source: trunk/packages/vizservers/nanovis/PlaneRenderer.cpp @ 1452

/*
 * ----------------------------------------------------------------------
 * PlaneRenderer.cpp : PlaneRenderer class for volume visualization
 *
 * ======================================================================
 *  AUTHOR:  Wei Qiao <qiaow@purdue.edu>
 *           Purdue Rendering and Perceptualization Lab (PURPL)
 *
 *  Copyright (c) 2004-2006  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */

#include "global.h"
#include "PlaneRenderer.h"

PlaneRenderer::PlaneRenderer(CGcontext _context, int _width, int _height):
    active_plane(-1),
    n_planes(0),
    render_width(_width),
    render_height(_height),
    g_context(_context)
{
    plane.clear();
    tf.clear();
    init_shaders();
}

PlaneRenderer::~PlaneRenderer() 
{
    /*empty*/
}

//initialize the render shader
void 
PlaneRenderer::init_shaders()
{
    //plane rendering shader
    m_fprog = LoadCgSourceProgram(g_context, "one_plane.cg", CG_PROFILE_FP30, 
        NULL);
    m_data_param = cgGetNamedParameter(m_fprog, "data");
    m_tf_param = cgGetNamedParameter(m_fprog, "tf");
    m_render_param = cgGetNamedParameter(m_fprog, "render_param");
}


int 
PlaneRenderer::add_plane(Texture2D* _p, TransferFunction* _tf)
{
    int ret = n_planes;

    plane.push_back(_p);
    tf.push_back(_tf);

    if(ret==0)
        active_plane = ret;

    n_planes++;
    return ret;
}

void
PlaneRenderer::remove_plane(int index) {
    vector<Texture2D*>::iterator piter = plane.begin()+index;
    vector<TransferFunction*>::iterator tfiter = tf.begin()+index;

    plane.erase(piter);
    tf.erase(tfiter);

    n_planes--;
}


void 
PlaneRenderer::render()
{
    if (n_planes == 0)
        return;

    glEnable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);

    glViewport(0, 0, render_width, render_height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, render_width, 0, render_height);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    //glColor3f(1.,1.,1.);         //MUST HAVE THIS LINE!!!

    //if no active plane
    if(active_plane == -1)
        return;

    activate_shader(active_plane);
    glBegin(GL_QUADS);
    glTexCoord2f(0, 0); glVertex2f(0, 0);
    glTexCoord2f(1, 0); glVertex2f(render_width, 0);
    glTexCoord2f(1, 1); glVertex2f(render_width, render_height);
    glTexCoord2f(0, 1); glVertex2f(0, render_height);
    glEnd();
    deactivate_shader();

}

void 
PlaneRenderer::activate_shader(int index)
{

    cgGLSetTextureParameter(m_data_param, plane[index]->id);
    cgGLSetTextureParameter(m_tf_param, tf[index]->id);
    cgGLEnableTextureParameter(m_data_param);
    cgGLEnableTextureParameter(m_tf_param);

    cgGLSetParameter4f(m_render_param, 0., 0., 0., 0.);

    cgGLBindProgram(m_fprog);
    cgGLEnableProfile(CG_PROFILE_FP30);
}


void 
PlaneRenderer::deactivate_shader()
{
    cgGLDisableProfile(CG_PROFILE_FP30);
    cgGLDisableTextureParameter(m_data_param);
    cgGLDisableTextureParameter(m_tf_param);
}

void
PlaneRenderer::set_active_plane(int index) 
{
    active_plane = index;
}

void
PlaneRenderer::set_screen_size(int w, int h) 
{
    render_width = w;
    render_height = h;
}