Refactoring: checkRow() has been rationalized; it does not need arguments that it can easily compute itself.
git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2408 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/unix/x0vncserver/PollingManager.cxx b/unix/x0vncserver/PollingManager.cxx
index 5285138..2ce75fa 100644
--- a/unix/x0vncserver/PollingManager.cxx
+++ b/unix/x0vncserver/PollingManager.cxx
@@ -197,11 +197,9 @@
// We compare the pixels of that line with previous framebuffer
// contents and raise corresponding elements of m_changeFlags[].
int scanOffset = m_pollingOrder[m_pollingStep++ % 32];
- bool *pChangeFlags = m_changeFlags;
int nTilesChanged = 0;
for (int y = scanOffset; y < m_height; y += 32) {
- nTilesChanged += checkRow(0, y, m_width, pChangeFlags);
- pChangeFlags += m_widthTiles;
+ nTilesChanged += checkRow(0, y, m_width);
}
// Do the work related to video area detection, if enabled.
@@ -248,23 +246,41 @@
return (nTilesChanged != 0 || haveVideoRect);
}
-int PollingManager::checkRow(int x, int y, int w, bool *pChangeFlags)
+int PollingManager::checkRow(int x, int y, int w)
{
int bytesPerPixel = m_image->xim->bits_per_pixel / 8;
int bytesPerLine = m_image->xim->bytes_per_line;
+ // If necessary, expand the row to the left, to the tile border.
+ // In other words, x must be a multiple of 32.
+ if (x % 32 != 0) {
+ int correction = x % 32;
+ x -= correction;
+ w += correction;
+ }
+
+ // Compute a pointer to the corresponding element of m_changeFlags.
+ // FIXME: Provide an inline function for that?
+ bool *pChangeFlags = &m_changeFlags[(y / 32) * m_widthTiles + (x / 32)];
+
+ // Read a row from the screen. Note that getFullRow() may be more
+ // efficient than getRow() which is more general.
+ // FIXME: Move the logic to getRow()?
if (x == 0 && w == m_width) {
- getFullRow(y); // use more efficient method if possible
+ getFullRow(y);
} else {
getRow(x, y, w);
}
+ // Compute pointers to images to be compared.
+ // FIXME: Provide an inline function Image::locatePixel(x, y).
char *ptr_old = m_image->xim->data + y * bytesPerLine + x * bytesPerPixel;
char *ptr_new = m_rowImage->xim->data;
+ // Compare pixels, raise corresponding elements of m_changeFlags[].
int nTilesChanged = 0;
- for (int i = 0; i < (w + 31) / 32; i++) {
- int tile_w = (w - i * 32 >= 32) ? 32 : w - i * 32;
+ for (int i = 0; i < w; i += 32) {
+ int tile_w = (w - i >= 32) ? 32 : w - i;
int nBytes = tile_w * bytesPerPixel;
if (memcmp(ptr_old, ptr_new, nBytes)) {
*pChangeFlags = true;
@@ -384,16 +400,14 @@
m_changeFlags[y * m_widthTiles + x] &&
!m_changeFlags[(y - 1) * m_widthTiles + x]) {
// FIXME: Check m_changeFlags[] to decrease height of the row.
- checkRow(x * 32, y * 32 - 1, m_width - x * 32,
- &m_changeFlags[(y - 1) * m_widthTiles + x]);
+ checkRow(x * 32, y * 32 - 1, m_width - x * 32);
doneAbove = true;
}
if (!doneBelow && y < m_heightTiles - 1 &&
m_changeFlags[y * m_widthTiles + x] &&
!m_changeFlags[(y + 1) * m_widthTiles + x]) {
// FIXME: Check m_changeFlags[] to decrease height of the row.
- checkRow(x * 32, (y + 1) * 32, m_width - x * 32,
- &m_changeFlags[(y + 1) * m_widthTiles + x]);
+ checkRow(x * 32, (y + 1) * 32, m_width - x * 32);
doneBelow = true;
}
if (doneBelow && doneAbove)
diff --git a/unix/x0vncserver/PollingManager.h b/unix/x0vncserver/PollingManager.h
index 2219136..8abf029 100644
--- a/unix/x0vncserver/PollingManager.h
+++ b/unix/x0vncserver/PollingManager.h
@@ -95,7 +95,7 @@
m_offsetLeft + x, m_offsetTop + y, 1, h);
}
- int checkRow(int x, int y, int w, bool *pChangeFlags);
+ int checkRow(int x, int y, int w);
int checkColumn(int x, int y, int h, bool *pChangeFlags);
int sendChanges();
void handleVideo();