From: Søren Sandmann Pedersen <s...@redhat.com>
This function can convert between any <= 32 bpp formats. Nothing uses
it yet.
---
pixman/pixman-access.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 100 insertions(+), 0 deletions(-)
diff --git a/pixman/pixman-access.c b/pixman/pixman-access.c
index 32c4d8b..2e9e536 100644
--- a/pixman/pixman-access.c
+++ b/pixman/pixman-access.c
@@ -86,6 +86,106 @@
((uint8_t *) ((bits) + offset0 + \
((stride) >> 1) * ((line) >> 1)))
+/* Misc. helpers */
+
+static force_inline void
+get_shifts (pixman_format_code_t format,
+ int *a,
+ int *r,
+ int *g,
+ int *b)
+{
+ switch (PIXMAN_FORMAT_TYPE (format))
+ {
+ case PIXMAN_TYPE_A:
+ *b = 0;
+ *g = 0;
+ *r = 0;
+ *a = 0;
+ break;
+
+ case PIXMAN_TYPE_ARGB:
+ *b = 0;
+ *g = *b + PIXMAN_FORMAT_B (format);
+ *r = *g + PIXMAN_FORMAT_G (format);
+ *a = *r + PIXMAN_FORMAT_R (format);
+ break;
+
+ case PIXMAN_TYPE_ABGR:
+ *r = 0;
+ *g = *r + PIXMAN_FORMAT_R (format);
+ *b = *g + PIXMAN_FORMAT_G (format);
+ *a = *b + PIXMAN_FORMAT_B (format);
+ break;
+
+ case PIXMAN_TYPE_BGRA:
+ /* With BGRA formats we start counting at the high end of the pixel */
+ *b = PIXMAN_FORMAT_BPP (format) - PIXMAN_FORMAT_B (format);
+ *g = *b - PIXMAN_FORMAT_B (format);
+ *r = *g - PIXMAN_FORMAT_G (format);
+ *a = *r - PIXMAN_FORMAT_R (format);
+ break;
+
+ case PIXMAN_TYPE_RGBA:
+ /* With BGRA formats we start counting at the high end of the pixel */
+ *r = PIXMAN_FORMAT_BPP (format) - PIXMAN_FORMAT_R (format);
+ *g = *r - PIXMAN_FORMAT_R (format);
+ *b = *g - PIXMAN_FORMAT_G (format);
+ *a = *b - PIXMAN_FORMAT_B (format);
+ break;
+
+ default:
+ assert (0);
+ break;
+ }
+}
+
+static force_inline uint32_t
+convert_channel (uint32_t pixel, uint32_t def_value,
+ int n_from_bits, int from_shift,
+ int n_to_bits, int to_shift)
+{
+ uint32_t v;
+
+ if (n_from_bits && n_to_bits)
+ v = unorm_to_unorm (pixel >> from_shift, n_from_bits, n_to_bits);
+ else if (n_to_bits)
+ v = def_value;
+ else
+ v = 0;
+
+ return (v & ((1 << n_to_bits) - 1)) << to_shift;
+}
+
+static force_inline uint32_t
+convert_pixel (pixman_format_code_t from, pixman_format_code_t to, uint32_t
pixel)
+{
+ int a_from_shift, r_from_shift, g_from_shift, b_from_shift;
+ int a_to_shift, r_to_shift, g_to_shift, b_to_shift;
+ uint32_t a, r, g, b;
+
+ get_shifts (from, &a_from_shift, &r_from_shift, &g_from_shift,
&b_from_shift);
+ get_shifts (to, &a_to_shift, &r_to_shift, &g_to_shift, &b_to_shift);
+
+ a = convert_channel (pixel, ~0,
+ PIXMAN_FORMAT_A (from), a_from_shift,
+ PIXMAN_FORMAT_A (to), a_to_shift);
+
+ r = convert_channel (pixel, 0,
+ PIXMAN_FORMAT_R (from), r_from_shift,
+ PIXMAN_FORMAT_R (to), r_to_shift);
+
+ g = convert_channel (pixel, 0,
+ PIXMAN_FORMAT_G (from), g_from_shift,
+ PIXMAN_FORMAT_G (to), g_to_shift);
+
+ b = convert_channel (pixel, 0,
+ PIXMAN_FORMAT_B (from), b_from_shift,
+ PIXMAN_FORMAT_B (to), b_to_shift);
+
+ return a | r | g | b;
+}
+
/********************************** Fetch ************************************/
static void
--
1.7.4
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