Steward

分享是一種喜悅、更是一種幸福

程式語言 - Simple DirectMedia Layer (SDL) - v1.2 - C/C++ - OpenGL 1.0 - Apply Sphere Mapping

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參考資訊：
https://github.com/gamedev-net/nehe-opengl

main.c

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <SDL.h>
#include <GL/gl.h>
#include <GL/glu.h>

int main(int argc, char *argv[])
{
    const int W = 320;
    const int H = 240;
    GLuint tex = 0;
    GLdouble nearPlane = 0.1;
    GLdouble farPlane = 100.0;
    GLdouble top = nearPlane * tan(45.0 * 3.14159 / 360.0);
    GLdouble right = top * ((GLfloat)W / (GLfloat)H);
    SDL_Surface *bmp = NULL;
    SDL_Surface *screen = NULL;

    SDL_Init(SDL_INIT_VIDEO);
    screen = SDL_SetVideoMode(W, H, 16, SDL_SWSURFACE | SDL_OPENGL);
    bmp = SDL_LoadBMP("main.bmp");

    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, bmp->w, bmp->h, 0, GL_BGR, GL_UNSIGNED_BYTE, bmp->pixels);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
    glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
    glEnable(GL_TEXTURE_GEN_S);
    glEnable(GL_TEXTURE_GEN_T);
    glEnable(GL_TEXTURE_2D);

    glViewport(0, 0, W, H);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-right, right, -top, top, nearPlane, farPlane);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glTranslatef(0.0f, 0.0f, -5.0f);
    glRotatef(45.0f, 0.0f, 1.0f, 0.0f);

    GLUquadric *quadric = gluNewQuadric();
    gluQuadricDrawStyle(quadric, GLU_FILL);
    gluQuadricNormals(quadric, GLU_SMOOTH);
    gluQuadricTexture(quadric, GL_FALSE);
    gluSphere(quadric, 1.5, 32, 32);
    gluDeleteQuadric(quadric);

    SDL_GL_SwapBuffers();
    SDL_Delay(3000);

    glDeleteTextures(1, &tex);

    SDL_FreeSurface(bmp);
    SDL_Quit();

    return 0;
}

編譯、執行

$ gcc main.c -I/usr/include/SDL -o main -lSDL -lGL -lGLU
$ ./main