port: use a separate fb for fullscreen menu background

src/game/menugfx.c

@@ -31,7 +31,8 @@
 #define PXTOBYTES(val) ((val) * 2)
 
 #ifndef PLATFORM_N64
-static s32 g_MenuBlurFb = 0;
+static s32 g_MenuBlurFb = -1;
+static s32 g_MenuScreenFb = -1;
 static bool g_MenuBlurDone = false;
 #endif
 
@@ -124,8 +125,9 @@ void menugfxCreateBlur(void)
 
 	g_ScaleX = 1;
 #else
-	if (g_MenuBlurFb == 0) {
+	if (g_MenuBlurFb < 0) {
 		g_MenuBlurFb = videoCreateFramebuffer(BLURIMG_WIDTH, BLURIMG_HEIGHT, true, false);
+		g_MenuScreenFb = videoCreateFramebuffer(0, 0, false, true);
 	}
 	// copy full viewport and downscale to 40x30
 	videoCopyFramebuffer(g_MenuBlurFb, 0, -1, -1);
@@ -151,14 +153,13 @@ Gfx *menugfxRenderBgBlur(Gfx *gdl, u32 colour, s16 arg2, s16 arg3)
 #ifndef PLATFORM_N64
 	width = viGetWidth();
 	height = viGetHeight();
-	if (g_MenuBlurFb && !g_MenuBlurDone) {
+	if (g_MenuBlurFb >= 0 && !g_MenuBlurDone) {
 		// blit the small blur texture onto a screen-sized framebuffer while blurring it
 		g_MenuBlurDone = true;
-		g_BlurFbDirty = true;
 		gdl = bviewPrepareStaticRgba16(gdl, 0xffffffff, 0xff);
 		gDPSetTextureFilter(gdl++, G_TF_BLUR_EXT);
 		gDPSetFramebufferTextureEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, BLURIMG_WIDTH, g_MenuBlurFb);
-		gDPSetFramebufferTargetEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, width, g_BlurFb);
+		gDPSetFramebufferTargetEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, width, g_MenuScreenFb);
 		gSPImageRectangleEXT(gdl++, 0, 0, 0, 0, width << 2, height << 2, BLURIMG_WIDTH, BLURIMG_HEIGHT, 0, BLURIMG_WIDTH, BLURIMG_HEIGHT);
 		gDPSetFramebufferTargetEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, width, 0);
 		gDPSetFramebufferTextureEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, BLURIMG_WIDTH, 0);
@@ -177,7 +178,7 @@ Gfx *menugfxRenderBgBlur(Gfx *gdl, u32 colour, s16 arg2, s16 arg3)
 
 #ifndef PLATFORM_N64
 	// LoadTextureBlock will set up the sizes, but we'll use the framebuffer instead of g_BlurBuffer
-	gDPSetFramebufferTextureEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, width, g_BlurFb);
+	gDPSetFramebufferTextureEXT(gdl++, G_IM_FMT_RGBA, G_IM_SIZ_16b, width, g_MenuScreenFb);
 #endif
 
 	gDPPipeSync(gdl++);