在opengl中加入�光照的效果，可用键盘控制放大缩小
w键放大 s键缩小 d键开关灯
预览效果例如以下：
源代码例如以下：
#include <gl/glut.h>
#include <gl/glaux.h>
#include <stdio.h>
#pragma comment(lib, "opengl32.lib")
#pragma comment(lib, "glut32.lib")
#pragma comment(lib, "glu32.lib")
#pragma comment(lib, "glut.lib")
#pragma comment(lib, "glaux.lib")
UINT g_bmp[1];//贴图编号
GLfloat LightAmbient[] = { 0.5f, 0.5f, 0.5f, 1.0f }; //环境光參数，半亮白色
GLfloat LightDiffuse[] = { 1.0f, 1.0f, 1.0f, 1.0f }; //漫射光參数，
GLfloat LightPosition[] = { 0.0f, 0.0f, 0.0f, 1.0f }; //光源位置
void Box(float x, float y, float z) //长方体
{
glPushMatrix();
glScalef(x, y, z);
glEnable(GL_TEXTURE_2D); //贴图有效
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);// 前
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);// 后
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);// 上
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);// 下
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);// 左
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);// 右
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd();
glDisable(GL_TEXTURE_2D);//取消贴图
glPopMatrix();
}
bool LoadTexture(char *filename, GLuint &texture)
{
AUX_RGBImageRec *pImage = auxDIBImageLoadA(filename); //装入位图
if (pImage == NULL) return false;
glGenTextures(1, &texture); //生成贴图
glBindTexture(GL_TEXTURE_2D, g_bmp[0]); //贴图生效
gluBuild2DMipmaps(GL_TEXTURE_2D, 4, pImage->sizeX, pImage->sizeY, GL_RGB, GL_UNSIGNED_BYTE, pImage->data); //贴图数据
return true;
}
void init()
{
LoadTexture("i:\4.bmp", g_bmp[0]);
glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient); //设置环境光
glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse); //设置漫射光
glLightfv(GL_LIGHT1, GL_POSITION, LightPosition); //设置光源位置
glEnable(GL_LIGHT1); //启用一号光源
glEnable(GL_LIGHTING); //开光
}
float s = 1, r = 0; //放大缩小的倍数和旋转參数
void renderScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear The Screen And The Depth Buffer
glLoadIdentity(); // Reset The View
glTranslatef(0.0f, 0.0f, -5);
glRotatef(r, 1.0f, 1.0f, 0.0f);
glScalef(s, s, s);
Box(1, 1, 1);
r += 0.01;//旋转
glutSwapBuffers();
}
void changeSize(int w, int h)
{
if (h == 0) h = 1;
float ratio = 1.0* w / h;
glMatrixMode(GL_PROJECTION);// 单位化投影矩阵。
glLoadIdentity();
glViewport(0, 0, w, h);// 设置视口大小为整个窗体大小
gluPerspective(45, ratio, 1, 1000);// 设置正确的投影矩阵
glMatrixMode(GL_MODELVIEW);//以下是设置模型视图矩阵
glLoadIdentity();
gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, -1.0, 0.0f, 1.0f, 0.0f);//设置观測点
}
int light = 1, bp = 0;
void keyfunc(unsigned char ch, int x, int y)
{
if (ch == 'w') //发大缩小
s += 0.1;
else if (ch == 's')
s -= 0.1;
if (ch == 'd')//d键开关灯
{
if (light)
{
light = 0;
glDisable(GL_LIGHTING);
printf("off
");
}
else
{
light = 1;
glEnable(GL_LIGHTING);
printf("on
");
}
}
}
int main(int argc, char * argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
glutInitWindowPosition(100, 100);
glutInitWindowSize(320, 320);
glutCreateWindow("Hello OpenGL");
init();
glutDisplayFunc(renderScene);
glutIdleFunc(renderScene); //指定程序空暇时调用函数
glutReshapeFunc(changeSize); //指定窗体形状变化时的回调函数
glEnable(GL_DEPTH_TEST);
glutKeyboardFunc(keyfunc);//键盘回调函数
glutMainLoop();
return 0;
}所用贴图例如以下：
