# Copyright 2013 The Flutter Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//flutter/impeller/tools/args.gni")
import("//flutter/impeller/tools/compiler.gni")
import("//flutter/impeller/tools/embed_blob.gni")
import("//flutter/impeller/tools/malioc.gni")
import("//flutter/impeller/tools/shader_archive.gni")

template("impeller_shaders_gles") {
  assert(defined(invoker.shaders), "Impeller shaders must be specified.")
  assert(defined(invoker.name), "Name of the shader library must be specified.")
  assert(defined(invoker.analyze), "Whether to analyze must be specified.")

  require_framebuffer_fetch = false
  if (defined(invoker.require_framebuffer_fetch) &&
      invoker.require_framebuffer_fetch) {
    require_framebuffer_fetch = invoker.require_framebuffer_fetch
  }

  is_300 = defined(invoker.is_300) && invoker.is_300

  shaders_base_name = string_join("",
                                  [
                                    invoker.name,
                                    "_shaders_gles",
                                  ])
  impellerc_gles = "impellerc_$target_name"
  impellerc(impellerc_gles) {
    shaders = invoker.shaders
    sl_file_extension = "gles"
    require_framebuffer_fetch = require_framebuffer_fetch
    if (defined(invoker.gles_language_version)) {
      gles_language_version = invoker.gles_language_version
    }

    # Metal reflectors generate a superset of information.
    if (impeller_enable_metal || impeller_enable_vulkan) {
      if (is_300) {
        intermediates_subdir = "gles3"
        mnemonic = "IMPELLERC_GLES3"
      } else {
        intermediates_subdir = "gles"
        mnemonic = "IMPELLERC_GLES2"
      }
    }
    shader_target_flags = [ "--opengl-es" ]

    defines = [ "IMPELLER_TARGET_OPENGLES" ]
    if (is_300) {
      defines += [ "IMPELLER_TARGET_OPENGLES3" ]
    }

    if (defined(invoker.entry_point_prefix)) {
      entry_point_prefix = invoker.entry_point_prefix
    }
  }

  gles_shaders =
      filter_include(get_target_outputs(":$impellerc_gles"), [ "*.gles" ])

  if (invoker.analyze) {
    analyze_lib = "analyze_$target_name"
    malioc_analyze_shaders(analyze_lib) {
      shaders = gles_shaders
      if (defined(invoker.gles_language_version)) {
        gles_language_version = invoker.gles_language_version
      }
      deps = [ ":$impellerc_gles" ]
    }
  }

  gles_lib = "genlib_$target_name"
  shader_archive(gles_lib) {
    shaders = gles_shaders
    deps = [ ":$impellerc_gles" ]
    if (defined(invoker.entry_point_prefix)) {
      entry_point_prefix = invoker.entry_point_prefix
    }
  }

  reflect_gles = "reflect_$target_name"
  impellerc_reflect(reflect_gles) {
    impellerc_invocation = ":$impellerc_gles"
  }

  embed_gles_lib = "embed_$target_name"
  if (is_300) {
    embed_blob(embed_gles_lib) {
      gles_library_files = get_target_outputs(":$gles_lib")
      symbol_name = shaders_base_name + "3"
      blob = gles_library_files[0]
      hdr = "$target_gen_dir/gles3/$shaders_base_name.h"
      cc = "$target_gen_dir/gles3/$shaders_base_name.cc"
      deps = [ ":$gles_lib" ]
    }
  } else {
    embed_blob(embed_gles_lib) {
      gles_library_files = get_target_outputs(":$gles_lib")
      symbol_name = shaders_base_name
      blob = gles_library_files[0]
      hdr = "$target_gen_dir/gles/$shaders_base_name.h"
      cc = "$target_gen_dir/gles/$shaders_base_name.cc"
      deps = [ ":$gles_lib" ]
    }
  }

  group(target_name) {
    public_deps = [ ":$embed_gles_lib" ]

    if (invoker.analyze) {
      public_deps += [ ":$analyze_lib" ]
    }

    if (!impeller_enable_metal && !impeller_enable_vulkan) {
      public_deps += [ ":$reflect_gles" ]
    }
  }
}