Optimize intersected rect clipping in raster engine..

If we have span based clipping (complex) and we manage to intersect
down to a plain rectangle, we switch back to rectangle mode which
speeds up filling significantly...

Reviewed-by: Samuel

1 files changed, 21 insertions, 2 deletions

diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp
index c44763d..bf84aa7 100644
--- a/src/gui/painting/qpaintengine_raster.cpp
+++ b/src/gui/painting/qpaintengine_raster.cpp
@@ -4401,20 +4401,39 @@ void QClipData::fixup()
     ymax = m_spans[count-1].y + 1;
     xmin = INT_MAX;
     xmax = 0;
+
+    bool isRect = true;
+    int left = m_spans[0].x;
+    int right = m_spans[0].x + m_spans[0].len;
+
     for (int i = 0; i < count; ++i) {
-//           qDebug() << "    " << spans[i].x << spans[i].y << spans[i].len << spans[i].coverage;
         if (m_spans[i].y != y) {
+            if (m_spans[i].y != y + 1 && y != -1) {
+                isRect = false;
+            }
             y = m_spans[i].y;
             m_clipLines[y].spans = m_spans+i;
             m_clipLines[y].count = 0;
 //              qDebug() << "        new line: y=" << y;
         }
         ++m_clipLines[y].count;
+        int sl = (int) m_spans[i].x;
+        int sr = sl + m_spans[i].len;
+
         xmin = qMin(xmin, (int)m_spans[i].x);
         xmax = qMax(xmax, (int)m_spans[i].x + m_spans[i].len);
+
+        if (sl != left || sr != right)
+            isRect = false;
     }
     ++xmax;
-//     qDebug("xmin=%d,xmax=%d,ymin=%d,ymax=%d", xmin, xmax, ymin, ymax);
+//     qDebug("xmin=%d,xmax=%d,ymin=%d,ymax=%d %s", xmin, xmax, ymin, ymax, isRect ? "rectangular" : "");
+
+    if (isRect) {
+        hasRectClip = true;
+        clipRect.setRect(xmin, ymin, xmax - xmin, ymax - ymin);
+    }
+
 }
 
 /*