/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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 2
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file gameengine/BlenderRoutines/KX_BlenderRenderTools.cpp
 *  \ingroup blroutines
 */


#include "GL/glew.h"

#include "RAS_IRenderTools.h"
#include "RAS_IRasterizer.h"
#include "RAS_LightObject.h"
#include "RAS_ICanvas.h"
#include "RAS_GLExtensionManager.h"
#include "RAS_MeshObject.h"

#include "KX_GameObject.h"
#include "KX_PolygonMaterial.h"
#include "KX_BlenderMaterial.h"
#include "KX_RayCast.h"
#include "KX_IPhysicsController.h"
#include "KX_Light.h"

#include "PHY_IPhysicsEnvironment.h"

#include "STR_String.h"

#include "GPU_draw.h"

#include "KX_BlenderGL.h" // for text printing
#include "KX_BlenderRenderTools.h"

unsigned int KX_BlenderRenderTools::m_numgllights;

KX_BlenderRenderTools::KX_BlenderRenderTools()
{
	glGetIntegerv(GL_MAX_LIGHTS, (GLint *) &m_numgllights);
	if (m_numgllights < 8)
		m_numgllights = 8;
}

KX_BlenderRenderTools::~KX_BlenderRenderTools()
{
}

void KX_BlenderRenderTools::BeginFrame(RAS_IRasterizer* rasty)
{
	m_clientobject = NULL;
	m_lastlightlayer = -1;
	m_lastauxinfo = NULL;
	m_lastlighting = true; /* force disable in DisableOpenGLLights() */
	DisableOpenGLLights();
}

void KX_BlenderRenderTools::EndFrame(RAS_IRasterizer* rasty)
{
}

/* ProcessLighting performs lighting on objects. the layer is a bitfield that
 * contains layer information. There are 20 'official' layers in blender. A
 * light is applied on an object only when they are in the same layer. OpenGL
 * has a maximum of 8 lights (simultaneous), so 20 * 8 lights are possible in
 * a scene. */

void KX_BlenderRenderTools::ProcessLighting(RAS_IRasterizer *rasty, bool uselights, const MT_Transform& viewmat)
{
	bool enable = false;
	int layer= -1;

	/* find the layer */
	if (uselights) {
		if (m_clientobject)
			layer = static_cast<KX_GameObject*>(m_clientobject)->GetLayer();
	}

	/* avoid state switching */
	if (m_lastlightlayer == layer && m_lastauxinfo == m_auxilaryClientInfo)
		return;

	m_lastlightlayer = layer;
	m_lastauxinfo = m_auxilaryClientInfo;

	/* enable/disable lights as needed */
	if (layer >= 0)
		enable = applyLights(layer, viewmat);

	if (enable)
		EnableOpenGLLights(rasty);
	else
		DisableOpenGLLights();
}

void KX_BlenderRenderTools::EnableOpenGLLights(RAS_IRasterizer *rasty)
{
	if (m_lastlighting == true)
		return;

	glEnable(GL_LIGHTING);
	glEnable(GL_COLOR_MATERIAL);

	glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
	glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, (rasty->GetCameraOrtho())? GL_FALSE: GL_TRUE);
	if (GLEW_EXT_separate_specular_color || GLEW_VERSION_1_2)
		glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL, GL_SEPARATE_SPECULAR_COLOR);
	
	m_lastlighting = true;
}

void KX_BlenderRenderTools::DisableOpenGLLights()
{
	if (m_lastlighting == false)
		return;

	glDisable(GL_LIGHTING);
	glDisable(GL_COLOR_MATERIAL);

	m_lastlighting = false;
}


void KX_BlenderRenderTools::SetClientObject(RAS_IRasterizer *rasty, void* obj)
{
	if (m_clientobject != obj)
	{
		bool ccw = (obj == NULL || !((KX_GameObject*)obj)->IsNegativeScaling());
		rasty->SetFrontFace(ccw);

		m_clientobject = obj;
	}
}

bool KX_BlenderRenderTools::RayHit(KX_ClientObjectInfo *client, KX_RayCast *result, void * const data)
{
	double* const oglmatrix = (double* const) data;

	RAS_Polygon* poly = result->m_hitMesh->GetPolygon(result->m_hitPolygon);
	if (!poly->IsVisible())
		return false;

