/*
gl_rmath.c - renderer mathlib
Copyright (C) 2010 Uncle Mike

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
*/

#include "r_local.h"
#include "xash3d_mathlib.h"

/*
========================================================================

	       Matrix4x4 operations (private to renderer)

========================================================================
*/
void Matrix4x4_Concat( matrix4x4 out, const matrix4x4 in1, const matrix4x4 in2 )
{
	out[0][0] = in1[0][0] * in2[0][0] + in1[0][1] * in2[1][0] + in1[0][2] * in2[2][0] + in1[0][3] * in2[3][0];
	out[0][1] = in1[0][0] * in2[0][1] + in1[0][1] * in2[1][1] + in1[0][2] * in2[2][1] + in1[0][3] * in2[3][1];
	out[0][2] = in1[0][0] * in2[0][2] + in1[0][1] * in2[1][2] + in1[0][2] * in2[2][2] + in1[0][3] * in2[3][2];
	out[0][3] = in1[0][0] * in2[0][3] + in1[0][1] * in2[1][3] + in1[0][2] * in2[2][3] + in1[0][3] * in2[3][3];
	out[1][0] = in1[1][0] * in2[0][0] + in1[1][1] * in2[1][0] + in1[1][2] * in2[2][0] + in1[1][3] * in2[3][0];
	out[1][1] = in1[1][0] * in2[0][1] + in1[1][1] * in2[1][1] + in1[1][2] * in2[2][1] + in1[1][3] * in2[3][1];
	out[1][2] = in1[1][0] * in2[0][2] + in1[1][1] * in2[1][2] + in1[1][2] * in2[2][2] + in1[1][3] * in2[3][2];
	out[1][3] = in1[1][0] * in2[0][3] + in1[1][1] * in2[1][3] + in1[1][2] * in2[2][3] + in1[1][3] * in2[3][3];
	out[2][0] = in1[2][0] * in2[0][0] + in1[2][1] * in2[1][0] + in1[2][2] * in2[2][0] + in1[2][3] * in2[3][0];
	out[2][1] = in1[2][0] * in2[0][1] + in1[2][1] * in2[1][1] + in1[2][2] * in2[2][1] + in1[2][3] * in2[3][1];
	out[2][2] = in1[2][0] * in2[0][2] + in1[2][1] * in2[1][2] + in1[2][2] * in2[2][2] + in1[2][3] * in2[3][2];
	out[2][3] = in1[2][0] * in2[0][3] + in1[2][1] * in2[1][3] + in1[2][2] * in2[2][3] + in1[2][3] * in2[3][3];
	out[3][0] = in1[3][0] * in2[0][0] + in1[3][1] * in2[1][0] + in1[3][2] * in2[2][0] + in1[3][3] * in2[3][0];
	out[3][1] = in1[3][0] * in2[0][1] + in1[3][1] * in2[1][1] + in1[3][2] * in2[2][1] + in1[3][3] * in2[3][1];
	out[3][2] = in1[3][0] * in2[0][2] + in1[3][1] * in2[1][2] + in1[3][2] * in2[2][2] + in1[3][3] * in2[3][2];
	out[3][3] = in1[3][0] * in2[0][3] + in1[3][1] * in2[1][3] + in1[3][2] * in2[2][3] + in1[3][3] * in2[3][3];
}

/*
================
Matrix4x4_CreateProjection

NOTE: produce quake style world orientation
================
*/
void Matrix4x4_CreateProjection( matrix4x4 out, float xMax, float xMin, float yMax, float yMin, float zNear, float zFar )
{
	out[0][0] = ( 2.0f * zNear ) / ( xMax - xMin );
	out[1][1] = ( 2.0f * zNear ) / ( yMax - yMin );
	out[2][2] = -( zFar + zNear ) / ( zFar - zNear );
	out[3][3] = out[0][1] = out[1][0] = out[3][0] = out[0][3] = out[3][1] = out[1][3] = 0.0f;

	out[2][0] = 0.0f;
	out[2][1] = 0.0f;
	out[0][2] = ( xMax + xMin ) / ( xMax - xMin );
	out[1][2] = ( yMax + yMin ) / ( yMax - yMin );
	out[3][2] = -1.0f;
	out[2][3] = -( 2.0f * zFar * zNear ) / ( zFar - zNear );
}

void Matrix4x4_CreateOrtho( matrix4x4 out, float xLeft, float xRight, float yBottom, float yTop, float zNear, float zFar )
{
	out[0][0] = 2.0f / ( xRight - xLeft );
	out[1][1] = 2.0f / ( yTop - yBottom );
	out[2][2] = -2.0f / ( zFar - zNear );
	out[3][3] = 1.0f;
	out[0][1] = out[0][2] = out[1][0] = out[1][2] = out[3][0] = out[3][1] = out[3][2] = 0.0f;

	out[2][0] = 0.0f;
	out[2][1] = 0.0f;
	out[0][3] = -( xRight + xLeft ) / ( xRight - xLeft );
	out[1][3] = -( yTop + yBottom ) / ( yTop - yBottom );
	out[2][3] = -( zFar + zNear ) / ( zFar - zNear );
}

