Surface: Make pixel format conversion explicit.

Instead of having the copy constructor convert to display format, the new
copy constructor preserves the pixel format and a separate method was
introduced to convert surfaces to display format.

The code was made more robust as well: it should no longer crash if the
wallpaper cannot be loaded.

src/gmenu2x.cpp

@@ -344,14 +344,11 @@ void GMenu2X::quit() {
 void GMenu2X::initBG() {
 	sc.del("bgmain");
 
-	if (bg != NULL) free(bg);
-
-	if (!fileExists(confStr["wallpaper"])) {
-		bg = new Surface(s);
-		bg->box(0,0,resX,resY,0,0,0);
-	} else {
-		// Note: Copy constructor converts to display format.
-		bg = new Surface(Surface::loadImage(confStr["wallpaper"]));
+	// Load wallpaper.
+	free(bg);
+	bg = Surface::loadImage(confStr["wallpaper"]);
+	if (!bg) {
+		bg = Surface::emptySurface(resX, resY);
 	}
 
 	drawTopBar(bg);
@@ -361,20 +358,20 @@ void GMenu2X::initBG() {
 	sc.add(bgmain,"bgmain");
 
 	Surface *sd = Surface::loadImage("imgs/sd.png", confStr["skin"]);
-	if (sd) sd->blit(sc["bgmain"], 3, bottomBarIconY);
+	if (sd) sd->blit(bgmain, 3, bottomBarIconY);
 	string df = getDiskFree();
-	sc["bgmain"]->write(font, df, 22, bottomBarTextY, ASFont::HAlignLeft, ASFont::VAlignMiddle);
+	bgmain->write(font, df, 22, bottomBarTextY, ASFont::HAlignLeft, ASFont::VAlignMiddle);
 	free(sd);
 
 	Surface *volume = Surface::loadImage("imgs/volume.png", confStr["skin"]);
 	volumeX = 27+font->getTextWidth(df);
-	if (volume) volume->blit(sc["bgmain"], volumeX, bottomBarIconY);
+	if (volume) volume->blit(bgmain, volumeX, bottomBarIconY);
 	volumeX += 19;
 	free(volume);
 
 	Surface *cpu = Surface::loadImage("imgs/cpu.png", confStr["skin"]);
 	cpuX = volumeX+font->getTextWidth("100")+5;
-	if (cpu) cpu->blit(sc["bgmain"], cpuX, bottomBarIconY);
+	if (cpu) cpu->blit(bgmain, cpuX, bottomBarIconY);
 	cpuX += 19;
 	manualX = cpuX+font->getTextWidth("300Mhz")+5;
 	free(cpu);
@@ -384,24 +381,26 @@ void GMenu2X::initBG() {
 		if (web) {
 			Surface *webserver = Surface::loadImage(
 				"imgs/webserver.png", confStr["skin"]);
-			if (webserver) webserver->blit(sc["bgmain"], serviceX, bottomBarIconY);
+			if (webserver) webserver->blit(bgmain, serviceX, bottomBarIconY);
 			serviceX -= 19;
 			free(webserver);
 		}
 		if (samba) {
 			Surface *sambaS = Surface::loadImage(
 				"imgs/samba.png", confStr["skin"]);
-			if (sambaS) sambaS->blit(sc["bgmain"], serviceX, bottomBarIconY);
+			if (sambaS) sambaS->blit(bgmain, serviceX, bottomBarIconY);
 			serviceX -= 19;
 			free(sambaS);
 		}
 		if (inet) {
 			Surface *inetS = Surface::loadImage("imgs/inet.png", confStr["skin"]);
-			if (inetS) inetS->blit(sc["bgmain"], serviceX, bottomBarIconY);
+			if (inetS) inetS->blit(bgmain, serviceX, bottomBarIconY);
 			serviceX -= 19;
 			free(inetS);
 		}
 	}
+
+	bgmain->convertToDisplayFormat();
 }
 
 void GMenu2X::initFont() {
@@ -1632,6 +1631,7 @@ void GMenu2X::scanner() {
 	drawButton(&scanbg, "x", tr["Exit"],
 	drawButton(&scanbg, "b", "", 5)-10);
 	scanbg.write(font,tr["Link Scanner"],halfX,7,ASFont::HAlignCenter,ASFont::VAlignMiddle);
+	scanbg.convertToDisplayFormat();
 
 	uint lineY = 42;
 

src/linkapp.cpp

@@ -304,8 +304,12 @@ void LinkApp::showManual() {
 		if (!pngman) {
 			return;
 		}
-		// Note: Copy constructor converts to display format.
-		Surface bg(Surface::loadImage(gmenu2x->confStr["wallpaper"]));
+		Surface *bg = Surface::loadImage(gmenu2x->confStr["wallpaper"]);
+		if (!bg) {
+			bg = Surface::emptySurface(gmenu2x->s->width(), gmenu2x->s->height());
+		}
+		bg->convertToDisplayFormat();
+
 		stringstream ss;
 		string pageStatus;
 
