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authorGabe Black <gabeblack@google.com>2017-12-04 20:22:43 -0800
committerGabe Black <gabeblack@google.com>2017-12-06 01:14:52 +0000
commit7eb8d007a502d6c6d62eab590d71f6085aef78f9 (patch)
tree126343c64cd79fdababa821726a55213e751892c /src/base/pixel.hh
parent3017314d05695207e09e87b08ca5c3cbf182c646 (diff)
downloadgem5-7eb8d007a502d6c6d62eab590d71f6085aef78f9.tar.xz
base: Split out the pixel class in framebuffer.(cc|hh).
These are really two separate things. Also, while it's realitively straightforward to write a unit test for the pixel conversion code, the framebuffer object is serializable and brings in more dependencies. Change-Id: If954caeb0bfedb1002cfb1a7a115a00c90d56d19 Reviewed-on: https://gem5-review.googlesource.com/6341 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
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+/*
+ * 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__