Externalize assets (#3515)

1 files changed, 78 insertions, 0 deletions

diff --git a/crates/typst-pdf/src/oklab.ps b/crates/typst-pdf/src/oklab.ps
new file mode 100644
index 00000000..e766bbd8
--- /dev/null
+++ b/crates/typst-pdf/src/oklab.ps
@@ -0,0 +1,78 @@
+{
+    % Starting stack: L, A, B
+    % /!\ WARNING: The A and B components **MUST** be encoded
+    %     in the range [0, 1] before calling this function.
+    %     This is because the function assumes that the
+    %     A and B components are offset by a factor of 0.5
+    %     in order to meet the range requirements of the
+    %     PDF specification.
+
+    exch 0.5 sub
+    exch 0.5 sub
+
+    % Load L a and b into the stack
+    2 index
+    2 index
+    2 index
+
+    % Compute f1 = ((0.3963377774 * a) + (0.2158037573 * b) + L)^3
+    0.2158037573 mul exch
+    0.3963377774 mul add add
+    dup dup mul mul
+
+    % Load L, a, and b into the stack
+    3 index
+    3 index
+    3 index
+
+    % Compute f2 = ((-0.1055613458 * a) + (-0.0638541728 * b) + L)^3
+    -0.0638541728 mul exch
+    -0.1055613458 mul add add
+    dup dup mul mul
+
+    % Load L, a, and b into the stack
+    4 index
+    4 index
+    4 index
+
+    % Compute f3 = ((-0.0894841775 * a) + (-1.2914855480 * b) + L)^3
+    -1.2914855480 mul exch
+    -0.0894841775 mul add add
+    dup dup mul mul
+
+    % Discard L, a, and b by rolling the stack and popping
+    6 3 roll pop pop pop
+
+    % Load f1, f2, and f3 into the stack
+    2 index
+    2 index
+    2 index
+
+    % Compute R = f1 * 4.0767416621 + f2 * -3.3077115913 + f3 * 0.2309699292
+    0.2309699292 mul exch
+    -3.3077115913 mul add exch
+    4.0767416621 mul add
+
+    % Load f1, f2, and f3 into the stack
+    3 index
+    3 index
+    3 index
+
+    % Compute G = f1 * -1.2684380046 + f2 * 2.6097574011 + f3 * -0.3413193965
+    -0.3413193965 mul exch
+    2.6097574011 mul add exch
+    -1.2684380046 mul add
+
+    % Load f1, f2, and f3 into the stack
+    4 index
+    4 index
+    4 index
+
+    % Compute B = f1 * -0.0041960863 + f2 * -0.7034186147 + f3 * 1.7076147010
+    1.7076147010 mul exch
+    -0.7034186147 mul add exch
+    -0.0041960863 mul add
+
+    % Discard f1, f2, and f3 by rolling the stack and popping
+    6 3 roll pop pop pop
+}