Renderer.cpp

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// Copyright (C) 2005 Dave Griffiths
//
// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

#include "Renderer.h"
#include "State.h"
#include "Primitive.h"
#include "PNGLoader.h"
#include "Trace.h"
#include <sys/time.h>
#include <stdio.h>
#include <unistd.h>

using namespace Fluxus;

//#define DEBUG_TRACE

// should use glew for this?
#ifndef GL_POLYGON_OFFSET
#define GL_POLYGON_OFFSET GL_POLYGON_OFFSET_EXT
#endif

static const int FRAMES_PER_TIME = 10;
static int TimeCounter = 0;
static timeval StartTime;
static float FPS;

static const int MAXLIGHTS = 8;

Renderer::Renderer() :
m_Initialised(false),
m_InitLights(false),
m_Width(640),
m_Height(480),
m_MotionBlur(false),
m_Fade(0.02f),
m_ShowAxis(false),
m_Grabbed(NULL),
m_ClearFrame(true),
m_ClearZBuffer(true),
m_ClearAccum(false),
m_BackFaceCull(true),
m_FaceOrderClockwise(false),
m_FogDensity(0), 
m_FogStart(0),
m_FogEnd(100),  
m_ShadowLight(0),
m_StereoMode(noStereo),
m_MaskRed(true),
m_MaskGreen(true),
m_MaskBlue(true),
m_MaskAlpha(true),
m_Deadline(1/25.0f),
m_FPSDisplay(false),
m_Time(0),
m_Delta(0)
{
    State InitialState;
    m_StateStack.push_back(InitialState);
    
    // stop valgrind complaining
    m_LastTime.tv_sec=0;
    m_LastTime.tv_usec=0;
}

Renderer::~Renderer()
{
    TexturePainter::Shutdown();
}


void Renderer::Render()
{           
    if (m_ClearFrame && !m_MotionBlur)
    {
        glClearColor(m_BGColour.r,m_BGColour.g,m_BGColour.b,m_BGColour.a);  
        glClear(GL_COLOR_BUFFER_BIT);   
    }
    
    if (m_ClearZBuffer)
    {
        glClear(GL_DEPTH_BUFFER_BIT);
    }

    if (m_ClearAccum)
    {
        glClear(GL_ACCUM_BUFFER_BIT);
    }
    
    // need to clear this even if we aren't using shadows
    m_World.GetShadowVolumeGen()->Clear();
    
    if (m_ShadowLight!=0)
    {       
        RenderStencilShadows();
    }
    else
    {
        PreRender();
        m_World.Render();
        m_ImmediateMode.Render();
        m_ImmediateMode.Clear();
        PostRender();
    }       
            
    timeval ThisTime;
    // stop valgrind complaining
    ThisTime.tv_sec=0;
    ThisTime.tv_usec=0;
    
    gettimeofday(&ThisTime,NULL);
    m_Delta=(ThisTime.tv_sec-m_LastTime.tv_sec)+
            (ThisTime.tv_usec-m_LastTime.tv_usec)*0.000001f;

    if (m_Delta<m_Deadline)
    {
        //min 1 hz
        if(m_Deadline-m_Delta<1.0f)
        {
            usleep((int)((m_Deadline-m_Delta)*1000000.0f));
        }
    }
    
    m_LastTime=ThisTime;
    //if (m_Delta>0) m_Time=ThisTime.tv_sec+ThisTime.tv_usec*0.000001f;
    if (m_Delta>0.0f && m_Delta<100.0f) m_Time+=m_Delta;
}

void Renderer::RenderStencilShadows()
{
    if (m_LightVec.size()>m_ShadowLight)
    {
        m_World.GetShadowVolumeGen()->SetLightPosition(m_LightVec[m_ShadowLight]->GetPosition());
    }
    
    PreRender();
    glDisable(GL_LIGHT0+m_ShadowLight); 
    m_World.Render();
    m_ImmediateMode.Render();

    glClear(GL_STENCIL_BUFFER_BIT);
    glEnable(GL_STENCIL_TEST);
    glStencilFunc(GL_ALWAYS, 0, ~0);
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
    glDepthMask(GL_FALSE);
    glEnable(GL_CULL_FACE);

    glCullFace(GL_BACK);
    glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
    m_World.GetShadowVolumeGen()->GetVolume()->Render();

    glCullFace(GL_FRONT);
    glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
    m_World.GetShadowVolumeGen()->GetVolume()->Render();

