1/*
2 * Copyright (c) 2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Sandberg
38 */
39
40#ifndef __BASE_PIXEL_HH__
41#define __BASE_PIXEL_HH__
42
43#include <cmath>
44#include <cstdint>
45#include <string>
46#include <vector>
47
48#include "base/compiler.hh"
49#include "base/cprintf.hh"
50#include "base/str.hh"
51#include "base/types.hh"
52
53/**
54 * Internal gem5 representation of a Pixel.
55 */
56struct Pixel
57{
58    Pixel()
59        : red(0), green(0), blue(0), padding(0) {}
60
61    Pixel(uint8_t _red, uint8_t _green, uint8_t _blue)
62        : red(_red), green(_green), blue(_blue), padding(0) {}
63
64    uint8_t red;
65    uint8_t green;
66    uint8_t blue;
67    uint8_t padding;
68};
69
70inline bool
71operator==(const Pixel &lhs, const Pixel &rhs)
72{
73    return lhs.red == rhs.red &&
74        lhs.green == rhs.green &&
75        lhs.blue == rhs.blue &&
76        lhs.padding == rhs.padding;
77}
78
79/**
80 * Configurable RGB pixel converter.
81 *
82 * This class converts between external RGB representations and gem5's
83 * internal Pixel representation. The class assumes that pixels are
84 * stored in a word of configurable length (up to 32 bits). Individual
85 * pixels are assumed to be represented by contiguous bit ranges in
86 * the word (i.e., it is possible to shift and mask out a contiguous
87 * bit range for each pixel).
88 */
89class PixelConverter
90{
91  public:
92    /**
93     * Color channel conversion and scaling helper class.
94     */
95    struct Channel {
96        /**
97         * @param offset Offset in bits.
98         * @param width Width in bits.
99         */
100        Channel(unsigned offset, unsigned width);
101
102        /**
103         * Get the value of a single color channel represented as an
104         * 8-bit number.
105         */
106        uint8_t toPixel(uint32_t word) const {
107            return round(((word >> offset) & mask) * factor);
108        }
109
110        /**
111         * Convert an 8-bit representation of a color into an external
112         * format.
113         */
114        uint32_t fromPixel(uint8_t ch) const {
115            return (static_cast<uint8_t>(round(ch / factor)) & mask) << offset;
116        }
117
118        /** Offset in bits */
119        unsigned offset;
120        /** Bit mask (after shifting) */
121        unsigned mask;
122        /**
123         * Scaling factor when converting to the full range of an
124         * 8-bit color channel
125         */
126        float factor;
127    };
128
129    PixelConverter(unsigned length,
130                   unsigned ro, unsigned go, unsigned bo,
131                   unsigned rw, unsigned gw, unsigned bw,
132                   ByteOrder byte_order = LittleEndianByteOrder);
133
134    /** Get the Pixel representation of a color word. */
135    Pixel toPixel(uint32_t word) const {
136        return Pixel(ch_r.toPixel(word),
137                     ch_g.toPixel(word),
138                     ch_b.toPixel(word));
139    }
140
141    /** Get a Pixel representation by reading a word from memory. */
142    Pixel toPixel(const uint8_t *rfb) const {
143        return toPixel(readWord(rfb));
144    }
145
146    /** Convert a Pixel into a color word */
147    uint32_t fromPixel(const Pixel &pixel) const {
148        return ch_r.fromPixel(pixel.red) |
149            ch_g.fromPixel(pixel.green) |
150            ch_b.fromPixel(pixel.blue);
151    }
152
153    /**
154     * Convert a pixel into a color word and store the resulting word
155     * in memory.
156     */
157    void fromPixel(uint8_t *rfb, const Pixel &pixel) const {
158        writeWord(rfb, fromPixel(pixel));
159    }
160
161    /**
162     * Read a word of a given length and endianness from memory.
163     *
164     * The number of bytes read from memory is determined by the
165     * length of a color word. Note that some of the bytes may be
166     * padding.
167     *
168     * @param p Pointer to the first byte in the word.
169     * @return Word in host endianness.
170     */
171    uint32_t readWord(const uint8_t *p) const;
172    /**
173     * Write a word of a given length and endianness to memory.
174     *
175     * @param p Pointer to the first byte in memory.
176     * @param word Word to store (host endianness).
177     */
178    void writeWord(uint8_t *p, uint32_t word) const;
179
180    /** Bytes per pixel when stored in memory (including padding) */
181    unsigned length;
182    /**
183     * Number of bits used to represent one pixel value (excluding
184     * padding). This could be less than length * 8 if the pixel value
185     * is padded.
186     */
187    unsigned depth;
188    /** Byte order when stored to memory. */
189    ByteOrder byte_order;
190
191    /** Red channel conversion helper */
192    Channel ch_r;
193    /** Green channel conversion helper */
194    Channel ch_g;
195    /** Blue channel conversion helper */
196    Channel ch_b;
197
198    /** Predefined 32-bit RGB (red in least significant bits, 8
199     * bits/channel, little endian) conversion helper */
200    static const PixelConverter rgba8888_le;
201    /** Predefined 16-bit RGB565 (red in least significant bits,
202     * little endian) conversion helper */
203    static const PixelConverter rgb565_le;
204
205    /** Predefined 32-bit RGB (red in least significant bits, 8
206     * bits/channel, big endian) conversion helper */
207    static const PixelConverter rgba8888_be;
208    /** Predefined 16-bit RGB565 (red in least significant bits,
209     * big endian) conversion helper */
210    static const PixelConverter rgb565_be;
211};
212
213inline bool
214to_number(const std::string &value, Pixel &retval)
215{
216    uint32_t num;
217    if (!to_number(value, num))
218        return false;
219
220    retval = PixelConverter::rgba8888_le.toPixel(num);
221    return true;
222}
223
224inline std::ostream &
225operator<<(std::ostream &os, const Pixel &pxl)
226{
227    os << csprintf("%#.08x", PixelConverter::rgba8888_le.fromPixel(pxl));
228    return os;
229}
230
231#endif // __BASE_PIXEL_HH__
232