[API] + OSM.SlippyMapUtils.pas, add ToTileHeightGreater, ToTileHeight…

…Lesser, ToTileWidthGreater, ToTileWidthLesser, ToTileBoundary functions (first 4 extrated from private section of OSM.MapControl.pas)
Fr0sT-Brutal · Oct 4, 2021 · 5a5513f · 5a5513f
1 parent 0c86ade
commit 5a5513f
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Showing 2 changed files with 58 additions and 35 deletions.
diff --git a/Source/OSM.MapControl.pas b/Source/OSM.MapControl.pas
@@ -324,9 +324,15 @@   TMapControl = class(TScrollBox)
     property OnSelectionBox: TOnSelectionBox read FOnSelectionBox write FOnSelectionBox;
   end;
 
+// Like Client<=>Screen
+
+// Convert absolute map coords to a point inside a viewport having given top-left point
 function ToInnerCoords(const StartPt, Pt: TPoint): TPoint; overload; inline;
+// Convert a point inside a viewport having given top-left point to absolute map coords
 function ToOuterCoords(const StartPt, Pt: TPoint): TPoint; overload; inline;
+// Convert absolute map rect to a rect inside a viewport having given top-left point
 function ToInnerCoords(const StartPt: TPoint; const Rect: TRect): TRect; overload; inline;
+// Convert a rect inside a viewport having given top-left point to absolute map rect
 function ToOuterCoords(const StartPt: TPoint; const Rect: TRect): TRect; overload; inline;
 
 const
@@ -394,34 +400,6 @@ function ToOuterCoords(const StartPt: TPoint; const Rect: TRect): TRect;
   );
 end;
 
-// Floor value to tile size
-
-function ToTileWidthLesser(Width: Cardinal): Cardinal; inline;
-begin
-  Result := (Width div TILE_IMAGE_WIDTH)*TILE_IMAGE_WIDTH;
-end;
-
-function ToTileHeightLesser(Height: Cardinal): Cardinal; inline;
-begin
-  Result := (Height div TILE_IMAGE_HEIGHT)*TILE_IMAGE_HEIGHT;
-end;
-
-// Ceil value to tile size
-
-function ToTileWidthGreater(Width: Cardinal): Cardinal; inline;
-begin
-  Result := ToTileWidthLesser(Width);
-  if Width mod TILE_IMAGE_WIDTH > 0 then
-    Inc(Result, TILE_IMAGE_WIDTH);
-end;
-
-function ToTileHeightGreater(Height: Cardinal): Cardinal; inline;
-begin
-  Result := ToTileHeightLesser(Height);
-  if Height mod TILE_IMAGE_HEIGHT > 0 then
-    Inc(Result, TILE_IMAGE_HEIGHT);
-end;
-
 // Draw triangle on canvas
 procedure Triangle(Canvas: TCanvas; const Rect: TRect);
 begin
@@ -1025,13 +1003,7 @@ procedure TMapControl.MoveCache;
   ViewRect: TRect;
   MarginH, MarginV: Cardinal;
 begin
-  ViewRect := ViewAreaRect;
-  // move view rect to the border of tiles (to lesser value)
-  ViewRect.Left := ToTileWidthLesser(ViewRect.Left);
-  ViewRect.Top := ToTileHeightLesser(ViewRect.Top);
-  // resize view rect to the border of tiles (to greater value)
-  ViewRect.Right := ToTileWidthGreater(ViewRect.Right);
-  ViewRect.Bottom := ToTileHeightGreater(ViewRect.Bottom);
+  ViewRect := ToTileBoundary(ViewAreaRect);
 
   // reposition new cache rect to cover tile-aligned view area
   // calc margins

diff --git a/Source/OSM.SlippyMapUtils.pas b/Source/OSM.SlippyMapUtils.pas
@@ -103,6 +103,17 @@ function TileToStr(const Tile: TTile): string;
 // Compares tiles
 function TilesEqual(const Tile1, Tile2: TTile): Boolean; inline;
 
+// Floor horizontal map coord to tile size
+function ToTileWidthLesser(Width: Cardinal): Cardinal; inline;
+// Floor vertical map coord to tile size
+function ToTileHeightLesser(Height: Cardinal): Cardinal; inline;
+// Ceil horizontal map coord to tile size
+function ToTileWidthGreater(Width: Cardinal): Cardinal; inline;
+// Ceil vertical map coord to tile size
+function ToTileHeightGreater(Height: Cardinal): Cardinal; inline;
+// Align absolute map rect to tile boundaries
+function ToTileBoundary(const Rect: TRect): TRect;
+
 // Returns width of map at zoom level `Zoom` in pixels
 function MapWidth(Zoom: TMapZoomLevel): Cardinal; inline;
 // Returns height of map at zoom level `Zoom` in pixels
@@ -182,6 +193,46 @@ function TilesEqual(const Tile1, Tile2: TTile): Boolean;
     (Tile1.ParameterY = Tile2.ParameterY);
 end;
 
+// Floor value to tile size
+
+function ToTileWidthLesser(Width: Cardinal): Cardinal; inline;
+begin
+  Result := (Width div TILE_IMAGE_WIDTH)*TILE_IMAGE_WIDTH;
+end;
+
+function ToTileHeightLesser(Height: Cardinal): Cardinal; inline;
+begin
+  Result := (Height div TILE_IMAGE_HEIGHT)*TILE_IMAGE_HEIGHT;
+end;
+
+// Ceil value to tile size
+
+function ToTileWidthGreater(Width: Cardinal): Cardinal; inline;
+begin
+  Result := ToTileWidthLesser(Width);
+  if Width mod TILE_IMAGE_WIDTH > 0 then
+    Inc(Result, TILE_IMAGE_WIDTH);
+end;
+
+function ToTileHeightGreater(Height: Cardinal): Cardinal; inline;
+begin
+  Result := ToTileHeightLesser(Height);
+  if Height mod TILE_IMAGE_HEIGHT > 0 then
+    Inc(Result, TILE_IMAGE_HEIGHT);
+end;
+
+function ToTileBoundary(const Rect: TRect): TRect;
+begin
+  Result := TRect.Create(
+    // move view rect to the border of tiles (to lesser value)
+    ToTileWidthLesser(Rect.Left),
+    ToTileHeightLesser(Rect.Top),
+    // resize view rect to the border of tiles (to greater value)
+    ToTileWidthGreater(Rect.Right),
+    ToTileHeightGreater(Rect.Bottom)
+  );
+end;
+
 function MapWidth(Zoom: TMapZoomLevel): Cardinal;
 begin
   Result := TileCount(Zoom)*TILE_IMAGE_WIDTH;