    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glDepthFunc(GL_EQUAL);
    glStencilFunc(GL_EQUAL, 0, ~0);
    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);

    glEnable(GL_BLEND);
    glBlendFunc(GL_ONE, GL_ONE);
    glCullFace(GL_BACK);

    glEnable(GL_LIGHT0+m_ShadowLight);

    m_World.Render();
    m_ImmediateMode.Render();

    glDepthMask(GL_TRUE);
    glDepthFunc(GL_LEQUAL);
    glStencilFunc(GL_ALWAYS, 0, ~0);

    if (m_World.GetShadowVolumeGen()->GetDebug())
    {
        m_World.GetShadowVolumeGen()->GetVolume()->GetState()->Hints=HINT_WIRE;
        m_World.GetShadowVolumeGen()->GetVolume()->Render();
        m_World.GetShadowVolumeGen()->GetVolume()->GetState()->Hints=HINT_SOLID;
    }

    PostRender();
}

void Renderer::PreRender(bool PickMode)
{
    if (!m_Initialised || PickMode || m_Camera.NeedsInit())
    {
        glViewport(0,0,m_Width,m_Height);

        glMatrixMode (GL_PROJECTION);
        glLoadIdentity();
        
        if (PickMode) 
        {       
            GLint viewport[4]={0,0,m_Width,m_Height};
            gluPickMatrix(m_SelectInfo.x,m_Height-m_SelectInfo.y,
                        m_SelectInfo.size,m_SelectInfo.size,viewport);
        }
        
        m_Camera.DoProjection();
        
        glEnable(GL_BLEND);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);  
        glEnable(GL_LIGHTING);
        
        if (m_BackFaceCull)
        {
            glEnable(GL_CULL_FACE);
            glCullFace(GL_BACK);
        }
        else
        {
            glDisable(GL_CULL_FACE);
        }
        
        if (m_FaceOrderClockwise) glFrontFace(GL_CW);
        else glFrontFace(GL_CCW);
                 
        glEnable(GL_RESCALE_NORMAL);
        glDisable(GL_COLOR_MATERIAL);

        glEnableClientState(GL_VERTEX_ARRAY);
        glEnableClientState(GL_NORMAL_ARRAY);
        glEnableClientState(GL_TEXTURE_COORD_ARRAY);
        glEnableClientState(GL_COLOR_ARRAY);
        glEnable(GL_POLYGON_OFFSET);
        
        if (m_FogDensity>0)
        {
            glEnable(GL_FOG);
            glFogf(GL_FOG_MODE, GL_EXP);
            glFogfv(GL_FOG_COLOR, m_FogColour.arr());
            glFogf(GL_FOG_DENSITY, m_FogDensity);
            glFogf(GL_FOG_HINT, GL_DONT_CARE);
            glFogf(GL_FOG_START, m_FogStart);
            glFogf(GL_FOG_END, m_FogEnd);
        }
        else
        {
            glDisable(GL_FOG);
        }   
            
        glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL,GL_SEPARATE_SPECULAR_COLOR);
    
        TexturePainter::Get()->Initialise();
        
        m_Initialised=true;
    }
    
    if (!m_InitLights)
    {
        // builds the default camera light
        ClearLights();
        m_InitLights=true;
    }
    
    
    glMatrixMode (GL_MODELVIEW);
    glLoadIdentity();
    
    PushState();
    
    if (m_MotionBlur)
    {
        glEnable(GL_COLOR_MATERIAL);
        glPolygonMode(GL_FRONT,GL_FILL);
        glDisable(GL_DEPTH_TEST);
        glPushMatrix();
        glTranslatef(0,0,-10);
        glBegin(GL_QUADS);
            glColor4f(m_BGColour.r,m_BGColour.g,m_BGColour.b,m_Fade);
            glVertex3f(-10,-10,0);
            glVertex3f(10,-10,0);
            glVertex3f(10,10,0);
            glVertex3f(-10,10,0);
        glEnd();
        glPopMatrix();
        glEnable(GL_DEPTH_TEST);
        glDisable(GL_COLOR_MATERIAL);
    }
        
    if (m_FPSDisplay && !PickMode)
    {
        PushState();
        GetState()->Transform.translate(m_Camera.GetUp(),m_Camera.GetLeft(),0);
        GetState()->Colour=dColour(0,0,1);
        char s[32];
        sprintf(s,"%f fps",FPS);
        DrawText(s);
        PopState();
    }

    RenderLights(true); // camera locked
    m_Camera.DoCamera();
    RenderLights(false); // world space
    
    glColorMask(m_MaskRed,m_MaskGreen,m_MaskBlue,m_MaskAlpha);
        
    /* ???
    RenderLights(true); // camera locked
    
    glMultMatrixf(m_Camera.arr());
    
