/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file palette_func.h Functions related to palettes. */

#ifndef PALETTE_FUNC_H
#define PALETTE_FUNC_H

#include "core/enum_type.hpp"
#include "gfx_type.h"

extern Palette _cur_palette; ///< Current palette

void GfxInitPalettes();

uint8_t GetNearestColourIndex(uint8_t r, uint8_t g, uint8_t b);

inline uint8_t GetNearestColourIndex(const Colour colour)
{
	return GetNearestColourIndex(colour.r, colour.g, colour.b);
}

/**
 * Checks if a Colours value is valid.
 *
 * @param colours The value to check
 * @return true if the given value is a valid Colours.
 */
inline bool IsValidColours(Colours colours)
{
	return colours < COLOUR_END;
}

TextColour GetContrastColour(uint8_t background, uint8_t threshold = 128);

extern byte _colour_value[COLOUR_END];

enum ColourShade : uint8_t {
	SHADE_BEGIN = 0,
	SHADE_DARKEST = SHADE_BEGIN,
	SHADE_DARKER,
	SHADE_DARK,
	SHADE_NORMAL,
	SHADE_LIGHT,
	SHADE_LIGHTER,
	SHADE_LIGHTEST,
	SHADE_LIGHTEREST,
	SHADE_END,
};
DECLARE_POSTFIX_INCREMENT(ColourShade)

byte GetColourGradient(Colours colour, ColourShade shade);
void SetColourGradient(Colours colour, ColourShade shade, byte palette_colour);

/**
 * Return the colour for a particular greyscale level.
 * @param level Intensity, 0 = black, 15 = white
 * @return colour
 */
#define GREY_SCALE(level) (level)

static const uint8_t PC_BLACK              = GREY_SCALE(1);  ///< Black palette colour.
static const uint8_t PC_DARK_GREY          = GREY_SCALE(6);  ///< Dark grey palette colour.
static const uint8_t PC_GREY               = GREY_SCALE(10); ///< Grey palette colour.
static const uint8_t PC_WHITE              = GREY_SCALE(15); ///< White palette colour.

static const uint8_t PC_VERY_DARK_RED      = 0xB2;           ///< Almost-black red palette colour.
static const uint8_t PC_DARK_RED           = 0xB4;           ///< Dark red palette colour.
static const uint8_t PC_RED                = 0xB8;           ///< Red palette colour.

static const uint8_t PC_VERY_DARK_BROWN    = 0x56;           ///< Almost-black brown palette colour.

static const uint8_t PC_ORANGE             = 0xC2;           ///< Orange palette colour.

static const uint8_t PC_YELLOW             = 0xBF;           ///< Yellow palette colour.
static const uint8_t PC_LIGHT_YELLOW       = 0x44;           ///< Light yellow palette colour.
static const uint8_t PC_VERY_LIGHT_YELLOW  = 0x45;           ///< Almost-white yellow palette colour.

static const uint8_t PC_GREEN              = 0xD0;           ///< Green palette colour.

static const uint8_t PC_VERY_DARK_BLUE     = 0x9A;           ///< Almost-black blue palette colour.
static const uint8_t PC_DARK_BLUE          = 0x9D;           ///< Dark blue palette colour.
static const uint8_t PC_LIGHT_BLUE         = 0x98;           ///< Light blue palette colour.

static const uint8_t PC_ROUGH_LAND         = 0x52;           ///< Dark green palette colour for rough land.
static const uint8_t PC_GRASS_LAND         = 0x54;           ///< Dark green palette colour for grass land.
static const uint8_t PC_BARE_LAND          = 0x37;           ///< Brown palette colour for bare land.
static const uint8_t PC_RAINFOREST         = 0x5C;           ///< Pale green palette colour for rainforest.
static const uint8_t PC_FIELDS             = 0x25;           ///< Light brown palette colour for fields.
static const uint8_t PC_TREES              = 0x57;           ///< Green palette colour for trees.
static const uint8_t PC_WATER              = 0xC9;           ///< Dark blue palette colour for water.

#endif /* PALETTE_FUNC_H */
