Problems with Frambuffer Object - limitation related to my screen resolution - opengl

Question

I need to have an image as output of my code (dimension: 3507x3281) composed by two triangles (upper-left corner and lower-right corner), each triangle will give me one different color/image on my output.
I read both images and bound them with 2 textures (texture_1 and texture_2).
Afterwards I created both triangles related to their respective image.
I created and bound the Framebuffer Object and attached the textures. Finally, I saved the content to a image file (.ppm).
PROBLEM:
My result (output image) is coherent and geometrically correct. However, only part of my output image is visible. The part that it is visible has 1366x768 as dimension, which is exactely my screen resolution. Am I missing something on the code?
Is there anything related to the options "GL_DRAW_FRAMEBUFFER, GL_READ_FRAMEBUFFER and GL_FRAMEBUFFER"? Only "GL_DRAW_FRAMEBUFFER" gives the coherent result.
Am I really using the Framebuffer? Because, I read that since you use the FBO this kind of problem does not appear.
CODE:
#include <windows.h>
#define GLEW_STATIC
#include <GL/glew.h>
#include <GL/glut.h>
#include <GL/freeglut.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <cstdio>
#include <string>
/// Definitions
#define checkImageWidth 500 /// for image - texture 1
#define checkImageHeight 500
#define width 2464 /// for image - texture 2
#define height 1648
static GLuint texture_1, texture_2;
static GLubyte checkImage[checkImageHeight][checkImageWidth][3];
GLuint fb = 1; ///Frame-buffer Object
/// Headers
GLuint raw_texture_load();
void FBO_2_PPM_file(int output_width, int output_height);
/// Functions
GLuint raw_texture_load()
{
/// image used for texture 1
unsigned char *data;
FILE *file;
// open texture data
file = fopen("C:\\Dataset\\image_1.raw", "rb");
if (file == NULL) return 0;
// allocate buffer
data = (unsigned char*) malloc(width * height * 3);
// read texture data
fread(data, width * height * 3, 1, file);
fclose(file);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
/// Texture 1
// allocate a texture name
glGenTextures(1, &texture_1);
// select our current texture
glBindTexture(GL_TEXTURE_2D, texture_1);
// select modulate to mix texture with color for shading
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_DECAL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_DECAL);
// when texture area is small, bilinear filter the closest mipmap
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
// when texture area is large, bilinear filter the first mipmap
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// texture should tile
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// build our texture mipmaps
gluBuild2DMipmaps(GL_TEXTURE_2D, 3, width, height, GL_RGB, GL_UNSIGNED_BYTE, data);
// free buffer
free(data);
/// image used for texture 2
FILE *image_4tx2;
if( (image_4tx2 = fopen("C:\\dataset\\image2.ppm","r")) == NULL )
{
printf("\n Problem with input for texture 2\n");
system("pause");
exit(1);
}
int i, j, max_ND, n_col, n_lin, Red, G, B;
char s1[20];
/// Read header
fscanf(image_4tx2,"%s",&s1);
fscanf(image_4tx2,"%s %s %s %s",&s1, &s1, &s1, &s1);
fscanf(image_4tx2,"%d %d",&n_col, &n_lin);
fscanf(image_4tx2,"%d",&max_ND);
for (i = 0; i < checkImageWidth; i++)
{
for (j = 0; j < checkImageHeight; j++)
{
fscanf(image_4tx2,"%d %d %d ",&Red, &G, &B);
checkImage[i][j][0] = (GLubyte) Red;
checkImage[i][j][1] = (GLubyte) G;
checkImage[i][j][2] = (GLubyte) B;
}
}
fclose(image_4tx2);
/// Texture 2
glGenTextures(2, &texture_2);
glBindTexture(GL_TEXTURE_2D, texture_2);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, checkImageWidth, checkImageHeight,
0, GL_RGB, GL_UNSIGNED_BYTE, checkImage);
return texture_1;
}
void render()
{
GLdouble COORD_1[3], COORD_2[3], COORD_3[3], COORD[3];
/// Output image size
double col_siz_double = 3507.0;
double row_siz_double = 3281.0;
int col_siz_output_image = 3507;
int row_siz_output_image = 3281;
/// Aspect ratio
double ratio_col_row = col_siz_double/row_siz_double;
double aspect_E, aspect_N;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if(ratio_col_row>=0.0)
