如何使用openGL在屏幕上显示加载的纹理

Question

I am using the function :

GLuint LoadTexture(const char* filename)
{

    GLuint texture;

    int width, height;

    unsigned char* data;

    FILE* file;

    file = fopen(filename, "rb");

    if (file == NULL) return 0;
    width = 1024;
    height = 512;
    data = (unsigned char*)malloc(width * height * 3);
    //int size = fseek(file,);
    fread(data, width * height * 3, 1, file);
    fclose(file);

    for (int i = 0; i < width * height; ++i)
    {
        int index = i * 3;
        unsigned char B, R;
        B = data[index];
        R = data[index + 2];

        data[index] = R;
        data[index + 2] = B;

    }


    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);


    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    gluBuild2DMipmaps(GL_TEXTURE_2D, 3, width, height, GL_RGB, GL_UNSIGNED_BYTE, data);
    free(data);

    return texture;
}

in display() function :

GLuint texture;
texture = LoadTexture("bubble.png");
glBindTexture(GL_TEXTURE_2D, texture);

how do i make the texture appear on the screen? what do i need to do after i have binded the texture?

Answer 1

If your Texture is loaded correctly, what you need is a shader pipeline containing a Vertex shader and a Fragment shader. Then you can Render a rectangle and apply the Texture in the Fragment shader Stage.

Btw. SOIL is great lib for loading textures