platform, add integer scaling for sdl windows

platform/common/menu_pico.c

@@ -104,24 +104,24 @@ static void make_bg(int no_scale, int from_screen)
 	if (!no_scale && g_menuscreen_w / w >= 2 && g_menuscreen_h / h >= 2)
 	{
 		int xf = g_menuscreen_w / w, yf = g_menuscreen_h / h;
-		int f = no_scale ? 1 : xf < yf ? xf : yf;
-		int xs = f * w, ys = f * h;
-		unsigned short t;
-		int i, j, k, l;
+		int f = no_scale ? 1 : xf < yf ? xf : yf, xs = f * w, ys = f * h;
+		int x = (g_menuscreen_w - xs)/2, y = (g_menuscreen_h - ys)/2;
+		uint16_t *p = (uint16_t *)g_menubg_ptr;
+		uint16_t *q = (uint16_t *)src;
 
-		x = (g_menuscreen_w - xs)/2, y = (g_menuscreen_h - ys)/2;
-		dst = (short *)g_menubg_ptr + y * g_menuscreen_w + x;
+		int i, j, k, l;
+		p += y * g_menuscreen_pp + x;
 		for (i = 0; i < h; i++) {
-			for (j = 0; j < w; j++, src++) {
-				t = (PXMASKH(*src,1)>>1) - (PXMASKH(*src,3)>>3);
+			for (j = 0; j < w; j++, q++) {
+				uint16_t t = (PXMASKH(*q,1)>>1) - (PXMASKH(*q,3)>>3);
 				for (l = 0; l < f; l++)
-					*dst++ = t;
+					*p++ = t;
 			}
-			src += pp - w;
-			dst += g_menuscreen_w - xs;
+			p += g_menuscreen_pp - xs;
+			q += pp - w;
 			for (k = 1; k < f; k++) {
-				memcpy(dst, dst-g_menuscreen_w, g_menuscreen_w*2);
-				dst += g_menuscreen_w;
+				memcpy(p, p-g_menuscreen_pp, g_menuscreen_w*2);
+				p += g_menuscreen_pp;
 			}
 		}
 		return;

platform/common/plat_sdl.c

@@ -174,6 +174,29 @@ void rgb565_to_uyvy(void *d, const void *s, int w, int h, int pitch, int dpitch,
   }
 }
 
+void copy_intscale(void *dst, int w, int h, int pp, void *src, int sw, int sh, int spp)
+{
+	int xf = w / sw, yf = h / sh;
+	int f = xf < yf ? xf : yf, xs = f * sw, ys = f * sh;
+	int x = (w - xs)/2, y = (h - ys)/2;
+	uint16_t *p = (uint16_t *)dst;
+	uint16_t *q = (uint16_t *)src;
+
+	int i, j, k, l;
+	p += y * pp + x;
+	for (i = 0; i < sh; i++) {
+		for (j = 0; j < sw; j++, q++)
+			for (l = 0; l < f; l++)
+				*p++ = *q;
+		p += pp - xs;
+		q += spp - sw;
+		for (k = 1; k < f; k++) {
+			memcpy(p, p-pp, w*2);
+			p += pp;
+		}
+	}
+}
+
 static int clear_buf_cnt, clear_stat_cnt;
 
 static void resize_buffers(void)
@@ -190,17 +213,12 @@ void plat_video_set_size(int w, int h)
 {
 	if (area.w != w || area.h != h) {
 		area = (struct area) { w, h };
-		if (plat_sdl_change_video_mode(w, h, 0) < 0) {
-			// failed, revert to original resolution
-			area = (struct area) { g_screen_width,g_screen_height };
-			plat_sdl_change_video_mode(g_screen_width, g_screen_height, 0);
-		}
-		if (!plat_sdl_overlay && !plat_sdl_gl_active) {
-			g_screen_width = plat_sdl_screen->w;
-			g_screen_height = plat_sdl_screen->h;
-			g_screen_ppitch = plat_sdl_screen->pitch/2;
-			g_screen_ptr = plat_sdl_screen->pixels;
-		} else {
+		if (plat_sdl_overlay || plat_sdl_gl_active) {
+			if (plat_sdl_change_video_mode(w, h, 0) < 0) {
+				// failed, revert to original resolution
+				area = (struct area) { g_screen_width,g_screen_height };
+				plat_sdl_change_video_mode(g_screen_width, g_screen_height, 0);
+			}
 			g_screen_width = w;
 			g_screen_height = h;
 			g_screen_ppitch = w;
@@ -236,15 +254,13 @@ void plat_video_flip(void)
 		gl_flip(shadow_fb, g_screen_ppitch, g_screen_height);
 	}
 	else {
-		if (SDL_MUSTLOCK(plat_sdl_screen)) {
+		copy_intscale(plat_sdl_screen->pixels, plat_sdl_screen->w, plat_sdl_screen->h, plat_sdl_screen->pitch/2, shadow_fb, 320, 240, 320);
+		if (SDL_MUSTLOCK(plat_sdl_screen))
 			SDL_UnlockSurface(plat_sdl_screen);
-			SDL_Flip(plat_sdl_screen);
+		SDL_Flip(plat_sdl_screen);
+		if (SDL_MUSTLOCK(plat_sdl_screen))
 			SDL_LockSurface(plat_sdl_screen);
-		} else
-			SDL_Flip(plat_sdl_screen);
-		g_screen_ppitch = plat_sdl_screen->pitch/2;
-		g_screen_ptr = plat_sdl_screen->pixels;
-		plat_video_set_buffer(g_screen_ptr);
+
 		if (clear_buf_cnt) {
 			memset(g_screen_ptr, 0, plat_sdl_screen->pitch*plat_sdl_screen->h);
 			clear_buf_cnt--;
@@ -356,17 +372,17 @@ void plat_video_loop_prepare(void)
 		}
 		g_screen_ppitch = g_screen_width;
 		g_screen_ptr = shadow_fb;
+		plat_video_set_size(g_screen_width, g_screen_height);
 	}
 	else {
-		g_screen_width = plat_sdl_screen->w;
-		g_screen_height = plat_sdl_screen->h;
-		g_screen_ppitch = plat_sdl_screen->pitch/2;
+		g_screen_width = 320;
+		g_screen_height = 240;
+		g_screen_ppitch = 320;
 		if (SDL_MUSTLOCK(plat_sdl_screen))
 			SDL_LockSurface(plat_sdl_screen);
-		g_screen_ptr = plat_sdl_screen->pixels;
+		g_screen_ptr = shadow_fb;
 	}
 
-	plat_video_set_size(g_screen_width, g_screen_height);
 	plat_video_set_buffer(g_screen_ptr);
 }