GLSL: Need extension to use bitcast on GLSL < 330.

spirv_glsl.cpp

@@ -5919,13 +5919,38 @@ string CompilerGLSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &i
 	// Floating <-> Integer special casts. Just have to enumerate all cases. :(
 	// 16-bit, 32-bit and 64-bit floats.
 	if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Float)
+	{
+		if (is_legacy_es())
+			SPIRV_CROSS_THROW("Float -> Uint bitcast not supported on legacy ESSL.");
+		else if (!options.es && options.version < 330)
+			require_extension_internal("GL_ARB_shader_bit_encoding");
 		return "floatBitsToUint";
+	}
 	else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Float)
+	{
+		if (is_legacy_es())
+			SPIRV_CROSS_THROW("Float -> Int bitcast not supported on legacy ESSL.");
+		else if (!options.es && options.version < 330)
+			require_extension_internal("GL_ARB_shader_bit_encoding");
 		return "floatBitsToInt";
+	}
 	else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::UInt)
+	{
+		if (is_legacy_es())
+			SPIRV_CROSS_THROW("Uint -> Float bitcast not supported on legacy ESSL.");
+		else if (!options.es && options.version < 330)
+			require_extension_internal("GL_ARB_shader_bit_encoding");
 		return "uintBitsToFloat";
+	}
 	else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::Int)
+	{
+		if (is_legacy_es())
+			SPIRV_CROSS_THROW("Int -> Float bitcast not supported on legacy ESSL.");
+		else if (!options.es && options.version < 330)
+			require_extension_internal("GL_ARB_shader_bit_encoding");
 		return "intBitsToFloat";
+	}
+
 	else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Double)
 		return "doubleBitsToInt64";
 	else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Double)