# HG changeset patch
# User Chris Cannam
# Date 1485431711 0
# Node ID eaab8bab352252e8c88fec6e91a6426a39557bfa
# Parent  2954e9952b78004a53d4e8cb9acd70470322c80a
Measure time taken to render per pixel, and use the time last time around to decide whether to be time constrained this time around

diff -r 2954e9952b78 -r eaab8bab3522 layer/Colour3DPlotLayer.cpp
--- a/layer/Colour3DPlotLayer.cpp	Thu Jan 26 10:41:50 2017 +0000
+++ b/layer/Colour3DPlotLayer.cpp	Thu Jan 26 11:55:11 2017 +0000
@@ -1110,12 +1110,11 @@
         }
     }
     
-    cerr << "mag range in this view: "
-         << m_viewMags[v->getId()].getMin()
-         << " -> "
-         << m_viewMags[v->getId()].getMax()
-         << endl;
-        
+    SVDEBUG << "Colour3DPlotRenderer::paintWithRenderer: mag range in this view: "
+            << m_viewMags[v->getId()].getMin()
+            << " -> "
+            << m_viewMags[v->getId()].getMax()
+            << endl;
 }
 
 void
diff -r 2954e9952b78 -r eaab8bab3522 layer/Colour3DPlotRenderer.cpp
--- a/layer/Colour3DPlotRenderer.cpp	Thu Jan 26 10:41:50 2017 +0000
+++ b/layer/Colour3DPlotRenderer.cpp	Thu Jan 26 11:55:11 2017 +0000
@@ -95,14 +95,30 @@
 {
     RenderType renderType = decideRenderType(v);
 
-    if (renderType != DrawBufferPixelResolution) {
-        // Rendering should be fast in bin-resolution and direct draw
-        // cases because we are quite well zoomed-in, and the sums are
-        // easier this way. Calculating boundaries later will be
-        // fiddly for partial paints otherwise.
-        timeConstrained = false;
+    if (timeConstrained) {
+        if (renderType != DrawBufferPixelResolution) {
+            // Rendering should be fast in bin-resolution and direct
+            // draw cases because we are quite well zoomed-in, and the
+            // sums are easier this way. Calculating boundaries later
+            // will be fiddly for partial paints otherwise.
+            timeConstrained = false;
+
+        } else if (m_secondsPerXPixelValid) {
+            double predicted = m_secondsPerXPixel * rect.width();
+#ifdef DEBUG_COLOUR_PLOT_REPAINT
+            SVDEBUG << "Predicted time for width " << rect.width() << " = "
+                    << predicted << endl;
+#endif
+            if (predicted < 0.1) {
+#ifdef DEBUG_COLOUR_PLOT_REPAINT
+                SVDEBUG << "Predicted time looks fast enough: no partial renders"
+                        << endl;
+#endif
+                timeConstrained = false;
+            }
+        }
     }
-
+            
     int x0 = v->getXForViewX(rect.x());
     int x1 = v->getXForViewX(rect.x() + rect.width());
     if (x0 < 0) x0 = 0;
@@ -882,7 +898,7 @@
         step = -1;
     }
 
-    int columnCount = 0;
+    int xPixelCount = 0;
     
     vector<float> preparedColumn;
 
@@ -897,7 +913,7 @@
         // x is the on-canvas pixel coord; sx (later) will be the
         // source column index
         
-        ++columnCount;
+        ++xPixelCount;
         
         if (binforx[x] < 0) continue;
 
@@ -978,16 +994,18 @@
             m_magRanges.push_back(magRange);
         }
 
-        double fractionComplete = double(columnCount) / double(w);
+        double fractionComplete = double(xPixelCount) / double(w);
         if (timer.outOfTime(fractionComplete)) {
 #ifdef DEBUG_COLOUR_PLOT_REPAINT
             SVDEBUG << "out of time" << endl;
 #endif
-            return columnCount;
+            updateTimings(timer, xPixelCount);
+            return xPixelCount;
         }
     }
 
-    return columnCount;
+    updateTimings(timer, xPixelCount);
+    return xPixelCount;
 }
 
 int
@@ -1003,7 +1021,7 @@
     // fft model exists)
     
     RenderTimer timer(timeConstrained ?
-                      RenderTimer::FastRender :
+                      RenderTimer::SlowRender :
                       RenderTimer::NoTimeout);
 
     const FFTModel *fft = m_sources.fft;
@@ -1031,7 +1049,7 @@
         step = -1;
     }
     
-    int columnCount = 0;
+    int xPixelCount = 0;
     
     vector<float> preparedColumn;
 
