[cogl/wip/pixel-format-2101010: 9/14] Add 30-bit color depth pixel formats X101010 and 2101010

[Robert Bragg <rbragg src gnome org>]

commit 28e899642a3070abd442ff4ed1d665d8bf391c95
Author: Damien Leone <dleone nvidia com>
Date:   Mon Nov 21 15:39:49 2011 -0800

    Add 30-bit color depth pixel formats X101010 and 2101010
    
    30-bit color depth formats are defined by using value 13 in the least
    significant nibble of the pixel format enumeration. This nibble
    encodes bytes-per-pixel and byte alignment.
    
    The _cogl_pixel_format_get_bytes_per_pixl() function is updated
    accordingly to support these new formats.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=660188
    
    edit: dropped the X101010 formats but also added 1010102 formats since
    Cogl avoids exposing any padded formats and leaves it to applications to
    consider the A component to be padding as needed. -- Robert Bragg
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 cogl/cogl-types.h |   20 +++++++++++++++++++-
 cogl/cogl.c       |   35 ++++++++++++++++++++++++-----------
 2 files changed, 43 insertions(+), 12 deletions(-)
---
diff --git a/cogl/cogl-types.h b/cogl/cogl-types.h
index 96a44e1..3abd302 100644
--- a/cogl/cogl-types.h
+++ b/cogl/cogl-types.h
@@ -183,12 +183,20 @@ typedef struct _CoglTextureVertex       CoglTextureVertex;
  * @COGL_PIXEL_FORMAT_BGRA_8888: BGRA, 32 bits
  * @COGL_PIXEL_FORMAT_ARGB_8888: ARGB, 32 bits
  * @COGL_PIXEL_FORMAT_ABGR_8888: ABGR, 32 bits
+ * @COGL_PIXEL_FORMAT_RGBA_1010102 : RGBA, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_BGRA_1010102 : BGRA, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_ARGB_2101010 : ARGB, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_ABGR_2101010 : ABGR, 32 bits, 10 bpc
  * @COGL_PIXEL_FORMAT_RGBA_8888_PRE: Premultiplied RGBA, 32 bits
  * @COGL_PIXEL_FORMAT_BGRA_8888_PRE: Premultiplied BGRA, 32 bits
  * @COGL_PIXEL_FORMAT_ARGB_8888_PRE: Premultiplied ARGB, 32 bits
  * @COGL_PIXEL_FORMAT_ABGR_8888_PRE: Premultiplied ABGR, 32 bits
  * @COGL_PIXEL_FORMAT_RGBA_4444_PRE: Premultiplied RGBA, 16 bits
  * @COGL_PIXEL_FORMAT_RGBA_5551_PRE: Premultiplied RGBA, 16 bits
+ * @COGL_PIXEL_FORMAT_RGBA_1010102_PRE: Premultiplied RGBA, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_BGRA_1010102_PRE: Premultiplied BGRA, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_ARGB_2101010_PRE: Premultiplied ARGB, 32 bits, 10 bpc
+ * @COGL_PIXEL_FORMAT_ABGR_2101010_PRE: Premultiplied ABGR, 32 bits, 10 bpc
  *
  * Pixel formats used by COGL. For the formats with a byte per
  * component, the order of the components specify the order in
@@ -228,12 +236,22 @@ typedef enum { /*< prefix=COGL_PIXEL_FORMAT >*/
   COGL_PIXEL_FORMAT_ARGB_8888     = (3 | COGL_A_BIT | COGL_AFIRST_BIT),
   COGL_PIXEL_FORMAT_ABGR_8888     = (3 | COGL_A_BIT | COGL_BGR_BIT | COGL_AFIRST_BIT),
 
