/*      Steven Billington
        January 13, 2003
        May 26, 2003 - UPDATE
        RobotOGL.cpp
        rod@cprogramming.com

        The following program creates a window and then
        uses multiple OpenGL functions to display a
        animated robot constructed of different size
        cubes. To compile this code you must make the
        proper library links in project--->settings.

        I apologize for any amount of scatterd code or
        mis-formatting that printing this may occur. Please
        feel free to email me at the address above for the .cpp
        file.
*/

/*      These are what we refer to as Pre-processor
        Directives. In order for certain functions in
        C++ to operate you must include certain header
        files. Each header file below contains different
        functions needed throughout this program.
*/

#pragma comment(linker, "/subsystem:windows")

#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>
#include <gl/glaux.h>

/*      Here we find a few global variables. While
        i don't really like to use global variables,
        i found them very handy for this particular
        program. These variables will control angles,
        fullscreen, and the global device context.
*/

HDC g_HDC;
float angle = 0.0f;
float legAngle[2] = {0.0f, 0.0f};
float armAngle[2] = {0.0f, 0.0f};
bool fullScreen = false;

/*      Function:       DrawCube
        Purpose:        As the name would suggest, this is
                                the function for drawing the cubes.
*/

void DrawCube(float xPos, float yPos, float zPos)
{
        glPushMatrix();
        glBegin(GL_POLYGON);

                /*      This is the top face*/
                glVertex3f(0.0f, 0.0f, 0.0f);
                glVertex3f(0.0f, 0.0f, -1.0f);
                glVertex3f(-1.0f, 0.0f, -1.0f);
                glVertex3f(-1.0f, 0.0f, 0.0f);

                /*      This is the front face*/
                glVertex3f(0.0f, 0.0f, 0.0f);
                glVertex3f(-1.0f, 0.0f, 0.0f);
                glVertex3f(-1.0f, -1.0f, 0.0f);
                glVertex3f(0.0f, -1.0f, 0.0f);

                /*      This is the right face*/
                glVertex3f(0.0f, 0.0f, 0.0f);
                glVertex3f(0.0f, -1.0f, 0.0f);
                glVertex3f(0.0f, -1.0f, -1.0f);
                glVertex3f(0.0f, 0.0f, -1.0f);

                /*      This is the left face*/
                glVertex3f(-1.0f, 0.0f, 0.0f);
                glVertex3f(-1.0f, 0.0f, -1.0f);
                glVertex3f(-1.0f, -1.0f, -1.0f);
                glVertex3f(-1.0f, -1.0f, 0.0f);

                /*      This is the bottom face*/
                glVertex3f(0.0f, 0.0f, 0.0f);
                glVertex3f(0.0f, -1.0f, -1.0f);
                glVertex3f(-1.0f, -1.0f, -1.0f);
                glVertex3f(-1.0f, -1.0f, 0.0f);

                /*      This is the back face*/
                glVertex3f(0.0f, 0.0f, 0.0f);
                glVertex3f(-1.0f, 0.0f, -1.0f);
                glVertex3f(-1.0f, -1.0f, -1.0f);
                glVertex3f(0.0f, -1.0f, -1.0f);

        glEnd();
        glPopMatrix();
}

/*      Function:       DrawArm
        Purpose:        This function draws the arm
                                for the robot.
*/

void DrawArm(float xPos, float yPos, float zPos)
{
        glPushMatrix();

                /*      Sets color to red*/
                glColor3f(1.0f, 0.0f, 0.0f);
                glTranslatef(xPos, yPos, zPos);

                /*      Creates 1 x 4 x 1 cube*/
                glScalef(1.0f, 4.0f, 1.0f);
                DrawCube(0.0f, 0.0f, 0.0f);

        glPopMatrix();
}

/*      Function:       DrawHead
        Purpose:        This function will create the
                                head for the robot.
*/

void DrawHead(float xPos, float yPos, float zPos)
{
        glPushMatrix();

                /*      Sets color to white*/
                glColor3f(1.0f, 1.0f, 1.0f);
                glTranslatef(xPos, yPos, zPos);

                /*      Creates 2 x 2 x 2 cube*/
                glScalef(2.0f, 2.0f, 2.0f);
                DrawCube(0.0f, 0.0f, 0.0f);

        glPopMatrix();
}

/*      Function:       DrawTorso
        Purpose:        Function will do as suggested
                                and draw a torso for our robot.
*/

void DrawTorso(float xPos, float yPos, float zPos)
{
        glPushMatrix();

                /*      Sets color to blue*/
                glColor3f(0.0f, 0.0f, 1.0f);
                glTranslatef(xPos, yPos, zPos);

