Use new blend helper

This commit is contained in:
Jeroen van Rijn
2024-06-09 16:37:27 +02:00
parent d2a2c1e74e
commit 6b88d0a820
2 changed files with 41 additions and 28 deletions
+35 -18
View File
@@ -42,23 +42,6 @@ GA_Pixel :: [2]u8
G_Pixel_16 :: [1]u16
GA_Pixel_16 :: [2]u16
blend_single_channel :: #force_inline proc(fg, alpha, bg: $T) -> (res: T) where T == u8 || T == u16 {
MAX :: 256 when T == u8 else 65536
c := u32(fg) * (MAX - u32(alpha)) + u32(bg) * (1 + u32(alpha))
return T(c & (MAX - 1))
}
blend_pixel :: #force_inline proc(fg: [$N]$T, alpha: T, bg: [N]T) -> (res: [N]T) where (T == u8 || T == u16), N >= 1 && N <= 4 {
MAX :: 256 when T == u8 else 65536
r_a := u32(fg) * (MAX - u32(alpha)) + u32(bg) * (1 + u32(alpha))
return
}
blend :: proc{blend_single_channel, blend_pixel}
Image :: struct {
width: int,
height: int,
@@ -1276,6 +1259,40 @@ apply_palette_rgba :: proc(img: ^Image, palette: [256]RGBA_Pixel, allocator := c
}
apply_palette :: proc{apply_palette_rgb, apply_palette_rgba}
blend_single_channel :: #force_inline proc(fg, alpha, bg: $T) -> (res: T) where T == u8 || T == u16 {
MAX :: 256 when T == u8 else 65536
c := u32(fg) * (MAX - u32(alpha)) + u32(bg) * (1 + u32(alpha))
return T(c & (MAX - 1))
}
blend_pixel :: #force_inline proc(fg: [$N]$T, alpha: T, bg: [N]T) -> (res: [N]T) where (T == u8 || T == u16), N >= 1 && N <= 4 {
MAX :: 256 when T == u8 else 65536
when N == 1 {
r := u32(fg.r) * (MAX - u32(alpha)) + u32(bg.r) * (1 + u32(alpha))
return {T(r & (MAX - 1))}
}
when N == 2 {
r := u32(fg.r) * (MAX - u32(alpha)) + u32(bg.r) * (1 + u32(alpha))
g := u32(fg.g) * (MAX - u32(alpha)) + u32(bg.g) * (1 + u32(alpha))
return {T(r & (MAX - 1)), T(g & (MAX - 1))}
}
when N == 3 || N == 4 {
r := u32(fg.r) * (MAX - u32(alpha)) + u32(bg.r) * (1 + u32(alpha))
g := u32(fg.g) * (MAX - u32(alpha)) + u32(bg.g) * (1 + u32(alpha))
b := u32(fg.b) * (MAX - u32(alpha)) + u32(bg.b) * (1 + u32(alpha))
when N == 3 {
return {T(r & (MAX - 1)), T(g & (MAX - 1)), T(b & (MAX - 1))}
} else {
return {T(r & (MAX - 1)), T(g & (MAX - 1)), T(b & (MAX - 1)), MAX - 1}
}
}
unreachable()
}
blend :: proc{blend_single_channel, blend_pixel}
// Replicates grayscale values into RGB(A) 8- or 16-bit images as appropriate.
// Returns early with `false` if already an RGB(A) image.
@@ -1388,4 +1405,4 @@ write_bytes :: proc(buf: ^bytes.Buffer, data: []u8) -> (err: compress.General_Er
return .Resize_Failed
}
return nil
}
}
+6 -10
View File
@@ -749,10 +749,10 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
}
}
} else if add_alpha || .alpha_drop_if_present in options {
bg := [3]f32{0, 0, 0}
bg := PLTE_Entry{0, 0, 0}
if premultiply && seen_bkgd {
c16 := img.background.([3]u16)
bg = [3]f32{f32(c16.r), f32(c16.g), f32(c16.b)}
bg = {u8(c16.r), u8(c16.g), u8(c16.b)}
}
no_alpha := (.alpha_drop_if_present in options || premultiply) && .alpha_add_if_missing not_in options
@@ -766,14 +766,10 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
a := int(index) < len(trns.data) ? trns.data[index] : 255
if blend_background {
c.r = image.blend(c.r, a, u8(u32(bg.r)))
c.g = image.blend(c.g, a, u8(u32(bg.g)))
c.b = image.blend(c.b, a, u8(u32(bg.b)))
c = image.blend(c, a, bg)
a = 255
} else if premultiply {
c.r = image.blend(u8(0), a, c.r)
c.g = image.blend(u8(0), a, c.g)
c.b = image.blend(u8(0), a, c.b)
c = image.blend(PLTE_Entry{}, a, c)
}
t.buf[j ] = c.r
@@ -1014,8 +1010,8 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
return {}, .Unable_To_Allocate_Or_Resize
}
p := mem.slice_data_cast([]u8, temp.buf[:])
o := mem.slice_data_cast([]u8, t.buf[:])
p := temp.buf[:]
o := t.buf[:]
switch raw_image_channels {
case 1: