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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
| commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
| tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /layout/reftests/css-blending/background-blending-alpha-ref.html | |
| parent | Initial commit. (diff) | |
| download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip | |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'layout/reftests/css-blending/background-blending-alpha-ref.html')
| -rw-r--r-- | layout/reftests/css-blending/background-blending-alpha-ref.html | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/layout/reftests/css-blending/background-blending-alpha-ref.html b/layout/reftests/css-blending/background-blending-alpha-ref.html new file mode 100644 index 0000000000..6a7055938d --- /dev/null +++ b/layout/reftests/css-blending/background-blending-alpha-ref.html @@ -0,0 +1,62 @@ +<!-- + Any copyright is dedicated to the Public Domain. + http://creativecommons.org/publicdomain/zero/1.0/ +--> +<html> +<style> +.reftest { + background-color: rgba(0, 255, 0, 0.5); +} + +.child { + width: 100px; + height: 100px; + opacity: 0.5; + background-color: rgb(0, 127, 0); +} + +.topleft { + float:left; + + width: 100px; + height: 100px; + + /*First blend black rect with green in place*/ + /* Cs = (1 - αb) x Cs + αb x B(Cb, Cs)*/ + /* B(Cb, Cs) = | Cb - Cs | = (0, 0, 0) */ + /* 0.5 * (0, 255, 0) + 0.5 * (0, 0, 0) = (0, 127.5, 0)*/ + + /* Now, composite the resulting color with src-over; the alpha is the original alpha for the top layer + while the color is the blending result*/ + /* co = αs x Fa x Cs + αb x Fb x Cb - this is premultiplied */ + /* αo = αs + αb x (1 – αs) */ + /* Source over: Fa = 1; Fb = 1 – αs */ + /*co = 0.5 * 1 * (0, 127.5, 0) + 0.5 * 0.5 * (0, 255, 0) = (0, 63.5, 0) + 0.25 * (0, 255, 0) = (0, 127.5, 0)*/ + /*ao = 0.5 + 0.5 * 0.5 = 0.75*/ + /* Co = co/ao = (0, 127.5, 0) / 0.75*/ + + /* Now alpha composite on white background */ + /*co = 0.75 * 1 * (0, 127.5, 0) / 0.75 + 1 * 0.25 * (255, 255, 255) = (0, 127.5, 0) + (63.75, 63.75, 63.75) = (63.75, 159, 63.75) = (64, 191, 64) */ + + background-color: rgb(64, 191, 64); +} + +.topright { + float:left; + width: 100px; + height: 100px; +} + +.bottom { + width:200px; + height: 100px; + clear:both; +} + +</style> + +<div class="topleft"></div> +<div class="reftest topright"></div> +<div class="reftest bottom"></div> + +</html> |