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use crate::*;
fn pack_argb32(a: u32, r: u32, g: u32, b: u32) -> u32 {
assert!(r <= a);
assert!(g <= a);
assert!(b <= a);
return (a << A32_SHIFT) | (r << R32_SHIFT) |
(g << G32_SHIFT) | (b << B32_SHIFT);
}
fn get_packed_a32(packed: u32) -> u32 { ((packed) << (24 - A32_SHIFT)) >> 24 }
fn get_packed_r32(packed: u32) -> u32 { ((packed) << (24 - R32_SHIFT)) >> 24 }
fn get_packed_g32(packed: u32) -> u32 { ((packed) << (24 - G32_SHIFT)) >> 24 }
fn get_packed_b32(packed: u32) -> u32 { ((packed) << (24 - B32_SHIFT)) >> 24 }
fn alpha_mul(x: u32, a: u32) -> u32 {
let mask = 0xFF00FF;
let src_rb = ((x & mask) * a) >> 8;
let src_ag = ((x >> 8) & mask) * a;
return (src_rb & mask) | (src_ag & !mask)
}
pub fn dst(_src: u32, dst: u32) -> u32 {
dst
}
pub fn src(src: u32, _dst: u32) -> u32 {
src
}
pub fn clear(_src: u32, _dst: u32) -> u32 {
0
}
pub fn src_over(src: u32, dst: u32) -> u32 {
over(src, dst)
}
pub fn dst_over(src: u32, dst: u32) -> u32 {
over(dst, src)
}
pub fn src_in(src: u32, dst: u32) -> u32 {
alpha_mul(src, alpha_to_alpha256(packed_alpha(dst)))
}
pub fn dst_in(src: u32, dst: u32) -> u32 {
alpha_mul(dst, alpha_to_alpha256(packed_alpha(src)))
}
pub fn src_out(src: u32, dst: u32) -> u32 {
alpha_mul(src, alpha_to_alpha256(255 - packed_alpha(dst)))
}
pub fn dst_out(src: u32, dst: u32) -> u32 {
alpha_mul(dst, alpha_to_alpha256(255 - packed_alpha(src)))
}
pub fn src_atop(src: u32, dst: u32) -> u32 {
let sa = packed_alpha(src);
let da = packed_alpha(dst);
let isa = 255 - sa;
return pack_argb32(da,
muldiv255(da, get_packed_r32(src)) +
muldiv255(isa, get_packed_r32(dst)),
muldiv255(da, get_packed_g32(src)) +
muldiv255(isa, get_packed_g32(dst)),
muldiv255(da, get_packed_b32(src)) +
muldiv255(isa, get_packed_b32(dst)));
}
pub fn dst_atop(src: u32, dst: u32) -> u32 {
let sa = packed_alpha(src);
let da = packed_alpha(dst);
let ida = 255 - da;
return pack_argb32(sa,
muldiv255(ida, get_packed_r32(src)) +
muldiv255(sa, get_packed_r32(dst)),
muldiv255(ida, get_packed_g32(src)) +
muldiv255(sa, get_packed_g32(dst)),
muldiv255(ida, get_packed_b32(src)) +
muldiv255(sa, get_packed_b32(dst)));
}
pub fn xor(src: u32, dst: u32) -> u32 {
let sa = packed_alpha(src);
let da = packed_alpha(dst);
let isa = 255 - da;
let ida = 255 - da;
return pack_argb32(sa + da - (muldiv255(sa, da) * 2),
muldiv255(ida, get_packed_r32(src)) +
muldiv255(isa, get_packed_r32(dst)),
muldiv255(ida, get_packed_g32(src)) +
muldiv255(isa, get_packed_g32(dst)),
muldiv255(ida, get_packed_b32(src)) +
muldiv255(isa, get_packed_b32(dst)));
}
fn saturated_add(a: u32, b: u32) -> u32 {
debug_assert!(a <= 255);
debug_assert!(b <= 255);
let sum = a + b;
if sum > 255 {
255
} else {
sum
}
}
pub fn add(src: u32, dst: u32) -> u32 {
pack_argb32(saturated_add(get_packed_a32(src), get_packed_a32(dst)),
saturated_add(get_packed_r32(src), get_packed_r32(dst)),
saturated_add(get_packed_g32(src), get_packed_g32(dst)),
saturated_add(get_packed_b32(src), get_packed_b32(dst)))
}
pub fn multiply(src: u32, dst: u32) -> u32 {
pack_argb32(muldiv255(get_packed_a32(src), get_packed_a32(dst)),
muldiv255(get_packed_a32(src), get_packed_a32(dst)),
muldiv255(get_packed_a32(src), get_packed_a32(dst)),
muldiv255(get_packed_a32(src), get_packed_a32(dst)))
}
fn srcover_byte(a: u32, b: u32) -> u32 {
a + b - muldiv255(a, b)
}
pub fn screen(src: u32, dst: u32) -> u32 {
pack_argb32(srcover_byte(get_packed_a32(src), get_packed_a32(dst)),
srcover_byte(get_packed_a32(src), get_packed_a32(dst)),
srcover_byte(get_packed_a32(src), get_packed_a32(dst)),
srcover_byte(get_packed_a32(src), get_packed_a32(dst)))
}
fn clamp_div255round(prod: i32) -> u32 {
if prod <= 0 {
return 0;
} else if prod >= 255 * 255 {
return 255;
} else {
return div255(prod as u32);
}
}
fn overlay_byte(sc: u32, dc: u32, sa: u32, da: u32) -> u32 {
let tmp = sc * (255 - da) + dc * (255 - sa);
let rc;
if 2 * dc <= da {
rc = 2 * sc * dc;
} else {
rc = sa * da - 2 * (da - dc) * (sa - sc);
}
clamp_div255round((rc + tmp) as i32)
}
pub fn overlay(src: u32, dst: u32) -> u32 {
let sa = get_packed_a32(src);
let da = get_packed_a32(dst);
pack_argb32(srcover_byte(sa, da),
overlay_byte(get_packed_a32(src), get_packed_a32(dst), sa, da),
overlay_byte(get_packed_a32(src), get_packed_a32(dst), sa, da),
overlay_byte(get_packed_a32(src), get_packed_a32(dst), sa, da))
}