Add ForcedGpu option (#206)

* Minor formatting fix

* WIP: Added ForcedGpuId and PrimeOffload options

* Global.PrimeOffload set to true by default

* Remove unnecessary error handling for sysfs IO

* Refactor: Merge Prime & ForcedGpuId into ForcedGpu

* ForcedGpu is now validated by config.go
Also did some refactoring to share validation logic across binaries

* prime: Do not redefine existing env vars

* prime: handle cases with 3+ gpus and opengl
In these circumstances, there's no way for us to determine the right gpu
...so abort and prompt the user to explictly choose it...
...or to try the vulkan renderer

* prime: Remove vendor check, only probe driver.
It's actually unnecessary to check the card's vendor.
Instead, just check for its driver. If it's nvidia, apply the...
...GLX workaround.

* prime -> gpu: major codebase refactor

* Yet another refactor: removed vid:nid logic
Now gpu works entirely around indexes

* oops: fixed inverted condition in gpu probe

* gpu: validate if index exists by checking length

* gpu: use PrimeNone string instead of literal
I just noticed this and it was really bothering me. It had to be fixed.

* card: Refactor prime logic around new sysinfo
Hopefully the last refactor of this code

* cardpick: Remove unnecessary env return

* cardpick: improve readbility, consolidate prime

* setIfUndefined as env method instead of function

* Simplify prime check variable names

Co-authored-by: sewn <sewn@disroot.org>
Signed-off-by: Jrelvas <55360900+Noted-Jrelvas@users.noreply.github.com>

* Fix env "set if undefined" method

Co-authored-by: sewn <sewn@disroot.org>
Signed-off-by: Jrelvas <55360900+Noted-Jrelvas@users.noreply.github.com>

* Remove log for env set

Co-authored-by: sewn <sewn@disroot.org>
Signed-off-by: Jrelvas <55360900+Noted-Jrelvas@users.noreply.github.com>

* Update cardpick code for suggestions made

* Consolidate BinaryParse into setup method

* Do not run pickCard logic if opt is empty string

* Reduced complexity of cardpick prime check

* The pickCard rewrite.

* Turn pickCard into a binary method

* config: return error directly in binary setup

* cardpick: Declare aIdx and prime in one var clause

* cardpick: removed unnecessary opt var

* Update internal/config/cardpick.go (format change)

Co-authored-by: sewn <sewn@disroot.org>
Signed-off-by: Jrelvas <55360900+Noted-Jrelvas@users.noreply.github.com>

* env: use self directly in set

* binary: Moved setenv from pickCard into setup.

---------

Signed-off-by: Jrelvas <55360900+Noted-Jrelvas@users.noreply.github.com>
Co-authored-by: sewn <sewn@disroot.org>

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)