From ad6fd451fbe3da28ce41e553d31e6bb37f8483ab Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Mon, 17 Jun 2024 07:56:06 -0400
Subject: [PATCH] gdk: Create our egl surface with srgb colorspace

For GDK_MEMORY_U8_SRGB depth, try to create an SRGB surface.

This requires the EXT_KHR_gl_colorspace extension, which
isn't super-common in the wild (37%), so we fall back to regular U8 if
that fails.

But if we have the extension, create our egl surface with the
srgb colorspace, and report that fact in gdk_surface_gl_is_srgb().
---
 gdk/gdkdisplay.c        |  2 ++
 gdk/gdkdisplayprivate.h |  1 +
 gdk/gdksurface.c        | 24 +++++++++++++++++++++++-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/gdk/gdkdisplay.c b/gdk/gdkdisplay.c
index df2a939c40..fb7467faee 100644
--- a/gdk/gdkdisplay.c
+++ b/gdk/gdkdisplay.c
@@ -1870,6 +1870,8 @@ gdk_display_init_egl (GdkDisplay  *self,
     epoxy_has_egl_extension (priv->egl_display, "EGL_EXT_image_dma_buf_import_modifiers");
   self->have_egl_dma_buf_export =
     epoxy_has_egl_extension (priv->egl_display, "EGL_MESA_image_dma_buf_export");
+  self->have_egl_gl_colorspace =
+    epoxy_has_egl_extension (priv->egl_display, "EGL_KHR_gl_colorspace");
 
   if (self->have_egl_no_config_context)
     priv->egl_config_high_depth = gdk_display_create_egl_config (self,
diff --git a/gdk/gdkdisplayprivate.h b/gdk/gdkdisplayprivate.h
index b9b794d3a2..d0f02f2cba 100644
--- a/gdk/gdkdisplayprivate.h
+++ b/gdk/gdkdisplayprivate.h
@@ -131,6 +131,7 @@ struct _GdkDisplay
   guint have_egl_pixel_format_float : 1;
   guint have_egl_dma_buf_import : 1;
   guint have_egl_dma_buf_export : 1;
+  guint have_egl_gl_colorspace : 1;
 
   GdkDmabufFormats *dmabuf_formats;
   GdkDmabufDownloader *dmabuf_downloaders[4];
diff --git a/gdk/gdksurface.c b/gdk/gdksurface.c
index 1ee40fce0c..aa1cdefd53 100644
--- a/gdk/gdksurface.c
+++ b/gdk/gdksurface.c
@@ -1159,10 +1159,32 @@ gdk_surface_ensure_egl_surface (GdkSurface     *self,
 
   if (priv->egl_surface == NULL)
     {
+      EGLint attribs[4];
+      int i;
+
+      i = 0;
+      if (depth == GDK_MEMORY_U8_SRGB && display->have_egl_gl_colorspace)
+        {
+          attribs[i++] = EGL_GL_COLORSPACE_KHR;
+          attribs[i++] = EGL_GL_COLORSPACE_SRGB_KHR;
+          self->is_srgb = TRUE;
+        }
+      g_assert (i < G_N_ELEMENTS (attribs));
+      attribs[i++] = EGL_NONE;
+
       priv->egl_surface = eglCreateWindowSurface (gdk_display_get_egl_display (display),
                                                   gdk_display_get_egl_config (display, depth),
                                                   (EGLNativeWindowType) priv->egl_native_window,
-                                                  NULL);
+                                                  attribs);
+      if (priv->egl_surface == EGL_NO_SURFACE)
+        {
+          /* just assume the error is no srgb support and try again without */
+          self->is_srgb = FALSE;
+          priv->egl_surface = eglCreateWindowSurface (gdk_display_get_egl_display (display),
+                                                      gdk_display_get_egl_config (display, depth),
+                                                      (EGLNativeWindowType) priv->egl_native_window,
+                                                      NULL);
+        }
       priv->egl_surface_depth = depth;
     }
 #endif