OpenGL tutorial 14 - functions.cpp

//http://www.youtube.com/user/thecplusplusguy
//Thanks for the typed in code to Tapit85
#include "functions.h"

float camX = 0., camY = 0., camZ = 5.;
float camYaw = 0.;
float camPitch = 0.;
#ifndef M_PI
#define M_PI 3.1415926535
#endif

void lockCamera()
{
    if(camPitch > 90)
        camPitch = 90;
    if(camPitch < -90)
        camPitch = -90;
    if(camYaw < 0.)
        camYaw += 360.;
    if(camYaw > 360.)
        camYaw -= 360;
}

void moveCamera(float dist, float dir)
{
    float rad = (camYaw+dir)*M_PI/180.;
    camX -= sin(rad)*dist;
    camZ -= cos(rad)*dist;
}

void moveCameraUp(float dist, float dir)
{
    float rad = (camPitch+dir)*M_PI/180.;
    camY += sin(rad)*dist;
}

void Control(float movevel, float mousevel, bool mi)
{
    if(mi)
    {
        int MidX = 320;
        int MidY = 240;
        SDL_ShowCursor(SDL_DISABLE);
        int tmpx, tmpy;
        SDL_GetMouseState(&tmpx, &tmpy);
        camYaw += mousevel*(MidX-tmpx);
        camPitch += mousevel*(MidY-tmpy);
        lockCamera();
        SDL_WarpMouse(MidX, MidY);
        Uint8* state = SDL_GetKeyState(NULL);
        if(state[SDLK_w])
        {
//          if(camPitch!=90 && camPitch!=-90)   // comment in if you want to be able to go up and down
                moveCamera(movevel,0.);
//          moveCameraUp(movevel,0.);               // comment in if you want to be able to go up and down
        }
        else if(state[SDLK_s])
        {
//          if(camPitch!=90 && camPitch!=-90)   // comment in if you want to be able to go up and down
                moveCamera(movevel,180.);
//          moveCameraUp(movevel,180.);         // comment in if you want to be able to go up and down
        }
        if(state[SDLK_a])
            moveCamera(movevel,90.);
        else if(state[SDLK_d])
            moveCamera(movevel,270.);
    }
    glRotatef(-camPitch,1.,0.,0.);
    glRotatef(-camYaw,0.,1.,0.);
}

void UpdateCamera()
{
    glTranslatef(-camX,-camY,-camZ);
}

void drawCube(float size)
{
    glBegin(GL_QUADS);
        // front face
        glColor3f(1.0,0.0,0.0);
        glVertex3f(size/2,size/2,size/2);
        glVertex3f(-size/2,size/2,size/2);
        glVertex3f(-size/2,-size/2,size/2);
        glVertex3f(size/2,-size/2,size/2);
        // left face
        glColor3f(0.0,1.0,0.0);
        glVertex3f(-size/2,size/2,size/2);
        glVertex3f(-size/2,-size/2,size/2);
        glVertex3f(-size/2,-size/2,-size/2);
        glVertex3f(-size/2,size/2,-size/2);
        // back face
        glColor3f(0.0,0.0,1.0);
        glVertex3f(size/2,size/2,-size/2);
        glVertex3f(-size/2,size/2,-size/2);
        glVertex3f(-size/2,-size/2,-size/2);
        glVertex3f(size/2,-size/2,-size/2);
        // right face
        glColor3f(1.0,1.0,0.0);
        glVertex3f(size/2,size/2,size/2);
        glVertex3f(size/2,-size/2,size/2);
        glVertex3f(size/2,-size/2,-size/2);
        glVertex3f(size/2,size/2,-size/2);
        // top face
        glColor3f(1.0,0.0,1.0);
        glVertex3f(size/2,size/2,size/2);
        glVertex3f(-size/2,size/2,size/2);
        glVertex3f(-size/2,size/2,-size/2);
        glVertex3f(size/2,size/2,-size/2);
        // bottom face
        glColor3f(0.0,1.0,1.0);
        glVertex3f(size/2,-size/2,size/2);
        glVertex3f(-size/2,-size/2,size/2);
        glVertex3f(-size/2,-size/2,-size/2);
        glVertex3f(size/2,-size/2,-size/2);
    glEnd();
}