Add screenshot option for sdl backends, patch #590233

svn-id: r9821

backends/sdl/sdl-common.cpp

@@ -554,6 +554,25 @@ bool OSystem_SDL_Common::poll_event(Event *event) {
 				break;
 			}
 
+			if (b == KBD_ALT && ev.key.keysym.sym == 's') {
+				char filename[20];
+
+				for (int n = 0;; n++) {
+					SDL_RWops *file;
+
+					sprintf(filename, "scummvm%05d.bmp", n);
+					file = SDL_RWFromFile(filename, "r");
+					if (!file)
+						break;
+					SDL_RWclose(file);
+				}
+				if (save_screenshot(filename))
+					printf("Saved '%s'\n", filename);
+				else
+					printf("Could not save screenshot!\n");
+				break;
+			}
+
 #ifdef MACOSX
 			// On Macintosh', Cmd-Q quits
 			if ((ev.key.keysym.mod & KMOD_META) && ev.key.keysym.sym=='q') {

backends/sdl/sdl-common.h

@@ -225,6 +225,8 @@ protected:
 	virtual void load_gfx_mode() = 0;
 	virtual void unload_gfx_mode() = 0;
 
+	virtual bool save_screenshot(const char *filename) = 0;
+
 	void setup_icon();
 	void kbd_mouse();
 	void init_joystick() { _joystick = SDL_JoystickOpen(0); }

backends/sdl/sdl.cpp

@@ -42,6 +42,7 @@ protected:
 
 	virtual void load_gfx_mode();
 	virtual void unload_gfx_mode();
+	virtual bool save_screenshot(const char *filename);
 	void hotswap_gfx_mode();
 };
 
@@ -376,3 +377,10 @@ uint32 OSystem_SDL::property(int param, Property *value) {
 	return OSystem_SDL_Common::property(param, value);
 }
 
+bool OSystem_SDL::save_screenshot(const char *filename) {
+	assert(_hwscreen != NULL);
+
+	StackLock lock(_graphicsMutex, this);	// Lock the mutex until this function ends
+	SDL_SaveBMP(_hwscreen, filename);
+	return true;
+}

backends/sdl/sdl_gl.cpp

@@ -64,6 +64,7 @@ protected:
 	
 	virtual void load_gfx_mode();
 	virtual void unload_gfx_mode();
+	virtual bool save_screenshot(const char *filename);
 	void hotswap_gfx_mode();
 };
 
@@ -668,3 +669,15 @@ uint32 OSystem_SDL_OpenGL::property(int param, Property *value) {
 
 	return OSystem_SDL_Common::property(param, value);
 }
+
+bool OSystem_SDL_OpenGL::save_screenshot(const char *filename) {
+	// FIXME: I don't know how to do this yet.
+	if (_usingOpenGL)
+		return false;
+
+	StackLock lock(_graphicsMutex, this);	// Lock the mutex until this function ends
+
+	assert(_hwscreen != NULL);
+	SDL_SaveBMP(_hwscreen, filename);
+	return true;
+}