER} -o ${SHADER_DIR}/${FILENAME}.h
                OUTPUT ${SHADER_DIR}/${FILENAME}.h
                DEPENDS ${SHADER} ${SHADER_DIR}
                COMMENT "Compiling ${FILENAME}"
            )
            list(APPEND SPV_SHADERS ${SHADER_DIR}/${FILENAME}.h)
        endforeach(SHADER IN LISTS SHADERS)
        add_custom_target(shaders ALL DEPENDS ${SPV_SHADERS})   
        
    endif()
endif()

## setup common source 
set(COMMON_SOURCE ${COMMON_SOURCE}
    ./src/mkBaseObject.cpp
    ./src/mkBatch.cpp
    ./src/mkContext.cpp
    ./src/mkFont.cpp
    ./src/mkImage.cpp
    ./src/mkMath.cpp
    ./src/mkPaint.cpp
    ./src/mkParameter.cpp
    ./src/mkPath.cpp
    ./src/mkVGU.cpp
    ./src/mkBmpFnt.cpp
    ./src/mkTessellator.cpp
    ./src/mkGradient.cpp
)
set(COMMON_INCLUDE ${COMMON_INCLUDE} ${CMAKE_CURRENT_SOURCE_DIR}/src)


## Build the MonkVG library
message(STATUS "MNKVG_COMPILE_DEFS: ${MNKVG_COMPILE_DEFS}")
add_library(monkvg ${COMMON_SOURCE} ${BACKEND_SOURCE})
add_dependencies(monkvg ${GLU_LIBRARIES} ${MNKVG_DEPENDENCIES})
target_compile_definitions(monkvg PRIVATE ${MNKVG_COMPILE_DEFS})

target_include_directories(monkvg 
                            PUBLIC 
                            ${CMAKE_CURRENT_SOURCE_DIR}/include 
                            PRIVATE 
                            ${COMMON_INCLUDE} 
                            ${BACKEND_INCLUDE})
target_link_libraries(monkvg ${GLU_LIBRARIES} ${MNKVG_LIBRARIES})

if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" 
    OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang" 
    OR CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")

    # stop annoying warnings.  assuming this is okay.
    # Disable annoying warnings from vulkan memory allocator with -Wno-nullability-completeness
    # Disable annoying warnings from OpenVG with -Wno-deprecated-enum-enum-conversion
    target_compile_options(monkvg PUBLIC -Wno-deprecated-enum-enum-conversion -Wno-nullability-completeness)
endif()

### Language Bindings
if (MKVG_DO_PYTHON_BINDINGS)
    add_subdirectory(bindings)
endif()


if (MKVG_DO_EXAMPLES)
    add_subdirectory(examples)
endif()

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)