Add bit casting to HLSL

spirv_glsl.hpp

@@ -371,7 +371,7 @@ protected:
 	uint32_t type_to_std430_size(const SPIRType &type, uint64_t flags);
 
 	std::string bitcast_glsl(const SPIRType &result_type, uint32_t arg);
-	std::string bitcast_glsl_op(const SPIRType &result_type, const SPIRType &argument_type);
+	virtual std::string bitcast_glsl_op(const SPIRType &result_type, const SPIRType &argument_type);
 	std::string build_composite_combiner(const uint32_t *elems, uint32_t length);
 	bool remove_duplicate_swizzle(std::string &op);
 	bool remove_unity_swizzle(uint32_t base, std::string &op);

spirv_hlsl.cpp

@@ -1242,6 +1242,36 @@ void CompilerHLSL::emit_uniform(const SPIRVariable &var)
 	statement(variable_decl(var), ";");
 }
 
+string CompilerHLSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &in_type)
+{
+	if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Int)
+		return type_to_glsl(out_type);
+	else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Int64)
+		return type_to_glsl(out_type);
+	else if (out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Float)
+		return "asuint";
+	else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::UInt)
+		return type_to_glsl(out_type);
+	else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::UInt64)
+		return type_to_glsl(out_type);
+	else if (out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Float)
+		return "asint";
+	else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::UInt)
+		return "asfloat";
+	else if (out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::Int)
+		return "asfloat";
+	else if (out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Double)
+		SPIRV_CROSS_THROW("Double to Int64 is not supported in HLSL.");
+	else if (out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Double)
+		SPIRV_CROSS_THROW("Double to UInt64 is not supported in HLSL.");
+	else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::Int64)
+		return "asdouble";
+	else if (out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::UInt64)
+		return "asdouble";
+	else
+		return "";
+}
+
 void CompilerHLSL::emit_glsl_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args, uint32_t count)
 {
 	GLSLstd450 op = static_cast<GLSLstd450>(eop);

spirv_hlsl.hpp

@@ -69,6 +69,7 @@ private:
 	void emit_uniform(const SPIRVariable &var) override;
 	std::string layout_for_member(const SPIRType &type, uint32_t index) override;
 	std::string to_interpolation_qualifiers(uint64_t flags) override;
+	std::string bitcast_glsl_op(const SPIRType &result_type, const SPIRType &argument_type) override;
 
 	const char *to_storage_qualifiers_glsl(const SPIRVariable &var) override;