Reduced the memory footprint of qttrace files.

A couple of improvements have been made:

 * Use single precision floats for the traces.
 * Reduce the number of variant wrapped transforms by introducing a new
   translate command.
 * Reduce the number of bytes streamed per image / pixmap draw command.
 * Add versioning info to qttrace files to be more future proof.

Reviewed-by: Gunnar Sletta

1 files changed, 7 insertions, 2 deletions

diff --git a/src/plugins/graphicssystems/trace/qgraphicssystem_trace.cpp b/src/plugins/graphicssystems/trace/qgraphicssystem_trace.cpp
index 13044f4..6bf9d6b 100644
--- a/src/plugins/graphicssystems/trace/qgraphicssystem_trace.cpp
+++ b/src/plugins/graphicssystems/trace/qgraphicssystem_trace.cpp
@@ -82,8 +82,13 @@ QTraceWindowSurface::~QTraceWindowSurface()
         QFile outputFile(QString(QLatin1String("qtgraphics-%0.trace")).arg(winId));
         if (outputFile.open(QIODevice::WriteOnly)) {
             QDataStream out(&outputFile);
-            out.writeBytes("qttrace", 7);
-            out << *buffer << updates;
+            out.setFloatingPointPrecision(QDataStream::SinglePrecision);
+
+            out.writeBytes("qttraceV2", 9);
+
+            uint version = 1;
+
+            out << version << *buffer << updates;
         }
         delete buffer;
     }