Added stretch_surface_horizontal and stretch_surface_vertical.

The functions stretch a surface based on the first row/column. This
looks better for the widget borders as scale_surface and should be
faster (not tested).  Added the option to the widget library to use
these functions and convert the window borders to use the new option.

data/gui/default/widget/window_default.cfg

@@ -48,6 +48,7 @@
 					x = 5
 					y = 0
 					w = "(width - 14)"
+					stretch = "true"
 					name = "dialogs/opaque-border-top.png"
 				[/image]
 
@@ -61,6 +62,7 @@
 					x = "(width - 9)"
 					y = 5
 					h = "(height - 14)"
+					stretch = "true"
 					name = "dialogs/opaque-border-right.png"
 				[/image]
 
@@ -74,6 +76,7 @@
 					x = 5
 					y = "(height - 9)"
 					w = "(width - 14)"
+					stretch = "true"
 					name = "dialogs/opaque-border-bottom.png"
 				[/image]
 
@@ -87,6 +90,7 @@
 					x = 0
 					y = 5
 					h = "(height - 14)"
+					stretch = "true"
 					name = "dialogs/opaque-border-left.png"
 				[/image]
 

src/gui/widgets/canvas.cpp

@@ -596,7 +596,8 @@ tcanvas::timage::timage(const config& cfg) :
 	h_formula_(""),
 	src_clip_(),
 	dst_clip_(),
-	image_()
+	image_(),
+	stretch_(utils::string_bool(cfg["stretch"]))
 {
 /*WIKI
  * [image]
@@ -608,6 +609,11 @@ tcanvas::timage::timage(const config& cfg) :
  *                                     image will be scaled to the desired width.
  *     h (f_unsigned = 0)              The height of the image, if not zero the
  *                                     image will be scaled to the desired height.
+ *     stretch (bool = false)          Border images often need to be either 
+ *                                     stretched in the width or the height. If
+ *                                     that's the case use stretch. It only works
+ *                                     if only the heigth or the width is not zero.
+ *                                     It will copy the first pixel the the others.
  *     name (string = "")              The name of the image.
  *     debug = (string = "")           Debug message to show upon creation
  *                                     this message is not stored.
@@ -668,18 +674,37 @@ void tcanvas::timage::draw(surface& canvas,
 
 	// Test whether we need to scale and do the scaling if needed.
 	if(w || h) {
+		bool done = false;
+		bool stretch = stretch_ && (!!w ^ !!h);
 		if(!w) {
+			if(stretch) { 
+				DBG_G_D << "Image: vertical stretch from " << image_->w 
+					<< ',' << image_->h << " to a height of " << h << ".\n";
+
+				surf = stretch_surface_vertical(image_, h);	
+				done = true;
+			}
 			w = image_->w;
 		}
 
 		if(!h) {
+			if(stretch) { 
+				DBG_G_D << "Image: horizontal stretch from " << image_->w 
+					<< ',' << image_->h << " to a width of " << w << ".\n";
+
+				surf = stretch_surface_horizontal(image_, w);	
+				done = true;
+			}
 			h = image_->h;
 		}
 
-		DBG_G_D << "Image: scaling from " << image_->w 
-			<< ',' << image_->h << " to " << w << ',' << h << ".\n";
+		if(!done) {
 
-		surf = scale_surface(image_, w, h);
+			DBG_G_D << "Image: scaling from " << image_->w 
+				<< ',' << image_->h << " to " << w << ',' << h << ".\n";
+
+			surf = scale_surface(image_, w, h);
+		}
 		src_clip.w = w;
 		src_clip.h = h;
 	} else {

src/gui/widgets/canvas.hpp

@@ -147,6 +147,8 @@ public:
 		SDL_Rect src_clip_;
 		SDL_Rect dst_clip_;
 		surface image_;
+
+		bool stretch_;
 	};
 
 	//! Definition of a text shape.

src/sdl_utils.cpp

@@ -151,6 +151,119 @@ surface create_optimized_surface(surface const &surf)
 	return result;
 }
 
