# HG changeset patch
# User Chris Cannam
# Date 1468244223 -3600
# Node ID 6288f1b5f49b0abde97eabe530341081f7d8a7b9
# Parent  ba62684a4512ea3ee544e5d2f9e91ab827ea2f71
Far more pragmatic update strategy

diff -r ba62684a4512 -r 6288f1b5f49b layer/Colour3DPlotRenderer.cpp
--- a/layer/Colour3DPlotRenderer.cpp	Mon Jul 11 10:38:23 2016 +0100
+++ b/layer/Colour3DPlotRenderer.cpp	Mon Jul 11 14:37:03 2016 +0100
@@ -42,6 +42,22 @@
     return render(v, paint, rect, true);
 }
 
+QRect
+Colour3DPlotRenderer::getLargestUncachedRect()
+{
+    int h = m_cache.getSize().height();
+
+    QRect areaLeft(0, 0, m_cache.getValidLeft(), h);
+    QRect areaRight(m_cache.getValidRight(), 0,
+                    m_cache.getSize().width() - m_cache.getValidRight(), h);
+
+    if (areaRight.width() > areaLeft.width()) {
+        return areaRight;
+    } else {
+        return areaLeft;
+    }
+}
+
 Colour3DPlotRenderer::RenderResult
 Colour3DPlotRenderer::render(LayerGeometryProvider *v,
                              QPainter &paint, QRect rect, bool timeConstrained)
@@ -184,8 +200,6 @@
 
     //!!! todo: transparent style from Colour3DPlot
 
-    //!!! todo: bin boundary alignment when in BinResolution
-
     //!!! todo: view magnitudes / normalise visible area
 
     //!!! todo: alter documentation for view mag stuff (cached paints
diff -r ba62684a4512 -r 6288f1b5f49b layer/Colour3DPlotRenderer.h
--- a/layer/Colour3DPlotRenderer.h	Mon Jul 11 10:38:23 2016 +0100
+++ b/layer/Colour3DPlotRenderer.h	Mon Jul 11 14:37:03 2016 +0100
@@ -147,6 +147,20 @@
      */
     RenderResult renderTimeConstrained(LayerGeometryProvider *v,
                                        QPainter &paint, QRect rect);
+
+    /**
+     * Return the area of the largest rectangle within the entire area
+     * of the cache that is unavailable in the cache. This is only
+     * valid in relation to a preceding render() call which is
+     * presumed to have set the area, start frame, and zoom level for
+     * the cache. It could be used to establish a suitable region for
+     * a subsequent paint request (because if an area is not in the
+     * cache, it cannot have been rendered since the cache was
+     * cleared).
+     *
+     * Returns an empty QRect if the cache is entirely valid.
+     */
+    QRect getLargestUncachedRect();
     
 private:
     Sources m_sources;
diff -r ba62684a4512 -r 6288f1b5f49b layer/SpectrogramLayer.cpp
--- a/layer/SpectrogramLayer.cpp	Mon Jul 11 10:38:23 2016 +0100
+++ b/layer/SpectrogramLayer.cpp	Mon Jul 11 14:37:03 2016 +0100
@@ -1556,54 +1556,11 @@
 
     //!!! + mag range
 
-    QRect rendered = result.rendered;
-    if (rendered == rect) {
-        cerr << "exiting paint depth " << depth << endl;
-        --depth;
-        return;
-    }
-
-    int rLeft = rendered.x();
-    int rRight = rendered.x() + rendered.width();
-
-    if (rLeft < rect.x()) {
-        rLeft = rect.x();
-    }
-    if (rRight > rect.x() + rect.width()) {
-        rRight = rect.x() + rect.width();
-    }
-    
-    QRect areaLeft(rect.x(), rect.y(),
-                   rLeft - rect.x(), rect.height());
-
-    QRect areaRight(rRight, rect.y(),
-                    rect.x() + rect.width() - rRight, rect.height());
-    
-    bool updateLeft = (areaLeft.width() > 0);
-    bool updateRight = (areaRight.width() > 0);
-
-    if (updateLeft) {
-        if (updateRight) {
-            if (areaLeft.width() > areaRight.width()) {
-                cerr << "update left then right, widths "
-                     << areaLeft.width() << " and "
-                     << areaRight.width() << endl;
-                v->updatePaintRect(areaLeft);
-                v->updatePaintRect(areaRight);
-            } else {
-                cerr << "update right then left, widths "
-                     << areaLeft.width() << " and "
-                     << areaRight.width() << endl;
-                v->updatePaintRect(areaRight);
-                v->updatePaintRect(areaLeft);
-            }
-        } else {
-            cerr << "update left, width " << areaLeft.width() << endl;
-            v->updatePaintRect(areaLeft);
-        }
-    } else {
-        cerr << "update right, width " << areaRight.width() << endl;
-        v->updatePaintRect(areaRight);
+    QRect uncached = renderer->getLargestUncachedRect();
+    if (uncached.width() > 0) {
+        cerr << "updating rect at " << uncached.x() << " width "
+             << uncached.width() << endl;
+        v->updatePaintRect(uncached);
     }
 
     cerr << "exiting paint depth " << depth << endl;