source: trunk/vizservers/nanovis/ScreenSnapper.cpp @ 750

/*
 * ----------------------------------------------------------------------
 * ScreenSnapper.h: ScreenSnapper class. It captures the render result
 *                      and stores it in an array of chars or floats 
 *                      depending on chosen format.
 *
 * ======================================================================
 *  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 <memory.h>
#include <assert.h>
#include "ScreenSnapper.h"

ScreenSnapper::ScreenSnapper(int w, int h, NVISdatatype type, int channel_per_pixel){
  width = w;
  height = h;

  assert(type == NVIS_FLOAT || type == NVIS_UNSIGNED_BYTE); //only allow two types
  data_type = type;
  
  assert(channel_per_pixel == 3 || channel_per_pixel == 4); //only allow RGB or RGBA
  n_channels_per_pixel = channel_per_pixel;

  if(type == NVIS_FLOAT)
     data = new float[w*h*channel_per_pixel];
  else if(type == NVIS_UNSIGNED_BYTE)
     data = new unsigned char[w*h*channel_per_pixel];
  
  assert(data!=0);
  reset(0);     //reset data
}

ScreenSnapper::~ScreenSnapper(){
  if(data_type == NVIS_FLOAT)
    delete[] (float*)data;
  else if(data_type == NVIS_UNSIGNED_BYTE)
    delete[] (unsigned char*)data;
}

void ScreenSnapper::reset(char c){
  int size;
  if(data_type == NVIS_FLOAT)
    size = sizeof(float)*width*height*n_channels_per_pixel;  
  else if(data_type == NVIS_UNSIGNED_BYTE)
    size = sizeof(unsigned char)*width*height*n_channels_per_pixel;  

  memset(data, size, c);
}

void ScreenSnapper::capture(){

  if(data_type == NVIS_FLOAT){
    if(n_channels_per_pixel==3)
      glReadPixels(0, 0, width, height, GL_RGB, GL_FLOAT, data);
    else if(n_channels_per_pixel==4)
      glReadPixels(0, 0, width, height, GL_RGBA, GL_FLOAT, data);
  }
  else if(data_type == NVIS_UNSIGNED_BYTE){
    if(n_channels_per_pixel==3)
      glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, data);
    else if(n_channels_per_pixel==4)
      glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
  }

  assert(glGetError()==0);
}

void ScreenSnapper::print(){
 for(int i=0; i<width*height; i++){
  if(data_type == NVIS_FLOAT){
    if(n_channels_per_pixel==3)
      fprintf(stderr, "(%f %f %f) ", 
                      ((float*)data)[3*i], 
                      ((float*)data)[3*i+1], 
                      ((float*)data)[3*i+2]);
    else if(n_channels_per_pixel==4)
      fprintf(stderr, "(%f %f %f %f) ", 
                      ((float*)data)[4*i], 
                      ((float*)data)[4*i+1],
                      ((float*)data)[4*i+2],
                      ((float*)data)[4*i+3]);
  }
  else if(data_type == NVIS_UNSIGNED_BYTE){
    if(n_channels_per_pixel==3)
      fprintf(stderr, "(%d %d %d) ", 
                      ((unsigned char*)data)[3*i], 
                      ((unsigned char*)data)[3*i+1], 
                      ((unsigned char*)data)[3*i+2]);
    else if(n_channels_per_pixel==4)
      fprintf(stderr, "(%d %d %d %d) ", 
                      ((unsigned char*)data)[4*i], 
                      ((unsigned char*)data)[4*i+1],
                      ((unsigned char*)data)[4*i+2],
                      ((unsigned char*)data)[4*i+3]);
  }
 }
}