Cleanup.

src/renderer_gl.cpp

@@ -533,6 +533,7 @@ namespace bgfx { namespace gl
 			EXT_shader_image_load_store,
 			EXT_shader_texture_lod,
 			EXT_shadow_samplers,
+			EXT_sRGB_write_control,
 			EXT_texture_array,
 			EXT_texture_compression_dxt1,
 			EXT_texture_compression_latc,
@@ -737,6 +738,7 @@ namespace bgfx { namespace gl
 		{ "EXT_shader_image_load_store",           false,                             true  },
 		{ "EXT_shader_texture_lod",                false,                             true  }, // GLES2 extension.
 		{ "EXT_shadow_samplers",                   false,                             true  },
+		{ "EXT_sRGB_write_control",                false,                             true  }, // GLES2 extension.
 		{ "EXT_texture_array",                     BGFX_CONFIG_RENDERER_OPENGL >= 30, true  },
 		{ "EXT_texture_compression_dxt1",          false,                             true  },
 		{ "EXT_texture_compression_latc",          false,                             true  },
@@ -1224,6 +1226,7 @@ namespace bgfx { namespace gl
 			, m_vaoSupport(false)
 			, m_samplerObjectSupport(false)
 			, m_shadowSamplersSupport(false)
+			, m_srgbWriteControlSupport(BX_ENABLED(BGFX_CONFIG_RENDERER_OPENGL) )
 			, m_borderColorSupport(BX_ENABLED(BGFX_CONFIG_RENDERER_OPENGL) )
 			, m_programBinarySupport(false)
 			, m_textureSwizzleSupport(false)
@@ -1850,6 +1853,8 @@ namespace bgfx { namespace gl
 
 			if (BX_ENABLED(BGFX_CONFIG_RENDERER_OPENGLES) )
 			{
+				m_srgbWriteControlSupport = s_extension[Extension::EXT_sRGB_write_control].m_supported;
+
 				m_borderColorSupport = s_extension[Extension::NV_texture_border_clamp].m_supported;
 				s_textureAddress[BGFX_TEXTURE_U_BORDER>>BGFX_TEXTURE_U_SHIFT] = s_extension[Extension::NV_texture_border_clamp].m_supported
 					? GL_CLAMP_TO_BORDER
@@ -2481,14 +2486,17 @@ namespace bgfx { namespace gl
 			if (!isValid(_fbh) )
 			{
 				GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, m_msaaBackBufferFbo) );
-				
-				if (0 != (m_resolution.m_flags & BGFX_RESET_SRGB_BACKBUFFER))
-				{
-					GL_CHECK(glEnable(GL_FRAMEBUFFER_SRGB));
-				}
-				else
+
+				if (m_srgbWriteControlSupport)
 				{
-					GL_CHECK(glDisable(GL_FRAMEBUFFER_SRGB));
+					if (0 != (m_resolution.m_flags & BGFX_RESET_SRGB_BACKBUFFER) )
+					{
+						GL_CHECK(glEnable(GL_FRAMEBUFFER_SRGB) );
+					}
+					else
+					{
+						GL_CHECK(glDisable(GL_FRAMEBUFFER_SRGB) );
+					}
 				}
 			}
 			else
@@ -3223,6 +3231,7 @@ namespace bgfx { namespace gl
 		bool m_vaoSupport;
 		bool m_samplerObjectSupport;
 		bool m_shadowSamplersSupport;
+		bool m_srgbWriteControlSupport;
 		bool m_borderColorSupport;
 		bool m_programBinarySupport;
 		bool m_textureSwizzleSupport;

src/renderer_gl.h

@@ -738,6 +738,10 @@ typedef uint64_t GLuint64;
 #	define GL_UNSIGNED_INT_10_10_10_2 0x8DF6
 #endif // GL_UNSIGNED_INT_10_10_10_2
 
+#ifndef GL_FRAMEBUFFER_SRGB
+#	define GL_FRAMEBUFFER_SRGB 0x8DB9
+#endif // GL_FRAMEBUFFER_SRGB
+
 // _KHR or _ARB...
 #define GL_DEBUG_OUTPUT_SYNCHRONOUS         0x8242
 #define GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH 0x8243