//
//  basics.hpp
//  ImageStreams
//
//  Created by Joshua Moerman on 9/7/12.
//  Copyright (c) 2012 Vadovas. All rights reserved.
//

#ifndef ImageStreams_basics_hpp
#define ImageStreams_basics_hpp

/*
 A PixelFormat p should have the following constructors (depending on number
 of colors):
	p(int r, int g, int b, int a)
	p(double r, double g, double b, double a)
	
	p(int v)
	p(double v)
 
 It should be trivially writable with memcpy (TODO: check exact requirement)
 
 Furthermore it should have a static constexpr size_t num_colors indicating the
 number of colors and a static constexpr size_t bit_per_color indicating the
 number of bits per color (TODO: what to do with encodings like 565 ?)
 */

namespace pixel_formats {
	inline uint8_t clamp(int n){
		return std::min(255, std::max(0, n));
	}
	
	struct Gray {
		static constexpr size_t num_colors = 1;
		static constexpr size_t bits_per_color = 8;
		
		Gray() : value(0) {}
		Gray(double intensity) : value(clamp(255*intensity)) {}
		Gray(int intensity) : value(clamp(intensity)) {}
		
	private:
		uint8_t value;
	};
	
	struct RGB {
		static constexpr size_t num_colors = 3;
		static constexpr size_t bits_per_color = 8;
		
		RGB()
		: red(0)
		, green(0)
		, blue(0)
		{}
		
		RGB(double red, double green, double blue)
		: red(clamp(255*red))
		, green(clamp(255*green))
		, blue(clamp(255*blue))
		{}
		
		RGB(int red, int green, int blue)
		: red(clamp(red))
		, green(clamp(green))
		, blue(clamp(blue))
		{}
		
	private:
		uint8_t red;
		uint8_t green;
		uint8_t blue;
	};
	
	struct BGR{
		static constexpr size_t num_colors = 3;
		static constexpr size_t bits_per_color = 8;
		
		BGR()
		: blue(0)
		, green(0)
		, red(0)
		{}
		
		BGR(double red, double green, double blue)
		: blue(clamp(255*blue))
		, green(clamp(255*green))
		, red(clamp(255*red))
		{}
		
		BGR(int red, int green, int blue)
		: blue(clamp(blue))
		, green(clamp(green))
		, red(clamp(red))
		{}
		
	private:
		uint8_t blue;
		uint8_t green;
		uint8_t red;
	};

	template <typename PixelType>
	struct traits {
		static constexpr size_t num_colors = PixelType::num_colors;
		static constexpr size_t bits_per_color = PixelType::bits_per_color;
		static constexpr size_t bits_per_pixel = num_colors * bits_per_color;
	};
}

#endif