sdl: Remove usage of SDL_SoftStretch

SDL 2 lets us take advantage of a fixed logical resolution,
where the renderer scales content up or down automatically.

Relative mouse motion is also affected by renderer scaling
by default (see SDL_HINT_MOUSE_RELATIVE_SCALING).

If window zoom has been enabled from the command line,
set scaling quality to "nearest pixel sampling" instead
of "best" to allow pixel peeping.

Change-Id: I4e5c19d36b55c985c26ac5ae64c4a6b8dd9b308d

firmware/target/hosted/sdl/button-sdl.c

@@ -284,8 +284,8 @@ static bool event_handler(SDL_Event *event)
     case SDL_MOUSEMOTION:
         if (event->motion.state & SDL_BUTTON(1))
         {
-            int x = event->motion.x / display_zoom;
+            int x = event->motion.x;
-            int y = event->motion.y / display_zoom;
+            int y = event->motion.y;
             touchscreen_event(x, y);
         }
         break;
@@ -295,8 +295,6 @@ static bool event_handler(SDL_Event *event)
     case SDL_MOUSEBUTTONDOWN:
     {
         SDL_MouseButtonEvent *mev = &event->button;
-        mev->x /= display_zoom;
-        mev->y /= display_zoom;
         mouse_event(mev, event->type == SDL_MOUSEBUTTONUP);
         break;
     }

firmware/target/hosted/sdl/lcd-bitmap.c

@@ -183,15 +183,11 @@ void sim_backlight(int value)
 void lcd_init_device(void)
 {
 #if LCD_DEPTH >= 16
-    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
+    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, SIM_LCD_WIDTH, SIM_LCD_HEIGHT,
-                                       SIM_LCD_WIDTH * display_zoom,
-                                       SIM_LCD_HEIGHT * display_zoom,
                                        LCD_DEPTH, 0, 0, 0, 0);
     SDL_SetSurfaceBlendMode(lcd_surface, SDL_BLENDMODE_BLEND);
 #elif LCD_DEPTH <= 8
-    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
+    lcd_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, SIM_LCD_WIDTH, SIM_LCD_HEIGHT,
-                                       SIM_LCD_WIDTH * display_zoom,
-                                       SIM_LCD_HEIGHT * display_zoom,
                                        8, 0, 0, 0, 0);
 
 #ifdef HAVE_BACKLIGHT

firmware/target/hosted/sdl/lcd-remote-bitmap.c

@@ -102,10 +102,8 @@ void lcd_remote_init_device(void)
 {
     if (!showremote)
         return;
-    remote_surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
+    remote_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, LCD_REMOTE_WIDTH,
-                                          LCD_REMOTE_WIDTH * display_zoom,
+                                          LCD_REMOTE_HEIGHT, 8, 0, 0, 0, 0);
-                                          LCD_REMOTE_HEIGHT * display_zoom,
-                                          8, 0, 0, 0, 0);
 
     sdl_set_gradient(remote_surface, &remote_bl_color_dark,
                      &remote_bl_color_bright, 0, NUM_SHADES);

firmware/target/hosted/sdl/lcd-sdl.c

@@ -26,7 +26,6 @@
 #include "misc.h"
 
 double display_zoom = 1;
-
 static bool window_needs_update;
 
 void sdl_get_window_dimensions(int *w, int *h)
@@ -138,18 +137,8 @@ void sdl_update_rect(SDL_Surface *surface, int x_start, int y_start, int width,
     src.w = width;
     src.h = height;
 
-    if (display_zoom == 1) {
     dest = src;
     SDL_BlitSurface(lcd, &src, surface, &dest);
-    } else {
-        /* Note: SDL_SoftStretch is currently marked as DO NOT USE
-           but there are no real alternatives for efficent zooming. */
-        dest.x = src.x * display_zoom;
-        dest.y = src.y * display_zoom;
-        dest.w = src.w * display_zoom;
-        dest.h = src.h * display_zoom;
-        SDL_SoftStretch(lcd, &src, surface, &dest);
-    }
     SDL_FreeSurface(lcd);
 #else
     int x, y;
@@ -163,26 +152,26 @@ void sdl_update_rect(SDL_Surface *surface, int x_start, int y_start, int width,
     if(ymax >= max_y)
         ymax = max_y;
 
-    dest.w = display_zoom;
+    dest.w = 1;
-    dest.h = display_zoom;
+    dest.h = 1;
 
     for (x = x_start; x < xmax; x++) {
-        dest.x = x * display_zoom;
+        dest.x = x;
 
 #ifdef HAVE_LCD_SPLIT
         for (y = y_start; y < MIN(ymax, LCD_SPLIT_POS); y++) {
-            dest.y = y * display_zoom;
+            dest.y = y;
 
             SDL_FillRect(surface, &dest, (Uint32)(getpixel(x, y) | 0x80));
         }
         for (y = MAX(y_start, LCD_SPLIT_POS); y < ymax; y++) {
-            dest.y = (y + LCD_SPLIT_LINES) * display_zoom ;
+            dest.y = (y + LCD_SPLIT_LINES) ;
 
             SDL_FillRect(surface, &dest, (Uint32)getpixel(x, y));
         }
 #else
         for (y = y_start; y < ymax; y++) {
-            dest.y = y * display_zoom;
+            dest.y = y;
 
             SDL_FillRect(surface, &dest, (Uint32)getpixel(x, y));
         }
@@ -199,11 +188,8 @@ void sdl_gui_update(SDL_Surface *surface, int x_start, int y_start, int width,
     if (y_start + height > max_y)
         height = max_y - y_start;
 
-    SDL_Rect src = {x_start * display_zoom, y_start * display_zoom,
+    SDL_Rect src = {x_start, y_start, width, height};
-                    width * display_zoom, height * display_zoom};
+    SDL_Rect dest= {ui_x + x_start, ui_y + y_start, width, height};
-    SDL_Rect dest= {(ui_x + x_start) * display_zoom,
-                    (ui_y + y_start) * display_zoom,
-                    width * display_zoom, height * display_zoom};
 
     uint8_t alpha;
     if (SDL_GetSurfaceAlphaMod(surface,&alpha) == 0 && alpha < 255)

firmware/target/hosted/sdl/system-sdl.c

@@ -112,10 +112,10 @@ static void sdl_window_setup(void)
     if ((sdlRenderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC)) == NULL)
         panicf("%s", SDL_GetError());
 
-    SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "linear");
+    SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, display_zoom == 1 ? "best" : "nearest");
-    SDL_RenderSetLogicalSize(sdlRenderer, width * display_zoom, height * display_zoom);
+    SDL_RenderSetLogicalSize(sdlRenderer, width, height);
 
-    if ((gui_surface = SDL_CreateRGBSurface(0, width * display_zoom, height * display_zoom, depth,
+    if ((gui_surface = SDL_CreateRGBSurface(0, width, height, depth,
                                        0, 0, 0, 0)) == NULL)
         panicf("%s", SDL_GetError());