    RenderLights(false); // world space
    
    if (m_LockedCamera)
    {
        Primitive *p = GetPrimitive(m_CameraAttached);
        if (p)
        {
            if (m_CameraLag!=0)
            {
                m_LockedMatrix.blend(p->GetState()->Transform.inverse(),m_CameraLag);
            }
            else
            {
                m_LockedMatrix=p->GetState()->Transform.inverse();
            }
            
            glMultMatrixf(m_LockedMatrix.arr());        
        }
        else m_LockedCamera=false;
    }*/

    //m_World.GetShadowVolumeGen()->SetLightPosition(m_Camera.inverse().transform((*m_LightVec.begin())->GetPosition()));

}


void Renderer::PostRender()
{
    // clear the texture, if the last primitive assigned one...
    glDisable(GL_TEXTURE_2D);
    GLSLShader::Unapply();

    glDisable(GL_DEPTH_TEST);
    if (m_ShowAxis) Primitive::RenderAxes();
    glEnable(GL_DEPTH_TEST);
    glColorMask(true,true,true,true);
    
    PopState();
    
    if (m_FPSDisplay)
    {
        if (!(TimeCounter%FRAMES_PER_TIME))
        {
            timeval TimeNow;
            gettimeofday(&TimeNow,NULL);    
            FPS = (TimeNow.tv_sec-StartTime.tv_sec)+(TimeNow.tv_usec-StartTime.tv_usec)*0.000001f;
            FPS/=(float)FRAMES_PER_TIME;
            FPS=1/FPS;  
            gettimeofday(&StartTime,NULL);
        }
        TimeCounter++;
    }
    
    //if (m_StateStack.size()!=1)
    //{
    //  Trace::Stream<<"State mismatch: stack size "<<m_StateStack.size()<<" at end scene"<<endl;
    //}
}

void Renderer::RenderLights(bool camera)
{
    int n=0;
    for (vector<Light*>::iterator i=m_LightVec.begin(); i!=m_LightVec.end(); i++)
    {
        if (n<MAXLIGHTS && (*i)->GetCameraLock()==camera) 
        {
            (*i)->Render();
        }
        n++;
    }
}

int Renderer::AddLight(Light *l)
{
    l->SetIndex(m_LightVec.size());
    m_LightVec.push_back(l);
    return m_LightVec.size()-1;
}

Light *Renderer::GetLight(int id)
{
    if (id<(int)m_LightVec.size()) return m_LightVec[id];
    else return NULL;
}

void Renderer::ClearLights()
{
    for (unsigned int n=0; n<m_LightVec.size(); n++)
    {
        glDisable(GL_LIGHT0+n);
    }
    
    m_LightVec.clear();
    
    // add a default light
    Light *light=new Light;
    light->SetPosition(dVector(0,0,0));
    light->SetCameraLock(true);
    AddLight(light);
}

int Renderer::Select(int x, int y, int size)
{
    static const int SELECT_SIZE=512;
    unsigned int IDs[SELECT_SIZE];
    memset(IDs,0,SELECT_SIZE);
    GLuint ID=0;
    glSelectBuffer(SELECT_SIZE,(GLuint*)IDs);
    glRenderMode(GL_SELECT);
    glInitNames();
    
    m_SelectInfo.x=x;
    m_SelectInfo.y=y;
    m_SelectInfo.size=size;
    
    // the problem here is that select is called mid-scene, so we have to set up for 
    // picking mode here...
    PreRender(true);
    
    // render the scene for picking
    m_World.Render(SceneGraph::SELECT);
    
    int hits=glRenderMode(GL_RENDER);
    unsigned int *ptr=IDs, numnames;
    float minz,maxz,closest=1000000;

    // process the hit records
    for (int n=0; n<hits; n++)
    {
        numnames=*ptr;
        ptr++;
        minz = (float) *ptr++/0x7fffffff;
        maxz = (float) *ptr++/0x7fffffff;
                
        // find the closest one
        if (closest>minz) 
        {
            closest=minz;
            ID=*ptr;
        }
        for (unsigned int i=0; i<numnames; i++) *ptr++;
    }
    
    // ... and reset the scene back here so we can carry on afterwards as if nothing
    // has happened...
    m_Initialised=false;
    PreRender();
    
    return ID;
}

void Renderer::Clear()
{
    m_World.Clear();
    m_StateStack.clear();
    UnGrab();
    State InitialState;
    m_StateStack.push_back(InitialState);
}   

int Renderer::AddPrimitive(Primitive *Prim)
{
    Prim->SetState(GetState());
    SceneNode *node = new SceneNode(Prim);
    return m_World.AddNode(GetState()->Parent,node);
}

