Question

这是我当前的代码：

所有包含

#define GLEW_STATIC
#include <stdlib.h>
#include <SDL2/SDL.h>
#include <math.h>
#include <stdio.h>
#include <iostream>
#include<conio.h>
#include<dos.h>
#include <GL/glew.h>
#include "SceneOpenGL.h"
#include <SDL2/SDL_image.h>

using namespace std;

#ifdef WIN32
#include <GL/glew.h>

#else
#define GL3_PROTOTYPES 1
#include <GL3/gl3.h>

#endif

#include <SDL2/SDL.h>
#include <iostream>

无效我的功能

void DrawCircle(float cx, float cy, float r, int num_segments);
void DrawEllipse(float cx, float cy, float a, float b, int num_segments);
void Rotation(float a,float b,float r, float g_theta );

主要功能

int main(int argc, char **argv)
{
SDL_Window* fenetre(0);
SDL_GLContext contexteOpenGL(0);

SDL_Event evenements;
bool terminer(false);

if(SDL_Init(SDL_INIT_VIDEO) < 0)
{
    std::cout << "Erreur lors de l'initialisation de la SDL : " << SDL_GetError() << std::endl;
    SDL_Quit();

    return -1;
}

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);


SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);


fenetre = SDL_CreateWindow("Test SDL 2.0", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 600, 600, SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);

if(fenetre == 0)
{
    std::cout << "Erreur lors de la creation de la fenetre : " << SDL_GetError() << std::endl;
    SDL_Quit();

    return -1;
}

contexteOpenGL = SDL_GL_CreateContext(fenetre);

if(contexteOpenGL == 0)
{
    std::cout << SDL_GetError() << std::endl;
    SDL_DestroyWindow(fenetre);
    SDL_Quit();

    return -1;
}


#ifdef WIN32

    GLenum initialisationGLEW( glewInit() );

    if(initialisationGLEW != GLEW_OK)
    {

        std::cout << "Erreur d'initialisation de GLEW : " << glewGetErrorString(initialisationGLEW) << std::endl;

        SDL_GL_DeleteContext(contexteOpenGL);
        SDL_DestroyWindow(fenetre);
        SDL_Quit();

        return -1;
    }

#endif

带有圆形和椭圆形显示的主循环

 while(!terminer)
{
    SDL_WaitEvent(&evenements);

    if(evenements.window.event == SDL_WINDOWEVENT_CLOSE)
        terminer = true;

glClear(GL_COLOR_BUFFER_BIT);

float g_theta = 0.0f;

while (g_theta<360)
{
glClear(GL_COLOR_BUFFER_BIT);
g_theta += 1.0f;
DrawCircle(0, 0, 0.3, 50);
Rotation(0.8,0.65,0.1,g_theta);
Rotation(0.5,0.5,0.2,g_theta);
Rotation(0.1,0.1,0.01,g_theta);

    glDisableVertexAttribArray(0);
    SDL_GL_SwapWindow(fenetre);
}
}
SDL_GL_DeleteContext(contexteOpenGL);
SDL_DestroyWindow(fenetre);
SDL_Quit();

return 0;

}

创建圆的功能

void DrawCircle(float cx, float cy, float r, int num_segments)
{
    glBegin(GL_LINE_LOOP);
for(int ii = 0; ii < num_segments; ii++)
{
    float theta = 2.0 * M_PI * float(ii) / float(num_segments);

    float x_c = r * cosf(theta);//calculate the x component
    float y_c = r * sinf(theta);//calculate the y component
    glColor3f(1.0f,0.0f,0.0f);
    glVertex2f(x_c + cx, y_c + cy);//output vertex
}
glEnd();
}

创建椭圆的功能

    void DrawEllipse(float cx, float cy, float a, float b, int num_segments)
{
        glBegin(GL_LINE_LOOP);
    for(int ii = 0; ii < num_segments; ii++)
    {
        float theta = 2.0 * M_PI * float(ii) / float(num_segments);

        float x_e = a * cosf(theta);//calculate the x component
        float y_e = b * sinf(theta);//calculate the y component
        glColor3f(0.0f,0.0f,1.0f);
        glVertex2f(x_e + cx, y_e + cy);//output vertex
    }
    glEnd();
}

将圆与椭圆连接的功能

    void Rotation(float a,float b,float r, float g_theta )
{

float x = a * cosf(g_theta * M_PI / 180.0f);
float y = b * sinf(g_theta * M_PI / 180.0f);
float d = sqrtf( x*x + y*y );

glMatrixMode( GL_MODELVIEW );
glLoadIdentity();

glPushMatrix();
glRotatef( g_theta, 0, 0, 1 );  // rotation around the z axis
glTranslatef( d, 0, 0 );        // translation by the distance

DrawCircle(0, 0, r, 50);
glPopMatrix();

DrawEllipse(0, 0, a, b, 50);

}

其结果是：

编译的结果：红色的景深实际上在移动自己的蓝色椭圆形

我希望每个圆圈都有自己的纹理。我已经下载了SDL2_image并尝试了以下代码：

  IMG_Init(IMG_INIT_JPG);
  SDL_Surface * image = IMG_Load("PICT3159.JPG");
  IMG_Quit();

但是什么也没发生。如何在移动的圆上渲染纹理？

（PS：我的最终目标是创建我们太阳系的2D表示。）

编辑：

我知道如何显示图像。我是这样的：

    SDL_Renderer *pRenderer = 
    SDL_CreateRenderer(fenetre,-1,SDL_RENDERER_ACCELERATED); // Création d'un 
    SDL_Renderer utilisant l'accélération matérielle

    if ( pRenderer )
{
        SDL_Surface* pSprite = SDL_LoadBMP("earth.bmp");
        if ( pSprite )
    {
            SDL_Texture* pTexture = 
SDL_CreateTextureFromSurface(pRenderer,pSprite); // Préparation du sprite
        if ( pTexture )
        {
            SDL_Rect dest = { 640/2 - pSprite->w/2,480/2 - pSprite->h/2, pSprite->w, pSprite->h};
            SDL_RenderCopy(pRenderer,pTexture,NULL,&dest); // Copie du sprite grâce au SDL_Renderer

            SDL_RenderPresent(pRenderer); // Affichage
           SDL_Delay(3000); /* Attendre trois secondes, que l'utilisateur voit la fenêtre */

          //  SDL_DestroyTexture(pTexture); // Libération de la mémoire associée à la texture
        }
        else
        {
            fprintf(stdout,"Échec de création de la texture (%s)\n",SDL_GetError());
        }

        SDL_FreeSurface(pSprite); // Libération de la ressource occupée par le sprite
    }
    else
    {
        fprintf(stdout,"Échec de chargement du sprite (%s)\n",SDL_GetError());
    }

    SDL_DestroyRenderer(pRenderer); // Libération de la mémoire du SDL_Renderer
}
else
{
    fprintf(stdout,"Échec de création du renderer (%s)\n",SDL_GetError());
}

也许调整图像大小，将其切成圆形并在椭圆上旋转会更容易吗？（但我也不知道该怎么做）

如何在C ++中使用SDL2和OpenGL在运动的圆上渲染纹理？

0 个答案: