vello/piet-wgsl/shader/shared/clip.wgsl

// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense
 
struct Bic {
    a: u32,
    b: u32,
}

fn bic_combine(x: Bic, y: Bic) -> Bic {
    let m = min(x.b, y.a);
    return Bic(x.a + y.a - m, x.b + y.b - m);
}

struct ClipEl {
    parent_ix: u32,
    bbox: vec4<f32>,
}
Clarify licensing for WGSL shaders (#205) As stated by the README, the intention is for the shaders to be provided under the terms of the Unlicense in addition to the MIT and Apache-2.0 licenses. While here, add a self-contained UNLICENSE file to replace the external reference to unlicense.org. 2022-11-20 03:45:42 +11:00			`// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense`

Checkpoint of clip and gradient work This is a checkpoint of partly completed work. Much of the GPU side is done, very little of the CPU side. For clips, the clip_els bindings (binding 6 of draw_leaf) are not added. Clip logic is missing from coarse. The overflow buffer is missing from fine, as is its size calculation in coarse (but it should work as long as the max depth fits within BLEND_STACK_SPLIT). For gradients, the texture binding is missing (binding 6) is missing from fine, as is the infrastructure in engine to deal with texture resources, and of course porting over the logic to fill it. The code is not tested, bugs may lurk. 2022-11-11 14:48:36 +11:00			`struct Bic {`
			`a: u32,`
			`b: u32,`
			`}`

			`fn bic_combine(x: Bic, y: Bic) -> Bic {`
			`let m = min(x.b, y.a);`
			`return Bic(x.a + y.a - m, x.b + y.b - m);`
			`}`

			`struct ClipEl {`
			`parent_ix: u32,`
			`bbox: vec4<f32>,`
			`}`