Archived
1
Fork 0
This repository has been archived on 2025-04-12. You can view files and clone it, but cannot push or open issues or pull requests.
prism/engine/shadercompiler/include/shadercompiler.hpp
redstrate ae599ba744 Make fragment shader stage optional
Removes the fragment on (normal) shadow pass
2021-02-04 09:36:06 -05:00

82 lines
2.6 KiB
C++
Executable file

#pragma once
#include <variant>
#include <string>
#include <vector>
#include <string_view>
#include <optional>
/// The shader stage that the shader is written in.
enum class ShaderStage {
Vertex,
Fragment,
Compute
};
/// The shader language that the shader is written in.
enum class ShaderLanguage {
GLSL,
MSL,
SPIRV
};
/// Compilation options when compiling shaders.
class CompileOptions {
public:
/// Adds a GLSL define.
void add_definition(const std::string_view name) {
definitions.emplace_back(name);
}
std::vector<std::string> definitions;
/// When compiling MSL, the result may differ whether or not we're targetting non-Mac Metal platforms.
bool is_apple_mobile = false;
};
/// Represents the source code of a shader either in plaintext (GLSL, MSL) or bytecode (SPIR-V).
class ShaderSource {
public:
ShaderSource() : source(std::monostate()) {}
ShaderSource(const ShaderSource& rhs) : source (rhs.source) {}
ShaderSource(const std::string source_string) : source(source_string) {}
ShaderSource(const std::vector<uint32_t> source_bytecode) : source(source_bytecode) {}
std::variant<std::monostate, std::string, std::vector<uint32_t>> source;
/// Returns a view of the shader source as plaintext.
std::string_view as_string() const {
return std::get<std::string>(source);
}
/// Returns a copy of the shader source as bytecode.
std::vector<uint32_t> as_bytecode() const {
return std::get<std::vector<uint32_t>>(source);
}
bool empty() const {
return std::holds_alternative<std::monostate>(source);
}
};
/// Compiles GLSL shaders to a specified shader language offline or at runtime.
class ShaderCompiler {
public:
ShaderCompiler();
/// Sets the include directory used to search for files inside of #include directives.
void set_include_path(const std::string_view path);
/**
Compiles from one shader language to another shader language.
@param from_language The language the shader passed by shader_source is written in.
@param shader_stage The shader stage of the shader.
@param shader_source The shader code.
@param to_language The shader language to compile to.
@param options Optional compilation parameters.
@note Right now, only GLSL is supported as a source shader language.
*/
std::optional<ShaderSource> compile(const ShaderLanguage from_language, const ShaderStage shader_stage, const ShaderSource& shader_source, const ShaderLanguage to_language, const CompileOptions& options = CompileOptions());
};
static inline ShaderCompiler shader_compiler;