/*************************************************************************/
/*  terrain_mesher_default.cpp                                           */
/*************************************************************************/
/*                         This file is part of:                         */
/*                          PANDEMONIUM ENGINE                           */
/*             https://github.com/Relintai/pandemonium_engine            */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar.                              */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
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/* the following conditions:                                             */
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/* The above copyright notice and this permission notice shall be        */
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/*************************************************************************/

#include "terrain_mesher_default.h"

#include "../../world/default/terrain_chunk_default.h"

#include "../../defines.h"

#include "scene/3d/mesh_instance.h"
#include "servers/rendering_server.h"

_FORCE_INLINE_ int TerrainMesherDefault::get_build_flags() const {
	return _build_flags;
}
_FORCE_INLINE_ void TerrainMesherDefault::set_build_flags(const int flags) {
	_build_flags = flags;

	if ((_build_flags & TerrainChunkDefault::BUILD_FLAG_USE_LIGHTING) != 0) {
		_format |= RenderingServer::ARRAY_FORMAT_COLOR;
	} else {
		_format ^= RenderingServer::ARRAY_FORMAT_COLOR;
	}
}

void TerrainMesherDefault::_bake_colors(Ref<TerrainChunk> chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	//if ((get_build_flags() & TerrainChunkDefault::BUILD_FLAG_USE_LIGHTING) == 0)
	//	return;

	if (_vertices.size() == 0)
		return;

	uint8_t *channel_color_r = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_R);
	uint8_t *channel_color_g = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_G);
	uint8_t *channel_color_b = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_B);
	uint8_t *channel_ao = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_AO);
	uint8_t *channel_rao = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_RANDOM_AO);

	Color base_light(_base_light_value, _base_light_value, _base_light_value);

	for (int i = 0; i < _vertices.size(); ++i) {
		Vertex vertex = _vertices[i];
		Vector3 vert = vertex.vertex;

		unsigned int x = (unsigned int)(vert.x / _voxel_scale);
		unsigned int z = (unsigned int)(vert.z / _voxel_scale);

		if (chunk->validate_data_position(x, z)) {
			int indx = chunk->get_data_index(x, z);

			Color light = Color(
					channel_color_r[indx] / 255.0,
					channel_color_g[indx] / 255.0,
					channel_color_b[indx] / 255.0);

			float ao = (channel_ao[indx] / 255.0) * _ao_strength;
			float rao = channel_rao[indx] / 255.0;

			ao += rao;

			light.r += _base_light_value;
			light.g += _base_light_value;
			light.b += _base_light_value;

			light.r -= ao;
			light.g -= ao;
			light.b -= ao;

			light.r = CLAMP(light.r, 0, 1.0);
			light.g = CLAMP(light.g, 0, 1.0);
			light.b = CLAMP(light.b, 0, 1.0);

			Color c = vertex.color;
			light.a = c.a;
			vertex.color = light;

			_vertices.set(i, vertex);
		} else {
			vertex.color = base_light;
			_vertices.set(i, vertex);
		}
	}
}

void TerrainMesherDefault::_bake_liquid_colors(Ref<TerrainChunk> chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	if ((get_build_flags() & TerrainChunkDefault::BUILD_FLAG_USE_LIGHTING) == 0)
		return;

	if (_vertices.size() == 0)
		return;

	uint8_t *channel_color_r = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_R);
	uint8_t *channel_color_g = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_G);
	uint8_t *channel_color_b = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_LIGHT_COLOR_B);
	uint8_t *channel_ao = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_AO);
	uint8_t *channel_rao = chunk->channel_get_valid(TerrainChunkDefault::DEFAULT_CHANNEL_RANDOM_AO);

	Color base_light(_base_light_value, _base_light_value, _base_light_value);

	for (int i = 0; i < _vertices.size(); ++i) {
		Vertex vertex = _vertices[i];
		Vector3 vert = vertex.vertex;

		//Is this needed?
		if (vert.x < 0 || vert.y < 0 || vert.z < 0) {
			continue;
		}

		unsigned int x = (unsigned int)(vert.x / _voxel_scale);
		//unsigned int y = (unsigned int)(vert.y / _voxel_scale);
		unsigned int z = (unsigned int)(vert.z / _voxel_scale);

		if (chunk->validate_data_position(x, z)) {
			int indx = chunk->get_data_index(x, z);

			Color light = Color(
					channel_color_r[indx] / 255.0,
					channel_color_g[indx] / 255.0,
					channel_color_b[indx] / 255.0);

			float ao = (channel_ao[indx] / 255.0) * _ao_strength;
			float rao = channel_rao[indx] / 255.0;

			ao += rao;

			light.r += _base_light_value;
			light.g += _base_light_value;
			light.b += _base_light_value;

			light.r -= ao;
			light.g -= ao;
			light.b -= ao;

			light.r = CLAMP(light.r, 0, 1.0);
			light.g = CLAMP(light.g, 0, 1.0);
			light.b = CLAMP(light.b, 0, 1.0);

			Color c = vertex.color;
			light.a = c.a;
			vertex.color = light;

			_vertices.set(i, vertex);
		} else {
			vertex.color = base_light;
			_vertices.set(i, vertex);
		}
	}
}

TerrainMesherDefault::TerrainMesherDefault() {
	_build_flags = TerrainChunkDefault::BUILD_FLAG_CREATE_COLLIDER | TerrainChunkDefault::BUILD_FLAG_CREATE_LODS;

	_format = RenderingServer::ARRAY_FORMAT_NORMAL | RenderingServer::ARRAY_FORMAT_TEX_UV;
}

TerrainMesherDefault::~TerrainMesherDefault() {
}

void TerrainMesherDefault::_bind_methods() {
	ClassDB::bind_method(D_METHOD("_bake_colors", "chunk"), &TerrainMesherDefault::_bake_colors);
	ClassDB::bind_method(D_METHOD("_bake_liquid_colors", "chunk"), &TerrainMesherDefault::_bake_liquid_colors);

	ClassDB::bind_method(D_METHOD("get_build_flags"), &TerrainMesherDefault::get_build_flags);
	ClassDB::bind_method(D_METHOD("set_build_flags", "value"), &TerrainMesherDefault::set_build_flags);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "build_flags", PROPERTY_HINT_FLAGS, TerrainChunkDefault::BINDING_STRING_BUILD_FLAGS), "set_build_flags", "get_build_flags");
}