From f8221bb2ab3a15c5665f34a5cdf8deebaf6b0d8f Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Fri, 6 Jan 2023 18:51:20 -0600
Subject: [PATCH] gpu/internal/opengl: don't query
 FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING on GLES2

It's not supported in OpenGL ES 2.

References: https://todo.sr.ht/~eliasnaur/gio/469
Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 gpu/internal/opengl/opengl.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/gpu/internal/opengl/opengl.go b/gpu/internal/opengl/opengl.go
index 4cb3f88f..889a464e 100644
--- a/gpu/internal/opengl/opengl.go
+++ b/gpu/internal/opengl/opengl.go
@@ -245,13 +245,17 @@ func (b *Backend) BeginFrame(target driver.RenderTarget, clear bool, viewport im
 	b.glstate.bindFramebuffer(b.funcs, gl.FRAMEBUFFER, renderFBO)
 	if b.gles {
 		// If the output framebuffer is not in the sRGB colorspace already, emulate it.
-		var fbEncoding int
-		if !renderFBO.Valid() {
-			fbEncoding = b.funcs.GetFramebufferAttachmentParameteri(gl.FRAMEBUFFER, gl.BACK, gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING)
-		} else {
-			fbEncoding = b.funcs.GetFramebufferAttachmentParameteri(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING)
+		fbSRGB := false
+		if !b.gles || b.glver[0] > 2 {
+			var fbEncoding int
+			if !renderFBO.Valid() {
+				fbEncoding = b.funcs.GetFramebufferAttachmentParameteri(gl.FRAMEBUFFER, gl.BACK, gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING)
+			} else {
+				fbEncoding = b.funcs.GetFramebufferAttachmentParameteri(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING)
+			}
+			fbSRGB = fbEncoding != gl.LINEAR
 		}
-		if fbEncoding == gl.LINEAR && viewport != (image.Point{}) {
+		if !fbSRGB && viewport != (image.Point{}) {
 			if b.sRGBFBO == nil {
 				sfbo, err := NewSRGBFBO(b.funcs, &b.glstate)
 				if err != nil {