internal/shader: Bug fix: Treat a non-typed consntat argument as a float

Closes #1874

internal/shader/expr.go

@@ -200,6 +200,13 @@ func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariable
 				cs.addError(e.Pos(), fmt.Sprintf("single-value context and multiple-value context cannot be mixed: %s", e.Fun))
 				return nil, nil, nil, false
 			}
+			// If the argument is a non-typed constant value, treat is as a float value (#1874).
+			for i, e := range es {
+				if e.Type == shaderir.NumberExpr && e.ConstType == shaderir.ConstTypeNone {
+					e.ConstType = shaderir.ConstTypeFloat
+					ts[i] = shaderir.Type{Main: shaderir.Float}
+				}
+			}
 			args = append(args, es...)
 			argts = append(argts, ts...)
 			stmts = append(stmts, ss...)

internal/shader/testdata/issue1874.expected.vs

@@ -0,0 +1,6 @@
+void F0(out float l0);
+
+void F0(out float l0) {
+	l0 = (sin(1.0000000000e-01)) + (cos(2.0000000000e-01));
+	return;
+}

internal/shader/testdata/issue1874.go

@@ -0,0 +1,9 @@
+package main
+
+func Foo() float {
+	const (
+		s = 0.1
+		c = 0.2
+	)
+	return sin(s) + cos(c)
+}