Scanline screen effect

It can be activated by the -scanline command line flag, system3.ini, or
the menubar on Windows. Effective especially for games with 200-line
screen mode, such as Little Vampire and Intruder.

src/config.cpp

@@ -104,6 +104,8 @@ Config::Config(int argc, char *argv[])
 			title = argv[++i];
 		else if (strcmp(argv[i], "-timiditycfg") == 0)
 			timidity_cfg = argv[++i];
+		else if (strcmp(argv[i], "-scanline") == 0)
+			scanline = true;
 	}
 }
 
@@ -158,6 +160,8 @@ void Config::load_ini()
 				title = val;
 			else if (!strcasecmp(key, "timiditycfg"))
 				timidity_cfg = normalize_path(val);
+			else if (!strcasecmp(key, "scanline"))
+				scanline = to_bool(val, lineno);
 			else
 				WARNING(INIFILENAME ":%d unknown key '%s'", lineno, key);
 		} else if (current_section == STRING) {

src/config.h

@@ -31,6 +31,7 @@ struct Config {
 	std::string timidity_cfg;
 	bool use_fm = false;
 	bool no_antialias = false;
+	bool scanline = false;
 
  private:
 	void load_ini();

src/sys/ags.cpp

@@ -36,6 +36,28 @@ static SDL_Surface* display_surface;
 	box[n].ey = y2; \
 }
 
+namespace {
+
+const uint32 SCANLINE_ALPHA = 0x38;  // 0-255
+
+SDL_Texture* create_scanline_texture(SDL_Renderer* renderer, int width, int height)
+{
+	SDL_Surface* sf = SDL_CreateRGBSurfaceWithFormat(0, width, height, 32, SDL_PIXELFORMAT_ARGB8888);
+	for (int y = 0; y < height; y++) {
+		uint32* p = surface_line(sf, y);
+		uint32 v = y % 2 ? (SCANLINE_ALPHA << 24) : 0;
+		for (int x = 0; x < width; x++) {
+			p[x] = v;
+		}
+	}
+	SDL_Texture* tx = SDL_CreateTextureFromSurface(renderer, sf);
+	SDL_SetTextureBlendMode(tx, SDL_BLENDMODE_BLEND);
+	SDL_FreeSurface(sf);
+	return tx;
+}
+
+} // namespace
+
 AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 {
 	// 画面サイズ
@@ -52,6 +74,7 @@ AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 	SDL_SetWindowSize(g_window, window_width, window_height);
 	SDL_RenderSetLogicalSize(g_renderer, window_width, window_height);
 	sdlTexture = SDL_CreateTexture(g_renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, screen_width, screen_height); // TOOD: pixelformat?
+	scanline_texture = NULL;
 
 	// DIBSection 8bpp * 3 (表, 裏, メニュー)
 	for(int i = 0; i < 3; i++) {
@@ -358,6 +381,8 @@ AGS::AGS(NACT* parent, const Config& config) : nact(parent), dirty(false)
 	// マウスカーソル
 	cursor_color = 15;
 	cursor_index = 0;
+
+	set_scanline_mode(config.scanline);
 }
 
 AGS::~AGS()
@@ -527,10 +552,26 @@ void AGS::update_screen()
 		SDL_SetRenderDrawColor(g_renderer, 0, 0, 0, 255);
 		SDL_SetRenderDrawBlendMode(g_renderer, SDL_BLENDMODE_NONE);
 	}
+	if (scanline_texture)
+		SDL_RenderCopy(g_renderer, scanline_texture, NULL, NULL);
 	SDL_RenderPresent(g_renderer);
 	dirty = false;
 }
 
+void AGS::set_scanline_mode(bool enable)
+{
+	if (enable && !scanline_texture) {
+		scanline_texture = create_scanline_texture(g_renderer, screen_width, screen_height);
+		dirty = true;
+		update_screen();
+	} else if (!enable && scanline_texture) {
+		SDL_DestroyTexture(scanline_texture);
+		scanline_texture = NULL;
+		dirty = true;
+		update_screen();
+	}
+}
+
 void AGS::save_screenshot(const char* path)
 {
 	SDL_Surface* sf = SDL_CreateRGBSurface(0, screen_width, screen_height, 32, 0, 0, 0, 0);
@@ -539,6 +580,14 @@ void AGS::save_screenshot(const char* path)
 	SDL_BlitSurface(hBmpDest, &r, sf, NULL);
 	SDL_LockSurface(hBmpDest);
 