+//! Streches a surface in the horizontal direction.
+//!
+//! The stretches a surface it uses the first pixel in the horizontal
+//! direction of the original surface and copies that to the destination.
+//! This means only the first column of the original is used for the destination.
+//! @param surf              The source surface.
+//! @param w                 The width of the resulting surface.
+//!
+//! @return                  An optimized surface.
+//!                          returned. 
+//! @retval 0                Returned upon error.
+//! @retval surf             Returned if w == surf->w.
+surface stretch_surface_horizontal(const surface& surf, const unsigned w)
+{
+	// Since SDL version 1.1.5 0 is transparent, before 255 was transparent.
+	assert(SDL_ALPHA_TRANSPARENT==0);
+
+	if(surf == NULL)
+		return NULL;
+
+	if(w == surf->w) {
+		return surf;
+	}
+	assert(w > 0);
+
+	surface dst(SDL_CreateRGBSurface(SDL_SWSURFACE, 
+		w, surf->h, 32, 0xFF0000, 0xFF00, 0xFF, 0xFF000000));
+		
+	surface src(make_neutral_surface(surf));
+	// Now both surfaces are always in the "neutral" pixel format
+
+	if(src == NULL || dst == NULL) {
+		std::cerr << "Could not create surface to scale onto\n";
+		return NULL;
+	}
+
+	{
+		// Extra scoping used for the surface_lock.
+		surface_lock src_lock(src);
+		surface_lock dst_lock(dst);
+
+		Uint32* const src_pixels = reinterpret_cast<Uint32*>(src_lock.pixels());
+		Uint32* dst_pixels = reinterpret_cast<Uint32*>(dst_lock.pixels());
+
+		for(unsigned y = 0; y < src->h; ++y) {
+			const Uint32 pixel = src_pixels [y * src->w];
+			for(unsigned x = 0; x < w; ++x) {
+
+				*dst_pixels++ = pixel;
+			
+			}
+		}
+	}
+
+	return create_optimized_surface(dst);
+}
+
+//! Streches a surface in the vertical direction.
+//!
+//! The stretches a surface it uses the first pixel in the vertical
+//! direction of the original surface and copies that to the destination.
+//! This means only the first row of the original is used for the destination.
+//! @param surf              The source surface.
+//! @param h                 The height of the resulting surface.
+//!
+//! @return                  An optimized surface.
+//!                          returned. 
+//! @retval 0                Returned upon error.
+//! @retval surf             Returned if h == surf->h.
+surface stretch_surface_vertical(const surface& surf, const unsigned h)
+{
+	// Since SDL version 1.1.5 0 is transparent, before 255 was transparent.
+	assert(SDL_ALPHA_TRANSPARENT==0);
+
+	if(surf == NULL)
+		return NULL;
+
+	if(h == surf->h) {
+		return surf;
+	}
+	assert(h > 0);
+
+	surface dst(SDL_CreateRGBSurface(SDL_SWSURFACE, 
+		surf->w, h, 32, 0xFF0000, 0xFF00, 0xFF, 0xFF000000));
+		
+	surface src(make_neutral_surface(surf));
+	// Now both surfaces are always in the "neutral" pixel format
+
+	if(src == NULL || dst == NULL) {
+		std::cerr << "Could not create surface to scale onto\n";
+		return NULL;
+	}
+
+	{
+		// Extra scoping used for the surface_lock.
+		surface_lock src_lock(src);
+		surface_lock dst_lock(dst);
+
+		Uint32* const src_pixels = reinterpret_cast<Uint32*>(src_lock.pixels());
+		Uint32* dst_pixels = reinterpret_cast<Uint32*>(dst_lock.pixels());
+
+		for(unsigned y = 0; y < h; ++y) {
+			for(unsigned x = 0; x < src->w; ++x) {
+
+				*dst_pixels++ = src_pixels[x];
+			}
+		}
+	}
+
+	return create_optimized_surface(dst);
+}
+
+
 // NOTE: Don't pass this function 0 scaling arguments.
 surface scale_surface(surface const &surf, int w, int h)
 {

src/sdl_utils.hpp

@@ -119,6 +119,13 @@ bool operator<(const surface& a, const surface& b);
 
 surface make_neutral_surface(surface const &surf);
 surface create_optimized_surface(surface const &surf);
+
+//! Streches a surface in the horizontal direction.
+surface stretch_surface_horizontal(const surface& surf, const unsigned w);
+
+//! Streches a surface in the vertical direction.
+surface stretch_surface_vertical(const surface& surf, const unsigned h);
+
 surface scale_surface(surface const &surf, int w, int h);
 surface scale_surface_blended(surface const &surf, int w, int h);
 surface adjust_surface_colour(surface const &surf, int r, int g, int b);