@@ -321,7 +325,7 @@ void LinkApp::showManual() {
 
 		while (!close) {
 			if (repaint) {
-				bg.blit(gmenu2x->s, 0, 0);
+				bg->blit(gmenu2x->s, 0, 0);
 				pngman->blit(gmenu2x->s, -page*320, 0);
 
 				gmenu2x->drawBottomBar();
@@ -361,6 +365,7 @@ void LinkApp::showManual() {
                     break;
             }
         }
+		free(bg);
 		return;
 	}
 

src/messagebox.cpp

@@ -99,6 +99,7 @@ int MessageBox::exec() {
 		}
 	}
 
+	bg.convertToDisplayFormat();
 	bg.blit(gmenu2x->s,0,0);
 	gmenu2x->s->flip();
 

src/selector.cpp

@@ -71,6 +71,8 @@ int Selector::exec(int startSelection) {
 		gmenu2x->drawButton(&bg, "b", gmenu2x->tr["Select a file"], 5));
 	}
 
+	bg.convertToDisplayFormat();
+
 	Uint32 selTick = SDL_GetTicks(), curTick;
 	uint i, firstElement = 0, iY;
 

src/settingsdialog.cpp

@@ -45,8 +45,8 @@ SettingsDialog::~SettingsDialog() {
 }
 
 bool SettingsDialog::exec() {
-	//Surface bg (gmenu2x->confStr["wallpaper"],false);
 	Surface bg(gmenu2x->bg);
+	bg.convertToDisplayFormat();
 
 	bool close = false, ts_pressed = false;
 	uint i, sel = 0, iY, firstElement = 0, action;

src/surface.cpp

@@ -44,6 +44,14 @@ Surface *Surface::openOutputSurface(int width, int height, int bitsperpixel) {
 	return raw ? new Surface(raw, false) : NULL;
 }
 
+Surface *Surface::emptySurface(int width, int height) {
+	SDL_Surface *raw = SDL_CreateRGBSurface(
+		SDL_SWSURFACE, width, height, 32, 0, 0, 0, 0);
+	if (!raw) return NULL;
+	SDL_FillRect(raw, NULL, SDL_MapRGB(raw->format, 0, 0, 0));
+	return new Surface(raw, true);
+}
+
 Surface *Surface::loadImage(const string &img, const string &skin) {
 	string skinpath;
 	if (!skin.empty() && !img.empty() && img[0]!='/') {
@@ -72,7 +80,7 @@ Surface::Surface(SDL_Surface *raw_, bool freeWhenDone_)
 }
 
 Surface::Surface(Surface *s) {
-	raw = SDL_DisplayFormat(s->raw);
+	raw = SDL_ConvertSurface(s->raw, s->raw->format, SDL_SWSURFACE);
 	freeWhenDone = true;
 	halfW = raw->w/2;
 	halfH = raw->h/2;
@@ -84,6 +92,17 @@ Surface::~Surface() {
 	}
 }
 
+void Surface::convertToDisplayFormat() {
+	SDL_Surface *newSurface = SDL_DisplayFormat(raw);
+	if (newSurface) {
+		if (freeWhenDone) {
+			SDL_FreeSurface(raw);
+		}
+		raw = newSurface;
+		freeWhenDone = true;
+	}
+}
+
 void Surface::flip() {
 	SDL_Flip(raw);
 }

src/surface.h

@@ -40,11 +40,18 @@ RGBAColor strtorgba(const string &strColor);
 class Surface {
 public:
 	static Surface *openOutputSurface(int width, int height, int bitsperpixel);
+	static Surface *emptySurface(int width, int height);
 	static Surface *loadImage(const string &img, const string &skin="");
 
 	Surface(Surface *s);
 	~Surface();
 
+	/** Converts the underlying surface to the same pixel format as the frame
+	  * buffer, for faster blitting. This removes the alpha channel if the
+	  * image has done.
+	  */
+	void convertToDisplayFormat();
+
 	int width() { return raw->w; }
 	int height() { return raw->h; }
 

src/textdialog.cpp

@@ -110,6 +110,8 @@ void TextDialog::exec() {
 	gmenu2x->drawButton(&bg, "down", gmenu2x->tr["Scroll"],
 	gmenu2x->drawButton(&bg, "up", "", 5)-10));
 
+	bg.convertToDisplayFormat();
+
 	uint firstRow = 0, rowsPerPage = (gmenu2x->resY-60)/gmenu2x->font->getHeight();
 	while (!close) {
 		bg.blit(gmenu2x->s,0,0);

src/textmanualdialog.cpp

@@ -80,6 +80,8 @@ void TextManualDialog::exec() {
 	gmenu2x->drawButton(&bg, "down", gmenu2x->tr["Scroll"],
 	gmenu2x->drawButton(&bg, "up", "", 5)-10))-10));
 
+	bg.convertToDisplayFormat();
+
 	uint firstRow = 0, rowsPerPage = 180/gmenu2x->font->getHeight();
 	stringstream ss;
 	ss << pages.size();