gob.h

gob.h

#pragma once

#include <stdint.h>

#pragma pack(push, 8)

#if __cplusplus >= 201103L || (__cplusplus && _MSC_VER >= 1900)
#define GOB_DISALLOW_COPYING(type) type(const type&) = delete;
#else
#define GOB_DISALLOW_COPYING(type)
#endif

#define GOB_FOURCC(code) ((code[0]) | (code[1] << 8) | (code[2] << 16) | (code[3] << 24))

typedef int32_t Gob_Offset;

struct Gob_Reference {
	Gob_Offset offset;
	GOB_DISALLOW_COPYING(Gob_Reference)
};

#define GOB_POINTER(reference) \
	((void *)((char *)&(reference) + (reference).offset))

#define GOB_DECLARE_REFERENCE_TYPE(type) \
	union type##Reference { \
		Gob_Offset offset; \
		Gob_Offset offset_##type; \
		GOB_DISALLOW_COPYING(type##Reference) \
	};

#define GOB_GET_POINTER_FROM_REFERENCE(type, reference) \
	((type *)((char *)&(reference) + (reference).offset_##type))

#define GOB_SET_REFERENCE_FROM_POINTER(reference, pointer) \
	(reference).offset = (Gob_Offset)((char *)(pointer) - (char *)&(reference))

#define GOB_GET_SIZE(type, array, count) \
	(sizeof(type) - sizeof(((type *)0)->array[0]) + sizeof(((type *)0)->array[0]) * (count))

GOB_DECLARE_REFERENCE_TYPE(Gob_DescriptorTable)
GOB_DECLARE_REFERENCE_TYPE(Gob_String)
GOB_DECLARE_REFERENCE_TYPE(Gob_Buffer)
GOB_DECLARE_REFERENCE_TYPE(Gob_Node)
GOB_DECLARE_REFERENCE_TYPE(Gob_Mesh)
GOB_DECLARE_REFERENCE_TYPE(Gob_Material)
GOB_DECLARE_REFERENCE_TYPE(Gob_Light)

enum {
	GOB_SIGNATURE = GOB_FOURCC("GOB ")
};

struct Gob_Header {
	uint32_t signature;
	Gob_DescriptorTableReference descriptor_table;
};

typedef uint32_t Gob_Type;

enum {
	GOB_TYPE_BUFFER = GOB_FOURCC("BUFF"),
	GOB_TYPE_MESH = GOB_FOURCC("MESH"),
	GOB_TYPE_NODE = GOB_FOURCC("NODE"),
	GOB_TYPE_MATERIAL = GOB_FOURCC("MATE"),
	GOB_TYPE_LIGHT = GOB_FOURCC("LIGH"),
	GOB_TYPE_SCENE = GOB_FOURCC("SCEN")
};

struct Gob_Descriptor {
	Gob_Type type;
	Gob_Reference reference;
};

struct Gob_DescriptorTable {
	uint32_t descriptors_count;
	Gob_Descriptor descriptors[1];
};

struct Gob_Buffer {
	uint32_t size;
	char data[1];
};

struct Gob_BufferRange {
	Gob_BufferReference buffer;
	uint32_t start;
	uint32_t stride;
};

typedef char *Gob_String;

struct Gob_Float2 {
	float x;
	float y;
};

struct Gob_Float3 {
	float x;
	float y;
	float z;
};

struct Gob_Float4 {
	float x;
	float y;
	float z;
	float w;
};

struct Gob_Transform {
	Gob_Float3 translation;
	Gob_Float3 scale;
	Gob_Float4 rotation;
};

typedef uint8_t Gob_NodeKind;

enum {
	GOB_TRANSFORM_NODE,
	GOB_MESH_NODE,
	GOB_LIGHT_NODE
};

struct Gob_Node {
	Gob_NodeKind kind;
	union {
		Gob_MeshReference mesh;
		Gob_LightReference light;
	};
	Gob_StringReference name;
	Gob_Transform transform;
	uint32_t children_count;
	Gob_NodeReference children[1];
};

struct Gob_Material {
	// ...
};

struct Gob_IndexBuffer {
	uint8_t index_size;
	Gob_BufferReference buffer;
};

typedef uint8_t Gob_MeshTopology;

enum {
	GOB_TRIANGLE_LIST,
	GOB_TRIANGLE_STRIP
};

struct Gob_MeshSection {
	uint32_t index_start;
	uint32_t index_count;
	Gob_MaterialReference material;
};

struct Gob_Mesh {
	Gob_MeshTopology topology;
	Gob_BufferRange positions;
	Gob_BufferRange normals;
	Gob_BufferRange tangents;
	Gob_BufferRange bitangents;
	Gob_IndexBuffer indices;
	uint32_t sections_count;
	Gob_MeshSection sections[1];
};

typedef uint8_t Gob_LightKind;

enum {
	GOB_POINT_LIGHT,
	GOB_DIRECTIONAL_LIGHT,
	GOB_SPOT_LIGHT
};

struct Gob_Light {
	Gob_LightKind kind;
	union {
		Gob_Float3 point;
		Gob_Float3 direction;
	};
	Gob_Float3 color;
};

struct Gob_Scene {
	Gob_NodeReference root;
};

#define GOB_BUFFER(reference) GOB_GET_POINTER_FROM_REFERENCE(Gob_Buffer, reference)
#define GOB_BUFFER_DATA(reference) (GOB_BUFFER(reference)->data)
#define GOB_DESCRIPTOR_TABLE(reference) GOB_GET_POINTER_FROM_REFERENCE(Gob_DescriptorTable, reference)
#define GOB_NODE(reference) GOB_GET_POINTER_FROM_REFERENCE(Gob_Node, reference)
#define GOB_MESH(reference) GOB_GET_POINTER_FROM_REFERENCE(Gob_Mesh, reference)

#pragma pack(pop)