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GRAPHICS: Optimise PixelBuffer::getValueAt and PixelBuffer::setPixelAt.

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Avoid doing a lot of operations just to move 2 or 4 bytes around.
Inline these methods as they are hot-spots and do very little: call
overhead becomes significant.
This commit is contained in:
Vincent Pelletier 2016-07-19 02:55:33 +02:00
parent d467980499
commit f4554c1541
2 changed files with 36 additions and 34 deletions
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32
graphics/pixelbuffer.cpp
View file

@ -86,20 +86,6 @@ void PixelBuffer::clear(int length) {
memset(_buffer, 0, length); memset(_buffer, 0, length);
} }
void PixelBuffer::setPixelAt(int pixel, uint32 value) {
#if defined(SCUMM_BIG_ENDIAN)
byte *buffer = _buffer + pixel * _format.bytesPerPixel;
for (int i = 0; i < _format.bytesPerPixel; ++i) {
buffer[i] = value >> ((_format.bytesPerPixel - i - 1) * 8) & 0xFF;
}
#elif defined(SCUMM_LITTLE_ENDIAN)
byte *buffer = _buffer + pixel * _format.bytesPerPixel;
for (int i = 0; i < _format.bytesPerPixel; ++i) {
buffer[i] = value >> (i * 8) & 0xFF;
}
#endif
}
void PixelBuffer::copyBuffer(int thisFrom, int otherFrom, int length, const PixelBuffer &buf) { void PixelBuffer::copyBuffer(int thisFrom, int otherFrom, int length, const PixelBuffer &buf) {
if (buf._format == _format) { if (buf._format == _format) {
memcpy(_buffer + thisFrom * _format.bytesPerPixel, buf._buffer + otherFrom * _format.bytesPerPixel, length * _format.bytesPerPixel); memcpy(_buffer + thisFrom * _format.bytesPerPixel, buf._buffer + otherFrom * _format.bytesPerPixel, length * _format.bytesPerPixel);
@ -112,24 +98,6 @@ void PixelBuffer::copyBuffer(int thisFrom, int otherFrom, int length, const Pixe
} }
} }
uint32 PixelBuffer::getValueAt(int i) const {
#if defined(SCUMM_BIG_ENDIAN)
byte *buffer = _buffer + i * _format.bytesPerPixel;
uint32 p = buffer[0] << ((_format.bytesPerPixel - 1) * 8);
for (int l = 1; l < _format.bytesPerPixel; ++l) {
p = p | (buffer[l] << (8 * (_format.bytesPerPixel - l - 1)));
}
return p;
#elif defined(SCUMM_LITTLE_ENDIAN)
byte *buffer = _buffer + i * _format.bytesPerPixel;
uint32 p = buffer[0];
for (int l = 1; l < _format.bytesPerPixel; ++l) {
p = p | (buffer[l] << (8 * l));
}
return p;
#endif
}
PixelBuffer &PixelBuffer::operator=(const PixelBuffer &buf) { PixelBuffer &PixelBuffer::operator=(const PixelBuffer &buf) {
_buffer = buf._buffer; _buffer = buf._buffer;
_format = buf._format; _format = buf._format;

38
graphics/pixelbuffer.h
View file

@ -24,6 +24,8 @@
#define GRAPHICS_PIXELBUFFER_H #define GRAPHICS_PIXELBUFFER_H
#include "common/types.h" #include "common/types.h"
#include "common/endian.h"
#include "common/textconsole.h"
#include "graphics/colormasks.h" #include "graphics/colormasks.h"
#include "graphics/pixelformat.h" #include "graphics/pixelformat.h"
@ -119,7 +121,24 @@ public:
/** /**
* Set the value of the pixel at index 'pixel' to 'value', * Set the value of the pixel at index 'pixel' to 'value',
*/ */
void setPixelAt(int pixel, uint32 value); inline void setPixelAt(int pixel, uint32 value) {
switch (_format.bytesPerPixel) {
case 2:
((uint16 *) _buffer)[pixel] = TO_LE_16((uint16) value);
return;
case 3:
pixel *= 3;
value = TO_LE_32(value);
_buffer[pixel + 0] = value & 0xFF;
_buffer[pixel + 1] = (value >> 8) & 0xFF;
_buffer[pixel + 2] = (value >> 16) & 0xFF;
return;
case 4:
((uint32 *) _buffer)[pixel] = TO_LE_32(value);
return;
}
error("setPixelAt: Unhandled bytesPerPixel %i", _format.bytesPerPixel);
}
/** /**
* Set the value of a pixel. The pixel will be converted from a pixel in another PixelBuffer, * Set the value of a pixel. The pixel will be converted from a pixel in another PixelBuffer,
* at the same index. * at the same index.
@ -180,7 +199,22 @@ public:
/** /**
* Return the encoded value of the pixel at the given index. * Return the encoded value of the pixel at the given index.
*/ */
uint32 getValueAt(int i) const; inline uint32 getValueAt(int i) const {
switch (_format.bytesPerPixel) {
case 2:
return FROM_LE_16(((uint16 *) _buffer)[i]);
case 3:
i *= 3;
#if defined(SCUMM_BIG_ENDIAN)
return (_buffer[i + 0] << 16) | (_buffer[i + 1] << 8) | _buffer[i + 2];
#elif defined(SCUMM_LITTLE_ENDIAN)
return _buffer[i + 0] | (_buffer[i + 1] << 8) | (_buffer[i + 2] << 16);
#endif
case 4:
return FROM_LE_32(((uint32 *) _buffer)[i]);
}
error("getValueAt: Unhandled bytesPerPixel %i", _format.bytesPerPixel);
}
/** /**
* Return the RGB value of the pixel at the given index. * Return the RGB value of the pixel at the given index.
*/ */