From 785042dc9ebde9a61e6989425ee4e7026833ea1f Mon Sep 17 00:00:00 2001
From: lhofhansl <larsh@apache.org>
Date: Fri, 14 Nov 2025 09:52:55 -0800
Subject: [PATCH] Force highp precision for float and sampler2d on GLES, if
 supported (#16671)

This sets the default precision for float and samper2d on GLES devices that support it.
---
 src/client/shader.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/client/shader.cpp b/src/client/shader.cpp
index 6fc5010af..6317d68e2 100644
--- a/src/client/shader.cpp
+++ b/src/client/shader.cpp
@@ -697,8 +697,15 @@ void ShaderSource::generateShader(ShaderInfo &shaderinfo)
 					<< "#define CENTROID_\n";
 			}
 			// Precision is only meaningful on GLES
-			shaders_header << "precision mediump float;\n"
-				"precision mediump sampler2D;\n";
+			shaders_header << R"(
+				#ifdef GL_FRAGMENT_PRECISION_HIGH
+				precision highp float;
+				precision highp sampler2D;
+				#else
+				precision mediump float;
+				precision mediump sampler2D;
+				#endif
+			)";
 		} else {
 			assert(false);
 		}