[loader] Adjust the background image for widescreen.

If the system's widescreen setting is enabled, scale the background image
to 480x480 and draw it in the center of the screen. This makes it look
correct on widescreen displays. Also, fill the now-unused area with the
same color as the image's primary background color.

Optimized background.png to take up slightly less space.
(91,149 -> 90,813)

(cherry picked from commit e3d878d)

Conflicts:
	loader/source/global.c

loader/include/global.h

@@ -24,7 +24,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include <gctypes.h>
 #include <stdio.h>
 #include <ogc/ipc.h>
-#include "background_png.h"
 #include "Config.h"
 #include "grrlib.h"
 

loader/source/global.c

@@ -42,9 +42,15 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "dip.h"
 #include "unzip/unzip.h"
 
+// Background image.
+#include "background_png.h"
+
 GRRLIB_ttfFont *myFont;
 GRRLIB_texImg *background;
 GRRLIB_texImg *screen_buffer;
+bool bg_isWidescreen = false;
+static float bg_xScale = 1.0f;
+static int bg_xPos = 0;
 
 u32 POffset;
 
@@ -168,7 +174,11 @@ void unzip_data(const void *input, const u32 input_size,
 static void *font_ttf = NULL;
 static u32 font_ttf_size = 0;
 
-void Initialise()
+/**
+ * Initialize the loader.
+ * This also loads the background image.
+ */
+void Initialise(void)
 {
 	int i;
 	AUDIO_Init(NULL);
@@ -182,9 +192,31 @@ void Initialise()
 	myFont = GRRLIB_LoadTTF(font_ttf, font_ttf_size);
 	background = GRRLIB_LoadTexturePNG(background_png);
 	screen_buffer = GRRLIB_CreateEmptyTexture(rmode->fbWidth, rmode->efbHeight);
+
+	// Calculate the background image scale.
+	bg_isWidescreen = (CONF_GetAspectRatio() == CONF_ASPECT_16_9);
+	if (bg_isWidescreen)
+	{
+		// Widescreen. 0.75x scaling, 80px offset.
+		bg_xScale = 0.75f;
+		bg_xPos = 80;
+	}
+	else
+	{
+		// Standard screen. 1.0x scaling, 0px offset.
+		bg_xScale = 1.0f;
+		bg_xPos = 0;
+	}
+
 	for (i=0; i<255; i +=5) // Fade background image in from black screen
 	{
-		GRRLIB_DrawImg(0, 0, background, 0, 1, 1, RGBA(255, 255, 255, i)); // Opacity increases as i does
+		if (bg_isWidescreen)
+		{
+			// Clear the sides.
+			GRRLIB_Rectangle(0, 0, 80, 480, RGBA(222, 223, 224, i), true);
+			GRRLIB_Rectangle(80+480, 0, 80, 480, RGBA(222, 223, 224, i), true);
+		}
+		GRRLIB_DrawImg(bg_xPos, 0, background, 0, bg_xScale, 1, RGBA(255, 255, 255, i)); // Opacity increases as i does
 		GRRLIB_Render();
 	}
 	ClearScreen();
@@ -314,7 +346,13 @@ bool LoadNinCFG(void)
 
 inline void ClearScreen()
 {
-	GRRLIB_DrawImg(0, 0, background, 0, 1, 1, 0xFFFFFFFF);
+	if (bg_isWidescreen)
+	{
+		// Clear the sides.
+		GRRLIB_Rectangle(0, 0, 80, 480, RGBA(222, 223, 224, 255), true);
+		GRRLIB_Rectangle(80+480, 0, 80, 480, RGBA(222, 223, 224, 255), true);
+	}
+	GRRLIB_DrawImg(bg_xPos, 0, background, 0, bg_xScale, 1, RGBA(255, 255, 255, 255));
 }
 
 static inline char ascii(char s)