Question

请OPenGL高手帮忙看看问题出在那儿？？谢谢！

在VC环境下编译下面一段代码，编译和连接过各都正常，只是最后执行时出错了：pixel format with necessary capabilities not found。请各位大侠指点一下错在那里了。万分感谢！
#include <GL/glew.h>
#include <GL/glut.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>

#define NUMCOLORS 32
#define RAMPSTART 16

static void init(void)
{
int i;

glEnable(GL_DEPTH_TEST);

for (i = 0; i < NUMCOLORS; i++) {
GLfloat shade;
shade = (GLfloat) (NUMCOLORS-i)/(GLfloat) NUMCOLORS;
glutSetColor (RAMPSTART + i, shade, shade, shade);
}
glEnable(GL_FOG);

glFogi (GL_FOG_MODE, GL_LINEAR);
glFogi (GL_FOG_INDEX, NUMCOLORS);
glFogf (GL_FOG_START, 1.0);
glFogf (GL_FOG_END, 6.0);
glHint (GL_FOG_HINT, GL_NICEST);
glClearIndex((GLfloat) (NUMCOLORS+RAMPSTART-1));
}

static void renderSphere (GLfloat x, GLfloat y, GLfloat z)
{
glPushMatrix();
glTranslatef (x, y, z);
glutWireSphere(0.4, 16, 16);
glPopMatrix();
}

void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glIndexi (RAMPSTART);

renderSphere (-2., -0.5, -1.0);
renderSphere (-1., -0.5, -2.0);
renderSphere (0., -0.5, -3.0);
renderSphere (1., -0.5, -4.0);
renderSphere (2., -0.5, -5.0);

glFlush();
}

void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
glOrtho (-2.5, 2.5, -2.5*(GLfloat)h/(GLfloat)w,
2.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
else
glOrtho (-2.5*(GLfloat)w/(GLfloat)h,
2.5*(GLfloat)w/(GLfloat)h, -2.5, 2.5, -10.0, 10.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity ();
}

void keyboard(unsigned char key, int x, int y)
{

switch (key) {
case 27:
exit(0);
}
}

int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_INDEX | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutCreateWindow(argv[0]);
init();
glutReshapeFunc (reshape);
glutKeyboardFunc (keyboard);
glutDisplayFunc (display);
glutMainLoop();
return 0;
}

Answer 1

glutInitDisplayMode (GLUT_SINGLE | GLUT_INDEX | GLUT_DEPTH);
改为
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGBA | GLUT_DEPTH);

原因可能是系统不支持索引模式。

应该先设置颜色表，才可以使用索引模式，具体函数我也不同清楚，
可能是auxSetOneColor之类的。。