@@ -1057,7 +1075,7 @@
         // x is the on-canvas pixel coord; sx (later) will be the
         // source column index
         
-        ++columnCount;
+        ++xPixelCount;
         
         if (binforx[x] < 0) continue;
 
@@ -1098,8 +1116,8 @@
         if (!pixelPeakColumn.empty()) {
 
 #ifdef DEBUG_COLOUR_PLOT_REPAINT
-            SVDEBUG << "found " << peakfreqs.size() << " peak freqs at column "
-                    << sx0 << endl;
+//            SVDEBUG << "found " << peakfreqs.size() << " peak freqs at column "
+//                    << sx0 << endl;
 #endif
 
             for (FFTModel::PeakSet::const_iterator pi = peakfreqs.begin();
@@ -1139,16 +1157,32 @@
 #endif
         }
 
-        double fractionComplete = double(columnCount) / double(w);
+        double fractionComplete = double(xPixelCount) / double(w);
         if (timer.outOfTime(fractionComplete)) {
 #ifdef DEBUG_COLOUR_PLOT_REPAINT
             SVDEBUG << "out of time" << endl;
 #endif
-            return columnCount;
+            updateTimings(timer, xPixelCount);
+            return xPixelCount;
         }
     }
 
-    return columnCount;
+    updateTimings(timer, xPixelCount);
+    return xPixelCount;
+}
+
+void
+Colour3DPlotRenderer::updateTimings(const RenderTimer &timer, int xPixelCount)
+{
+    m_secondsPerXPixel = timer.secondsPerItem(xPixelCount);
+    m_secondsPerXPixelValid = (xPixelCount > 10);
+
+#ifdef DEBUG_COLOUR_PLOT_REPAINT
+    SVDEBUG << "seconds per x pixel = " << m_secondsPerXPixel
+            << " (enough data? " << (m_secondsPerXPixelValid ? "yes" : "no")
+            << ")" << endl;
+#endif
+    
 }
 
 void
diff -r 2954e9952b78 -r eaab8bab3522 layer/Colour3DPlotRenderer.h
--- a/layer/Colour3DPlotRenderer.h	Thu Jan 26 10:41:50 2017 +0000
+++ b/layer/Colour3DPlotRenderer.h	Thu Jan 26 11:55:11 2017 +0000
@@ -32,6 +32,7 @@
 class DenseThreeDimensionalModel;
 class Dense3DModelPeakCache;
 class FFTModel;
+class RenderTimer;
 
 enum class BinDisplay {
     AllBins,
@@ -111,7 +112,9 @@
     
     Colour3DPlotRenderer(Sources sources, Parameters parameters) :
         m_sources(sources),
-	m_params(parameters)
+	m_params(parameters),
+        m_secondsPerXPixel(0.0),
+        m_secondsPerXPixelValid(false)
     { }
 
     struct RenderResult {
@@ -263,6 +266,9 @@
     // valid range in the magnitude cache, but not necessarily vice
     // versa (as the image cache is limited to contiguous ranges).
     ScrollableMagRangeCache m_magCache;
+
+    double m_secondsPerXPixel;
+    bool m_secondsPerXPixelValid;
     
     RenderResult render(const LayerGeometryProvider *v,
                         QPainter &paint, QRect rect, bool timeConstrained);
@@ -310,6 +316,8 @@
 
     void getPreferredPeakCache(const LayerGeometryProvider *,
                                int &peakCacheIndex, int &binsPerPeak) const;
+
+    void updateTimings(const RenderTimer &timer, int xPixelCount);
 };
 
 #endif
diff -r 2954e9952b78 -r eaab8bab3522 layer/RenderTimer.h
--- a/layer/RenderTimer.h	Thu Jan 26 10:41:50 2017 +0000
+++ b/layer/RenderTimer.h	Thu Jan 26 11:55:11 2017 +0000
@@ -90,12 +90,22 @@
 	return false;
     }
 
+    double secondsPerItem(int itemsRendered) const {
+
+        if (itemsRendered == 0) return 0.0;
+
+	auto t = std::chrono::steady_clock::now();
+	double elapsed = std::chrono::duration<double>(t - m_start).count();
+
+        return elapsed / itemsRendered;
+    }
+
 private:
     std::chrono::time_point<std::chrono::steady_clock> m_start;
     bool m_haveLimits;
-    double m_minFraction;
-    double m_softLimit;
-    double m_hardLimit;
+    double m_minFraction; // proportion, 0.0 -> 1.0
+    double m_softLimit; // seconds
+    double m_hardLimit; // seconds
     bool m_softLimitOverridden;
 };