How to draw board 3d? GLUT - c++

Question

I know how to draw rectangles, but I want to draw board. It will be part of my map where I wanted to create maze. It should be 3D. So I need to create simple board. I know that I need to create it using polygons. Can someone help?
glColor3f( 1.0, 0.0, 0.0 ); glVertex3f( 0.5, -0.5, -0.5 ); // P1 is red
glColor3f( 0.0, 1.0, 0.0 ); glVertex3f( 0.5, 0.5, -0.5 ); // P2 is green
glColor3f( 0.0, 0.0, 1.0 ); glVertex3f( -0.5, 0.5, -0.5 ); // P3 is blue
glColor3f( 1.0, 0.0, 1.0 ); glVertex3f( -0.5, -0.5, -0.5 ); // P4 is purple
glEnd();
// White side - BACK
glBegin(GL_POLYGON);
glColor3f( 1.0, 1.0, 1.0 );
glVertex3f( 0.5, -0.5, 0.5 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glVertex3f( -0.5, -0.5, 0.5 );
glEnd();
// Purple side - RIGHT
glBegin(GL_POLYGON);
glColor3f( 1.0, 0.0, 1.0 );
glVertex3f( 0.5, -0.5, -0.5 );
glVertex3f( 0.5, 0.5, -0.5 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( 0.5, -0.5, 0.5 );
glEnd();
// Green side - LEFT
glBegin(GL_POLYGON);
glColor3f( 0.0, 1.0, 0.0 );
glVertex3f( -0.5, -0.5, 0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glVertex3f( -0.5, 0.5, -0.5 );
glVertex3f( -0.5, -0.5, -0.5 );
glEnd();
// Blue side - TOP
glBegin(GL_POLYGON);
glColor3f( 0.0, 0.0, 1.0 );
glVertex3f( 0.5, 0.5, 0.5 );
glVertex3f( 0.5, 0.5, -0.5 );
glVertex3f( -0.5, 0.5, -0.5 );
glVertex3f( -0.5, 0.5, 0.5 );
glEnd();
// Red side - BOTTOM
glBegin(GL_POLYGON);
glColor3f( 1.0, 0.0, 0.0 );
glVertex3f( 0.5, -0.5, -0.5 );
glVertex3f( 0.5, -0.5, 0.5 );
glVertex3f( -0.5, -0.5, 0.5 );
glVertex3f( -0.5, -0.5, -0.5 );
glEnd();
It will draw a simple cube, but I need to transform it to the board. How can I do this?

Answer 1

To make your cube appear like the board (or floor) you described, you've got two main options.
The first is simply to change the coordinates of your polygons. At the moment, your cube runs from -0.5 to 0.5 on each axis. You could change the coordinates to run from e.g. -5.0f to 5.0f on X and Z, and -10.0f, to -9.0f on Y.
If you're not sure how to do that, it involves changing the numbers in the glVertex3f() calls. The parameters are in this order: X, Y, Z.
The second option is to use matrix transformations. A translation can move the cube downwards towards the floor, and a scale can stretch it out sideways:
glPushMatrix();
glTranslatef(0.0f, -9.5f, 0.0f); // move downwards
glScalef(10.0f, 1.0f, 10.0f); // stretch on X and Z
// insert your cube drawing code here
glPopMatrix();
The push/pop calls are there to prevent the matrix transformations from affecting other drawing, or from accumulating each time your drawing code is executed.