Implemented scaling images

CONTRIBUTORS

@@ -3750,3 +3750,6 @@ Timo Weing
 
 Jose Angel <joseangelpp@gmail.com>
  for reporting a bug in default values for DVB-T
+
+Andreas Baierl <post@andreasbaierl.de>
+ for implementing scaling images

HISTORY

@@ -9871,3 +9871,4 @@ Video Disk Recorder Revision History
   Ehrnsperger).
 - Using a dummy OSD if no OSD provider is available is not considered an error any
   more (thanks to Markus Ehrnsperger).
+- Implemented scaling images (thanks to Andreas Baierl).

osd.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: osd.c 5.1 2024/01/18 11:06:45 kls Exp $
+ * $Id: osd.c 5.2 2024/01/18 12:04:57 kls Exp $
  */
 
 #include "osd.h"
@@ -1139,6 +1139,49 @@ void cImage::Fill(tColor Color)
       data[i] = Color;
 }
 
+cImage *cImage::Scaled(double FactorX, double FactorY, bool AntiAlias) const
+{
+  int w = max(1, int(round(Width() * FactorX)));
+  int h = max(1, int(round(Height() * FactorY)));
+  cImage *i = new cImage(cSize(w, h));
+  int RatioX = (Width() << 16) / i->Width();
+  int RatioY = (Height() << 16) / i->Height();
+
+  if (!AntiAlias || FactorX <= 1.0 && FactorY <= 1.0) {
+     // Downscaling - no anti-aliasing:
+     int SourceY = 0;
+     for (int y = 0; y < i->Height(); y++) {
+         int SourceX = 0;
+         for (int x = 0; x < i->Width(); x++) {
+             tColor c1 = GetPixel(cPoint(SourceX >> 16, SourceY >> 16));
+             i->SetPixel(cPoint(x, y), c1);
+             SourceX += RatioX;
+             }
+         SourceY += RatioY;
+         }
+     }
+  else {
+     // Upscaling - anti-aliasing:
+     int SourceY = 0;
+     for (int y = 0; y < i->Height(); y++) {
+         int SourceX = 0;
+         int sy = min(SourceY >> 16, Height() - 2);
+         uint8_t BlendY = 0xFF - ((SourceY >> 8) & 0xFF);
+         for (int x = 0; x < i->Width(); x++) {
+             int sx = min(SourceX >> 16, Width() - 2);
+             uint8_t BlendX = 0xFF - ((SourceX >> 8) & 0xFF);
+             tColor c1 = AlphaBlend(GetPixel(cPoint(sx, sy)),     GetPixel(cPoint(sx + 1, sy)),     BlendX);
+             tColor c2 = AlphaBlend(GetPixel(cPoint(sx, sy + 1)), GetPixel(cPoint(sx + 1, sy + 1)), BlendX);
+             tColor c3 = AlphaBlend(c1, c2, BlendY);
+             i->SetPixel(cPoint(x, y), c3);
+             SourceX += RatioX;
+             }
+         SourceY += RatioY;
+         }
+     }
+  return i;
+}
+
 // --- cPixmapMemory ---------------------------------------------------------
 
 cPixmapMemory::cPixmapMemory(void)
@@ -1259,6 +1302,26 @@ void cPixmapMemory::DrawImage(const cPoint &Point, int ImageHandle)
   Unlock();
 }
 
+void cPixmapMemory::DrawScaledImage(const cPoint &Point, const cImage &Image, double FactorX, double FactorY, bool AntiAlias)
+{
+  Lock();
+  const cImage *i = &Image;
+  if (!DoubleEqual(FactorX, 1.0) || !DoubleEqual(FactorY, 1.0))
+     i = i->Scaled(FactorX, FactorY, AntiAlias);
+  DrawImage(Point, *i);
+  if (i != &Image)
+     delete i;
+  Unlock();
+}
+
+void cPixmapMemory::DrawScaledImage(const cPoint &Point, int ImageHandle, double FactorX, double FactorY, bool AntiAlias)
+{
+  Lock();
+  if (const cImage *Image = cOsdProvider::GetImageData(ImageHandle))
+     DrawScaledImage(Point, *Image, FactorX, FactorY, AntiAlias);
+  Unlock();
+}
+
 void cPixmapMemory::DrawPixel(const cPoint &Point, tColor Color)
 {
   Lock();
@@ -2118,6 +2181,18 @@ void cOsd::DrawImage(const cPoint &Point, int ImageHandle)
      pixmaps[0]->DrawImage(Point, ImageHandle);
 }
 
+void cOsd::DrawScaledImage(const cPoint &Point, const cImage &Image, double FactorX, double FactorY, bool AntiAlias)
+{
+  if (isTrueColor)
+     pixmaps[0]->DrawScaledImage(Point, Image, FactorX, FactorY, AntiAlias);
+}
+
+void cOsd::DrawScaledImage(const cPoint &Point, int ImageHandle, double FactorX, double FactorY, bool AntiAlias)
+{
+  if (isTrueColor)
+     pixmaps[0]->DrawScaledImage(Point, ImageHandle, FactorX, FactorY, AntiAlias);
+}
+
 void cOsd::DrawPixel(int x, int y, tColor Color)
 {
   if (isTrueColor)

osd.h

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: osd.h 5.1 2021/05/21 12:54:08 kls Exp $
+ * $Id: osd.h 5.2 2024/01/18 12:04:57 kls Exp $
  */
 
