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Ubuntuでopenglプログラミングを実験するためのコードをいくつか書きましたが、少し前ですが、以前はCについてある程度理解していました. .

これは、sdlを使用したopenglでの最初の実際の試みであり、ここまで到達しました.コンパイルして実行しますが、カメラ機能は何もしていないようです. この種のことを行うためのより良い方法がおそらくたくさんあることは知っていますが、より高度なものに移る前に基本を習得したかったのです.

main.cpp

#include <iostream>
#include <cmath>
#include "SDL/SDL.h"
#include "SDL/SDL_opengl.h"

int screen_width = 640;
int screen_height = 480;
const int screen_bpp = 32;
float rotqube = 0.9f;

float xpos = 0, ypos = 0, zpos = 0, xrot = 0, yrot = 0, angle=0.0;
float lastx, lasty;

SDL_Surface *screen = NULL; // create a default sdl_surface to render our opengl to

void camera (void) {
glRotatef(xrot,1.0,0.0,0.0);  // x-axis (left and right)
glRotatef(yrot,0.0,1.0,0.0);  // y-axis (up and down)
glTranslated(-xpos,-ypos,-zpos); // translate the screen to the position
SDL_GL_SwapBuffers();
}

int DrawCube(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();

glTranslatef(0.0f, 0.0f,-7.0f);
glRotatef(rotqube,0.0f,1.0f,0.0f);
glRotatef(rotqube,1.0f,1.0f,1.0f);
glBegin(GL_QUADS);
    glColor3f(0.0f,1.0f,0.0f);
    glVertex3f( 1.0f, 1.0f,-1.0f);
    glVertex3f(-1.0f, 1.0f,-1.0f);
    glVertex3f(-1.0f, 1.0f, 1.0f);
    glVertex3f( 1.0f, 1.0f, 1.0f);
    glColor3f(1.0f,0.5f,0.0f);
    glVertex3f( 1.0f,-1.0f, 1.0f);
    glVertex3f(-1.0f,-1.0f, 1.0f);
    glVertex3f(-1.0f,-1.0f,-1.0f);
    glVertex3f( 1.0f,-1.0f,-1.0f);
    glColor3f(1.0f,0.0f,0.0f);
    glVertex3f( 1.0f, 1.0f, 1.0f);
    glVertex3f(-1.0f, 1.0f, 1.0f);
    glVertex3f(-1.0f,-1.0f, 1.0f);
    glVertex3f( 1.0f,-1.0f, 1.0f);
    glColor3f(1.0f,1.0f,0.0f);
    glVertex3f( 1.0f,-1.0f,-1.0f);
    glVertex3f(-1.0f,-1.0f,-1.0f);
    glVertex3f(-1.0f, 1.0f,-1.0f);
    glVertex3f( 1.0f, 1.0f,-1.0f);
    glColor3f(0.0f,0.0f,1.0f);
    glVertex3f(-1.0f, 1.0f, 1.0f);
    glVertex3f(-1.0f, 1.0f,-1.0f);
    glVertex3f(-1.0f,-1.0f,-1.0f);
    glVertex3f(-1.0f,-1.0f, 1.0f);
    glColor3f(1.0f,0.0f,1.0f);
    glVertex3f( 1.0f, 1.0f,-1.0f);
    glVertex3f( 1.0f, 1.0f, 1.0f);
    glVertex3f( 1.0f,-1.0f, 1.0f);
    glVertex3f( 1.0f,-1.0f,-1.0f);
glEnd();
SDL_GL_SwapBuffers();

rotqube +=0.9f;
return true;
}

bool init_sdl(void)
{
if( SDL_Init( SDL_INIT_EVERYTHING ) != 0 )
{
    return false;
}

SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 5 );
SDL_GL_SetAttribute( SDL_GL_DEPTH_SIZE, 16 );
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );

