internal/cmd/convertshaders: parallelize compilation

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

internal/cmd/convertshaders/spirvcross.go

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+)
+
+// SPIRVCross cross-compiles spirv shaders to es, hlsl and others.
+type SPIRVCross struct {
+	Bin string
+}
+
+func NewSPIRVCross() *SPIRVCross { return &SPIRVCross{Bin: "spirv-cross"} }
+
+// Convert converts compute shader from spirv format to a target format.
+func (spirv *SPIRVCross) Convert(input []byte, target, version string) (string, error) {
+	var cmd *exec.Cmd
+	switch target {
+	case "es":
+		cmd = exec.Command(spirv.Bin,
+			"--es",
+			"--version", version,
+			"-",
+		)
+	case "hlsl":
+		cmd = exec.Command(spirv.Bin,
+			"--hlsl",
+			"--shader-model", version,
+			"-",
+		)
+	default:
+		return "", fmt.Errorf("unknown target %q", target)
+	}
+
+	cmd.Stdin = bytes.NewBuffer(input)
+	out, err := cmd.Output()
+	if err != nil {
+		return "", fmt.Errorf("failed to run %v: %w", cmd.Args, err)
+	}
+
+	return string(out), nil
+}