[gtk/wip.win32.fixes: 13/16] gsk/gl/resources/*.glsl: Add GLSL 300 ES items

[Chun-wei Fan <fanchunwei src gnome org>]

commit 690674d16f8839a7105fa847c62139979f76bd8f
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Nov 23 12:09:50 2021 +0800

    gsk/gl/resources/*.glsl: Add GLSL 300 ES items
    
    This attempts to make the shaders ready for use with GLSL 300 ES, which
    is necessary for libANGLE support, for EGL/GLES support on Windows.

 gsk/gl/resources/preamble.glsl | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/gsk/gl/resources/preamble.glsl b/gsk/gl/resources/preamble.glsl
index 8bc007ba67..9ca94e8b7c 100644
--- a/gsk/gl/resources/preamble.glsl
+++ b/gsk/gl/resources/preamble.glsl
@@ -10,7 +10,11 @@ precision highp float;
 #else
 #define _OUT_ out
 #define _IN_ in
+#if defined (GSK_GLES3)
+#define _NOPERSPECTIVE_
+#else
 #define _NOPERSPECTIVE_ noperspective
+#endif
 #define _GSK_ROUNDED_RECT_UNIFORM_ GskRoundedRect
 #endif