Programarea cu OpenGL in C folosind Code::Blocks

Descriere proiect:
Azi m-am jucat un pic cu OpenGL-ul. Am reușit să-l configurez în Code::Blocks, să compilez și să testez niște progrămele simple. Pentru a utiliza exclusiv OpenGL-ul a fost suficient să instalez MinGW , și pentru GLUT am copiat glut32.dll si glut32.lib in System32 si Mingw/lib am configurat ca in imaginea de mai jos:

Primul progrămel (listat mai jos) desenează un triunghi:

Al doilea progrămel desenează un pătrat:

Documentatie proiect:

• Configurare OpenGL si GLUT pentru Code::Blocks
• GLUT cu Code::Blocks
  
• OpenGL tutorial
• Deseneaza un cerc folosind OpenGL
• OpenGL phong shading
• Ball game
  

Cod de test folosind OpenGL:

#include "windows.h"
#include "gl/gl.h"

LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);
void EnableOpenGL(HWND hwnd, HDC*, HGLRC*);
void DisableOpenGL(HWND, HDC, HGLRC);


int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    WNDCLASSEX wcex;
    HWND hwnd;
    HDC hDC;
    HGLRC hRC;
    MSG msg;
    BOOL bQuit = FALSE;
    float theta = 0.0f;

    /* register window class */
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_OWNDC;
    wcex.lpfnWndProc = WindowProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = "GLSample";
    wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION);;


    if (!RegisterClassEx(&wcex))
        return 0;

    /* create main window */
    hwnd = CreateWindowEx(0,
                          "GLSample",
                          "OpenGL Sample",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT,
                          CW_USEDEFAULT,
                          256,
                          256,
                          NULL,
                          NULL,
                          hInstance,
                          NULL);

    ShowWindow(hwnd, nCmdShow);

    /* enable OpenGL for the window */
    EnableOpenGL(hwnd, &hDC, &hRC);

    /* program main loop */
    while (!bQuit)
    {
        /* check for messages */
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            /* handle or dispatch messages */
            if (msg.message == WM_QUIT)
            {
                bQuit = TRUE;
            }
            else
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }
        else
        {
            /* OpenGL animation code goes here */

            glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
            glClear(GL_COLOR_BUFFER_BIT);

            glPushMatrix();
            //glRotatef(theta, 0.0f, 0.0f, 1.0f);

            glBegin(GL_TRIANGLES);

                glColor3f(1.0f, 0.0f, 0.0f);   glVertex2f(0.0f,   1.0f);
                glColor3f(0.0f, 1.0f, 0.0f);   glVertex2f(0.87f,  -0.5f);
                glColor3f(0.0f, 0.0f, 1.0f);   glVertex2f(-0.87f, -0.5f);

            glEnd();

            glPopMatrix();

            SwapBuffers(hDC);

            theta += 1.0f;
            Sleep (1);
        }
    }

    /* shutdown OpenGL */
    DisableOpenGL(hwnd, hDC, hRC);

    /* destroy the window explicitly */
    DestroyWindow(hwnd);

    return msg.wParam;
}

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
        case WM_CLOSE:
            PostQuitMessage(0);
        break;

        case WM_DESTROY:
            return 0;

        case WM_KEYDOWN:
        {
            switch (wParam)
            {
                case VK_ESCAPE:
                    PostQuitMessage(0);
                break;
            }
        }
        break;

        default:
            return DefWindowProc(hwnd, uMsg, wParam, lParam);
    }

    return 0;
}

void EnableOpenGL(HWND hwnd, HDC* hDC, HGLRC* hRC)
{
    PIXELFORMATDESCRIPTOR pfd;

    int iFormat;

    /* get the device context (DC) */
    *hDC = GetDC(hwnd);

    /* set the pixel format for the DC */
    ZeroMemory(&pfd, sizeof(pfd));

    pfd.nSize = sizeof(pfd);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW |
                  PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 16;
    pfd.iLayerType = PFD_MAIN_PLANE;

    iFormat = ChoosePixelFormat(*hDC, &pfd);

    SetPixelFormat(*hDC, iFormat, &pfd);

    /* create and enable the render context (RC) */
    *hRC = wglCreateContext(*hDC);

    wglMakeCurrent(*hDC, *hRC);
}

void DisableOpenGL (HWND hwnd, HDC hDC, HGLRC hRC)
{
    wglMakeCurrent(NULL, NULL);
    wglDeleteContext(hRC);
    ReleaseDC(hwnd, hDC);
}

Cod de test folosind biblioteca GLUT:

#include "windows.h"
#include "gl/gl.h"
#include "GL/glut.h"
#include "math.h"
#define pi 3.142857



  void display()
  {
    glClear(GL_COLOR_BUFFER_BIT);

    glBegin(GL_POLYGON);
    glVertex2f(-0.5, -0.5);
    glVertex2f(-0.5,  0.5);
    glVertex2f(0.5,  0.5);
    glVertex2f(0.5, -0.5);
    glEnd();

    glFlush();
  }

  void init()
  {

    glClearColor(0.000, 0.110, 0.392, 0.0); // JMU Gold

    // making picture color green (in RGB mode), as middle argument is 1.0
    glColor3f(0.0, 1.0, 0.0);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-1.0, 1.0, -1.0, 1.0);
  }

  int main(int argc, char** argv)
  {

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(640, 480);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("Test X");
    glutDisplayFunc(display);
    init();
    glutMainLoop();
  }

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O seară plăcută tuturor !