Improving constness of surface: forbid to blit on a const surface.

src/dialogs.cpp

@@ -367,7 +367,7 @@ void save_preview_pane::draw_contents()
 		}
 	}
 
-	surface const screen = video().getSurface();
+	surface screen = video().getSurface();
 
 	SDL_Rect const &loc = location();
 	const SDL_Rect area = create_rect(loc.x + save_preview_border
@@ -746,7 +746,7 @@ void unit_preview_pane::draw_contents()
 
 	const bool right_align = left_side();
 
-	surface const screen = video().getSurface();
+	surface screen = video().getSurface();
 
 	SDL_Rect const &loc = location();
 	const SDL_Rect area = create_rect(loc.x + unit_preview_border

src/display.cpp

@@ -889,7 +889,7 @@ void display::drawing_buffer_commit()
 	drawing_buffer_.sort();
 
 	SDL_Rect clip_rect = map_area();
-	const surface screen = get_screen_surface();
+	surface screen = get_screen_surface();
 	clip_rect_setter set_clip_rect(screen, &clip_rect);
 
 	/*
@@ -948,7 +948,7 @@ void display::flip()
 		return;
 	}
 
-	const surface frameBuffer = get_video_surface();
+	surface frameBuffer = get_video_surface();
 
 	// This is just the debug function "sunset" to progressively darken the map area
 	static size_t sunset_timer = 0;
@@ -2039,7 +2039,7 @@ const map_labels& display::labels() const
 
 void display::clear_screen()
 {
-	surface const disp(screen_.getSurface());
+	surface disp(screen_.getSurface());
 	SDL_Rect area = screen_area();
 	sdl_fill_rect(disp, &area, SDL_MapRGB(disp->format, 0, 0, 0));
 }

src/halo.cpp

@@ -192,7 +192,7 @@ bool effect::render()
 		return false;
 	}
 
-	surface const screen = disp->get_screen_surface();
+	surface screen = disp->get_screen_surface();
 
 	const clip_rect_setter clip_setter(screen, &clip_rect);
 	if(buffer_ == NULL || buffer_->w != rect.w || buffer_->h != rect.h) {
@@ -216,7 +216,7 @@ void effect::unrender()
 		return;
 	}
 
-	surface const screen = disp->get_screen_surface();
+	surface screen = disp->get_screen_surface();
 
 	SDL_Rect clip_rect = disp->map_outside_area();
 	const clip_rect_setter clip_setter(screen, &clip_rect);

src/help.cpp

@@ -2616,7 +2616,7 @@ void help_text_area::draw_contents()
 {
 	SDL_Rect const &loc = inner_location();
 	bg_restore();
-	surface const screen = video().getSurface();
+	surface screen = video().getSurface();
 	clip_rect_setter clip_rect_set(screen, &loc);
 	for(std::list<item>::const_iterator it = items_.begin(), end = items_.end(); it != end; ++it) {
 		SDL_Rect dst = it->rect;

src/image.cpp

@@ -413,7 +413,7 @@ static std::string get_localized_path (const std::string& file, const std::strin
 }
 
 // Load overlay image and compose it with the original surface.
-static void add_localized_overlay (const std::string& ovr_file, const surface &orig_surf)
+static void add_localized_overlay (const std::string& ovr_file, surface &orig_surf)
 {
 	surface ovr_surf = IMG_Load(ovr_file.c_str());
 	if (ovr_surf.null()) {

src/loadscreen.cpp

@@ -106,7 +106,7 @@ void loadscreen::draw_screen(const std::string &text)
 	// Height of the lighting line.
 	int	lightning_thickness = 2;
 
-	surface const gdis = screen_.getSurface();
+	surface gdis = screen_.getSurface();
 	SDL_Rect area;
 
 	// Pump events and make sure to redraw the logo if there's a chance that it's been obscured
@@ -192,7 +192,7 @@ void loadscreen::clear_screen()
 	int scrx = screen_.getx();                     //< Screen width.
 	int scry = screen_.gety();                     //< Screen height.
 	SDL_Rect area = create_rect(0, 0, scrx, scry); // Screen area.
-	surface const disp(screen_.getSurface());      // Screen surface.
+	surface disp(screen_.getSurface());      // Screen surface.
 	// Make everything black.
 	sdl_fill_rect(disp,&area,SDL_MapRGB(disp->format,0,0,0));
 	update_whole_screen();

src/multiplayer_wait.cpp

@@ -68,7 +68,7 @@ void wait::leader_preview_pane::draw_contents()
 {
 	bg_restore();
 
-	surface const screen = video().getSurface();
+	surface screen = video().getSurface();
 
 	SDL_Rect const &loc = location();
 	const SDL_Rect area = create_rect(loc.x + leader_pane_border

src/sdl_utils.cpp

@@ -1752,7 +1752,7 @@ void blit_surface(const surface& src,
 
 
 