 #ifndef __OSD_H
@@ -447,6 +447,11 @@ public:
        ///< Clears the image data by setting all pixels to be fully transparent.
   void Fill(tColor Color);
        ///< Fills the image data with the given Color.
+  cImage *Scaled(double FactorX, double FactorY, bool AntiAlias = false) const;
+       ///< Creates a copy of this image, scaled by the given factors.
+       ///< If AntiAlias is true and either of the factors is greater than 1.0,
+       ///< anti-aliasing is applied.
+       ///< The caller must delete the returned image once it is no longer used.
   };
 
 #define MAXPIXMAPLAYERS    8
@@ -602,6 +607,23 @@ public:
        ///< the given Point. ImageHandle must be a value that has previously been
        ///< returned by a call to cOsdProvider::StoreImage(). If ImageHandle
        ///< has an invalid value, nothing happens.
+  virtual void DrawScaledImage(const cPoint &Point, const cImage &Image, double FactorX, double FactorY, bool AntiAlias = false) {};
+       ///< Draws the given Image into this pixmap at the given Point and scales it.
+       ///< If AntiAlias is true and either of the factors is greater than
+       ///< 1.0, anti-aliasing is applied.
+       ///< This function should be 'pure', just like all the others. However, since it was
+       ///< introduced when this class was already in widespread use, the default was made
+       ///< empty, so that existing code will still compile.
+  virtual void DrawScaledImage(const cPoint &Point, int ImageHandle, double FactorX, double FactorY, bool AntiAlias = false) {};
+       ///< Draws the image referenced by the given ImageHandle into this pixmap at
+       ///< the given Point and scales it. ImageHandle must be a value that has
+       ///< previously been returned by a call to cOsdProvider::StoreImage().
+       ///< If ImageHandle has an invalid value, nothing happens.
+       ///< If AntiAlias is true and either of the factors is greater than
+       ///< 1.0, anti-aliasing is applied.
+       ///< This function should be 'pure', just like all the others. However, since it was
+       ///< introduced when this class was already in widespread use, the default was made
+       ///< empty, so that existing code will still compile.
   virtual void DrawPixel(const cPoint &Point, tColor Color) = 0;
        ///< Sets the pixel at the given Point to the given Color, which is
        ///< a full 32 bit ARGB value. If the alpha value of Color is not 0xFF
@@ -700,6 +722,8 @@ public:
   virtual void Fill(tColor Color);
   virtual void DrawImage(const cPoint &Point, const cImage &Image);
   virtual void DrawImage(const cPoint &Point, int ImageHandle);
+  virtual void DrawScaledImage(const cPoint &Point, const cImage &Image, double FactorX, double FactorY, bool AntiAlias = false);
+  virtual void DrawScaledImage(const cPoint &Point, int ImageHandle, double FactorX, double FactorY, bool AntiAlias = false);
   virtual void DrawPixel(const cPoint &Point, tColor Color);
   virtual void DrawBlendedPixel(const cPoint &Point, tColor Color, uint8_t AlphaLayer = ALPHA_OPAQUE);
   virtual void DrawBitmap(const cPoint &Point, const cBitmap &Bitmap, tColor ColorFg = 0, tColor ColorBg = 0, bool Overlay = false);
@@ -857,6 +881,19 @@ public:
        ///< returned by a call to cOsdProvider::StoreImage(). If ImageHandle
        ///< has an invalid value, nothing happens.
        ///< If this is not a true color OSD, this function does nothing.
+  virtual void DrawScaledImage(const cPoint &Point, const cImage &Image, double FactorX, double FactorY, bool AntiAlias = false);
+       ///< Draws the given Image on this OSD at the given Point and scales it.
+       ///< If AntiAlias is true and either of the factors is greater than
+       ///< 1.0, anti-aliasing is applied.
+       ///< If this is not a true color OSD, this function does nothing.
+  virtual void DrawScaledImage(const cPoint &Point, int ImageHandle, double FactorX, double FactorY, bool AntiAlias = false);
+       ///< Draws the image referenced by the given ImageHandle on this OSD at
+       ///< the given Point and scales it. ImageHandle must be a value that has
+       ///< previously been returned by a call to cOsdProvider::StoreImage().
+       ///< If ImageHandle has an invalid value, nothing happens.
+       ///< If AntiAlias is true and either of the factors is greater than
+       ///< 1.0, anti-aliasing is applied.
+       ///< If this is not a true color OSD, this function does nothing.
   virtual eOsdError CanHandleAreas(const tArea *Areas, int NumAreas);
        ///< Checks whether the OSD can display the given set of sub-areas.
        ///< The return value indicates whether a call to SetAreas() with this