Engine: reimplemented fade effects outside of gfx drivers

Reimplemented each effect in screen.cpp, with a set of screen_effect_*() functions as transition "interface". Bring them to certain level of consistency in how they render and update frame.
Removed FadeIn(), FadeOut() and BoxOutEffect() methods from IGraphicsDriver, and respective implementations.
Removed redundant callbacks from gfx drivers.
Mark GameState.no_hicolor_fadein flag as deprecated, as it's purely an optimization, and should perhaps be a part of engine config rather than a part of script API.

Engine/ac/draw.cpp

@@ -677,7 +677,6 @@ void init_draw_method()
 
     if (drawstate.SoftwareRender)
     {
-        drawstate.SoftwareRender = true;
         drawstate.WalkBehindMethod = DrawOverCharSprite;
     }
     else
@@ -1197,12 +1196,6 @@ void clear_letterbox_borders()
     gfxDriver->ClearRectangle(0, viewport.Bottom + 1, game.GetGameRes().Width - 1, game.GetGameRes().Height - 1, nullptr);
 }
 
-void draw_game_screen_callback()
-{
-    construct_game_scene(true);
-    construct_game_screen_overlay(false);
-}
-
 void putpixel_compensate (Bitmap *ds, int xx,int yy, int col) {
     if ((ds->GetColorDepth() == 32) && (col != 0)) {
         // ensure the alpha channel is preserved if it has one

Engine/ac/draw.h

@@ -136,8 +136,6 @@ void draw_gui_sprite(Common::Bitmap *ds, bool use_alpha, int xpos, int ypos,
 
 // Render game on screen
 void render_to_screen();
-// Callbacks for the graphics driver
-void draw_game_screen_callback();
 void GfxDriverOnInitCallback(void *data);
 bool GfxDriverSpriteEvtCallback(int evt, int data);
 void putpixel_compensate (Common::Bitmap *g, int xx,int yy, int col);

Engine/ac/event.cpp

@@ -49,10 +49,11 @@ extern GameState play;
 extern RGB palette[256];
 extern IGraphicsDriver *gfxDriver;
 extern AGSPlatformDriver *platform;
-extern RGB old_palette[256];
 extern int displayed_room;
 extern ScriptHotspot scrHotspot[MAX_ROOM_HOTSPOTS];
 extern CCHotspot ccDynamicHotspot;
+// FIXME: refactor further to get rid of this extern, maybe move part of the code to screen.cpp?
+extern std::unique_ptr<Bitmap> saved_viewport_bitmap;
 
 int in_enters_screen=0,done_es_error = 0;
 int in_leaves_screen = -1;
@@ -204,7 +205,11 @@ void process_event(const EventHappened *evp) {
         if ((evp->data1 == EVB_ROOM) && (evp->data3 == EVROM_BEFOREFADEIN))
             in_enters_screen --;
     }
-    else if (evp->type==EV_FADEIN) {
+    else if (evp->type==EV_FADEIN)
+    {
+        // TODO: move most of this code into a separate function,
+        // see current_fade_out_effect() for example
+
         debug_script_log("Transition-in in room %d", displayed_room);
         // if they change the transition type before the fadein, make
         // sure the screen doesn't freeze up
@@ -232,131 +237,42 @@ void process_event(const EventHappened *evp) {
             // transition type was not crossfade/dissolve when the screen faded out,
             // but it is now when the screen fades in (Eg. a save game was restored
             // with a different setting). Therefore just fade normally.
-            fadeout_impl(5);
+            screen_effect_fade(false, 5);
             theTransition = FADE_NORMAL;
         }
 
 		// TODO: use normal coordinates instead of "native_size" and multiply_up_*?
         const Rect &viewport = play.GetMainViewport();
 
