# HG changeset patch
# User Chris Cannam
# Date 1469000524 -3600
# Node ID be5b91ec81a064c0c9f991c440426df02f66bbcb
# Parent  175d4e15884df680c6f4d1859d1379d5d15f4f26
Inch toward using the mag cache (currently will crash with debug exception)

diff -r 175d4e15884d -r be5b91ec81a0 layer/Colour3DPlotRenderer.cpp
--- a/layer/Colour3DPlotRenderer.cpp	Wed Jul 20 08:30:20 2016 +0100
+++ b/layer/Colour3DPlotRenderer.cpp	Wed Jul 20 08:42:04 2016 +0100
@@ -92,6 +92,9 @@
     m_cache.resize(v->getPaintSize());
     m_cache.setZoomLevel(v->getZoomLevel());
 
+    m_magCache.resize(v->getPaintSize().width());
+    m_magCache.setZoomLevel(v->getZoomLevel());
+    
     cerr << "cache start " << m_cache.getStartFrame()
          << " valid left " << m_cache.getValidLeft()
          << " valid right " << m_cache.getValidRight()
@@ -112,7 +115,17 @@
             
             // cache is valid for the complete requested area
             paint.drawImage(rect, m_cache.getImage(), rect);
-            return { rect, {} };
+
+            //!!! a dev debug check
+            if (!m_magCache.areColumnsSet(x0, x1 - x0)) {
+                cerr << "Columns (" << x0 << " -> " << x1-x0
+                     << ") not set in mag cache" << endl;
+                throw std::logic_error("Columns not set in mag cache");
+            }
+            
+            MagnitudeRange range = m_magCache.getRange(x0, x1-x0);
+
+            return { rect, range };
 
         } else {
             cerr << "cache partial hit" << endl;
@@ -121,6 +134,7 @@
             // contain the complete view, but might be scrollable or
             // partially usable
             m_cache.scrollTo(v, startFrame);
+            m_magCache.scrollTo(v, startFrame);
 
             // if we are not time-constrained, then we want to paint
             // the whole area in one go; we don't return a partial
@@ -138,6 +152,7 @@
     } else {
         // cache is completely invalid
         m_cache.setStartFrame(startFrame);
+        m_magCache.setStartFrame(startFrame);
     }
 
     bool rightToLeft = false;
diff -r 175d4e15884d -r be5b91ec81a0 layer/Colour3DPlotRenderer.h
--- a/layer/Colour3DPlotRenderer.h	Wed Jul 20 08:30:20 2016 +0100
+++ b/layer/Colour3DPlotRenderer.h	Wed Jul 20 08:42:04 2016 +0100
@@ -18,6 +18,7 @@
 
 #include "ColourScale.h"
 #include "ScrollableImageCache.h"
+#include "ScrollableMagRangeCache.h"
 
 #include "base/ColumnOp.h"
 #include "base/MagnitudeRange.h"
@@ -183,15 +184,24 @@
     // member is to avoid reallocation.
     QImage m_drawBuffer;
 
-    // Image cache is our persistent record of the visible area. It is
-    // always the same size as the view (i.e. the paint size reported
-    // by the LayerGeometryProvider) and is scrolled and partially
-    // repainted internally as appropriate. A render request is
-    // carried out by repainting to cache (via the draw buffer) any
+    // The image cache is our persistent record of the visible
+    // area. It is always the same size as the view (i.e. the paint
+    // size reported by the LayerGeometryProvider) and is scrolled and
+    // partially repainted internally as appropriate. A render request
+    // is carried out by repainting to cache (via the draw buffer) any
     // area that is being requested but is not valid in the cache, and
     // then repainting from cache to the requested painter.
     ScrollableImageCache m_cache;
 
+    // The mag range cache is our record of the column magnitude
+    // ranges for each of the columns in the cache. It always has the
+    // same start frame and width as the image cache, and the column
+    // indices match up across both. Our cache update mechanism
+    // guarantees that every valid column in the image cache has a
+    // valid range in the magnitude cache, but not necessarily vice
+    // versa (as the image cache is limited to contiguous ranges).
+    ScrollableMagRangeCache m_magCache;
+    
     RenderResult render(const LayerGeometryProvider *v,
                         QPainter &paint, QRect rect, bool timeConstrained);
 
diff -r 175d4e15884d -r be5b91ec81a0 layer/ScrollableMagRangeCache.h
--- a/layer/ScrollableMagRangeCache.h	Wed Jul 20 08:30:20 2016 +0100
+++ b/layer/ScrollableMagRangeCache.h	Wed Jul 20 08:42:04 2016 +0100
@@ -95,12 +95,33 @@
     bool isColumnSet(int column) const {
 	return in_range_for(m_ranges, column) && m_ranges.at(column).isSet();
     }
+
+    bool areColumnsSet(int x, int count) const {
+	for (int i = 0; i < count; ++i) {
+	    if (!isColumnSet(x + i)) return false;
+	}
+	return true;
+    }
     
-    const MagnitudeRange &getRange(int column) const {
+    /**
+     * Get the magnitude range for a single column.
+     */
+    MagnitudeRange getRange(int column) const {
 	return m_ranges.at(column);
     }
 
     /**
+     * Get the magnitude range for a range of columns.
+     */
+    MagnitudeRange getRange(int x, int count) const {
+	MagnitudeRange r;
+	for (int i = 0; i < count; ++i) {
+	    r.sample(m_ranges.at(x + i));
+	}
+	return r;
+    }
+    
+    /**
      * Set the new start frame for the cache, according to the
      * geometry of the supplied LayerGeometryProvider, if possible
      * also moving along any existing valid data within the cache so