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base: Split out the pixel class in framebuffer.(cc|hh).

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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>
This commit is contained in:
Gabe Black
2017-12-04 20:22:43 -08:00
parent 3017314d05
commit 7eb8d007a5
7 changed files with 334 additions and 240 deletions
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179
src/base/framebuffer.hh
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@@ -48,188 +48,11 @@
#include "base/compiler.hh"
#include "base/cprintf.hh"
#include "base/pixel.hh"
#include "base/str.hh"
#include "base/types.hh"
#include "sim/serialize.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("0x%.08x", PixelConverter::rgba8888_le.fromPixel(pxl));
return os;
}
/**
* Internal gem5 representation of a frame buffer
*