Video: add support for RGB/VGA output (#167)

* video: refactor magic register writes into named functions

* video: add generic RGB mode flag and allow re-configuring encoder

Previously, the encoder was configured only once during VIDEO_Init(),
and would not be re-configured when VIDEO_Configure(mode) was called.
Since we can switch from a non-RGB to an RGB mode, we need to be able
to reconfigure the encoder at configure-time. This commit extends the
mode-switching mechanism to also allow scheduling for encoder setting
changes at run-time.

Moreover, since there are more RGB video modes than EURGB60, we extend
the mode struct with a flag to indicate whether the mode is RGB or not
or not for easy internal use. Adding it to the VI_TVMODE enumeration
was also considered, but decided against since it would break the
VIDEO_GetCurrentTvMode() ABI for EURGB60 modes.

* video: fix encoder setup for RGB video modes

* video: add RGB 480p progressive mode

This mode was used in the Wii arcade board (RVA-001). Detecting it
for use with VIDEO_GetPreferredMode() would require some logic
involving reading /title/00000001/00000002/data/RVA.txt since that
is the main method used to detect the board instead of SC.
Due to the relative clumsiness involved I decided to leave it out
for now.

Author: shizmob

gc/ogc/gx_struct.h

@@ -65,6 +65,7 @@ typedef struct _gx_rmodeobj {
 	u16 viWidth;
 	u16 viHeight;
 	u32  xfbMode;
+	u8  rgb;
 	u8  field_rendering;
 	u8  aa;
 	u8  sample_pattern[12][2];

gc/ogc/video_types.h

@@ -107,6 +107,9 @@ distribution.
 #define VI_MAX_WIDTH_EURGB60        VI_MAX_WIDTH_NTSC
 #define VI_MAX_HEIGHT_EURGB60       VI_MAX_HEIGHT_NTSC
 
+#define VI_MAX_WIDTH_DEBUG          VI_MAX_WIDTH_NTSC
+#define VI_MAX_HEIGHT_DEBUG         VI_MAX_HEIGHT_NTSC
+
 #define VIDEO_PadFramebufferWidth(width)     ((u16)(((u16)(width) + 15) & ~15))			/*!< macro to pad the width to a multiple of 16 */
 
 /*!
@@ -133,6 +136,7 @@ distribution.
 #define VI_TVMODE_MPAL_PROG			VI_TVMODE(VI_MPAL,        VI_PROGRESSIVE)
 
 #define VI_TVMODE_DEBUG_INT			VI_TVMODE(VI_DEBUG,       VI_INTERLACE)
+#define VI_TVMODE_DEBUG_PROG        VI_TVMODE(VI_DEBUG,       VI_PROGRESSIVE)
 
 #define VI_TVMODE_DEBUG_PAL_INT		VI_TVMODE(VI_DEBUG_PAL,   VI_INTERLACE)
 #define VI_TVMODE_DEBUG_PAL_DS		VI_TVMODE(VI_DEBUG_PAL,   VI_NON_INTERLACE)
@@ -191,6 +195,9 @@ extern GXRModeObj TVEurgb60Hz480IntAa;
 extern GXRModeObj TVEurgb60Hz480Prog;
 extern GXRModeObj TVEurgb60Hz480ProgSoft;
 extern GXRModeObj TVEurgb60Hz480ProgAa;
+extern GXRModeObj TVRgb480Prog;             /*!< Video and render mode configuration for 480 lines,progressive,singlefield RGB mode */
+extern GXRModeObj TVRgb480ProgSoft;
+extern GXRModeObj TVRgb480ProgAa;
 
 /*!
  * @}