src/base/pixel.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2015 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Authors: Andreas Sandberg
  */

 #ifndef __BASE_PIXEL_HH__
 #define __BASE_PIXEL_HH__

 #include <cmath>
 #include <cstdint>
 #include <string>
 #include <vector>

 #include "base/compiler.hh"
 #include "base/cprintf.hh"
 #include "base/str.hh"
 #include "base/types.hh"

 /**
  * Internal gem5 representation of a Pixel.
  */
 struct Pixel
 {
     Pixel()
         : red(0), green(0), blue(0), padding(0) {}

     Pixel(uint8_t _red, uint8_t _green, uint8_t _blue)
         : red(_red), green(_green), blue(_blue), padding(0) {}

     uint8_t red;
     uint8_t green;
     uint8_t blue;
     uint8_t padding;
 };

 inline bool
 operator==(const Pixel &lhs, const Pixel &rhs)
 {
     return lhs.red == rhs.red &&
         lhs.green == rhs.green &&
         lhs.blue == rhs.blue &&
         lhs.padding == rhs.padding;
 }

 /**
  * Configurable RGB pixel converter.
  *
  * This class converts between external RGB representations and gem5's
  * internal Pixel representation. The class assumes that pixels are
  * stored in a word of configurable length (up to 32 bits). Individual
  * pixels are assumed to be represented by contiguous bit ranges in
  * the word (i.e., it is possible to shift and mask out a contiguous
  * bit range for each pixel).
  */
 class PixelConverter
 {
   public:
     /**
      * Color channel conversion and scaling helper class.
      */
     struct Channel {
         /**
          * @param offset Offset in bits.
          * @param width Width in bits.
          */
         Channel(unsigned offset, unsigned width);

         /**
          * Get the value of a single color channel represented as an
          * 8-bit number.
          */
         uint8_t toPixel(uint32_t word) const {
             return round(((word >> offset) & mask) * factor);
         }

         /**
          * Convert an 8-bit representation of a color into an external
          * format.
          */
         uint32_t fromPixel(uint8_t ch) const {
             return (static_cast<uint8_t>(round(ch / factor)) & mask) << offset;
         }

         /** Offset in bits */
         unsigned offset;
         /** Bit mask (after shifting) */
         unsigned mask;
         /**
          * Scaling factor when converting to the full range of an
          * 8-bit color channel
          */
         float factor;
     };

     PixelConverter(unsigned length,
                    unsigned ro, unsigned go, unsigned bo,
                    unsigned rw, unsigned gw, unsigned bw,
                    ByteOrder byte_order = LittleEndianByteOrder);

     /** Get the Pixel representation of a color word. */
     Pixel toPixel(uint32_t word) const {
         return Pixel(ch_r.toPixel(word),
                      ch_g.toPixel(word),
                      ch_b.toPixel(word));
     }

     /** Get a Pixel representation by reading a word from memory. */
     Pixel toPixel(const uint8_t *rfb) const {
         return toPixel(readWord(rfb));
     }

     /** Convert a Pixel into a color word */
     uint32_t fromPixel(const Pixel &pixel) const {
         return ch_r.fromPixel(pixel.red) |
             ch_g.fromPixel(pixel.green) |
             ch_b.fromPixel(pixel.blue);
     }

     /**
      * Convert a pixel into a color word and store the resulting word
      * in memory.
      */
     void fromPixel(uint8_t *rfb, const Pixel &pixel) const {
         writeWord(rfb, fromPixel(pixel));
     }

     /**
      * Read a word of a given length and endianness from memory.
      *
      * The number of bytes read from memory is determined by the
      * length of a color word. Note that some of the bytes may be
      * padding.
      *
      * @param p Pointer to the first byte in the word.
      * @return Word in host endianness.
      */
     uint32_t readWord(const uint8_t *p) const;
     /**
      * Write a word of a given length and endianness to memory.
      *
      * @param p Pointer to the first byte in memory.
      * @param word Word to store (host endianness).
      */
     void writeWord(uint8_t *p, uint32_t word) const;

     /** Bytes per pixel when stored in memory (including padding) */
     unsigned length;
     /**
      * Number of bits used to represent one pixel value (excluding
      * padding). This could be less than length * 8 if the pixel value
      * is padded.
      */
     unsigned depth;
     /** Byte order when stored to memory. */
     ByteOrder byte_order;

     /** Red channel conversion helper */
     Channel ch_r;
     /** Green channel conversion helper */
     Channel ch_g;
     /** Blue channel conversion helper */
     Channel ch_b;

     /** Predefined 32-bit RGB (red in least significant bits, 8
      * bits/channel, little endian) conversion helper */
     static const PixelConverter rgba8888_le;
     /** Predefined 16-bit RGB565 (red in least significant bits,
      * little endian) conversion helper */
     static const PixelConverter rgb565_le;

     /** Predefined 32-bit RGB (red in least significant bits, 8
      * bits/channel, big endian) conversion helper */
     static const PixelConverter rgba8888_be;
     /** Predefined 16-bit RGB565 (red in least significant bits,
      * big endian) conversion helper */
     static const PixelConverter rgb565_be;
 };

 inline bool
 to_number(const std::string &value, Pixel &retval)
 {
     uint32_t num;
     if (!to_number(value, num))
         return false;

     retval = PixelConverter::rgba8888_le.toPixel(num);
     return true;
 }

 inline std::ostream &
 operator<<(std::ostream &os, const Pixel &pxl)
 {
     os << csprintf("%#.08x", PixelConverter::rgba8888_le.fromPixel(pxl));
     return os;
 }

