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https://github.com/gfx-rs/wgpu.git
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4b6a2d1dfa
Allow constant evaluation of binary operators whose left and right operands are both vectors.
90 lines
2.5 KiB
WebGPU Shading Language
90 lines
2.5 KiB
WebGPU Shading Language
const TWO: u32 = 2u;
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const THREE: i32 = 3i;
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@compute @workgroup_size(TWO, THREE, TWO - 1u)
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fn main() {
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swizzle_of_compose();
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index_of_compose();
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compose_three_deep();
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non_constant_initializers();
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splat_of_constant();
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compose_of_constant();
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compose_of_splat();
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}
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// Swizzle the value of nested Compose expressions.
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fn swizzle_of_compose() {
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var out = vec4(vec2(1, 2), vec2(3, 4)).wzyx; // should assign vec4(4, 3, 2, 1);
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}
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// Index the value of nested Compose expressions.
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fn index_of_compose() {
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var out = vec4(vec2(1, 2), vec2(3, 4))[1]; // should assign 2
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}
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// Index the value of Compose expressions nested three deep
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fn compose_three_deep() {
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var out = vec4(vec3(vec2(6, 7), 8), 9)[0]; // should assign 6
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}
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// While WGSL allows local variables to be declared anywhere in the function,
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// Naga treats them all as appearing at the top of the function. To ensure that
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// WGSL initializer expressions are evaluated at the right time, in the general
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// case they need to be turned into Naga `Store` statements executed at the
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// point of the WGSL declaration.
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//
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// When a variable's initializer is a constant expression, however, it can be
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// evaluated at any time. The WGSL front end thus renders locals with
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// initializers that are constants as Naga locals with initializers. This test
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// checks that Naga local variable initializers are only used when safe.
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fn non_constant_initializers() {
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var w = 10 + 20;
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var x = w;
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var y = x;
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var z = 30 + 40;
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var out = vec4(w, x, y, z);
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}
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// Constant evaluation should be able to see through constants to
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// their values.
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const FOUR: i32 = 4;
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const FOUR_ALIAS: i32 = FOUR;
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const TEST_CONSTANT_ADDITION: i32 = FOUR + FOUR;
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const TEST_CONSTANT_ALIAS_ADDITION: i32 = FOUR_ALIAS + FOUR_ALIAS;
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fn splat_of_constant() {
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var out = -vec4(FOUR);
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}
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fn compose_of_constant() {
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var out = -vec4(FOUR, FOUR, FOUR, FOUR);
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}
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const PI: f32 = 3.141;
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const phi_sun: f32 = PI * 2.0;
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const DIV: vec4f = vec4(4.0 / 9.0, 0.0, 0.0, 0.0);
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const TEXTURE_KIND_REGULAR: i32 = 0;
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const TEXTURE_KIND_WARP: i32 = 1;
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const TEXTURE_KIND_SKY: i32 = 2;
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fn map_texture_kind(texture_kind: i32) -> u32 {
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switch (texture_kind) {
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case TEXTURE_KIND_REGULAR: { return 10u; }
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case TEXTURE_KIND_WARP: { return 20u; }
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case TEXTURE_KIND_SKY: { return 30u; }
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default: { return 0u; }
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}
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}
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fn compose_of_splat() {
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var x = vec4f(vec3f(1.0), 2.0).wzyx;
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}
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const add_vec = vec2(1.0f) + vec2(3.0f, 4.0f);
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const compare_vec = vec2(3.0f) == vec2(3.0f, 4.0f);
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