                /*      Creates 3 x 5 x 1 cube*/
                glScalef(3.0f, 5.0f, 1.0f);
                DrawCube(0.0f, 0.0f, 0.0f);

        glPopMatrix();
}

/*      Function:       DrawLeg
        Purpose:        Not to sound repetitve, but as suggested
                                this function will draw our robots legs.
*/

void DrawLeg(float xPos, float yPos, float zPos)
{
        glPushMatrix();

                /*      Sets color to yellow*/
                glColor3f(1.0f, 1.0f, 0.0f);
                glTranslatef(xPos, yPos, zPos);

                /*      Creates 1 x 5 x 1 cube*/
                glScalef(1.0f, 5.0f, 1.0f);
                DrawCube(0.0f, 0.0f, 0.0f);

        glPopMatrix();
}

/*      Function:       DrawRobot
        Purpose:        Function to draw our entire robot
*/

void DrawRobot(float xPos, float yPos, float zPos)
{
        /*      Variables for state of robots legs. True
                means the leg is forward, and False means
                the leg is back. The same applies to the
                robots arm states.
        */
        static bool leg1 = true;
        static bool leg2 = false;
        static bool arm1 = true;
        static bool arm2 = false;

        glPushMatrix();

                /*      This will draw our robot at the
                        desired coordinates.
                */
                glTranslatef(xPos, yPos, zPos);

                /*      These three lines will draw the
                        various components of our robot.
                */
                DrawHead(1.0f, 2.0f, 0.0f);
                DrawTorso(1.5f, 0.0f, 0.0f);
                glPushMatrix();


                /*      If the arm is moving forward we will increase
                        the angle; otherwise, we will decrease the
                        angle.
                */
                if (arm1)
                {
                        armAngle[0] = armAngle[0] + 1.0f;
                }
                else
                {
                        armAngle[0] = armAngle[0] - 1.0f;
                }

                /*      Once the arm has reached its max angle
                        in one direction, we want it to reverse
                        and change direction.
                */
                if (armAngle[0] >= 15.0f)
                {
                        arm1 = false;
                }
                if (armAngle[0] <= 15.0f)
                {
                        arm1 = true;
                }


                /*      Here we are going to move the arm away
                        from the torso and rotate. This will
                        create a walking effect.
                */
                glTranslatef(0.0f, -0.5f, 0.0f);
                glRotatef(armAngle[0], 1.0f, 0.0f, 0.0f);
                DrawArm(2.5f, 0.0f, -0.5f);

        glPopMatrix();

        glPushMatrix();


                /*      If the arm is moving forward we will increase
                        the angle, otherwise we will decrease the
                        angle
                */
                if (arm2)
                {
                        armAngle[1] = armAngle[1] + 1.0f;
                }
                else
                {
                        armAngle[1] = armAngle[1] - 1.0f;
                }

                /*      Here we are going to move the arm away
                        from the torso and rotate. This will
                        create a walking effect.
                */
                glTranslatef(0.0f, -0.5f, 0.0f);
                glRotatef(armAngle[1], 1.0f, 0.0f, 0.0f);
                DrawArm(-1.5f, 0.0f, -0.5f);

        glPopMatrix();

        /*      Now its time to rotate the legs relative to the
                robots position in the world, this is the first
                leg, ie the right one.
        */
        glPushMatrix();

                /*      If the leg is moving forward we will increase
                        the angle; otherwise, we will decrease the
                        angle.
                */
                if (leg1)
                {
                        legAngle[0] = legAngle[0] + 1.0f;
                }
                else
                {
                        legAngle[0] = legAngle[0] - 1.0f;
                }

                /*      Once the leg has reached its max angle
                        in one direction, we want it to reverse
                        and change direction.
                */
                if (legAngle[0] >= 15.0f)
                {
                        leg1 = false;
                }
                if (legAngle[0] <= -15.0f)
                {
                        leg1 = true;
                }


                /*      Here we are going to move the leg away
                        from the torso and rotate. This will
                        create a walking effect.
                */
                glTranslatef(0.0f, -0.5f, 0.0f);
                glRotatef(legAngle[0], 1.0f, 0.0f, 0.0f);


                /*      Time to draw the leg.
                */
                DrawLeg(-0.5f, -5.0f, -0.5f);

        glPopMatrix();

        /*      Same as above, for the left leg.
        */
        glPushMatrix();

                /*      If the leg is moving forward we will increase
                        the angle, otherwise we will decrease the
                        angle
                */
                if (leg2)
                {
                        legAngle[1] = legAngle[1] + 1.0f;
                }
                else
                {
                        legAngle[1] = legAngle[1] - 1.0f;