/*************************************************************************/
/*  pvrtc_compress.cpp                                                   */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
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/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
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/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
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/* The above copyright notice and this permission notice shall be        */
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/*************************************************************************/

#include "pvrtc_compress.h"

#include "core/io/resource_loader.h"
#include "core/io/resource_saver.h"
#include "core/os/dir_access.h"
#include "core/os/file_access.h"
#include "core/os/os.h"
#include "editor_settings.h"
#include "scene/resources/texture.h"

static void (*_base_image_compress_pvrtc2_func)(Image *) = NULL;
static void (*_base_image_compress_pvrtc4_func)(Image *) = NULL;

static void _compress_image(Image::CompressMode p_mode, Image *p_image) {

	String ttpath = EditorSettings::get_singleton()->get("filesystem/import/pvrtc_texture_tool");

	if (ttpath.strip_edges() == "" || !FileAccess::exists(ttpath)) {
		switch (p_mode) {

			case Image::COMPRESS_PVRTC2:
				if (_base_image_compress_pvrtc2_func)
					_base_image_compress_pvrtc2_func(p_image);
				else if (_base_image_compress_pvrtc4_func)
					_base_image_compress_pvrtc4_func(p_image);
				break;
			case Image::COMPRESS_PVRTC4:
				if (_base_image_compress_pvrtc4_func)
					_base_image_compress_pvrtc4_func(p_image);
				break;
			default:
				ERR_FAIL_MSG("Unsupported Image compress mode used in PVRTC module.");
		}
		return;
	}

	String tmppath = EditorSettings::get_singleton()->get_cache_dir();
	String src_img = tmppath.plus_file("_tmp_src_img.png");
	String dst_img = tmppath.plus_file("_tmp_dst_img.pvr");

	List<String> args;
	args.push_back("-i");
	args.push_back(src_img);
	args.push_back("-o");
	args.push_back(dst_img);
	args.push_back("-f");

	switch (p_mode) {
		case Image::COMPRESS_PVRTC2:
			args.push_back("PVRTC2");
			break;
		case Image::COMPRESS_PVRTC4:
			args.push_back("PVRTC4");
			break;
		case Image::COMPRESS_ETC:
			args.push_back("ETC");
			break;
		default:
			ERR_FAIL_MSG("Unsupported Image compress mode used in PVRTC module.");
	}

	if (EditorSettings::get_singleton()->get("filesystem/import/pvrtc_fast_conversion").operator bool()) {
		args.push_back("-pvrtcfast");
	}
	if (p_image->has_mipmaps()) {
		args.push_back("-m");
	}

	// Save source PNG.
	Ref<ImageTexture> t = memnew(ImageTexture);
	t->create_from_image(Ref<Image>(p_image));
	ResourceSaver::save(src_img, t);

	Error err = OS::get_singleton()->execute(ttpath, args, true);
	if (err != OK) {
		// Clean up generated files.
		DirAccess::remove_file_or_error(src_img);
		DirAccess::remove_file_or_error(dst_img);
		ERR_FAIL_MSG("Could not execute PVRTC tool: " + ttpath);
	}

	t = ResourceLoader::load(dst_img, "Texture2D");
	if (t.is_null()) {
		// Clean up generated files.
		DirAccess::remove_file_or_error(src_img);
		DirAccess::remove_file_or_error(dst_img);
		ERR_FAIL_MSG("Can't load back converted image using PVRTC tool.");
	}

	p_image->copy_internals_from(t->get_data());

	// Clean up generated files.
	DirAccess::remove_file_or_error(src_img);
	DirAccess::remove_file_or_error(dst_img);
}

static void _compress_pvrtc2(Image *p_image) {

	_compress_image(Image::COMPRESS_PVRTC2, p_image);
}

static void _compress_pvrtc4(Image *p_image) {

	_compress_image(Image::COMPRESS_PVRTC4, p_image);
}

void _pvrtc_register_compressors() {

	_base_image_compress_pvrtc2_func = Image::_image_compress_pvrtc2_func;
	_base_image_compress_pvrtc4_func = Image::_image_compress_pvrtc4_func;

	Image::_image_compress_pvrtc2_func = _compress_pvrtc2;
	Image::_image_compress_pvrtc4_func = _compress_pvrtc4;
}