/*
 * Copyright (C) 2018 Tomasz Kramkowski <tk@the-tk.com>
 * SPDX-License-Identifier: MIT
 */
#include <setjmp.h>

#include "loadgl.h"

#define LGL_FUNC(name, glname)				\
	name##_func *name;				\
	static const char *name##_gln = #glname;

LGL_FUNC(gl_viewport, glViewport);
LGL_FUNC(gl_clearcolor, glClearColor);
LGL_FUNC(gl_clear, glClear);
LGL_FUNC(gl_buf_gen, glGenBuffers);
LGL_FUNC(gl_buf_bind, glBindBuffer);
LGL_FUNC(gl_buf_data, glBufferData);
LGL_FUNC(gl_shdr_create, glCreateShader);
LGL_FUNC(gl_shdr_del, glDeleteShader);
LGL_FUNC(gl_shdr_source, glShaderSource);
LGL_FUNC(gl_shdr_compile, glCompileShader);
LGL_FUNC(gl_shdr_param, glGetShaderiv);
LGL_FUNC(gl_shdr_infolog, glGetShaderInfoLog);
LGL_FUNC(gl_prog_create, glCreateProgram);
LGL_FUNC(gl_prog_attachshdr, glAttachShader);
LGL_FUNC(gl_prog_link, glLinkProgram);
LGL_FUNC(gl_prog_use, glUseProgram);
LGL_FUNC(gl_prog_del, glDeleteProgram);
LGL_FUNC(gl_prog_param, glGetProgramiv);
LGL_FUNC(gl_prog_infolog, glGetProgramInfoLog);
LGL_FUNC(gl_va_define, glVertexAttribPointer);
LGL_FUNC(gl_va_enable, glEnableVertexAttribArray);
LGL_FUNC(gl_va_disable, glDisableVertexAttribArray);
LGL_FUNC(gl_va_gen, glGenVertexArrays);
LGL_FUNC(gl_va_bind, glBindVertexArray);
LGL_FUNC(gl_draw_arrays, glDrawArrays);
LGL_FUNC(gl_draw_elems, glDrawElements);
LGL_FUNC(gl_poly_mode, glPolygonMode);

static void *load_func(const char *name, lgl_loadfunc *load, jmp_buf env)
{
	void *ret;

	ret = load(name);
	if (ret == NULL)
		longjmp(env, LGL_MISSING);

	return ret;
}

enum lgl_status lgl_load(lgl_loadfunc *load)
{
	enum lgl_status status;
	jmp_buf env;

	status = setjmp(env);
	if (status != 0)
		return status;

#define LGL_LOAD(name) name = (name##_func *)load_func(name##_gln, load, env);
	LGL_LOAD(gl_viewport);
	LGL_LOAD(gl_clearcolor);
	LGL_LOAD(gl_clear);
	LGL_LOAD(gl_buf_gen);
	LGL_LOAD(gl_buf_bind);
	LGL_LOAD(gl_buf_data);
	LGL_LOAD(gl_shdr_create);
	LGL_LOAD(gl_shdr_del);
	LGL_LOAD(gl_shdr_source);
	LGL_LOAD(gl_shdr_compile);
	LGL_LOAD(gl_shdr_param);
	LGL_LOAD(gl_shdr_infolog);
	LGL_LOAD(gl_prog_create);
	LGL_LOAD(gl_prog_attachshdr);
	LGL_LOAD(gl_prog_link);
	LGL_LOAD(gl_prog_use);
	LGL_LOAD(gl_prog_del);
	LGL_LOAD(gl_prog_param);
	LGL_LOAD(gl_prog_infolog);
	LGL_LOAD(gl_va_define);
	LGL_LOAD(gl_va_enable);
	LGL_LOAD(gl_va_disable);
	LGL_LOAD(gl_va_gen);
	LGL_LOAD(gl_va_bind);
	LGL_LOAD(gl_draw_arrays);
	LGL_LOAD(gl_draw_elems);
	LGL_LOAD(gl_poly_mode);

	return LGL_OK;
}

const char *lgl_strerror(enum lgl_status status)
{
	switch (status) {
	case LGL_OK: return "Success";
	case LGL_MISSING: return "Missing function";
	}
	return "Unknown";
}