/* 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 scattered 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; } /* Once the leg has reached its max angle in one direction, we want it to reverse and change direction. */ if (legAngle[1] >= 15.0f) { leg2 = false; } if (legAngle[1] <= -15.0f) { leg2 = 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[1], 1.0f, 0.0f, 0.0f); DrawLeg(1.5f, -5.0f, -0.5f); glPopMatrix(); glPopMatrix();}/* Function: Render Purpose: This function will be responsible for the rendering, got to love my descriptive function names : )*/void Render(){ /* Enable depth testing */ glEnable(GL_DEPTH_TEST); /* Heres our rendering. Clears the screen to black, clear the color and depth buffers, and reset our modelview matrix. */ glClearColor(0.0f, 0.0f, 0.0f, 0.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); /* Increase rotation angle counter */ angle = angle + 1.0f; /* Reset after we have completed a circle */ if (angle >= 360.0f) { angle = 0.0f; } glPushMatrix(); glLoadIdentity(); /* Move to 0,0,-30 , rotate the robot on its y axis, draw the robot, and dispose of the current matrix. */ glTranslatef(0.0f, 0.0f, -30.0f); glRotatef(angle, 0.0f, 1.0f, 0.0f); DrawRobot(0.0f, 0.0f, 0.0f); glPopMatrix(); glFlush(); /* Bring back buffer to foreground */ SwapBuffers(g_HDC);}//function to set the pixel format for the device context/* Function: SetupPixelFormat Purpose: This function will be responsible for setting the pixel format for the device context.*/void SetupPixelFormat(HDC hDC){ /* Pixel format index */ int nPixelFormat; static PIXELFORMATDESCRIPTOR pfd = { sizeof(PIXELFORMATDESCRIPTOR), //size of structure 1, //default version PFD_DRAW_TO_WINDOW | //window drawing support PFD_SUPPORT_OPENGL | //opengl support PFD_DOUBLEBUFFER, //double buffering support PFD_TYPE_RGBA, //RGBA color mode 32, //32 bit color mode 0, 0, 0, 0, 0, 0, //ignore color bits 0, //no alpha buffer 0, //ignore shift bit 0, //no accumulation buffer 0, 0, 0, 0, //ignore accumulation bits 16, //16 bit z-buffer size 0, //no stencil buffer 0, //no aux buffer PFD_MAIN_PLANE, //main drawing plane 0, //reserved 0, 0, 0 }; //layer masks ignored /* Choose best matching format*/ nPixelFormat = ChoosePixelFormat(hDC, &pfd); /* Set the pixel format to the device context*/ SetPixelFormat(hDC, nPixelFormat, &pfd);}/* Windows Event Procedure Handler*/LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){ /* Rendering and Device Context variables are declared here. */ static HGLRC hRC; static HDC hDC; /* Width and Height for the window our robot is to be displayed in. */ int width, height; switch(message) { case WM_CREATE: //window being created hDC = GetDC(hwnd); //get current windows device context g_HDC = hDC; SetupPixelFormat(hDC); //call our pixel format setup function /* Create rendering context and make it current */ hRC = wglCreateContext(hDC); wglMakeCurrent(hDC, hRC); return 0; break; case WM_CLOSE: //window is closing /* Deselect rendering context and delete it*/ wglMakeCurrent(hDC, NULL); wglDeleteContext(hRC); /* Send quit message to queue*/ PostQuitMessage(0); return 0; break; case WM_SIZE: /* Retrieve width and height*/ height = HIWORD(lParam); width = LOWORD(lParam); /* Don't want a divide by 0*/ if (height == 0) { height = 1; } /* Reset the viewport to new dimensions*/ glViewport(0, 0, width, height); /* Set current Matrix to projection*/ glMatrixMode(GL_PROJECTION); glLoadIdentity(); //reset projection matrix /* Time to calculate aspect ratio of our window. */ gluPerspective(54.0f, (GLfloat)width/(GLfloat)height, 1.0f, 1000.0f); glMatrixMode(GL_MODELVIEW); //set modelview matrix glLoadIdentity(); //reset modelview matrix return 0; break; default: break; } return (DefWindowProc(hwnd, message, wParam, lParam));}int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow){ WNDCLASSEX windowClass; //window class HWND hwnd; //window handle MSG msg; //message bool done; //flag for completion of app DWORD dwExStyle; //window extended style DWORD dwStyle; //window style RECT windowRect; /* Screen/display attributes*/ int width = 800; int height = 600; int bits = 32; windowRect.left =(long)0; //set left value to 0 windowRect.right =(long)width; //set right value to requested width windowRect.top =(long)0; //set top value to 0 windowRect.bottom =(long)height;//set bottom value to requested height /* Fill out the window class structure*/ windowClass.cbSize = sizeof(WNDCLASSEX); windowClass.style = CS_HREDRAW | CS_VREDRAW; windowClass.lpfnWndProc = WndProc; windowClass.cbClsExtra = 0; windowClass.cbWndExtra = 0; windowClass.hInstance = hInstance; windowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION); windowClass.hCursor = LoadCursor(NULL, IDC_ARROW); windowClass.hbrBackground = NULL; windowClass.lpszMenuName = NULL; windowClass.lpszClassName = "MyClass"; windowClass.hIconSm = LoadIcon(NULL, IDI_WINLOGO); /* Register window class*/ if (!RegisterClassEx(&windowClass)) { return 0; } /* Check if fullscreen is on*/ if (fullScreen) { DEVMODE dmScreenSettings; memset(&dmScreenSettings, 0, sizeof(dmScreenSettings)); dmScreenSettings.dmSize = sizeof(dmScreenSettings); dmScreenSettings.dmPelsWidth = width; //screen width dmScreenSettings.dmPelsHeight = height; //screen height dmScreenSettings.dmBitsPerPel = bits; //bits per pixel dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT; if (ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN != DISP_CHANGE_SUCCESSFUL)) { /* Setting display mode failed, switch to windowed*/ MessageBox(NULL, "Display mode failed", NULL, MB_OK); fullScreen = false; } } /* Check if fullscreen is still on*/ if (fullScreen) { dwExStyle = WS_EX_APPWINDOW; //window extended style dwStyle = WS_POPUP; //windows style ShowCursor(FALSE); //hide mouse pointer } else { dwExStyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE; //window extended style dwStyle = WS_OVERLAPPEDWINDOW; //windows style } AdjustWindowRectEx(&windowRect, dwStyle, FALSE, dwExStyle); /* Class registerd, so now create our window*/ hwnd = CreateWindowEx(NULL, "MyClass", //class name "OpenGL Robot", //app name dwStyle | WS_CLIPCHILDREN | WS_CLIPSIBLINGS, 0, 0, //x and y coords windowRect.right - windowRect.left, windowRect.bottom - windowRect.top,//width, height NULL, //handle to parent NULL, //handle to menu hInstance, //application instance NULL); //no xtra params /* Check if window creation failed (hwnd = null ?)*/ if (!hwnd) { return 0; } ShowWindow(hwnd, SW_SHOW); //display window UpdateWindow(hwnd); //update window done = false; //initialize loop condition variable /* Main message loop*/ while (!done) { PeekMessage(&msg, hwnd, NULL, NULL, PM_REMOVE); if (msg.message == WM_QUIT) //did we revieve a quit message? { done = true; } else { Render(); TranslateMessage(&msg); DispatchMessage(&msg); } } if (fullScreen) { ChangeDisplaySettings(NULL, 0); ShowCursor(TRUE); } return msg.wParam;}