         if ((theTransition == FADE_INSTANT) || ignore_transition)
+        {
             set_palette_range(palette, 0, 255, 0);
+        }
         else if (theTransition == FADE_NORMAL)
         {
-            fadein_impl(palette, 5);
+            screen_effect_fade(true, 5);
         }
         else if (theTransition == FADE_BOXOUT) 
         {
-            if (!gfxDriver->UsesMemoryBackBuffer())
-            {
-                gfxDriver->BoxOutEffect(false, get_fixed_pixel_size(16), 1000 / GetGameSpeed());
-            }
-            else
-            {
-                // First of all we render the game once again and save backbuffer from further editing.
-                // We put temporary bitmap as a new backbuffer for the transition period, and
-                // will be drawing saved image of the game over to that backbuffer, simulating "box-out".
-                set_palette_range(palette, 0, 255, 0);
-                construct_game_scene(true);
-                construct_game_screen_overlay(false);
-                gfxDriver->RenderToBackBuffer();
-                Bitmap *saved_backbuf = gfxDriver->GetMemoryBackBuffer();
-                Bitmap *temp_scr = new Bitmap(saved_backbuf->GetWidth(), saved_backbuf->GetHeight(), saved_backbuf->GetColorDepth());
-                gfxDriver->SetMemoryBackBuffer(temp_scr);
-                temp_scr->Clear();
-                render_to_screen();
-
-                const int speed = get_fixed_pixel_size(16);
-                const int yspeed = viewport.GetHeight() / (viewport.GetWidth() / speed);
-                int boxwid = speed, boxhit = yspeed;
-                while (boxwid < temp_scr->GetWidth())
-                {
-                    boxwid += speed;
-                    boxhit += yspeed;
-                    boxwid = Math::Clamp(boxwid, 0, viewport.GetWidth());
-                    boxhit = Math::Clamp(boxhit, 0, viewport.GetHeight());
-                    int lxp = viewport.GetWidth() / 2 - boxwid / 2;
-                    int lyp = viewport.GetHeight() / 2 - boxhit / 2;
-                    temp_scr->Blit(saved_backbuf, lxp, lyp, lxp, lyp, 
-                        boxwid, boxhit);
-                    render_to_screen();
-                    WaitForNextFrame();
-                }
-                gfxDriver->SetMemoryBackBuffer(saved_backbuf);
-            }
-            play.screen_is_faded_out = 0;
+            screen_effect_box(true, get_fixed_pixel_size(16));
         }
         else if (theTransition == FADE_CROSSFADE) 
         {
-            if (game.color_depth == 1)
-                quit("!Cannot use crossfade screen transition in 256-colour games");
-
-            IDriverDependantBitmap *ddb = prepare_screen_for_transition_in();
-            for (int alpha = 254; alpha > 0; alpha -= 16)
-            {
-                // do the crossfade
-                ddb->SetAlpha(alpha);
-                invalidate_screen();
-                construct_game_scene(true);
-                construct_game_screen_overlay(false);
-                // draw old screen on top while alpha > 16
-                if (alpha > 16)
-                {
-                    gfxDriver->BeginSpriteBatch(play.GetMainViewport(), SpriteTransform());
-                    gfxDriver->DrawSprite(0, 0, ddb);
-                    gfxDriver->EndSpriteBatch();
-                }
-                render_to_screen();
-                update_polled_stuff();
-                WaitForNextFrame();
-            }
-
-            delete saved_viewport_bitmap;
-            saved_viewport_bitmap = nullptr;
-            set_palette_range(palette, 0, 255, 0);
-            gfxDriver->DestroyDDB(ddb);
+            screen_effect_crossfade();
         }
-        else if (theTransition == FADE_DISSOLVE) {
-            int pattern[16]={0,4,14,9,5,11,2,8,10,3,12,7,15,6,13,1};
-            int aa,bb,cc;
-            RGB interpal[256];
-
-            IDriverDependantBitmap *ddb = prepare_screen_for_transition_in();
-            for (aa=0;aa<16;aa++) {
-                // merge the palette while dithering
-                if (game.color_depth == 1) 
-                {
-                    fade_interpolate(old_palette,palette,interpal,aa*4,0,255);
-                    set_palette_range(interpal, 0, 255, 0);
-                }
-                // do the dissolving
-                int maskCol = saved_viewport_bitmap->GetMaskColor();
-                for (bb=0;bb<viewport.GetWidth();bb+=4) {
-                    for (cc=0;cc<viewport.GetHeight();cc+=4) {
-                        saved_viewport_bitmap->PutPixel(bb+pattern[aa]/4, cc+pattern[aa]%4, maskCol);
-                    }
-                }
-                gfxDriver->UpdateDDBFromBitmap(ddb, saved_viewport_bitmap, false);
-                construct_game_scene(true);
-                construct_game_screen_overlay(false);
-                gfxDriver->BeginSpriteBatch(play.GetMainViewport(), SpriteTransform());
-                gfxDriver->DrawSprite(0, 0, ddb);
-                gfxDriver->EndSpriteBatch();
-                render_to_screen();
-                update_polled_stuff();
-                WaitForNextFrame();
-            }
-
-            delete saved_viewport_bitmap;
-            saved_viewport_bitmap = nullptr;
-            set_palette_range(palette, 0, 255, 0);
-            gfxDriver->DestroyDDB(ddb);
+        else if (theTransition == FADE_DISSOLVE)
+        {
+            screen_effect_dissolve();
         }
-
     }
-    else if (evp->type==EV_IFACECLICK)
+    else if (evp->type == EV_IFACECLICK)
+    {
         process_interface_click(evp->data1, evp->data2, evp->data3);
-    else quit("process_event: unknown event to process");
+    }
+    else
+    {
+        quit("process_event: unknown event to process");
+    }
 }
 
 

Engine/ac/gamestate.h

@@ -95,7 +95,7 @@ struct GameState
     int  used_inv_on = 0;       // inv item they clicked on
     int  no_textbg_when_voice = 0; // no textwindow bgrnd when voice speech is used
     int  max_dialogoption_width = 0; // max width of dialog options text window
-    int  no_hicolor_fadein = 0; // fade out but instant in for hi-color
+    int  no_hicolor_fadein = 0; // (DEPRECATED, lo-end optimization) fade out but instant in for hi-color
     int  bgspeech_game_speed = 0; // is background speech relative to game speed
     int  bgspeech_stay_on_display = 0; // whether to remove bg speech when DisplaySpeech is used
     int  unfactor_speech_from_textlength = 0; // remove "&10" when calculating time for text to stay

Engine/ac/global_screen.cpp

@@ -142,20 +142,10 @@ void FadeOut(int sppd) {
     // FIXME: we have to sync audio here explicitly, because FadeOut
     // does not call any game update function while it works
     sync_audio_playback();
-    fadeout_impl(sppd);
+    screen_effect_fade(false, sppd);
     sync_audio_playback();
 }
 
-void fadeout_impl(int spdd) {
-    if (play.screen_is_faded_out == 0)
-    {
-        gfxDriver->FadeOut(spdd, play.fade_to_red, play.fade_to_green, play.fade_to_blue);
-    }
-
-    if (game.color_depth > 1)
-        play.screen_is_faded_out = 1;
-}
-
 void SetScreenTransition(int newtrans) {
     if ((newtrans < 0) || (newtrans > FADE_LAST))
         quit("!SetScreenTransition: invalid transition type");
@@ -193,6 +183,6 @@ void FadeIn(int sppd) {
     // FIXME: we have to sync audio here explicitly, because FadeIn
     // does not call any game update function while it works
     sync_audio_playback();
-    fadein_impl(palette,sppd);
+    screen_effect_fade(true, sppd);
     sync_audio_playback();
 }