fix Overlays when changing depth

When changing depth or other reasons that update the Chunk in
background, the Overlay is overwritten.
By using separated images for the Chunk data and "the rest" (Overlays)
these two categories to not interfear anymore.

chunkcache.cpp

@@ -69,6 +69,14 @@ QString ChunkCache::getPath() const {
   return path;
 }
 
+int ChunkCache::getCost() const {
+  return cache.totalCost();
+}
+
+int ChunkCache::getMaxCost() const {
+  return cache.maxCost();
+}
+
 QSharedPointer<Chunk> ChunkCache::fetchCached(int cx, int cz) {
   // try to get Chunk from Cache
   ChunkID id(cx, cz);

chunkcache.h

@@ -37,6 +37,8 @@ class ChunkCache : public QObject {
   QString getPath() const;
   QSharedPointer<Chunk> fetch(int cx, int cz);         // fetch Chunk and load when not found
   QSharedPointer<Chunk> fetchCached(int cx, int cz);   // fetch Chunk only if cached
+  int getCost() const;
+  int getMaxCost() const;
 
  signals:
   void chunkLoaded(int cx, int cz);

mapview.cpp

@@ -144,8 +144,8 @@ void MapView::mouseMoveEvent(QMouseEvent *event) {
     int centerblockx = floor(this->x);
     int centerblockz = floor(this->z);
 
-    int centerx = image.width() / 2;
-    int centery = image.height() / 2;
+    int centerx = imageChunks.width() / 2;
+    int centery = imageChunks.height() / 2;
 
     centerx -= (this->x - centerblockx) * zoom;
     centery -= (this->z - centerblockz) * zoom;
@@ -172,8 +172,8 @@ void MapView::mouseDoubleClickEvent(QMouseEvent *event) {
   int centerblockx = floor(this->x);
   int centerblockz = floor(this->z);
 
-  int centerx = image.width() / 2;
-  int centery = image.height() / 2;
+  int centerx = imageChunks.width() / 2;
+  int centery = imageChunks.height() / 2;
 
   centerx -= (this->x - centerblockx) * zoom;
   centery -= (this->z - centerblockz) * zoom;
@@ -270,24 +270,22 @@ void MapView::keyPressEvent(QKeyEvent *event) {
 }
 
 void MapView::resizeEvent(QResizeEvent *event) {
-  image = QImage(event->size(), QImage::Format_RGB32);
+  imageChunks   = QImage(event->size(), QImage::Format_RGB32);
+  imageOverlays = QImage(event->size(), QImage::Format_RGBA8888);
   redraw();
 }
 
 void MapView::paintEvent(QPaintEvent * /* event */) {
   QPainter p(this);
-  p.drawImage(QPoint(0, 0), image);
+  p.drawImage(QPoint(0, 0), imageChunks);
+  p.drawImage(QPoint(0, 0), imageOverlays);
   p.end();
 }
 
 void MapView::redraw() {
   if (!this->isEnabled()) {
     // blank
-    uchar *bits = image.bits();
-    int imgstride = image.bytesPerLine();
-    int imgoffset = 0;
-    for (int y = 0; y < image.height(); y++, imgoffset += imgstride)
-      memset(bits + imgoffset, 0xee, imgstride);
+    imageChunks.fill(0xeeeeee);
     update();
     return;
   }
@@ -298,26 +296,29 @@ void MapView::redraw() {
   int centerchunkx = floor(x / 16);
   int centerchunkz = floor(z / 16);
   // and the center of the screen
-  int centerx = image.width() / 2;
-  int centery = image.height() / 2;
+  int centerx = imageChunks.width() / 2;
+  int centery = imageChunks.height() / 2;
   // and align for panning
   centerx -= (x - centerchunkx * 16) * zoom;
   centery -= (z - centerchunkz * 16) * zoom;
   // now calculate the topleft block on the screen
   int startx = centerchunkx - floor(centerx / chunksize) - 1;
   int startz = centerchunkz - floor(centery / chunksize) - 1;
   // and the dimensions of the screen in blocks
-  int blockswide = image.width() / chunksize + 3;
-  int blockstall = image.height() / chunksize + 3;
+  int blockswide = imageChunks.width() / chunksize + 3;
+  int blockstall = imageChunks.height() / chunksize + 3;
 
   for (int cz = startz; cz < startz + blockstall; cz++)
     for (int cx = startx; cx < startx + blockswide; cx++)
       drawChunk(cx, cz);
 
+  // clear the overlay layer
+  imageOverlays.fill(0);
+
   // add on the entity layer
-  QPainter canvas(&image);
-  double halfviewwidth = image.width() / 2 / zoom;
-  double halvviewheight = image.height() / 2 / zoom;
+  QPainter canvas(&imageOverlays);
+  double halfviewwidth  = imageOverlays.width() / 2 / zoom;
+  double halvviewheight = imageOverlays.height() / 2 / zoom;
   double x1 = x - halfviewwidth;
   double z1 = z - halvviewheight;
   double x2 = x + halfviewwidth;
@@ -392,8 +393,8 @@ void MapView::drawChunk(int x, int z) {
   int centerchunkx = floor(this->x / 16);
   int centerchunkz = floor(this->z / 16);
   // and the center chunk screen coordinates
-  int centerx = image.width() / 2;
-  int centery = image.height() / 2;
+  int centerx = imageChunks.width() / 2;
+  int centery = imageChunks.height() / 2;
   // which need to be shifted to account for panning inside that chunk
   centerx -= (this->x - centerchunkx * 16) * zoom;
   centery -= (this->z - centerchunkz * 16) * zoom;
@@ -404,8 +405,8 @@ void MapView::drawChunk(int x, int z) {
   centery += (z - centerchunkz) * chunksize;
 
   int srcoffset = 0;
-  uchar *bits = image.bits();
-  int imgstride = image.bytesPerLine();
+  uchar *bits   = imageChunks.bits();
+  int imgstride = imageChunks.bytesPerLine();
 
   int skipx = 0, skipy = 0;
   int blockwidth = chunksize, blockheight = chunksize;
@@ -419,10 +420,10 @@ void MapView::drawChunk(int x, int z) {
     centery = 0;
   }
   // or the other side, we need to trim
-  if (centerx + blockwidth > image.width())
-    blockwidth = image.width() - centerx;
-  if (centery + blockheight > image.height())
-    blockheight = image.height() - centery;
+  if (centerx + blockwidth > imageChunks.width())
+    blockwidth = imageChunks.width() - centerx;
+  if (centery + blockheight > imageChunks.height())
+    blockheight = imageChunks.height() - centery;
   if (blockwidth <= 0 || skipx >= blockwidth) return;
   int imgoffset = centerx * 4 + centery * imgstride;
   if (chunk)
@@ -511,6 +512,13 @@ void MapView::getToolTip(int x, int z) {
     hovertext += " (" + blockstate + ")";
   if (entityStr.length() > 0)
     hovertext += " - " + entityStr;
+
+#ifdef DEBUG
+  hovertext += " [Cache:"
+            + QString().number(this->cache.getCost()) + "/"
+            + QString().number(this->cache.getMaxCost()) + "]";
+#endif
+
   emit hoverTextChanged(hovertext);
 }
 

mapview.h

@@ -96,7 +96,8 @@ class MapView : public QWidget {
   double zoom;
   int flags;
   ChunkCache &cache;
-  QImage image;
+  QImage imageChunks;
+  QImage imageOverlays;
   DefinitionManager *dm;
   uchar placeholder[16 * 16 * 4];  // no chunk found placeholder
   QSet<QString> overlayItemTypes;