-void fill_rect_alpha(SDL_Rect &rect, Uint32 color, Uint8 alpha, const surface &target)
+void fill_rect_alpha(SDL_Rect &rect, Uint32 color, Uint8 alpha, surface &target)
 {
 	if(alpha == SDL_ALPHA_OPAQUE) {
 		sdl_fill_rect(target,&rect,color);

src/sdl_utils.hpp

@@ -126,11 +126,11 @@ private:
 
 bool operator<(const surface& a, const surface& b);
 
-inline void sdl_blit(const surface& src, SDL_Rect* src_rect, const surface& dst, SDL_Rect* dst_rect){
+inline void sdl_blit(const surface& src, SDL_Rect* src_rect, surface& dst, SDL_Rect* dst_rect){
 	SDL_BlitSurface(src, src_rect, dst, dst_rect);
 }
 
-inline void sdl_fill_rect(const surface& dst, SDL_Rect* dst_rect, const Uint32 color){
+inline void sdl_fill_rect(surface& dst, SDL_Rect* dst_rect, const Uint32 color){
 	SDL_FillRect(dst, dst_rect, color);
 }
 
@@ -305,7 +305,7 @@ surface create_compatible_surface(const surface &surf, int width = -1, int heigh
 void blit_surface(const surface& src,
 	const SDL_Rect* srcrect, surface& dst, const SDL_Rect* dstrect);
 
-void fill_rect_alpha(SDL_Rect &rect, Uint32 color, Uint8 alpha, const surface &target);
+void fill_rect_alpha(SDL_Rect &rect, Uint32 color, Uint8 alpha, surface &target);
 
 SDL_Rect get_non_transparent_portion(const surface &surf);
 

src/tools/dummy_video.cpp

@@ -18,9 +18,11 @@
 #include "../video.hpp"
 #include "../sdl_utils.hpp"
 
-surface CVideo::getSurface()
+static surface dummy_screen_surface(NULL);
+
+surface& CVideo::getSurface()
 {
-	return NULL;
+	return dummy_screen_surface;
 }
 
 void update_rect(const SDL_Rect&)

src/video.cpp

@@ -326,7 +326,7 @@ CVideo::~CVideo()
 
 void CVideo::blit_surface(int x, int y, surface surf, SDL_Rect* srcrect, SDL_Rect* clip_rect)
 {
-	const surface target(getSurface());
+	surface target(getSurface());
 	SDL_Rect dst = create_rect(x, y, 0, 0);
 
 	const clip_rect_setter clip_setter(target, clip_rect, clip_rect != NULL);
@@ -437,7 +437,7 @@ bool CVideo::update_locked() const
 	return updatesLocked_ > 0;
 }
 
-surface CVideo::getSurface()
+surface& CVideo::getSurface()
 {
 	return frameBuffer;
 }

src/video.hpp

@@ -64,7 +64,7 @@ class CVideo : private boost::noncopyable {
 	void blit_surface(int x, int y, surface surf, SDL_Rect* srcrect=NULL, SDL_Rect* clip_rect=NULL);
 	void flip();
 
-	surface getSurface();
+	surface& getSurface();
 
 	bool isFullScreen() const;
 

src/widgets/progressbar.cpp

@@ -42,7 +42,7 @@ void progress_bar::set_text(const std::string& text)
 
 void progress_bar::draw_contents()
 {
-	surface const surf = video().getSurface();
+	surface surf = video().getSurface();
 	SDL_Rect area = location();
 
 	if(area.w >= 2 && area.h >= 2) {

src/widgets/slider.cpp

@@ -147,7 +147,7 @@ void slider::draw_contents()
 	if (image->w >= loc.w)
 		return;
 
-	surface const screen = video().getSurface();
+	surface screen = video().getSurface();
 
 	SDL_Rect line_rect = create_rect(loc.x + image->w / 2
 			, loc.y + loc.h / 2

src/widgets/textbox.cpp

@@ -95,7 +95,7 @@ void textbox::append_text(const std::string& text, bool auto_scroll, const SDL_C
 	const wide_string& wtext = utils::string_to_wstring(text);
 
 	const surface new_text = add_text_line(wtext, color);
-	const surface new_surface = create_compatible_surface(text_image_,std::max<size_t>(text_image_->w,new_text->w),text_image_->h+new_text->h);
+	surface new_surface = create_compatible_surface(text_image_,std::max<size_t>(text_image_->w,new_text->w),text_image_->h+new_text->h);
 
 	SDL_SetAlpha(new_text.get(),0,0);
 	SDL_SetAlpha(text_image_.get(),0,0);
@@ -140,7 +140,7 @@ void textbox::draw_cursor(int pos, CVideo &video) const
 				, 1
 				, location().h);
 
-		surface const frame_buffer = video.getSurface();
+		surface frame_buffer = video.getSurface();
 		sdl_fill_rect(frame_buffer,&rect,SDL_MapRGB(frame_buffer->format,255,255,255));
 	}
 }