# Copyright 2022 The Dawn & Tint Authors
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

cmake_minimum_required(VERSION 3.10.2)

# When upgrading to CMake 3.11 we can remove SAMPLES_PLACEHOLDER_FILE because source-less add_library
# becomes available.
# When upgrading to CMake 3.12 we should remove the CACHE "" FORCE stuff to
# override options in third_party dependencies. We can also add the HOMEPAGE_URL
# entry to the project `HOMEPAGE_URL "https://dawn.googlesource.com/samples"`

project(
    DawnSamples
    DESCRIPTION "Samples for Dawn, a WebGPU implementation"
    LANGUAGES C CXX
)
enable_testing()

set_property(GLOBAL PROPERTY USE_FOLDERS ON)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR})
set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_DEBUG_POSTFIX "")

if ("${CMAKE_BUILD_TYPE}" STREQUAL "")
  message(STATUS "No build type selected, default to Debug")
  set(CMAKE_BUILD_TYPE "Debug")
endif()

set(SAMPLES_SRC_DIR "${DawnSamples_SOURCE_DIR}/src")

set(SAMPLES_PLACEHOLDER_FILE "${SAMPLES_SRC_DIR}/Placeholder.cpp")

################################################################################
# Configuration options
################################################################################

# option_if_not_defined(name description default)
# Behaves like:
#   option(name description default)
# If a variable is not already defined with the given name, otherwise the
# function does nothing.
# Simplifies customization by projects that use Dawn as a dependency.
function (option_if_not_defined name description default)
    if(NOT DEFINED ${name})
        option(${name} ${description} ${default})
    endif()
endfunction()

# set_if_not_defined(name value description)
# Behaves like:
#   set(${name} ${value} CACHE STRING ${description})
# If a variable is not already defined with the given name, otherwise the
# function does nothing.
# Simplifies customization by projects that use Dawn as a dependency.
function (set_if_not_defined name value description)
    if(NOT DEFINED ${name})
        set(${name} ${value} CACHE STRING ${description})
    endif()
endfunction()

# Default values for the backend-enabling options
set(USE_WAYLAND OFF)
set(USE_X11 OFF)

if(UNIX)
    set(USE_X11 ON)
endif()

# GLFW is not supported in UWP
set(SAMPLES_SUPPORTS_GLFW_FOR_WINDOWING OFF)

if ((WIN32 AND NOT WINDOWS_STORE) OR (UNIX AND NOT ANDROID))
    set(SAMPLES_SUPPORTS_GLFW_FOR_WINDOWING ON)
endif()

# Current examples are depend on GLFW
if (SAMPLES_SUPPORTS_GLFW_FOR_WINDOWING)
    set(BUILD_SAMPLES ON)
endif()

option_if_not_defined(SAMPLES_USE_GLFW "Enable compilation of the GLFW windowing utils" ${SAMPLES_SUPPORTS_GLFW_FOR_WINDOWING})

if (NOT SAMPLES_USE_GLFW)
  message(SEND_ERROR "Dawn samples require GLFW")
endif()

set_if_not_defined(SAMPLES_THIRD_PARTY_DIR "${DawnSamples_SOURCE_DIR}/third_party" "Directory in which to find third-party dependencies.")

set_if_not_defined(SAMPLES_DIR "${SAMPLES_THIRD_PARTY_DIR}/dawn" "Directory in which to find Dawn")
set_if_not_defined(SAMPLES_GLFW_DIR "${SAMPLES_THIRD_PARTY_DIR}/glfw" "Directory in which to find GLFW")
set_if_not_defined(SAMPLES_DAWN_DIR "${SAMPLES_THIRD_PARTY_DIR}/dawn" "Directory in which to find Dawm")

option_if_not_defined(DAWN_USE_WAYLAND "Enable support for Wayland surface" ${USE_WAYLAND})
option_if_not_defined(DAWN_USE_X11 "Enable support for X11 surface" ${USE_X11})
option_if_not_defined(DAWN_FETCH_DEPENDENCIES "Use fetch_dawn_dependencies.py as an alternative to using depot_tools" ON)

message(STATUS "Samples build GLFW support: ${SAMPLES_USE_GLFW}")

message(STATUS "Using python3")
find_package(PythonInterp 3 REQUIRED)

################################################################################
# common_compile_options - sets compiler and linker options common for dawn and
# tint on the given target
################################################################################
function(common_compile_options TARGET)
  if (COMPILER_IS_LIKE_GNU)
    target_compile_options(${TARGET} PRIVATE
      -fno-exceptions
      -fno-rtti

      -Wno-deprecated-builtins
      -Wno-unknown-warning-option
    )

  endif(COMPILER_IS_LIKE_GNU)

  if(MSVC)
      target_compile_options(${TARGET} PUBLIC /utf-8)
  endif()
endfunction()

################################################################################
# Run on all subdirectories
################################################################################

add_subdirectory(third_party)

add_subdirectory(src/samples)