tmxrasterizer: Use smooth pixmap transform by default

This is to increase the default quality of the rendered map, especially
when rendering thumbnails. It can be turned off separately from anti-
aliasing using the new --no-smoothing parameter.

Anti-aliasing remains off by default since it is usually not what you
want. It applies anti-aliasing to edges of primitives, including tiles.
This creates visible seems at tile boundaries when the tiles are not
pixel-aligned.

src/tmxrasterizer/main.cpp

@@ -43,6 +43,7 @@ struct CommandLineOptions {
         , tileSize(0)
         , size(0)
         , useAntiAliasing(false)
+        , smoothImages(true)
         , ignoreVisibility(false)
     {}
 
@@ -54,6 +55,7 @@ struct CommandLineOptions {
     int tileSize;
     int size;
     bool useAntiAliasing;
+    bool smoothImages;
     bool ignoreVisibility;
     QStringList layersToHide;
 };
@@ -75,7 +77,8 @@ static void showHelp()
             "                            Overrides the --scale option\n"
             "     --size SIZE          : The output image fits within a SIZE x SIZE square\n"
             "                            Overrides the --scale and --tilesize options\n"
-            "  -a --anti-aliasing      : Smooth the output image using anti-aliasing\n"
+            "  -a --anti-aliasing      : Antialias edges of primitives\n"
+            "     --no-smoothing       : Use nearest neighbour instead of smooth blending of pixels\n"
             "     --ignore-visibility  : Ignore all layer visibility flags in the map file, and render all\n"
             "                            layers in the output (default is to omit invisible layers)\n"
             "     --hide-layer         : Specifies a layer to omit from the output image\n"
@@ -147,6 +150,8 @@ static void parseCommandLineArguments(CommandLineOptions &options)
         } else if (arg == QLatin1String("--anti-aliasing")
                 || arg == QLatin1String("-a")) {
             options.useAntiAliasing = true;
+        } else if (arg == QLatin1String("--no-smoothing")) {
+            options.smoothImages = false;
         } else if (arg == QLatin1String("--ignore-visibility")) {
             options.ignoreVisibility = true;
         } else if (arg.isEmpty()) {
@@ -195,6 +200,7 @@ int main(int argc, char *argv[])
 
     TmxRasterizer w;
     w.setAntiAliasing(options.useAntiAliasing);
+    w.setSmoothImages(options.smoothImages);
     w.setIgnoreVisibility(options.ignoreVisibility);
     w.setLayersToHide(options.layersToHide);
 
@@ -208,4 +214,3 @@ int main(int argc, char *argv[])
 
     return w.render(options.fileToOpen, options.fileToSave);
 }
-

src/tmxrasterizer/tmxrasterizer.cpp

@@ -47,7 +47,8 @@ TmxRasterizer::TmxRasterizer():
     mScale(1.0),
     mTileSize(0),
     mSize(0),
-    mUseAntiAliasing(true),
+    mUseAntiAliasing(false),
+    mSmoothImages(true),
     mIgnoreVisibility(false)
 {
 }
@@ -124,13 +125,9 @@ int TmxRasterizer::render(const QString &mapFileName,
     image.fill(Qt::transparent);
     QPainter painter(&image);
 
-    if (xScale != qreal(1) || yScale != qreal(1)) {
-        if (mUseAntiAliasing) {
-            painter.setRenderHints(QPainter::SmoothPixmapTransform |
-                                   QPainter::Antialiasing);
-        }
-        painter.setTransform(QTransform::fromScale(xScale, yScale));
-    }
+    painter.setRenderHint(QPainter::Antialiasing, mUseAntiAliasing);
+    painter.setRenderHint(QPainter::SmoothPixmapTransform, mSmoothImages);
+    painter.setTransform(QTransform::fromScale(xScale, yScale));
 
     painter.translate(margins.left(), margins.top());
 

src/tmxrasterizer/tmxrasterizer.h

@@ -46,12 +46,14 @@ class TmxRasterizer
     qreal scale() const { return mScale; }
     int tileSize() const { return mTileSize; }
     bool useAntiAliasing() const { return mUseAntiAliasing; }
+    bool smoothImages() const { return mSmoothImages; }
     bool IgnoreVisibility() const { return mIgnoreVisibility; }
 
     void setScale(qreal scale) { mScale = scale; }
     void setTileSize(int tileSize) { mTileSize = tileSize; }
     void setSize(int size) { mSize = size; }
     void setAntiAliasing(bool useAntiAliasing) { mUseAntiAliasing = useAntiAliasing; }
+    void setSmoothImages(bool smoothImages) { mSmoothImages = smoothImages; }
     void setIgnoreVisibility(bool IgnoreVisibility) { mIgnoreVisibility = IgnoreVisibility; }
 
     void setLayersToHide(QStringList layersToHide) { mLayersToHide = layersToHide; }
@@ -63,6 +65,7 @@ class TmxRasterizer
     int mTileSize;
     int mSize;
     bool mUseAntiAliasing;
+    bool mSmoothImages;
     bool mIgnoreVisibility;
     QStringList mLayersToHide;