/*
================
Matrix4x4_CreateModelview

NOTE: produce quake style world orientation
================
*/
void Matrix4x4_CreateModelview( matrix4x4 out )
{
	out[0][0] = out[1][1] = out[2][2] = 0.0f;
	out[3][0] = out[0][3] = 0.0f;
	out[3][1] = out[1][3] = 0.0f;
	out[3][2] = out[2][3] = 0.0f;
	out[3][3] = 1.0f;
	out[1][0] = out[0][2] = out[2][1] = 0.0f;
	out[2][0] = out[0][1] = -1.0f;
	out[1][2] = 1.0f;
}

void Matrix4x4_CreateTranslate( matrix4x4 out, float x, float y, float z )
{
	out[0][0] = 1.0f;
	out[0][1] = 0.0f;
	out[0][2] = 0.0f;
	out[0][3] = x;
	out[1][0] = 0.0f;
	out[1][1] = 1.0f;
	out[1][2] = 0.0f;
	out[1][3] = y;
	out[2][0] = 0.0f;
	out[2][1] = 0.0f;
	out[2][2] = 1.0f;
	out[2][3] = z;
	out[3][0] = 0.0f;
	out[3][1] = 0.0f;
	out[3][2] = 0.0f;
	out[3][3] = 1.0f;
}

void Matrix4x4_CreateRotate( matrix4x4 out, float angle, float x, float y, float z )
{
	float len, c, s;

	len = x * x + y * y + z * z;
	if( len != 0.0f )
		len = 1.0f / sqrt( len );
	x *= len;
	y *= len;
	z *= len;

	angle *= ( -M_PI_F / 180.0f );
	SinCos( angle, &s, &c );

	out[0][0] = x * x + c * ( 1 - x * x );
	out[0][1] = x * y * ( 1 - c ) + z * s;
	out[0][2] = z * x * ( 1 - c ) - y * s;
	out[0][3] = 0.0f;
	out[1][0] = x * y * ( 1 - c ) - z * s;
	out[1][1] = y * y + c * ( 1 - y * y );
	out[1][2] = y * z * ( 1 - c ) + x * s;
	out[1][3] = 0.0f;
	out[2][0] = z * x * ( 1 - c ) + y * s;
	out[2][1] = y * z * ( 1 - c ) - x * s;
	out[2][2] = z * z + c * ( 1 - z * z );
	out[2][3] = 0.0f;
	out[3][0] = 0.0f;
	out[3][1] = 0.0f;
	out[3][2] = 0.0f;
	out[3][3] = 1.0f;
}

static void Matrix4x4_CreateScale( matrix4x4 out, float x )
{
	out[0][0] = x;
	out[0][1] = 0.0f;
	out[0][2] = 0.0f;
	out[0][3] = 0.0f;
	out[1][0] = 0.0f;
	out[1][1] = x;
	out[1][2] = 0.0f;
	out[1][3] = 0.0f;
	out[2][0] = 0.0f;
	out[2][1] = 0.0f;
	out[2][2] = x;
	out[2][3] = 0.0f;
	out[3][0] = 0.0f;
	out[3][1] = 0.0f;
	out[3][2] = 0.0f;
	out[3][3] = 1.0f;
}

static void Matrix4x4_CreateScale3( matrix4x4 out, float x, float y, float z )
{
	out[0][0] = x;
	out[0][1] = 0.0f;
	out[0][2] = 0.0f;
	out[0][3] = 0.0f;
	out[1][0] = 0.0f;
	out[1][1] = y;
	out[1][2] = 0.0f;
	out[1][3] = 0.0f;
	out[2][0] = 0.0f;
	out[2][1] = 0.0f;
	out[2][2] = z;
	out[2][3] = 0.0f;
	out[3][0] = 0.0f;
	out[3][1] = 0.0f;
	out[3][2] = 0.0f;
	out[3][3] = 1.0f;
}

void Matrix4x4_ConcatTranslate( matrix4x4 out, float x, float y, float z )
{
	matrix4x4 base, temp;

	Matrix4x4_Copy( base, out );
	Matrix4x4_CreateTranslate( temp, x, y, z );
	Matrix4x4_Concat( out, base, temp );
}

void Matrix4x4_ConcatRotate( matrix4x4 out, float angle, float x, float y, float z )
{
	matrix4x4 base, temp;

	Matrix4x4_Copy( base, out );
	Matrix4x4_CreateRotate( temp, angle, x, y, z );
	Matrix4x4_Concat( out, base, temp );
}