# Copyright 2018 The Dawn Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import("//build_overrides/build.gni")

if (build_with_chromium) {
  import("//build/config/sanitizers/sanitizers.gni")
  import("//build/config/ui.gni")

  dawn_use_x11 = use_x11
} else {
  declare_args() {
    # Whether Dawn should enable X11 support.
    dawn_use_x11 = is_linux && !is_chromeos
  }
}

# Enable the compilation for UWP
dawn_is_winuwp = is_win && target_os == "winuwp"

declare_args() {
  dawn_use_angle = true

  # Enables usage of swiftshader on the Vulkan backend.
  # Note that this will only work in standalone and in projects that set the
  # dawn_swiftshader_dir variable in build_overrides/dawn.gni
  # Because of how the Vulkan loader works, setting this makes Dawn only able
  # to find the Swiftshader ICD and not the others.
  # Enabled by default when fuzzing.
  dawn_use_swiftshader = build_with_chromium && use_fuzzing_engine
}

declare_args() {
  # Enable Dawn's ASSERTs even in release builds
  dawn_always_assert = false

  # Should the Dawn static libraries be fully linked vs. GN's default of
  # treating them as source sets. This is useful for people using Dawn
  # standalone to produce static libraries to use in their projects.
  dawn_complete_static_libs = false

  # Enables the compilation of Dawn's D3D12 backend
  dawn_enable_d3d12 = is_win

  # Enables the compilation of Dawn's Metal backend
  dawn_enable_metal = is_mac

  # Enables the compilation of Dawn's Null backend
  # (required for unittests, obviously non-conformant)
  dawn_enable_null = true

  # Enables the compilation of Dawn's OpenGL backend
  # (best effort, non-conformant)
  dawn_enable_desktop_gl = !build_with_chromium && (is_linux && !is_chromeos)

  # Enables the compilation of Dawn's OpenGLES backend
  # (WebGPU/Compat subset)
  # Disables OpenGLES when compiling for UWP, since UWP only supports d3d
  dawn_enable_opengles = !build_with_chromium && ((is_linux && !is_chromeos) ||
                                                  (is_win && !dawn_is_winuwp))

  # Enables the compilation of Dawn's Vulkan backend
  # Disables vulkan when compiling for UWP, since UWP only supports d3d
  dawn_enable_vulkan = is_linux || is_chromeos || (is_win && !dawn_is_winuwp) ||
                       is_fuchsia || is_android || dawn_use_swiftshader

  # Enable use of reflection compiler in spirv-cross. This is needed
  # if performing reflection on systems that the platform language
  # shader is SPIR-V, since there isn't an instance of the
  # GLSL/HLSL/MSL compiler. This implicitly pulls in the GLSL
  # compiler, since it is a sub-class of it.
  dawn_enable_cross_reflection = false

  # Enables error injection for faking failures to native API calls
  dawn_enable_error_injection =
      is_debug || (build_with_chromium && use_fuzzing_engine)
}

# GN does not allow reading a variable defined in the same declare_args().
# Put them in two separate declare_args() when setting the value of one
# argument based on another.
declare_args() {
  # Uses our built version of the Vulkan validation layers
  dawn_enable_vulkan_validation_layers =
      dawn_enable_vulkan && ((is_linux && !is_chromeos) || is_win || is_mac)

  # Uses our built version of the Vulkan loader on platforms where we can't
  # assume to have one present at the system level.
  dawn_enable_vulkan_loader = dawn_enable_vulkan && is_mac
}

# UWP only supports CoreWindow for windowing
dawn_supports_glfw_for_windowing =
    (is_win && !dawn_is_winuwp) || (is_linux && !is_chromeos) || is_mac

# Much of the GL backend code is shared, so define a convenience var.
dawn_enable_opengl = dawn_enable_opengles || dawn_enable_desktop_gl

# The GL backends are the last to use SPIRV-Cross, so only compile it in
# if they are enabled.
dawn_use_spirv_cross = dawn_enable_opengl