Added the much sought after horizontal gradient

otk/rendercontrol.cc

@@ -232,6 +232,9 @@ void RenderControl::drawGradientBackground(
   case RenderTexture::Vertical:
     verticalGradient(sf, texture);
     break;
+  case RenderTexture::Horizontal:
+    horizontalGradient(sf, texture);
+    break;
   case RenderTexture::Diagonal:
     diagonalGradient(sf, texture);
     break;
@@ -321,6 +324,36 @@ void RenderControl::verticalGradient(Surface &sf,
   }
 }
 
+void RenderControl::horizontalGradient(Surface &sf,
+                                         const RenderTexture &texture) const
+{
+  pixel32 *data = sf.pixelData();
+  pixel32 current;
+  float dr, dg, db;
+  unsigned int r,g,b;
+  int w = sf.size().width(), h = sf.size().height();
+
+  dr = (float)(texture.secondary_color().red() - texture.color().red());
+  dr/= (float)w;
+
+  dg = (float)(texture.secondary_color().green() - texture.color().green());
+  dg/= (float)w;
+
+  db = (float)(texture.secondary_color().blue() - texture.color().blue());
+  db/= (float)w;
+
+  for (int x = 0; x < w; ++x, ++data) {
+    r = texture.color().red() + (int)(dr * x);
+    g = texture.color().green() + (int)(dg * x);
+    b = texture.color().blue() + (int)(db * x);
+    current = (r << default_red_shift)
+            + (g << default_green_shift)
+            + (b << default_blue_shift);
+    for (int y = 0; y < h; ++y)
+      *(data + y*w) = current;
+  }
+}
+
 void RenderControl::diagonalGradient(Surface &sf,
                                          const RenderTexture &texture) const
 {

otk/rendercontrol.hh

@@ -28,6 +28,7 @@ protected:
 
   inline void highlight(pixel32 *x, pixel32 *y, bool raised) const;
   void verticalGradient(Surface &sf, const RenderTexture &texture) const;
+  void horizontalGradient(Surface &sf, const RenderTexture &texture) const;
   void diagonalGradient(Surface &sf, const RenderTexture &texture) const;
   void crossDiagonalGradient(Surface &sf, const RenderTexture &texture) const;
   virtual void drawGradientBackground(Surface &sf,