Further shader compilation development.

include/opengl/data_uploaders/shader_preprocessor.hpp

@@ -0,0 +1,110 @@
+#pragma once
+
+#include <string_view>
+#include <vector>
+#include <optional>
+#include <span>
+#include "util/string_lookup.hpp"
+
+#include "../metadata/shader_source_metadata.hpp"
+#include "opengl/shading/requirements/shader_source_requirements.hpp"
+#include "opengl/metadata/preprocessed_shader_source_metadata.hpp"
+
+#include "assets/dynamic_data_stores/dynamic_shader_source_store.hpp"
+#include "opengl/shading/shader_source_set.hpp"
+
+namespace zgl {
+
+class shader_preprocessor {
+
+public:
+	void preprocess(
+		const dynamic_shader_source_store& shader_sources
+	);
+
+	void fetch_shader_sources(
+		const dynamic_shader_source_store& shader_sources,
+		std::span<const shading::shader_source_requirements> requirements,
+		std::span<preprocessed_shader_source_metadata> metadata,
+		std::vector<const char*>& shader_strings
+	);
+
+
+protected:
+
+	void tokenize_declarations(std::string_view source);
+
+	std::optional<shader_source_metadata> parse_metadata_from_tokens();
+
+	[[nodiscard]] static bool parse_stage_declaration(
+		std::span<const std::string_view> values,
+		shader_source_metadata& metadata
+	);
+
+	[[nodiscard]] static bool parse_geometry_declaration(
+		std::span<const std::string_view> tokens,
+		shader_source_metadata& metadata
+	);
+
+	[[nodiscard]] static bool parse_features_declaration(
+		std::span<const std::string_view> values,
+		shader_source_metadata& metadata
+	);
+
+	[[nodiscard]] static bool parse_static_enable_declaration(
+		std::span<const std::string_view> values,
+		shader_source_metadata& metadata
+	);
+
+	[[nodiscard]] static bool parse_dynamic_enable_declaration(
+		std::span<const std::string_view> values,
+		shader_source_metadata& metadata
+	);
+
+	template<typename T>
+	static void parse_feature_tokens(
+		std::span<const std::string_view> values,
+		const ztu::string_lookup<T>& feature_lookup,
+		T& features
+	);
+
+	static void get_define_strings(
+		shading::model_geometry::types geometry,
+		shading::features::generic::type features,
+		shading::features::generic::type& feature_count,
+		std::vector<const char*>& defines
+	);
+
+private:
+	inline static auto mesh_feature_defines = std::array{
+		"#define FACE\n",
+		"#define LINE\n",
+		"#define POINT\n",
+		"#define V_L\n",
+		"#define V_RGB\n",
+		"#define V_A\n",
+		"#define LIGHTING\n",
+		"#define TEXTURE\n",
+		"#define U_RGBA\n",
+	};
+
+	inline static auto point_cloud_feature_defines = std::array{
+		"#define SQUARE\n",
+		"#define LIGHTING\n",
+		"#define V_L\n",
+		"#define V_RGB\n",
+		"#define V_A\n",
+		"#define U_RGBA\n",
+		"#define RAINBOW\n"
+	};
+
+	std::vector<std::string_view> m_value_token_buffer;
+	std::vector<std::size_t> m_declaration_token_count_buffer;
+	std::array<std::size_t, 4> m_declaration_type_index_buffer;
+
+	using source_lookup_entry_type = std::pair<shader_source_metadata, dynamic_shader_source_store::id_type>;
+	using source_lookup_type = std::vector<source_lookup_entry_type>;
+
+	source_lookup_type m_shader_source_lookup;
+};
+}