/********************************************************************
	Minecraft: Pocket Edition - Decompilation Project
	Copyright (C) 2023 iProgramInCpp
	
	The following code is licensed under the BSD 1 clause license.
	SPDX-License-Identifier: BSD-1-Clause
 ********************************************************************/

#pragma once

#ifdef USE_SDL

#ifdef USE_GLES1_COMPATIBILITY_LAYER
#include <GLES/gl.h>
#define GL_QUADS 0x7

#include <cmath>

// https://cgit.freedesktop.org/mesa/glu/tree/src/libutil/project.c
static inline void __gluMakeIdentityf(GLfloat m[16]) {
	m[0+4*0] = 1; m[0+4*1] = 0; m[0+4*2] = 0; m[0+4*3] = 0;
	m[1+4*0] = 0; m[1+4*1] = 1; m[1+4*2] = 0; m[1+4*3] = 0;
	m[2+4*0] = 0; m[2+4*1] = 0; m[2+4*2] = 1; m[2+4*3] = 0;
	m[3+4*0] = 0; m[3+4*1] = 0; m[3+4*2] = 0; m[3+4*3] = 1;
}
static inline void gluPerspective(GLfloat fovy, GLfloat aspect, GLfloat zNear, GLfloat zFar) {
	GLfloat m[4][4];
	float sine, cotangent, deltaZ;
	float radians = fovy / 2 * M_PI / 180;

	deltaZ = zFar - zNear;
	sine = sin(radians);
	if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {
		return;
	}
	cotangent = cosf(radians) / sine;

	__gluMakeIdentityf(&m[0][0]);
	m[0][0] = cotangent / aspect;
	m[1][1] = cotangent;
	m[2][2] = -(zFar + zNear) / deltaZ;
	m[2][3] = -1;
	m[3][2] = -2 * zNear * zFar / deltaZ;
	m[3][3] = 0;
	glMultMatrixf(&m[0][0]);
}
#else
#define GL_GLEXT_PROTOTYPES
#include <SDL2/SDL_opengl.h>
#include <SDL2/SDL_opengl_glext.h>
#ifdef __APPLE__
#include <OpenGL/glu.h>
#else
#include <GL/glu.h>
#endif
#endif

#define xglBindBuffer         glBindBuffer
#define xglBufferData         glBufferData
#define xglGenBuffers         glGenBuffers
#define xglDeleteBuffers      glDeleteBuffers
#define xglEnableClientState  glEnableClientState
#define xglDisableClientState glDisableClientState
#define xglTexCoordPointer    glTexCoordPointer
#define xglColorPointer       glColorPointer
#define xglVertexPointer      glVertexPointer
#define xglDrawArrays         glDrawArrays

// Note: don't use xglSwapIntervalEXT if you want vsync, you don't know if it's supported
// on your platform so you need to query the extension APIs

#ifdef USE_GLES1_COMPATIBILITY_LAYER
#define xglOrthof glOrthof
#else
#define xglOrthof(left, right, bottom, top, nearpl, farpl) glOrtho((GLdouble) (left), (GLdouble) (right), (GLdouble) (bottom), (GLdouble) (top), (GLdouble) (nearpl), (GLdouble) (farpl))
#endif

// @TODO: not the right place, but er, it's ok
void drawArrayVT(GLuint buffer, int count, int stride);
void drawArrayVTC(GLuint buffer, int count, int stride);

#else

#ifdef USE_OPENGL_2

#define xglBindBuffer         glBindBuffer
#define xglBufferData         glBufferData
#define xglGenBuffers         glGenBuffers
#define xglDeleteBuffers      glDeleteBuffers
#define xglEnableClientState  glEnableClientState
#define xglDisableClientState glDisableClientState
#define xglTexCoordPointer    glTexCoordPointer
#define xglColorPointer       glColorPointer
#define xglVertexPointer      glVertexPointer
#define xglDrawArrays         glDrawArrays

#else

#include "common/Utils.hpp"
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glext.h> // it'll include from a different dir, namely thirdparty/GL/glext.h

void xglInit();
bool xglInitted();

void xglBindBuffer(GLenum target, GLuint buffer);
void xglBufferData(GLenum target, GLsizeiptr size, const GLvoid* data, GLenum usage);
void xglGenBuffers(GLsizei num, GLuint* buffers);
void xglDeleteBuffers(GLsizei num, GLuint* buffers);
void xglOrthof(GLfloat left, GLfloat right, GLfloat bottom, GLfloat top, GLfloat nearpl, GLfloat farpl);
void xglSwapIntervalEXT(int interval);
void xglEnableClientState(GLenum _array);
void xglDisableClientState(GLenum _array);
void xglTexCoordPointer(GLint size, GLenum type, GLsizei stride, const GLvoid* pointer);
void xglColorPointer(GLint size, GLenum type, GLsizei stride, const GLvoid* pointer);
void xglVertexPointer(GLint size, GLenum type, GLsizei stride, const GLvoid* pointer);
void xglDrawArrays(GLenum mode, GLint first, GLsizei count);

// @TODO: not the right place, but er, it's ok
void drawArrayVT(GLuint buffer, int count, int stride);
void drawArrayVTC(GLuint buffer, int count, int stride);

#endif

#endif