internal/cmd/convertshaders: parallelize compilation

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

internal/cmd/convertshaders/hlsl.go

@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+// FXC is hlsl compiler that targets ShaderModel 5.x and lower.
+type FXC struct {
+	Bin     string
+	WorkDir WorkDir
+}
+
+func NewFXC() *FXC { return &FXC{Bin: "fxc.exe"} }
+
+// Compile compiles the input shader.
+func (fxc *FXC) Compile(path, variant string, input []byte, entryPoint string, profileVersion string) ([]byte, error) {
+	base := fxc.WorkDir.Path(filepath.Base(path), variant, profileVersion)
+	pathin := base + ".in"
+	pathout := base + ".out"
+	result := pathout
+
+	if err := fxc.WorkDir.WriteFile(pathin, input); err != nil {
+		return nil, fmt.Errorf("unable to write shader to disk: %w", err)
+	}
+
+	cmd := exec.Command(fxc.Bin)
+	if runtime.GOOS != "windows" {
+		cmd = exec.Command("wine", fxc.Bin)
+		if err := winepath(&pathin, &pathout); err != nil {
+			return nil, err
+		}
+	}
+
+	var profile string
+	switch filepath.Ext(path) {
+	case ".frag":
+		profile = "ps_" + profileVersion
+	case ".vert":
+		profile = "vs_" + profileVersion
+	default:
+		return nil, fmt.Errorf("unrecognized shader type %s", path)
+	}
+
+	cmd.Args = append(cmd.Args,
+		"/Fo", pathout,
+		"/T", profile,
+		"/E", entryPoint,
+		pathin,
+	)
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		info := ""
+		if runtime.GOOS != "windows" {
+			info = "If the fxc tool cannot be found, set WINEPATH to the Windows path for the Windows SDK.\n"
+		}
+		return nil, fmt.Errorf("%s\n%sfailed to run %v: %w", output, info, cmd.Args, err)
+	}
+
+	compiled, err := ioutil.ReadFile(result)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read output %q: %w", pathout, err)
+	}
+
+	return compiled, nil
+}
+
+// DXC is hlsl compiler that targets ShaderModel 6.0 and newer.
+type DXC struct {
+	Bin     string
+	WorkDir WorkDir
+}
+
+func NewDXC() *DXC { return &DXC{Bin: "dxc.exe"} }
+
+// Compile compiles the input shader.
+func (dxc *DXC) Compile(path, variant string, input []byte, entryPoint string, profile string) ([]byte, error) {
+	base := dxc.WorkDir.Path(filepath.Base(path), variant, profile)
+	pathin := base + ".in"
+	pathout := base + ".out"
+	result := pathout
+
+	if err := dxc.WorkDir.WriteFile(pathin, input); err != nil {
+		return nil, fmt.Errorf("unable to write shader to disk: %w", err)
+	}
+
+	cmd := exec.Command(dxc.Bin)
+	if runtime.GOOS != "windows" {
+		cmd = exec.Command("wine", dxc.Bin)
+		if err := winepath(&pathin, &pathout); err != nil {
+			return nil, err
+		}
+	}
+
+	cmd.Args = append(cmd.Args,
+		"-Fo", pathout,
+		"-T", profile,
+		"-E", entryPoint,
+		"-Qstrip_reflect",
+		pathin,
+	)
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		info := ""
+		if runtime.GOOS != "windows" {
+			info = "If the dxc tool cannot be found, set WINEPATH to the Windows path for the Windows SDK.\n"
+		}
+		return nil, fmt.Errorf("%s\n%sfailed to run %v: %w", output, info, cmd.Args, err)
+	}
+
+	compiled, err := ioutil.ReadFile(result)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read output %q: %w", pathout, err)
+	}
+
+	return compiled, nil
+}
+
+// winepath uses the winepath tool to convert a paths to Windows format.
+// The returned path can be used as arguments for Windows command line tools.
+func winepath(paths ...*string) error {
+	for _, path := range paths {
+		out, err := exec.Command("winepath", "--windows", *path).Output()
+		if err != nil {
+			return fmt.Errorf("unable to run `winepath --windows %q`: %w", *path, err)
+		}
+		*path = strings.TrimSpace(string(out))
+	}
+	return nil
+}