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Use float not double in webp_load alpha conversion

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* src/image.c (webp_load): Pacify gcc -Wdouble-promotion
by using (1 - a), where the 1 is converted to 1.0f, rather
than (1.0 - a), which mistakenly converts a to double.
Also, reindent to use GNU style.
This commit is contained in:
Paul Eggert 2023-08-25 18:43:57 -07:00
parent 4a6b32f72f
commit 8bc21ef110
1 changed files with 14 additions and 11 deletions
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25
src/image.c
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@ -10497,17 +10497,20 @@ webp_load (struct frame *f, struct image *img)
int r, g, b;
/* The WebP alpha channel allows 256 levels of partial
transparency. Blend it with the background manually. */
if (features.has_alpha || anim) {
float a = (float) p[3] / UINT8_MAX;
r = (int)(a * p[0] + (1.0 - a) * bg_color.red) << 8;
g = (int)(a * p[1] + (1.0 - a) * bg_color.green) << 8;
b = (int)(a * p[2] + (1.0 - a) * bg_color.blue) << 8;
p += 4;
} else {
r = *p++ << 8;
g = *p++ << 8;
b = *p++ << 8;
}
if (features.has_alpha || anim)
{
float a = (float) p[3] / UINT8_MAX;
r = (int)(a * p[0] + (1 - a) * bg_color.red) << 8;
g = (int)(a * p[1] + (1 - a) * bg_color.green) << 8;
b = (int)(a * p[2] + (1 - a) * bg_color.blue) << 8;
p += 4;
}
else
{
r = *p++ << 8;
g = *p++ << 8;
b = *p++ << 8;
}
PUT_PIXEL (ximg, x, y, lookup_rgb_color (f, r, g, b));
}
}