From c287e7bee6a93cda443407fd5f9656ce514a05de Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 4 Nov 2024 14:34:08 +0900
Subject: [PATCH] internal/graphicsdriver/opengl/gl: bug fix: check ES 3.0
 availability

Updates #3152
---
 .../opengl/gl/procaddr_linbsd.go              | 44 +++++++++++++++----
 1 file changed, 36 insertions(+), 8 deletions(-)

diff --git a/internal/graphicsdriver/opengl/gl/procaddr_linbsd.go b/internal/graphicsdriver/opengl/gl/procaddr_linbsd.go
index 794c9057ef4b..842d80ae60cd 100644
--- a/internal/graphicsdriver/opengl/gl/procaddr_linbsd.go
+++ b/internal/graphicsdriver/opengl/gl/procaddr_linbsd.go
@@ -17,8 +17,13 @@
 package gl
 
 import (
+	"bufio"
+	"bytes"
 	"errors"
 	"fmt"
+	"os/exec"
+	"regexp"
+	"strconv"
 
 	"github.com/ebitengine/purego"
 )
@@ -28,18 +33,41 @@ var (
 	libGLES uintptr
 )
 
+func isES30Available() bool {
+	var buf bytes.Buffer
+	cmd := exec.Command("glxinfo")
+	cmd.Stdout = &buf
+	if err := cmd.Run(); err != nil {
+		return false
+	}
+
+	re := regexp.MustCompile(`^OpenGL ES profile version string: OpenGL ES (\d+)\.\d+`)
+	s := bufio.NewScanner(&buf)
+	for s.Scan() {
+		m := re.FindStringSubmatch(s.Text())
+		if m == nil {
+			continue
+		}
+		major, _ := strconv.Atoi(m[1])
+		return major >= 3
+	}
+	return false
+}
+
 func (c *defaultContext) init() error {
 	var errs []error
 
-	// Try OpenGL ES first. Some machines like Android and Raspberry Pi might work only with OpenGL ES.
-	for _, name := range []string{"libGLESv2.so", "libGLESv2.so.2", "libGLESv2.so.1", "libGLESv2.so.0"} {
-		lib, err := purego.Dlopen(name, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
-		if err == nil {
-			libGLES = lib
-			c.isES = true
-			return nil
+	if isES30Available() {
+		// Try OpenGL ES first. Some machines like Android and Raspberry Pi might work only with OpenGL ES.
+		for _, name := range []string{"libGLESv2.so", "libGLESv2.so.2", "libGLESv2.so.1", "libGLESv2.so.0"} {
+			lib, err := purego.Dlopen(name, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
+			if err == nil {
+				libGLES = lib
+				c.isES = true
+				return nil
+			}
+			errs = append(errs, fmt.Errorf("gl: Dlopen failed: name: %s: %w", name, err))
 		}
-		errs = append(errs, fmt.Errorf("gl: Dlopen failed: name: %s: %w", name, err))
 	}
 
 	// Try OpenGL next.