Add ForcedGpu option

internal/config/cardpick.go

@@ -0,0 +1,79 @@
+package config
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/vinegarhq/vinegar/sysinfo"
+)
+
+// opt accepts the following values:
+// aliases - "integrated", "prime-discrete" and "none": Equivalent to "0", "1" or empty. Enables an extra "prime" check.
+// integer - GPU index
+// empty   - Skips logic and does nothing.
+func (b *Binary) pickCard() error {
+	aliases := map[string]string{
+		"integrated":     "0",
+		"prime-discrete": "1",
+		"none":           "",
+	}
+
+	var (
+		aIdx  string
+		prime bool
+	)
+
+	aIdx = b.ForcedGpu
+	if a, ok := aliases[b.ForcedGpu]; ok {
+		aIdx = a
+		prime = true
+	}
+
+	if aIdx == "" {
+		return nil
+	}
+
+	n := len(sysinfo.Cards)
+
+	// Check if the system actually has PRIME offload and there's no ambiguity with the GPUs.
+	if prime {
+		vk := (b.Dxvk && b.Renderer == "D3D11") || b.Renderer == "Vulkan"
+
+		if n != 2 && (!vk && n != 1) {
+			return fmt.Errorf("opengl is not capable of choosing the right gpu, it must be explicitly defined")
+		}
+
+		if n != 2 {
+			return nil
+		}
+
+		if !sysinfo.Cards[0].Embedded {
+			return nil
+		}
+	}
+
+	idx, err := strconv.Atoi(aIdx)
+	if err != nil {
+		return err
+	}
+
+	if idx < 0 {
+		return errors.New("gpu index cannot be negative")
+	}
+	if n < idx+1 {
+		return errors.New("gpu not found")
+	}
+	c := sysinfo.Cards[idx]
+
+	b.Env.Set("MESA_VK_DEVICE_SELECT_FORCE_DEFAULT_DEVICE", "1")
+	b.Env.Set("DRI_PRIME", aIdx)
+
+	if strings.HasSuffix(c.Driver, "nvidia") { //Workaround for OpenGL in nvidia GPUs
+		b.Env.Set("__GLX_VENDOR_LIBRARY_NAME", "nvidia")
+	} else {
+		b.Env.Set("__GLX_VENDOR_LIBRARY_NAME", "mesa")
+	}
+	return nil
+}

internal/config/config.go

@@ -33,6 +33,7 @@ type Binary struct {
 	Dxvk           bool          `toml:"dxvk"`
 	FFlags         roblox.FFlags `toml:"fflags"`
 	Env            Environment   `toml:"env"`
+	ForcedGpu      string        `toml:"gpu"`
 }
 
 type Config struct {
@@ -88,6 +89,9 @@ func Default() Config {
 			"__GL_THREADED_OPTIMIZATIONS": "1",
 		},
 
+		Global: Binary{
+			ForcedGpu: "prime-discrete",
+		},
 		Player: Binary{
 			DiscordRPC:     true,
 			Dxvk:           true,
@@ -113,6 +117,19 @@ func Default() Config {
 	}
 }
 
+func (b *Binary) setup() error {
+	if !roblox.ValidRenderer(b.Renderer) {
+		return errors.New("invalid renderer given")
+	}
+
+	if err := b.pickCard(); err != nil {
+		return err
+	}
+
+	b.Env.Setenv()
+	return nil
+}
+
 func (c *Config) setup() error {
 	if c.SanitizeEnv {
 		util.SanitizeEnv()
@@ -135,8 +152,12 @@ func (c *Config) setup() error {
 		log.Printf("Using Wine Root: %s", c.WineRoot)
 	}
 
-	if !roblox.ValidRenderer(c.Player.Renderer) || !roblox.ValidRenderer(c.Studio.Renderer) {
-		return fmt.Errorf("invalid renderer given to either player or studio")
+	if err := c.Player.setup(); err != nil {
+		return fmt.Errorf("player: %w", err)
+	}
+
+	if err := c.Studio.setup(); err != nil {
+		return fmt.Errorf("studio: %w", err)
 	}
 
 	c.Env.Setenv()

internal/config/env.go

@@ -6,6 +6,15 @@ import (
 
 type Environment map[string]string
 
+// Set will only set the given environment key and value if it isn't already set
+// within the Environment.
+func (e *Environment) Set(key, value string) {
+	if _, ok := (*e)[key]; ok {
+		return
+	}
+	(*e)[key] = value
+}
+
 func (e *Environment) Setenv() {
 	for name, value := range *e {
 		os.Setenv(name, value)