Primitive *Renderer::GetPrimitive(int ID)
{
    SceneNode *node = (SceneNode*)m_World.FindNode(ID);
    if (node==NULL) return NULL;
    return node->Prim;
}

void Renderer::RemovePrimitive(int ID)
{
    SceneNode *node = (SceneNode*)m_World.FindNode(ID);
    if (node!=NULL)
    {
        if (node->Prim==m_Grabbed) UnGrab();
        m_World.RemoveNode(node);
    }
}

void Renderer::DetachPrimitive(int ID)
{
    SceneNode *node=(SceneNode*)m_World.FindNode(ID);
    if (node) m_World.Detach(node);
}

// immediate mode
void Renderer::RenderPrimitive(Primitive *Prim)
{   
    m_ImmediateMode.Add(Prim,GetState());
}

dMatrix Renderer::GetGlobalTransform(int ID)
{
    dMatrix mat;
    SceneNode *node=(SceneNode*)m_World.FindNode(ID);
    if (node) mat=m_World.GetGlobalTransform(node);
    return mat;
}

dBoundingBox Renderer::GetBoundingBox(int ID)
{
    dBoundingBox bbox;
    SceneNode *node=(SceneNode*)m_World.FindNode(ID);
    if (node) m_World.GetBoundingBox(node,bbox);
    return bbox;
}

// state accessors
State *Renderer::GetState()
{
    if (m_StateStack.empty())
    {
        Trace::Stream<<"Renderer::GetState : State stack is empty"<<endl;
        return NULL;
    }
    
    return &(*m_StateStack.begin());
}

void Renderer::ApplyState()
{
    GetState()->Apply();
}

void Renderer::PushState()
{
    #ifdef DEBUG_TRACE
    Trace::Stream<<"Renderer::PushState"<<endl;
    #endif
    
    m_StateStack.push_front(*GetState());
}

void Renderer::PopState()
{
    #ifdef DEBUG_TRACE
    Trace::Stream<<"Renderer::PopState"<<endl;
    #endif
    
    if (m_StateStack.size()<2)
    {
        Trace::Stream<<"Renderer::PopState : only one state left, not popping"<<endl;
    }
    else
    {
        m_StateStack.pop_front();
    }
}

void Renderer::Grab(int ID)
{
    SceneNode *n=(SceneNode *)m_World.FindNode(ID);
    if (n)
    {
        Primitive *p=n->Prim;
        if (p)
        {
            m_Grabbed=p;
        }
    }
}

void Renderer::UnGrab()
{
    m_Grabbed=NULL;
}

//void Renderer::Apply(int id)
//{
//  Primitive *p = GetPrimitive(id);
//  if (p) p->ApplyTransform();
//}

void Renderer::DrawText(const string &Text)
{
    glPushMatrix(); 
    GetState()->Apply();
    //glDisable(GL_DEPTH_TEST);
    glDisable(GL_LIGHTING);
    glPushMatrix();
    glRasterPos3f(0.0, 0.0, -1.1);
    for (unsigned int n=0; n<Text.length(); n++)
    {
        glutBitmapCharacter(GLUT_BITMAP_HELVETICA_12, Text.c_str()[n]);
        glTranslatef(1.0f,0.0f,0.0f);
    }
    glPopMatrix();
    glEnable(GL_LIGHTING);
    //glEnable(GL_DEPTH_TEST);
    glPopMatrix();  
}

void Renderer::ShowCursor(bool s)
{
    if (s)
    {
        glutSetCursor(GLUT_CURSOR_INHERIT); 
    }
    else 
    {
        glutSetCursor(GLUT_CURSOR_NONE); 
    }

}

void Renderer::DrawBuffer(GLenum mode)
{
    glDrawBuffer(mode);
}

void Renderer::ReadBuffer(GLenum mode)
{
    glReadBuffer(mode);
}

bool Renderer::SetStereoMode(stereo_mode_t mode)
{
    GLboolean stereoWindowTest;
    switch(mode){
        case noStereo: m_StereoMode = noStereo;
            return true;
        case crystalEyes:
            //test for a stereo window
            glGetBooleanv (GL_STEREO, &stereoWindowTest);
            if(stereoWindowTest){
                m_StereoMode = crystalEyes;
                return true;
            } else {
                m_StereoMode = noStereo;
                return false;
            }
        case colourStereo:
            m_StereoMode = colourStereo;
            return true;
    };
    return false;
}

void Renderer::SetColourMask(bool inred, bool ingreen, bool inblue, bool inalpha)
{
    m_MaskRed=inred;
    m_MaskGreen=ingreen;
    m_MaskBlue=inblue;
    m_MaskAlpha=inalpha;
}

void Renderer::Accum(int mode, float factor)
{
    glAccum(mode,factor);
}

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