diff --git a/src/api.yaml b/src/api.yaml
index 8f9b9a5..94e19ea 100644
--- a/src/api.yaml
+++ b/src/api.yaml
@@ -129,6 +129,29 @@ enum:
for setting of the constant value.)
`(1 - R_const, 1 - G_const, 1 - B_const, 1 - A_const)`
+ blend operation:
+ description: >
+ The algorithm used to blend source and destination colors.
+ ref:
+ name: GPUBlendOperation
+ anchor: "#enumdef-gpublendoperation"
+ values:
+ add: >
+ Adds the scaled source and scaled destination together.
+ `(RGBA_src` × `RGBA_src_factor) + (RGBA_dst` × `RGBA_dst_factor)`
+ subtract: >
+ Subtracts the scaled destination from the scaled source.
+ `(RGBA_src` × `RGBA_src_factor) - (RGBA_dst` × `RGBA_dst_factor)`
+ reverse subtract: >
+ Subtracts the scaled source from the scaled destination.
+ `(RGBA_dst` × `RGBA_dst_factor) - (RGBA_src` × `RGBA_src_factor)`
+ min: >
+ Takes the minimum of the source and destination.
+ `min(RGBA_src, RGBA_dst)`
+ max: >
+ Takes the maximum of the source and destination.
+ `max(RGBA_src, RGBA_dst)`
+
bitmask:
texture usage:
description: Determine how a GPUTexture maybe be used after creation.