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Image::flipVertically(), Image::flipHorizontally() optimizations.

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This commit is contained in:
varnie 2014-03-20 10:49:01 +06:00
parent 185c09a95c
commit 83eab47c05
1 changed files with 20 additions and 20 deletions
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40
src/SFML/Graphics/Image.cpp
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@ -271,20 +271,19 @@ void Image::flipHorizontally()
{ {
if (!m_pixels.empty()) if (!m_pixels.empty())
{ {
std::vector<Uint8> before = m_pixels; std::size_t rowSize = m_size.x * 4;
for (unsigned int y = 0; y < m_size.y; ++y)
{
const Uint8* source = &before[y * m_size.x * 4];
Uint8* dest = &m_pixels[(y + 1) * m_size.x * 4 - 4];
for (unsigned int x = 0; x < m_size.x; ++x)
{
dest[0] = source[0];
dest[1] = source[1];
dest[2] = source[2];
dest[3] = source[3];
source += 4; for (std::size_t y = 0; y < m_size.y; ++y)
dest -= 4; {
std::vector<Uint8>::iterator left = m_pixels.begin() + y * rowSize;
std::vector<Uint8>::iterator right = m_pixels.begin() + (y + 1) * rowSize - 4;
for (std::size_t x = 0; x < m_size.x / 2; ++x)
{
std::swap_ranges(left, left + 4, right);
left += 4;
right -= 4;
} }
} }
} }
@ -296,16 +295,17 @@ void Image::flipVertically()
{ {
if (!m_pixels.empty()) if (!m_pixels.empty())
{ {
std::vector<Uint8> before = m_pixels;
const Uint8* source = &before[m_size.x * (m_size.y - 1) * 4];
Uint8* dest = &m_pixels[0];
std::size_t rowSize = m_size.x * 4; std::size_t rowSize = m_size.x * 4;
for (unsigned int y = 0; y < m_size.y; ++y) std::vector<Uint8>::iterator top = m_pixels.begin();
std::vector<Uint8>::iterator bottom = m_pixels.end() - rowSize;
for (std::size_t y = 0; y < m_size.y / 2; ++y)
{ {
std::memcpy(dest, source, rowSize); std::swap_ranges(top, top + rowSize, bottom);
source -= rowSize;
dest += rowSize; top += rowSize;
bottom -= rowSize;
} }
} }
} }