diff options
Diffstat (limited to 'pixman/pixman/pixman-utils.c')
| -rw-r--r-- | pixman/pixman/pixman-utils.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/pixman/pixman/pixman-utils.c b/pixman/pixman/pixman-utils.c index 2ec2594e1..93c061ad2 100644 --- a/pixman/pixman/pixman-utils.c +++ b/pixman/pixman/pixman-utils.c @@ -183,6 +183,22 @@ pixman_malloc_abc (unsigned int a, return malloc (a * b * c); } +static void +unorm_to_unorm_params (int in_width, int out_width, uint32_t *factor, int *shift) +{ + int w = 0; + + *factor = 0; + while (in_width != 0 && w < out_width) + { + *factor |= 1 << w; + w += in_width; + } + + /* Did we generate too many bits? */ + *shift = w - out_width; +} + /* * This function expands images from ARGB8 format to ARGB16. To preserve * precision, it needs to know the original source format. For example, if the @@ -212,8 +228,15 @@ pixman_expand (uint64_t * dst, r_mask = ~(~0 << r_size), g_mask = ~(~0 << g_size), b_mask = ~(~0 << b_size); + uint32_t au_factor, ru_factor, gu_factor, bu_factor; + int au_shift, ru_shift, gu_shift, bu_shift; int i; + unorm_to_unorm_params (a_size, 16, &au_factor, &au_shift); + unorm_to_unorm_params (r_size, 16, &ru_factor, &ru_shift); + unorm_to_unorm_params (g_size, 16, &gu_factor, &gu_shift); + unorm_to_unorm_params (b_size, 16, &bu_factor, &bu_shift); + /* Start at the end so that we can do the expansion in place * when src == dst */ @@ -226,7 +249,7 @@ pixman_expand (uint64_t * dst, if (a_size) { a = (pixel >> a_shift) & a_mask; - a16 = unorm_to_unorm (a, a_size, 16); + a16 = a * au_factor >> au_shift; } else { @@ -238,9 +261,9 @@ pixman_expand (uint64_t * dst, r = (pixel >> r_shift) & r_mask; g = (pixel >> g_shift) & g_mask; b = (pixel >> b_shift) & b_mask; - r16 = unorm_to_unorm (r, r_size, 16); - g16 = unorm_to_unorm (g, g_size, 16); - b16 = unorm_to_unorm (b, b_size, 16); + r16 = r * ru_factor >> ru_shift; + g16 = g * gu_factor >> gu_shift; + b16 = b * bu_factor >> bu_shift; } else { |