// TODO: Add error check to this screen surface init
screen = SDL_SetVideoMode( screen_width, screen_height, screen_bpp, SDL_OPENGL | SDL_HWSURFACE | SDL_RESIZABLE );

return true;
}

static void init_opengl()
{
float aspect = (float)screen_width / (float)screen_height;
glViewport(0, 0, screen_width, screen_height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, aspect, 0.1, 100.0);
glMatrixMode(GL_MODELVIEW);
glClearColor(0.0, 0.0 ,0.0, 0);
glEnable(GL_DEPTH_TEST);
}

void heartbeat()
{
float xrotrad, yrotrad;
int diffx, diffy;

SDL_Event event;

while(1)
{
    while(SDL_PollEvent(&event))
    {
        switch(event.type)
        {
            case SDL_KEYDOWN:
                switch(event.key.keysym.sym)
                {
                    case SDLK_ESCAPE:
                        exit(0);
                        break;
                    case SDLK_w:
                        yrotrad = (yrot / 180 * 3.141592654f);
                        xrotrad = (xrot / 180 * 3.141592654f);
                        xpos += (float)sin(yrotrad);
                        zpos -= (float)cos(yrotrad);
                        ypos -= (float)sin(xrotrad);
                        std::cout << "w pressed" << std::endl;
                        break;
                    case SDLK_s:
                        yrotrad = (yrot / 180 * 3.141592654f);
                        xrotrad = (xrot / 180 * 3.141592654f);
                        xpos -= (float)sin(yrotrad);
                        zpos += (float)cos(yrotrad);
                        ypos += (float)sin(xrotrad);
                        break;
                    case SDLK_d:
                        yrotrad = (yrot / 180 * 3.141592654f);
                        xpos += (float)cos(yrotrad) * 0.2;
                        zpos += (float)sin(yrotrad) * 0.2;
                            break;
                        case SDLK_a:
                        yrotrad = (yrot / 180 * 3.141592654f);
                        xpos -= (float)cos(yrotrad) * 0.2;
                        zpos -= (float)sin(yrotrad) * 0.2;
                            break;
                    default:
                        break;
                }
                break;

            case SDL_MOUSEMOTION:
                diffx=event.motion.x-lastx; //check the difference between the current x and the last x position
                diffy=event.motion.y-lasty; //check the difference between the current y and the last y position
                lastx=event.motion.x; //set lastx to the current x position
                lasty=event.motion.y; //set lasty to the current y position
                xrot += (float)diffy; //set the xrot to xrot with the addition of the difference in the y position
                yrot += (float)diffx;    //set the xrot to yrot with the addition of the difference in the x position
                break;

            case SDL_QUIT:
                exit(0);
                break;

            case SDL_VIDEORESIZE:
                screen = SDL_SetVideoMode( event.resize.w, event.resize.h, screen_bpp, SDL_OPENGL | SDL_HWSURFACE | SDL_RESIZABLE );
                screen_width = event.resize.w;
                screen_height = event.resize.h;
                init_opengl();
                std::cout << "Resized to width: " << event.resize.w << " height: " << event.resize.h << std::endl;
                break;

            default:
                break;
        }
    }

    DrawCube();
    camera();

    SDL_Delay( 50 );
}
}

int main(int argc, char* argv[])
{
if( init_sdl() != false )
{
    std::cout << "SDL Init Successful" << std::endl;
}

init_opengl();

std::cout << "Hello World" << std::endl;

heartbeat();    // this is essentially the main loop

SDL_Quit();

return 0;
}

メイクファイル

all:
g++ -o test main.cpp -lSDL -lGL -lGLU

コンパイルして実行します。カメラの変換を行う際に助けが必要なだけだと思います。ありがとう

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2 に答える 2

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DrawCube()からglLoadIdentity()呼び出しを削除します。最初にglPushMatrix()に、最後にglPopMatrix()に置き換えます。ここで「w」を押すと何かが行われます。(私はそれが何をすべきか完全にはわかりません。)

問題は、glLoadIdentityがglTranslatefなどで設定された以前のすべての変換をクリアすることです。詳細な説明:http ://www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/pushmatrix.html

于 2009-08-07T00:26:30.733 に答える