spirv-reader: polyfill scalar refract
Compute it in 2 dimensions, with a 0-valued y component,
then extract the x component of that result.
Fixed: tint:974
Change-Id: Ie23668d3403e68be14f34da9540f27f6f3c3aca2
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/58782
Auto-Submit: David Neto <dneto@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
Reviewed-by: James Price <jrprice@google.com>
diff --git a/src/reader/spirv/function.cc b/src/reader/spirv/function.cc
index c618d3a..7f302c3 100644
--- a/src/reader/spirv/function.cc
+++ b/src/reader/spirv/function.cc
@@ -3989,6 +3989,37 @@
create<ast::ScalarConstructorExpression>(
Source{}, create<ast::FloatLiteral>(Source{}, 1.0f))};
}
+ if ((ext_opcode == GLSLstd450Refract) && result_type->IsScalar()) {
+ // WGSL does not have scalar form of the refract builtin.
+ // It's a complicated expression. Implement it by /computing it in two
+ // dimensions, but with a 0-valued y component in both the incident and
+ // normal vectors, then take the x component of that result.
+ auto incident = MakeOperand(inst, 2);
+ auto normal = MakeOperand(inst, 3);
+ auto eta = MakeOperand(inst, 4);
+ TINT_ASSERT(Reader, incident.type->Is<F32>());
+ TINT_ASSERT(Reader, normal.type->Is<F32>());
+ TINT_ASSERT(Reader, eta.type->Is<F32>());
+ if (!success()) {
+ return {};
+ }
+ const Type* f32 = eta.type;
+ const Type* vec2 = ty_.Vector(f32, 2);
+ return {
+ f32,
+ builder_.MemberAccessor(
+ builder_.Call(
+ Source{}, "refract",
+ ast::ExpressionList{
+ builder_.Construct(vec2->Build(builder_),
+ ast::ExpressionList{
+ incident.expr, builder_.Expr(0.0f)}),
+ builder_.Construct(
+ vec2->Build(builder_),
+ ast::ExpressionList{normal.expr, builder_.Expr(0.0f)}),
+ eta.expr}),
+ "x")};
+ }
const auto name = GetGlslStd450FuncName(ext_opcode);
if (name.empty()) {
diff --git a/src/reader/spirv/function_glsl_std_450_test.cc b/src/reader/spirv/function_glsl_std_450_test.cc
index 3e5b5e4..599a016 100644
--- a/src/reader/spirv/function_glsl_std_450_test.cc
+++ b/src/reader/spirv/function_glsl_std_450_test.cc
@@ -53,6 +53,7 @@
OpName %v3f1 "v3f1"
OpName %v3f2 "v3f2"
OpName %v4f1 "v4f1"
+ OpName %v4f2 "v4f2"
%void = OpTypeVoid
%voidfn = OpTypeFunction %void
@@ -123,6 +124,7 @@
%v3f2 = OpCopyObject %v3float %v3float_60_70_50
%v4f1 = OpCopyObject %v4float %v4float_50_50_50_50
+ %v4f2 = OpCopyObject %v4float %v4f1
)";
}
@@ -1746,6 +1748,78 @@
{"UnpackUnorm2x16", "unpack2x16unorm", 2},
{"UnpackHalf2x16", "unpack2x16float", 2}}));
+TEST_F(SpvParserTest, GlslStd450_Refract_Scalar) {
+ const auto assembly = Preamble() + R"(
+ %1 = OpExtInst %float %glsl Refract %f1 %f2 %f3
+ OpReturn
+ OpFunctionEnd
+ )";
+ auto p = parser(test::Assemble(assembly));
+ ASSERT_TRUE(p->BuildAndParseInternalModuleExceptFunctions());
+ auto fe = p->function_emitter(100);
+ EXPECT_TRUE(fe.EmitBody()) << p->error();
+ const auto body = ToString(p->builder(), fe.ast_body());
+ const auto* expected = R"(VariableConst{
+ x_1
+ none
+ undefined
+ __f32
+ {
+ MemberAccessor[not set]{
+ Call[not set]{
+ Identifier[not set]{refract}
+ (
+ TypeConstructor[not set]{
+ __vec_2__f32
+ Identifier[not set]{f1}
+ ScalarConstructor[not set]{0.000000}
+ }
+ TypeConstructor[not set]{
+ __vec_2__f32
+ Identifier[not set]{f2}
+ ScalarConstructor[not set]{0.000000}
+ }
+ Identifier[not set]{f3}
+ )
+ }
+ Identifier[not set]{x}
+ }
+ }
+ })";
+
+ EXPECT_THAT(body, HasSubstr(expected)) << body;
+}
+
+TEST_F(SpvParserTest, GlslStd450_Refract_Vector) {
+ const auto assembly = Preamble() + R"(
+ %1 = OpExtInst %v2float %glsl Refract %v2f1 %v2f2 %f3
+ OpReturn
+ OpFunctionEnd
+ )";
+ auto p = parser(test::Assemble(assembly));
+ ASSERT_TRUE(p->BuildAndParseInternalModuleExceptFunctions());
+ auto fe = p->function_emitter(100);
+ EXPECT_TRUE(fe.EmitBody()) << p->error();
+ const auto body = ToString(p->builder(), fe.ast_body());
+ const auto* expected = R"(VariableConst{
+ x_1
+ none
+ undefined
+ __vec_2__f32
+ {
+ Call[not set]{
+ Identifier[not set]{refract}
+ (
+ Identifier[not set]{v2f1}
+ Identifier[not set]{v2f2}
+ Identifier[not set]{f3}
+ )
+ }
+ })";
+
+ EXPECT_THAT(body, HasSubstr(expected));
+}
+
} // namespace
} // namespace spirv
} // namespace reader