+	if (scanline_texture) {
+		SDL_Renderer* renderer = SDL_CreateSoftwareRenderer(sf);
+		SDL_Texture *tx = create_scanline_texture(renderer, screen_width, screen_height);
+		SDL_RenderCopy(renderer, tx, NULL, NULL);
+		SDL_DestroyTexture(tx);
+		SDL_DestroyRenderer(renderer);
+	}
+
 	if (SDL_SaveBMP(sf, path) != 0) {
 		SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "system3",
 								 SDL_GetError(), g_window);

src/sys/ags.h

@@ -40,6 +40,7 @@ protected:
 	NACT* nact;
 private:
 	SDL_Texture* sdlTexture;
+	SDL_Texture* scanline_texture;
 
 	// Surface
 	SDL_Surface* hBmpScreen[3]; // 8bpp * 3 (表, 裏, メニュー)
@@ -128,6 +129,8 @@ public:
 	void select_cursor();
 	void translate_mouse_coords(int* x, int* y);
 
+	bool get_scanline_mode() const { return scanline_texture; }
+	void set_scanline_mode(bool enable);
 	void save_screenshot(const char* path);
 	int calculate_menu_max(int window);
 

src/win/nact_win.cpp

@@ -21,13 +21,15 @@ HWND get_hwnd(SDL_Window* window) {
 	return info.info.win.window;
 }
 
-void init_menu(bool mouse_move_enabled)
+void init_menu(bool mouse_move_enabled, bool scanline_enabled)
 {
 	HINSTANCE hinst = (HINSTANCE)GetModuleHandle(NULL);
 	HMENU hmenu = LoadMenu(hinst, MAKEINTRESOURCE(IDR_MENU1));
 	SetMenu(get_hwnd(g_window), hmenu);
 	if (mouse_move_enabled)
 		CheckMenuItem(hmenu, ID_OPTION_MOUSE_MOVE, MF_BYCOMMAND | MFS_CHECKED);
+	if (scanline_enabled)
+		CheckMenuItem(hmenu, ID_SCANLINE, MF_BYCOMMAND | MFS_CHECKED);
 }
 
 void init_console(int sys_ver)
@@ -129,7 +131,7 @@ void NACT::text_dialog()
 
 void NACT::platform_initialize()
 {
-	init_menu(mouse_move_enabled);
+	init_menu(mouse_move_enabled, config.scanline);
 	init_console(sys_ver);
 	SDL_EventState(SDL_SYSWMEVENT, SDL_ENABLE);
 }
@@ -188,6 +190,11 @@ bool NACT::handle_platform_event(const SDL_Event& e)
 			SDL_SetWindowFullscreen(g_window, SDL_WINDOW_FULLSCREEN_DESKTOP);
 			ags->flush_screen(true);
 			break;
+		case ID_SCANLINE:
+			ags->set_scanline_mode(!ags->get_scanline_mode());
+			CheckMenuItem(GetMenu(get_hwnd(g_window)), ID_SCANLINE, MF_BYCOMMAND |
+						  ags->get_scanline_mode() ? MFS_CHECKED : MFS_UNCHECKED);
+			break;
 		case ID_OPTION_MOUSE_MOVE:
 			mouse_move_enabled = !mouse_move_enabled;
 			CheckMenuItem(GetMenu(get_hwnd(g_window)), ID_OPTION_MOUSE_MOVE,

src/win/resource.h

@@ -24,6 +24,7 @@
 #define ID_EXIT                         40002
 #define ID_SCREEN_WINDOW                40010
 #define ID_SCREEN_FULL                  40011
+#define ID_SCANLINE                     40012
 #define ID_OPTION_MOUSE_MOVE            40020
 #define ID_OPTION_FM                    40021
 #define ID_OPTION_MIDI                  40022

src/win/resource.rc

@@ -97,6 +97,8 @@ BEGIN
     BEGIN
         MENUITEM "Window",                      ID_SCREEN_WINDOW
         MENUITEM "Fullscreen",                  ID_SCREEN_FULL
+        MENUITEM SEPARATOR
+        MENUITEM "Scanline effect",             ID_SCANLINE
     END
     POPUP "Option"
     BEGIN
@@ -153,6 +155,8 @@ BEGIN
     BEGIN
         MENUITEM "ウィンドウ",                  ID_SCREEN_WINDOW
         MENUITEM "フルスクリーン",              ID_SCREEN_FULL
+        MENUITEM SEPARATOR
+        MENUITEM "走査線エフェクト",            ID_SCANLINE
     END
     POPUP "オプション"
     BEGIN
@@ -209,6 +213,8 @@ BEGIN
     BEGIN
         MENUITEM "窗口化",                      ID_SCREEN_WINDOW
         MENUITEM "全屏化",                      ID_SCREEN_FULL
+        MENUITEM SEPARATOR
+        MENUITEM "Scanline effect",             ID_SCANLINE
     END
     POPUP "选项"
     BEGIN