diff options
Diffstat (limited to 'gdk-pixbuf/pixops/pixops.c')
| -rw-r--r-- | gdk-pixbuf/pixops/pixops.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/gdk-pixbuf/pixops/pixops.c b/gdk-pixbuf/pixops/pixops.c index a1c3c9bfd..623dbd09e 100644 --- a/gdk-pixbuf/pixops/pixops.c +++ b/gdk-pixbuf/pixops/pixops.c @@ -956,11 +956,20 @@ scale_pixel (guchar *dest, int dest_x, int dest_channels, int dest_has_alpha, { if (src_has_alpha) { - if (a) + if (a == 0xff0000) { - dest[0] = r / a; - dest[1] = g / a; - dest[2] = b / a; + /* Division by a constant is converted into a multiplication by an optimizing C compiler */ + dest[0] = r / 0xff0000; + dest[1] = g / 0xff0000; + dest[2] = b / 0xff0000; + dest[3] = 0xff0000 >> 16; + } + else if (a) + { + double a1 = 1.0 / a; + dest[0] = r * a1; + dest[1] = g * a1; + dest[2] = b * a1; dest[3] = a >> 16; } else @@ -991,6 +1000,7 @@ scale_line (int *weights, int n_x, int n_y, guchar *dest, int dest_x, { int x = x_init; int i, j; + const int n_xy = n_x * n_y; while (dest < dest_end) { @@ -998,7 +1008,7 @@ scale_line (int *weights, int n_x, int n_y, guchar *dest, int dest_x, int *pixel_weights; pixel_weights = weights + - ((x >> (SCALE_SHIFT - SUBSAMPLE_BITS)) & SUBSAMPLE_MASK) * n_x * n_y; + ((x >> (SCALE_SHIFT - SUBSAMPLE_BITS)) & SUBSAMPLE_MASK) * n_xy; if (src_has_alpha) { @@ -1022,11 +1032,20 @@ scale_line (int *weights, int n_x, int n_y, guchar *dest, int dest_x, } } - if (a) + if (a == 0xff0000) + { + /* Division by a constant is converted into a multiplication by an optimizing C compiler */ + dest[0] = r / 0xff0000; + dest[1] = g / 0xff0000; + dest[2] = b / 0xff0000; + dest[3] = 0xff0000 >> 16; + } + else if (a) { - dest[0] = r / a; - dest[1] = g / a; - dest[2] = b / a; + double a1 = 1.0 / a; + dest[0] = r * a1; + dest[1] = g * a1; + dest[2] = b * a1; dest[3] = a >> 16; } else |