Fix preview with selection tools in tiles mode

src/app/tools/inks.h

@@ -446,9 +446,18 @@ public:
     gfx::Rect rc(x1, y, x2-x1+1, 1);
 
     // For tile point shape, the point shape is done in "tiles"
-    // coordinatse, but we want the selection in "canvas" coordinates.
-    if (loop->getPointShape()->isTile())
-      rc = loop->getGrid().tileToCanvas(rc);
+    // coordinates, but we want the selection in canvas/pixels
+    // coordinates.
+    if (loop->getPointShape()->isTile()) {
+      const Grid& grid = loop->getGrid();
+      rc = grid.tileToCanvas(rc);
+      if (!m_modify_selection) {
+        // For feedback purposes, the coordinates must be relative to
+        // the getDstImage() and not in absolute sprite canvas
+        // coordinates.
+        rc.offset(-grid.origin());
+      }
+    }
 
     if (m_modify_selection) {
       int modifiers = int(loop->getModifiers());

src/app/ui/editor/tool_loop_impl.cpp

@@ -512,6 +512,9 @@ public:
         // pixels. See ExpandCelCanvas::commit() for details about this flag.
         (getController()->isFreehand() ?
          ExpandCelCanvas::UseModifiedRegionAsUndoInfo:
+         ExpandCelCanvas::None) |
+        (!m_tilesMode || m_ink->isSelection() ?
+         ExpandCelCanvas::PixelsBounds:
          ExpandCelCanvas::None)));
 
     if (!m_floodfillSrcImage)
@@ -550,11 +553,7 @@ public:
     // Setup the new grid of ExpandCelCanvas which can be displaced to
     // match the new temporal cel position (m_celOrigin).
     m_grid = m_expandCelCanvas->getGrid();
-
-    if (m_tilesMode)
-      m_celOrigin = m_grid.origin();
-    else
-      m_celOrigin = m_expandCelCanvas->getCel()->position();
+    m_celOrigin = m_expandCelCanvas->getCel()->position();
 
     m_mask = m_document->mask();
     m_maskOrigin = (!m_mask->isEmpty() ? gfx::Point(m_mask->bounds().x-m_celOrigin.x,
@@ -768,9 +767,8 @@ tools::ToolLoop* create_tool_loop(
   if (params.ink->isSelection() &&
       !params.tool->getPointShape(
         button != tools::Pointer::Left ? 1: 0)->isFloodFill()) {
-    // TODO improve the selection preview without using a preview
-    // image (e.g. we could use a gfx::Path)
-    site.layer(nullptr);
+    // Don't call site.layer(nullptr) because we want to keep the
+    // site.layer() to know if we are in a tilemap layer
   }
   else {
     Layer* layer = site.layer();

src/app/util/expand_cel_canvas.cpp

@@ -118,7 +118,8 @@ ExpandCelCanvas::ExpandCelCanvas(
   m_origCelPos = m_cel->position();
 
   // Region to draw
-  gfx::Rect celBounds = (m_celCreated ? m_sprite->bounds(): m_cel->bounds());
+  gfx::Rect celBounds = (m_celCreated ? m_sprite->bounds():
+                                        m_cel->bounds());
 
   gfx::Rect spriteBounds(0, 0,
     m_sprite->width(),
@@ -131,20 +132,28 @@ ExpandCelCanvas::ExpandCelCanvas(
     m_bounds = spriteBounds;
   }
 
-  if (m_tilemapMode == TilemapMode::Tiles) {
+  if ((m_tilemapMode == TilemapMode::Tiles) ||
+      ((m_flags & PixelsBounds) == PixelsBounds)) {
     // Bounds of the canvas in tiles.
     m_bounds = m_grid.canvasToTile(m_bounds);
 
+    // New tiles bounds in pixels coordinates.
+    gfx::Rect newBoundsFromTiles = m_grid.tileToCanvas(m_bounds);
+
     // As the grid origin depends on the current cel position (see
     // Site::grid()), and we're going to modify the m_cel position
     // temporarily, we need to adjust the grid to the new temporal
     // grid origin matching the new m_dstImage position.
-    auto newCelPosition = m_grid.tileToCanvas(m_bounds.origin());
-    m_grid.origin(newCelPosition);
-
+    m_grid.origin(newBoundsFromTiles.origin());
 
     // The origin of m_bounds must be in canvas position
-    m_bounds.setOrigin(newCelPosition);
+    if ((m_flags & PixelsBounds) == PixelsBounds) {
+      m_bounds = newBoundsFromTiles;
+    }
+    else {
+      // Bounds for the new cel which is a tilemap
+      m_bounds.setOrigin(newBoundsFromTiles.origin());
+    }
   }
 
   // We have to adjust the cel position to match the m_dstImage

src/app/util/expand_cel_canvas.h

@@ -47,6 +47,9 @@ namespace app {
       None = 0,
       NeedsSource = 1,
       UseModifiedRegionAsUndoInfo = 2,
+      // Use tiles mode but with pixels bounds in dst image (e.g. for
+      // selection preview)
+      PixelsBounds = 4,
     };
 
     ExpandCelCanvas(Site site, Layer* layer,