	MT_Point3 resultpoint(result->m_hitPoint);
	MT_Vector3 resultnormal(result->m_hitNormal);
	MT_Vector3 left(oglmatrix[0],oglmatrix[1],oglmatrix[2]);
	MT_Vector3 dir = -(left.cross(resultnormal)).safe_normalized();
	left = (dir.cross(resultnormal)).safe_normalized();
	// for the up vector, we take the 'resultnormal' returned by the physics
	
	double maat[16] = {left[0],         left[1],         left[2],         0,
	                   dir[0],          dir[1],          dir[2],          0,
	                   resultnormal[0], resultnormal[1], resultnormal[2], 0,
	                   0,               0,               0,               1};

	glTranslated(resultpoint[0],resultpoint[1],resultpoint[2]);
	//glMultMatrixd(oglmatrix);
	glMultMatrixd(maat);
	return true;
}

void KX_BlenderRenderTools::applyTransform(RAS_IRasterizer* rasty,double* oglmatrix,int objectdrawmode )
{
	/* FIXME:
	blender: intern/moto/include/MT_Vector3.inl:42: MT_Vector3 operator/(const
	MT_Vector3&, double): Assertion `!MT_fuzzyZero(s)' failed. 
	
	Program received signal SIGABRT, Aborted. 
	[Switching to Thread 16384 (LWP 1519)] 
	0x40477571 in kill () from /lib/libc.so.6 
	(gdb) bt 
	#7  0x08334368 in MT_Vector3::normalized() const () 
	#8  0x0833e6ec in KX_BlenderRenderTools::applyTransform(RAS_IRasterizer*, double*, int) () 
	*/

	if (objectdrawmode & RAS_IPolyMaterial::BILLBOARD_SCREENALIGNED ||
		objectdrawmode & RAS_IPolyMaterial::BILLBOARD_AXISALIGNED)
	{
		// rotate the billboard/halo
		//page 360/361 3D Game Engine Design, David Eberly for a discussion
		// on screen aligned and axis aligned billboards
		// assumed is that the preprocessor transformed all billboard polygons
		// so that their normal points into the positive x direction (1.0, 0.0, 0.0)
		// when new parenting for objects is done, this rotation
		// will be moved into the object
		
		MT_Point3 objpos (oglmatrix[12],oglmatrix[13],oglmatrix[14]);
		MT_Point3 campos = rasty->GetCameraPosition();
		MT_Vector3 dir = (campos - objpos).safe_normalized();
		MT_Vector3 up(0,0,1.0);

		KX_GameObject* gameobj = (KX_GameObject*)m_clientobject;
		// get scaling of halo object
		MT_Vector3  size = gameobj->GetSGNode()->GetWorldScaling();
		
		bool screenaligned = (objectdrawmode & RAS_IPolyMaterial::BILLBOARD_SCREENALIGNED)!=0;//false; //either screen or axisaligned
		if (screenaligned)
		{
			up = (up - up.dot(dir) * dir).safe_normalized();
		} else
		{
			dir = (dir - up.dot(dir)*up).safe_normalized();
		}

		MT_Vector3 left = dir.normalized();
		dir = (up.cross(left)).normalized();

		// we have calculated the row vectors, now we keep
		// local scaling into account:

		left *= size[0];
		dir  *= size[1];
		up   *= size[2];

		double maat[16] = {left[0], left[1], left[2], 0,
		                   dir[0],  dir[1],  dir[2],  0,
		                   up[0],   up[1],   up[2],   0,
		                   0,       0,       0,       1};

		glTranslated(objpos[0],objpos[1],objpos[2]);
		glMultMatrixd(maat);

	}
	else {
		if (objectdrawmode & RAS_IPolyMaterial::SHADOW)
		{
			// shadow must be cast to the ground, physics system needed here!
			MT_Point3 frompoint(oglmatrix[12],oglmatrix[13],oglmatrix[14]);
			KX_GameObject *gameobj = (KX_GameObject*)m_clientobject;
			MT_Vector3 direction = MT_Vector3(0,0,-1);

			direction.normalize();
			direction *= 100000;

			MT_Point3 topoint = frompoint + direction;

			KX_Scene* kxscene = (KX_Scene*) m_auxilaryClientInfo;
			PHY_IPhysicsEnvironment* physics_environment = kxscene->GetPhysicsEnvironment();
			KX_IPhysicsController* physics_controller = gameobj->GetPhysicsController();
			
			KX_GameObject *parent = gameobj->GetParent();
			if (!physics_controller && parent)
				physics_controller = parent->GetPhysicsController();
			if (parent)
				parent->Release();
				
