//First we need a storage for our texture.
GLuint    texture;

//Here's the pointer to the image data in memory.
unsigned char    *texels = 0;
//This one holds the width and height of the image.
int                width, height;

//BITMAP LOADER
//LoadFileBMP will return false if not loaded properly.
if( LoadFileBMP( filename, &texels, &width, &height, true ) )
{
    // Now, we generate only one texture. Just increase the number if you're going to load more than one texture.
    glGenTextures( 1, &texture );
    
    // glBindTexture tells OpenGL to bind the named texture to a texture target. In this case, we are telling OpenGL that everything that will happen to the texture will be stored here.
    glBindTexture( GL_TEXTURE_2D, texture );
    
    //The next two lines will tell OpenGL what type of filtering to use.
    //GL_TEXTURE_MAG_FILTER is used when the pixel being textured maps to an area less than or equal to one texture element.
    //GL_TEXTURE_MIN_FILTER is used whenever the pixel being textured maps to an area greater than one texture element. 
    glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
    glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
    //GL_TEXTURE_2D tells OpenGL that the texture is 2D
    //0 represents the images level of detail
    //GL_RGBA because the image is made up of red, green and blue. 
    //width,height is of course the width and height of the texture
    //0 is the border
    //GL_RGB specifies the format of the pixel data
    //GL_UNSIGNED_BYTE specifies the data type of the pixel data
    //image specifies a pointer to the image data in memory.
    glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,width,height,0,GL_RGB,GL_UNSIGNED_BYTE,texels);
}

   
float vertices[8][3] = { { 1.0f, 1.0f, 0.0f },      //Vertex 0
                           { 0.0f, 1.0f, 0.0f },    //Vertex 1
                           { 0.0f, 0.0f, 0.0f },    //Vertex 2
                           { 1.0f, 0.0f, 0.0f },    //Vertex 3
                           { 1.0f, 0.0f, 1.0f },    //Vertex 4
                           { 1.0f, 1.0f, 1.0f },    //Vertex 5
                           { 0.0f, 1.0f, 1.0f },    //Vertex 6
                           { 0.0f, 0.0f, 1.0f }};   //Vertex 7 

//This will enable Texture Mapping
glEnable(GL_TEXTURE_2D);

//Selects the texture to use.
glBindTexture(GL_TEXTURE_2D, texture);

//We tell OpenGL that we want to make quads.
glBegin(GL_QUADS);

//glTexCoord2f(GLfloat s, GLfloat t) is used to specify the texture coordinates
//s is the x coordinate
//t is the y coordinate
//You can set it from 0 to 1. 0 = left side of the texture, 0.5 = middle of the texture, and 1 = right side of the texture. Take a look at the square above.
//Just to make it look nice I'm going to define it. lol.
//                  X, Y
#define TopRight    1, 1
#define TopLeft     0, 1
#define BottomRight 1, 0
#define BottomLeft  0, 0

//Front Face
glTexCoord2f(TopRight);     glVertex3fv(vertices[0]);    //Top Right
glTexCoord2f(TopLeft);      glVertex3fv(vertices[1]);   //Top Left
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[2]);   //Bottom Left
glTexCoord2f(BottomRight);  glVertex3fv(vertices[3]);   //Bottom Right

//Back Face
glTexCoord2f(TopRight);     glVertex3fv(vertices[4]);   //Top Right
glTexCoord2f(TopLeft);      glVertex3fv(vertices[7]);   //Top Left
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[6]);   //Bottom Left
glTexCoord2f(BottomRight);  glVertex3fv(vertices[5]);   //Bottom Right

//Right Face
glTexCoord2f(TopLeft);      glVertex3fv(vertices[0]);   //Top Left
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[3]);   //Bottom Left
glTexCoord2f(BottomRight);  glVertex3fv(vertices[4]);   //Bottom Right
glTexCoord2f(TopRight);     glVertex3fv(vertices[5]);   //Top Right

//Left Face
glTexCoord2f(TopRight);     glVertex3fv(vertices[1]);    //Top Right
glTexCoord2f(TopLeft);      glVertex3fv(vertices[6]);    //Top Left
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[7]);    //Bottom Left
glTexCoord2f(BottomRight);  glVertex3fv(vertices[2]);    //Bottom Right

//Top Face
glTexCoord2f(BottomRight);  glVertex3fv(vertices[0]);    //Bottom Right
glTexCoord2f(TopRight);     glVertex3fv(vertices[5]);    //Top Right
glTexCoord2f(TopLeft);      glVertex3fv(vertices[6]);    //Top Left
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[1]);    //Bottom Left

//Bottom Face
glTexCoord2f(TopLeft);      glVertex3fv(vertices[7]);    //Top Left
glTexCoord2f(TopRight);     glVertex3fv(vertices[4]);    //Top Right
glTexCoord2f(BottomRight);  glVertex3fv(vertices[3]);    //Bottom Right
glTexCoord2f(BottomLeft);   glVertex3fv(vertices[2]);    //Bottom Left
//Tells OpenGL that we are done.
glEnd();
//This will disable Texture Mapping
glDisable(GL_TEXTURE_2D);