 #endif // __BASE_PIXEL_HH__
	/*
	* Copyright (c) 2015 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	* Authors: Andreas Sandberg
	*/

	#ifndef __BASE_PIXEL_HH__
	#define __BASE_PIXEL_HH__

	#include <cmath>
	#include <cstdint>
	#include <string>
	#include <vector>

	#include "base/compiler.hh"
	#include "base/cprintf.hh"
	#include "base/str.hh"
	#include "base/types.hh"

	/**
	* Internal gem5 representation of a Pixel.
	*/
	struct Pixel
	{
	Pixel()
	: red(0), green(0), blue(0), padding(0) {}

	Pixel(uint8_t _red, uint8_t _green, uint8_t _blue)
	: red(_red), green(_green), blue(_blue), padding(0) {}

	uint8_t red;
	uint8_t green;
	uint8_t blue;
	uint8_t padding;
	};

	inline bool
	operator==(const Pixel &lhs, const Pixel &rhs)
	{
	return lhs.red == rhs.red &&
	lhs.green == rhs.green &&
	lhs.blue == rhs.blue &&
	lhs.padding == rhs.padding;
	}

	/**
	* Configurable RGB pixel converter.
	*
	* This class converts between external RGB representations and gem5's
	* internal Pixel representation. The class assumes that pixels are
	* stored in a word of configurable length (up to 32 bits). Individual
	* pixels are assumed to be represented by contiguous bit ranges in
	* the word (i.e., it is possible to shift and mask out a contiguous
	* bit range for each pixel).
	*/
	class PixelConverter
	{
	public:
	/**
	* Color channel conversion and scaling helper class.
	*/
	struct Channel {
	/**
	* @param offset Offset in bits.
	* @param width Width in bits.
	*/
	Channel(unsigned offset, unsigned width);

	/**
	* Get the value of a single color channel represented as an
	* 8-bit number.
	*/
	uint8_t toPixel(uint32_t word) const {
	return round(((word >> offset) & mask) * factor);
	}

	/**
	* Convert an 8-bit representation of a color into an external
	* format.
	*/
	uint32_t fromPixel(uint8_t ch) const {
	return (static_cast<uint8_t>(round(ch / factor)) & mask) << offset;
	}

	/** Offset in bits */
	unsigned offset;
	/** Bit mask (after shifting) */
	unsigned mask;
	/**
	* Scaling factor when converting to the full range of an
	* 8-bit color channel
	*/
	float factor;
	};

	PixelConverter(unsigned length,
	unsigned ro, unsigned go, unsigned bo,
	unsigned rw, unsigned gw, unsigned bw,
	ByteOrder byte_order = LittleEndianByteOrder);

	/** Get the Pixel representation of a color word. */
	Pixel toPixel(uint32_t word) const {
	return Pixel(ch_r.toPixel(word),
	ch_g.toPixel(word),
	ch_b.toPixel(word));
	}

	/** Get a Pixel representation by reading a word from memory. */
	Pixel toPixel(const uint8_t *rfb) const {
	return toPixel(readWord(rfb));
	}

	/** Convert a Pixel into a color word */
	uint32_t fromPixel(const Pixel &pixel) const {
	return ch_r.fromPixel(pixel.red) \|
	ch_g.fromPixel(pixel.green) \|
	ch_b.fromPixel(pixel.blue);
	}

	/**
	* Convert a pixel into a color word and store the resulting word
	* in memory.
	*/
	void fromPixel(uint8_t *rfb, const Pixel &pixel) const {
	writeWord(rfb, fromPixel(pixel));
	}

	/**
	* Read a word of a given length and endianness from memory.
	*
	* The number of bytes read from memory is determined by the
	* length of a color word. Note that some of the bytes may be
	* padding.
	*
	* @param p Pointer to the first byte in the word.
	* @return Word in host endianness.
	*/
	uint32_t readWord(const uint8_t *p) const;
	/**
	* Write a word of a given length and endianness to memory.
	*
	* @param p Pointer to the first byte in memory.
	* @param word Word to store (host endianness).
	*/
	void writeWord(uint8_t *p, uint32_t word) const;

	/** Bytes per pixel when stored in memory (including padding) */
	unsigned length;
	/**
	* Number of bits used to represent one pixel value (excluding
	* padding). This could be less than length * 8 if the pixel value
	* is padded.
	*/
	unsigned depth;
	/** Byte order when stored to memory. */
	ByteOrder byte_order;

	/** Red channel conversion helper */
	Channel ch_r;
	/** Green channel conversion helper */
	Channel ch_g;
	/** Blue channel conversion helper */
	Channel ch_b;

	/** Predefined 32-bit RGB (red in least significant bits, 8
	* bits/channel, little endian) conversion helper */
	static const PixelConverter rgba8888_le;
	/** Predefined 16-bit RGB565 (red in least significant bits,
	* little endian) conversion helper */
	static const PixelConverter rgb565_le;

	/** Predefined 32-bit RGB (red in least significant bits, 8
	* bits/channel, big endian) conversion helper */
	static const PixelConverter rgba8888_be;
	/** Predefined 16-bit RGB565 (red in least significant bits,
	* big endian) conversion helper */
	static const PixelConverter rgb565_be;
	};

	inline bool
	to_number(const std::string &value, Pixel &retval)
	{
	uint32_t num;
	if (!to_number(value, num))
	return false;

	retval = PixelConverter::rgba8888_le.toPixel(num);
	return true;
	}

	inline std::ostream &
	operator<<(std::ostream &os, const Pixel &pxl)
	{
	os << csprintf("%#.08x", PixelConverter::rgba8888_le.fromPixel(pxl));
	return os;
	}

	#endif // __BASE_PIXEL_HH__