Daviddoria: Created page with 'Requires VXL. ==Test.cxx== #include #include //for exit() #include #include #include #inc…'

2010-11-24T00:47:22Z

Created page with 'Requires VXL. ==Test.cxx== <source lang="cpp"> #include <iostream> #include <cstdlib> //for exit() #include <GL/glut.h> #include <vil/vil_rgb.h> #include <vil/vil_load.h> #inc…'

New page

Requires VXL.

==Test.cxx==
<source lang="cpp">
#include <iostream>
#include <cstdlib> //for exit()

#include <GL/glut.h>

#include <vil/vil_rgb.h>
#include <vil/vil_load.h>
#include <vil/vil_save.h>
#include <vil/vil_image_view.h>
#include <vil/vil_convert.h>

#include "Screenshot.h"

using namespace std;

void display(void);
void ProcessKeyboard(unsigned char key, int x, int y);
void DrawCube();
void DrawSizedCube(const float s);
void polygon(int a, int b, int c , int d);
void LookAt();

const unsigned int Width = 200;
const unsigned int Height = 100;

int main(int argc, char *argv[])
{
cout << "OpenGL" << endl;

glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(Width, Height);
glutInitWindowPosition(0, 0);

//setup the main window
glutCreateWindow("OpenGL Example");

glutDisplayFunc(display);
glutKeyboardFunc(ProcessKeyboard);

glutMainLoop();
return 0;
}

void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST);

LookAt();
DrawCube();

glutSwapBuffers();

}

void ProcessKeyboard(unsigned char key, int x, int y)
{
if (key == 27) //escape
{
exit(0);
}
else if(key == 'q')
{
exit(0);
}
else if(key == 's')
{
cout << "Screenshot." << endl;
Screenshot("Test.jpg");
//ScreenshotFixed("Fixed.jpg");
}

display();
}

void DrawSizedCube(const float s)
{
glPushMatrix();
glScalef(s,s,s);
DrawCube();
glPopMatrix();

}

void DrawCube()
{
//back
glColor3f(1.0f, 0.0f, 0.0f); // Color Red
polygon(0,3,2,1);

//top
glColor3f(0.0f,1.0f,0.0f); // Color Green
polygon(2,3,7,6);

//left
glColor3f(0.0f, 0.0f, 1.0f); // Color Blue
polygon(0,4,7,3);

//right
glColor3f(1.0f,1.0f,0.0f); // Color Yellow
polygon(1,2,6,5);

//front
glColor3f(0.0f,1.0f,1.0f); // Color Cyan
polygon(4,5,6,7);

//bottom
glColor3f(1.0f,0.0f,1.0f); // Color Magenta
polygon(0,1,5,4);

}

GLfloat vertices[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},
{1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},
{1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

void polygon(int a, int b, int c , int d)
{
glBegin(GL_QUADS);
glVertex3fv(vertices[a]);
glVertex3fv(vertices[b]);
glVertex3fv(vertices[c]);
glVertex3fv(vertices[d]);
glEnd();
}

void LookAt()
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(70, 1, 1, 100);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

gluLookAt(3, 5, 5, 0, 0, 0, 0, 1, 0);

}

</source>

==Screenshot.cxx==
<source lang="cpp">
#include <iostream>

#include <GL/glut.h>

#include <vil/vil_rgb.h>
#include <vil/vil_load.h>
#include <vil/vil_save.h>
#include <vil/vil_image_view.h>
#include <vil/vil_convert.h>

#include <vbl/vbl_array_3d.h>

using namespace std;

void Screenshot(const string &filename)
{
const unsigned int Width = glutGet(GLUT_WINDOW_WIDTH);
const unsigned int Height = glutGet(GLUT_WINDOW_HEIGHT);

vil_image_view<vil_rgb<vxl_byte> > RGBImage(Width, Height, 1, 1);

vbl_array_3d<GLubyte> buffer(Height,Width,3);

glReadBuffer(GL_FRONT);

glReadPixels(0, 0, Width, Height, GL_RGB, GL_UNSIGNED_BYTE, buffer.begin());

GLubyte r,g,b;
for(unsigned int col = 0; col < Width; col++)
{
for(unsigned int row = 0; row < Height; row++)
{
//works, but upside down
// r = buffer(row, col, 0);
// g = buffer(row, col, 1);
// b = buffer(row, col, 2);
r = buffer(Height - row - 1, col, 0);
g = buffer(Height - row - 1, col, 1);
b = buffer(Height - row - 1, col, 2);
RGBImage(col, row) = vil_rgb<vxl_byte>(r,g,b);
}
}

vil_save(RGBImage, filename.c_str());

cout << "Done writing RGB image." << endl;
}

void ScreenshotFixed(const string &filename)
{
unsigned int Width = 200;
unsigned int Height = 100;

GLubyte buffer[100][200][3];
glReadPixels(0, 0, Width, Height, GL_RGB, GL_UNSIGNED_BYTE, buffer);

vil_image_view<vil_rgb<vxl_byte> > RGBImage(Width, Height, 1, 1); //(cols, rows, 1, 1)

GLubyte r,g,b;

for(unsigned int i = 0; i < Width; ++i)
{
for(unsigned int j = 0; j < Height; ++j)
{
r = buffer[j][i][0];
g = buffer[j][i][1];
b = buffer[j][i][2];
RGBImage(i, j) = vil_rgb<vxl_byte>(r,g,b);
}
}

vil_save(RGBImage, filename.c_str());

cout << "Done writing RGB image." << endl;
}
</source>

==Screenshot.h==
<source lang="cpp">
#ifndef SCREENSHOT_H
#define SCREENSHOT_H

#include <string>

using namespace std;

void Screenshot(const string &filename);
void ScreenshotFixed(const string &filename);

#endif
</source>

==CMakeLists.txt==
<source lang="cmake">
cmake_minimum_required(VERSION 2.6)

PROJECT(Screenshot)

FIND_PACKAGE(VXL REQUIRED)
INCLUDE(${VXL_CMAKE_DIR}/UseVXL.cmake)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp") #g++

INCLUDE_DIRECTORIES(/usr/include/ /usr/local/include/)

LINK_DIRECTORIES(/usr/lib /usr/local/lib)

ADD_EXECUTABLE(Screenshot Test.cpp Screenshot.cpp)

TARGET_LINK_LIBRARIES(Screenshot
glut GLU GL Xmu X11
vil vgl vnl vgl_algo vbl
)

</source>

OpenGL/Screenshot - Revision history

Daviddoria: Created page with 'Requires VXL. ==Test.cxx== #include #include //for exit() #include #include #include #inc…'