{
aspect_E = 1.0;
aspect_N = 1.0/ratio_col_row;
glOrtho(0.0, 1.0*aspect_E, 0.0, 1.0*aspect_N, 0.0, 1.0);
}
else
{
aspect_E = 1.0/ratio_col_row;
aspect_N = 1.0;
glOrtho(0.0, 1.0*aspect_E, 0.0, 1.0*aspect_N, 0.0, 1.0);
}
gluLookAt( 0.0, 0.0, 1.0, /* eye */
0.0, 0.0, 0.0, /* center */
0, 1, 0); /* up */
/// Viewport
glViewport(0,0,col_siz_output_image,row_siz_output_image);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushAttrib(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_TEXTURE_2D);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
/// Triangle 1 (upper-left half of the output)
glBindTexture(GL_TEXTURE_2D, texture_1);
glBegin(GL_TRIANGLES);
glTexCoord2d(0.0, 0.0);
COORD[0]= 0.0*aspect_E;
COORD[1]= 0.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glTexCoord2d(1.0, 1.0);
COORD[0]= 1.0*aspect_E;
COORD[1]= 1.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glTexCoord2d(0.0, 1.0);
COORD[0]= 0.0*aspect_E;
COORD[1]= 1.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glEnd();
/// Triangle 2 (low-right half of the output)
glBindTexture(GL_TEXTURE_2D, texture_2);
glBegin(GL_TRIANGLES);
glTexCoord2d(0.0, 0.0);
COORD[0]= 0.0*aspect_E;
COORD[1]= 0.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glTexCoord2d(1.0, 1.0);
COORD[0]= 1.0*aspect_E;
COORD[1]= 1.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glTexCoord2d(1.0, 0.0);
COORD[0]= 1.0*aspect_E;
COORD[1]= 0.0*aspect_N;
COORD[2]= 1.0;
glVertex3d(COORD[0], COORD[1], COORD[2]);
glEnd();
glFlush();
glDisable(GL_TEXTURE_2D);
static const GLenum draw_buffers[] =
{
GL_COLOR_ATTACHMENT0,
GL_COLOR_ATTACHMENT1
};
/// Generating and Biding the Framebuffer Object (FBO)
glGenFramebuffers(1, &fb);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb);
///Attaching both 2D texture to the FBO as color attachments
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, draw_buffers[0], GL_TEXTURE_2D, texture_2, 0);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, draw_buffers[1], GL_TEXTURE_2D, texture_1, 0);
/// Specifying a list of color buffers to be drawn into
glDrawBuffers(2, draw_buffers);
/// Checking the FBO status
GLuint status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if( status != GL_FRAMEBUFFER_COMPLETE)
{
printf("\n\nFramebuffer status: %s\n\n",status);
system("pause");
}
/// Saving the results from the FBO (fb) to a PPM image file
FBO_2_PPM_file(col_siz_output_image,row_siz_output_image);
}
void init()
{
glClearColor(0.0, 0.0, 0.0, 0.0);
texture_1 = raw_texture_load();
render();
}
void FBO_2_PPM_file(int output_width, int output_height)
{
FILE *output_image;
/// READ THE PIXELS VALUES from FBO AND SAVE TO A .PPM FILE
int i, j, k;
unsigned char *pixels = (unsigned char*)malloc(output_width*output_height*4);
/// READ THE CONTENT FROM THE FBO
glReadBuffer(GL_COLOR_ATTACHMENT0);
glReadBuffer(GL_COLOR_ATTACHMENT1);
glReadPixels(0, 0, output_width, output_height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
output_image = fopen("C:\\Dataset\\output.ppm", "wt");
if(output_image == NULL)
{
printf("Problem # output file!\n\n");
system("pause");
}
fprintf(output_image,"P3\n");
fprintf(output_image,"# Created by Ricao\n");
fprintf(output_image,"%d %d\n",output_width,output_height);
fprintf(output_image,"255\n");
k = 0;
for(i=output_height-1; i>-1; i--)
{
for(j=0; j<output_width; j++)
{
k = (i*output_width)+j;
/// saving only RGB
fprintf(output_image,"%u %u %u ",(unsigned int)pixels[4*k],(unsigned int)pixels[(4*k)+1],
(unsigned int)pixels[(4*k)+2]);
}
fprintf(output_image,"\n");
}
free(pixels);
}
int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(3507, 3281);
glutCreateWindow("Do not close this window!");
glutHideWindow();
/// Checking GLEW library
glewExperimental=TRUE;
GLenum err=glewInit();
if(err!=GLEW_OK)
{
printf("glewInit failed, aborting.");
printf("\tError: %s\n\n",glewGetErrorString(err));
system("pause");
}
if (GLEW_EXT_framebuffer_object != GL_TRUE)
{
printf("\n\n\t ** Error! GLEW_EXT_framebuffer_object != GL_TRUE \n\n");
system("pause");
}
/// To check the max size of the Framebuffer
int dims[2];
glGetIntegerv(GL_MAX_VIEWPORT_DIMS, &dims[0]);
///Executing the rendering process
init();
return 0;