internal/cmd/convertshaders: parallelize compilation

Signed-off-by: Egon Elbre <egonelbre@gmail.com>

internal/cmd/convertshaders/glslvalidate.go

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os/exec"
+	"path/filepath"
+)
+
+// GLSLValidator is OpenGL reference compiler.
+type GLSLValidator struct {
+	Bin     string
+	WorkDir WorkDir
+}
+
+func NewGLSLValidator() *GLSLValidator { return &GLSLValidator{Bin: "glslangValidator"} }
+
+// ConvertCompute converts glsl compute shader to spirv.
+func (glsl *GLSLValidator) ConvertCompute(path string, input []byte) ([]byte, error) {
+	base := glsl.WorkDir.Path(filepath.Base(path))
+	pathout := base + ".out"
+
+	cmd := exec.Command(glsl.Bin,
+		"-G100", // OpenGL ES 3.1.
+		"-w",    // Suppress warnings.
+		"-S", "comp",
+		"-o", pathout,
+		path,
+	)
+	cmd.Stdin = bytes.NewBuffer(input)
+
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("%s\nfailed to run %v: %w", out, cmd.Args, err)
+	}
+
+	compiled, err := ioutil.ReadFile(pathout)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read output %q: %w", pathout, err)
+	}
+
+	return compiled, nil
+}