			KX_RayCast::Callback<KX_BlenderRenderTools> callback(this, physics_controller, oglmatrix);
			if (!KX_RayCast::RayTest(physics_environment, frompoint, topoint, callback))
			{
				// couldn't find something to cast the shadow on...
				glMultMatrixd(oglmatrix);
			}
			else
			{ // we found the "ground", but the cast matrix doesn't take
			  // scaling in consideration, so we must apply the object scale
				MT_Vector3  size = gameobj->GetSGNode()->GetLocalScale();
				glScalef(size[0], size[1], size[2]);
			}
		} else
		{

			// 'normal' object
			glMultMatrixd(oglmatrix);
		}
	}
}

void KX_BlenderRenderTools::RenderBox2D(int xco,
			int yco,
			int width,
			int height,
			float percentage)
{
	BL_draw_gamedebug_box(xco, yco, width, height, percentage);
}

void KX_BlenderRenderTools::RenderText3D(int fontid,
										 const char* text,
										 int size,
										 int dpi,
										 float* color,
										 double* mat,
										 float aspect)
{
	BL_print_game_line(fontid, text, size, dpi, color, mat, aspect);
}

void KX_BlenderRenderTools::RenderText2D(RAS_TEXT_RENDER_MODE mode,
										 const char* text,
										 int xco,
										 int yco,									 
										 int width,
										 int height)
{
	if (mode == RAS_IRenderTools::RAS_TEXT_PADDED)
		BL_print_gamedebug_line_padded(text, xco, yco, width, height);
	else
		BL_print_gamedebug_line(text, xco, yco, width, height);
}

/* Render Text renders text into a (series of) polygon, using a texture font,
 * Each character consists of one polygon (one quad or two triangles) */

void KX_BlenderRenderTools::RenderText(
	int mode,
	RAS_IPolyMaterial* polymat,
	float v1[3], float v2[3], float v3[3], float v4[3], int glattrib)
{
	const STR_String& mytext = ((CValue*)m_clientobject)->GetPropertyText("Text");
	
	const unsigned int flag = polymat->GetFlag();
	struct MTFace* tface = 0;
	unsigned int *col = 0;

	if (flag & RAS_BLENDERMAT) {
		KX_BlenderMaterial *bl_mat = static_cast<KX_BlenderMaterial*>(polymat);
		tface = bl_mat->GetMTFace();
		col = bl_mat->GetMCol();
	} else {
		KX_PolygonMaterial* blenderpoly = static_cast<KX_PolygonMaterial*>(polymat);
		tface = blenderpoly->GetMTFace();
		col = blenderpoly->GetMCol();
	}
	
	GPU_render_text(tface, mode, mytext, mytext.Length(), col, v1, v2, v3, v4, glattrib);
}


void KX_BlenderRenderTools::PushMatrix()
{
	glPushMatrix();
}

void KX_BlenderRenderTools::PopMatrix()
{
	glPopMatrix();
}


int KX_BlenderRenderTools::applyLights(int objectlayer, const MT_Transform& viewmat)
{
	// taken from blender source, incompatibility between Blender Object / GameObject
	KX_Scene* kxscene = (KX_Scene*)m_auxilaryClientInfo;
	float glviewmat[16];
	unsigned int count;
	std::vector<struct	RAS_LightObject*>::iterator lit = m_lights.begin();

	for (count=0; count<m_numgllights; count++)
		glDisable((GLenum)(GL_LIGHT0+count));

	viewmat.getValue(glviewmat);
	
	glPushMatrix();
	glLoadMatrixf(glviewmat);
	for (lit = m_lights.begin(), count = 0; !(lit==m_lights.end()) && count < m_numgllights; ++lit)
	{
		RAS_LightObject* lightdata = (*lit);
		KX_LightObject *kxlight = (KX_LightObject*)lightdata->m_light;

		if (kxlight->ApplyLight(kxscene, objectlayer, count))
			count++;
	}
	glPopMatrix();

	return count;
}

void KX_BlenderRenderTools::MotionBlur(RAS_IRasterizer* rasterizer)
{
	int state = rasterizer->GetMotionBlurState();
	float motionblurvalue;
	if (state)
	{
		motionblurvalue = rasterizer->GetMotionBlurValue();
		if (state==1)
		{
			//bugfix:load color buffer into accum buffer for the first time(state=1)
			glAccum(GL_LOAD, 1.0);
			rasterizer->SetMotionBlurState(2);
		}
		else if (motionblurvalue >= 0.0f && motionblurvalue <= 1.0f) {
			glAccum(GL_MULT, motionblurvalue);
			glAccum(GL_ACCUM, 1-motionblurvalue);
			glAccum(GL_RETURN, 1.0);
			glFlush();
		}
	}
}