/*****************************************************************************
                    The Dark Mod GPL Source Code
 
 This file is part of the The Dark Mod Source Code, originally based 
 on the Doom 3 GPL Source Code as published in 2011.
 
 The Dark Mod Source Code 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. For details, see LICENSE.TXT.
 
 Project: The Dark Mod (http://www.thedarkmod.com/)
 
******************************************************************************/
#include "precompiled.h"
#pragma hdrstop



#include "tr_local.h"

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

GUI SHADERS

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

/*
================
R_SurfaceToTextureAxis

Calculates two axis for the surface sutch that a point dotted against
the axis will give a 0.0 to 1.0 range in S and T when inside the gui surface
================
*/
void R_SurfaceToTextureAxis( const srfTriangles_t *tri, idVec3 &origin, idVec3 axis[3] ) {
	float		area, inva;
	float		d0[5], d1[5];
	idDrawVert	*a, *b, *c;
	float		bounds[2][2];
	float		boundsOrg[2];
	int			i, j;
	float		v;
	
	// find the bounds of the texture
	bounds[0][0] = bounds[0][1] = 999999;
	bounds[1][0] = bounds[1][1] = -999999;
	for ( i = 0 ; i < tri->numVerts ; i++ ) {
		for ( j = 0 ; j < 2 ; j++ ) {
			v = tri->verts[i].st[j];
			if ( v < bounds[0][j] ) {
				bounds[0][j] = v;
			}
			if ( v > bounds[1][j] ) {
				bounds[1][j] = v;
			}
		}
	}

	// use the floor of the midpoint as the origin of the
	// surface, which will prevent a slight misalignment
	// from throwing it an entire cycle off
	boundsOrg[0] = floor( ( bounds[0][0] + bounds[1][0] ) * 0.5 );
	boundsOrg[1] = floor( ( bounds[0][1] + bounds[1][1] ) * 0.5 );


	// determine the world S and T vectors from the first drawSurf triangle
	a = tri->verts + tri->indexes[0];
	b = tri->verts + tri->indexes[1];
	c = tri->verts + tri->indexes[2];

	VectorSubtract( b->xyz, a->xyz, d0 );
	d0[3] = b->st[0] - a->st[0];
	d0[4] = b->st[1] - a->st[1];
	VectorSubtract( c->xyz, a->xyz, d1 );
	d1[3] = c->st[0] - a->st[0];
	d1[4] = c->st[1] - a->st[1];

	area = d0[3] * d1[4] - d0[4] * d1[3];
	if ( area == 0.0 ) {
		axis[0].Zero();
		axis[1].Zero();
		axis[2].Zero();
		return;	// degenerate
	}
	inva = 1.0 / area;

    axis[0][0] = (d0[0] * d1[4] - d0[4] * d1[0]) * inva;
    axis[0][1] = (d0[1] * d1[4] - d0[4] * d1[1]) * inva;
    axis[0][2] = (d0[2] * d1[4] - d0[4] * d1[2]) * inva;
    
    axis[1][0] = (d0[3] * d1[0] - d0[0] * d1[3]) * inva;
    axis[1][1] = (d0[3] * d1[1] - d0[1] * d1[3]) * inva;
    axis[1][2] = (d0[3] * d1[2] - d0[2] * d1[3]) * inva;

	idPlane plane;
	plane.FromPoints( a->xyz, b->xyz, c->xyz );
	axis[2][0] = plane[0];
	axis[2][1] = plane[1];
	axis[2][2] = plane[2];

	// take point 0 and project the vectors to the texture origin
	VectorMA( a->xyz, boundsOrg[0] - a->st[0], axis[0], origin );
	VectorMA( origin, boundsOrg[1] - a->st[1], axis[1], origin );
}

/*
=================
R_RenderGuiSurf

Create a texture space on the given surface and
call the GUI generator to create quads for it.
=================
*/
void R_RenderGuiSurf( idUserInterface *gui, drawSurf_t *drawSurf ) {
	idVec3	origin, axis[3];

	// for testing the performance hit
	if ( r_skipGuiShaders.GetInteger() == 1 ) {
		return;
	}

	// don't allow an infinite recursion loop
	if ( tr.guiRecursionLevel == 4 ) {
		return;
	}

	tr.pc.c_guiSurfs++;

	// create the new matrix to draw on this surface
	R_SurfaceToTextureAxis( drawSurf->frontendGeo, origin, axis );

	float	guiModelMatrix[16];
	float	modelMatrix[16];

	guiModelMatrix[0] = axis[0][0] / 640.0;
	guiModelMatrix[4] = axis[1][0] / 480.0;
	guiModelMatrix[8] = axis[2][0];
	guiModelMatrix[12] = origin[0];

	guiModelMatrix[1] = axis[0][1] / 640.0;
	guiModelMatrix[5] = axis[1][1] / 480.0;
	guiModelMatrix[9] = axis[2][1];
	guiModelMatrix[13] = origin[1];

	guiModelMatrix[2] = axis[0][2] / 640.0;
	guiModelMatrix[6] = axis[1][2] / 480.0;
	guiModelMatrix[10] = axis[2][2];
	guiModelMatrix[14] = origin[2];

	guiModelMatrix[3] = 0;
	guiModelMatrix[7] = 0;
	guiModelMatrix[11] = 0;
	guiModelMatrix[15] = 1;

	myGlMultMatrix( guiModelMatrix, drawSurf->space->modelMatrix, 
			modelMatrix );

	tr.guiRecursionLevel++;

	// call the gui, which will call the 2D drawing functions
	tr.guiModel->Clear();
	gui->Redraw( tr.viewDef->renderView.time );
	tr.guiModel->EmitToCurrentView( modelMatrix, drawSurf->space->weaponDepthHack );
	tr.guiModel->Clear();

	tr.guiRecursionLevel--;
}

/*
================,
R_ReloadGuis_f

Reloads any guis that have had their file timestamps changed.
An optional "all" parameter will cause all models to reload, even
if they are not out of date.

Should we also reload the map models?
================
*/
void R_ReloadGuis_f( const idCmdArgs &args ) {
	bool all;

	if ( !idStr::Icmp( args.Argv(1), "all" ) ) {
		all = true;
		common->Printf( "Reloading all gui files...\n" );
	} else {
		all = false;
		common->Printf( "Checking for changed gui files...\n" );
	}

	uiManager->Reload( all );
}

/*
================,
R_ListGuis_f

================
*/
void R_ListGuis_f( const idCmdArgs &args ) {
	uiManager->ListGuis();
}