+  COGL_PIXEL_FORMAT_RGBA_1010102  = (13 | COGL_A_BIT),
+  COGL_PIXEL_FORMAT_BGRA_1010102  = (13 | COGL_A_BIT | COGL_BGR_BIT),
+  COGL_PIXEL_FORMAT_ARGB_2101010  = (13 | COGL_A_BIT | COGL_AFIRST_BIT),
+  COGL_PIXEL_FORMAT_ABGR_2101010  = (13 | COGL_A_BIT | COGL_BGR_BIT | COGL_AFIRST_BIT),
+
   COGL_PIXEL_FORMAT_RGBA_8888_PRE = (3 | COGL_A_BIT | COGL_PREMULT_BIT),
   COGL_PIXEL_FORMAT_BGRA_8888_PRE = (3 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_BGR_BIT),
   COGL_PIXEL_FORMAT_ARGB_8888_PRE = (3 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_AFIRST_BIT),
   COGL_PIXEL_FORMAT_ABGR_8888_PRE = (3 | COGL_A_BIT | COGL_PREMULT_BIT | COGL_BGR_BIT | COGL_AFIRST_BIT),
   COGL_PIXEL_FORMAT_RGBA_4444_PRE = (COGL_PIXEL_FORMAT_RGBA_4444 | COGL_A_BIT | COGL_PREMULT_BIT),
-  COGL_PIXEL_FORMAT_RGBA_5551_PRE = (COGL_PIXEL_FORMAT_RGBA_5551 | COGL_A_BIT | COGL_PREMULT_BIT)
+  COGL_PIXEL_FORMAT_RGBA_5551_PRE = (COGL_PIXEL_FORMAT_RGBA_5551 | COGL_A_BIT | COGL_PREMULT_BIT),
+
+  COGL_PIXEL_FORMAT_RGBA_1010102_PRE = (COGL_PIXEL_FORMAT_RGBA_1010102 | COGL_PREMULT_BIT),
+  COGL_PIXEL_FORMAT_BGRA_1010102_PRE = (COGL_PIXEL_FORMAT_BGRA_1010102 | COGL_PREMULT_BIT),
+  COGL_PIXEL_FORMAT_ARGB_2101010_PRE = (COGL_PIXEL_FORMAT_ARGB_2101010 | COGL_PREMULT_BIT),
+  COGL_PIXEL_FORMAT_ABGR_2101010_PRE = (COGL_PIXEL_FORMAT_ABGR_2101010 | COGL_PREMULT_BIT)
 } CoglPixelFormat;
 
 /**
diff --git a/cogl/cogl.c b/cogl/cogl.c
index 28ab146..deffacc 100644
--- a/cogl/cogl.c
+++ b/cogl/cogl.c
@@ -1006,20 +1006,33 @@ _cogl_init (void)
     }
 }
 
+/*
+ * Returns the number of bytes-per-pixel of a given format. The bpp
+ * can be extracted from the least significant nibble of the pixel
+ * format (see CoglPixelFormat).
+ *
+ * The mapping is the following (see discussion on bug #660188):
+ *
+ * 0     = undefined
+ * 1, 8  = 1 bpp (e.g. A_8, G_8)
+ * 2     = 3 bpp, aligned (e.g. 888)
+ * 3     = 4 bpp, aligned (e.g. 8888)
+ * 4-6   = 2 bpp, not aligned (e.g. 565, 4444, 5551)
+ * 7     = undefined yuv
+ * 9     = 2 bpp, aligned
+ * 10     = undefined
+ * 11     = undefined
+ * 12    = 3 bpp, not aligned
+ * 13    = 4 bpp, not aligned (e.g. 2101010)
+ * 14-15 = undefined
+ */
 int
 _cogl_pixel_format_get_bytes_per_pixel (CoglPixelFormat format)
 {
-  int bpp_lut[] = {
-    0, /* invalid  */
-    1, /* A_8      */
-    3, /* 888      */
-    4, /* 8888     */
-    2, /* 565      */
-    2, /* 4444     */
-    2, /* 5551     */
-    2, /* YUV      */
-    1  /* G_8      */
-  };
+  int bpp_lut[] = { 0, 1, 3, 4,
+                    2, 2, 2, 0,
+                    1, 2, 0, 0,
+                    3, 4, 0, 0 };
 
   return bpp_lut [format & 0xf];
 }