OpenGL之路（六）贴图

给物体贴上图片，图片宽高要为2的幂次

代码如下 （有的编译器不自带glaux，可以百度搜索进行配置，如有问题可进QQ群 116920287 咨询）

#include <gl/glut.h>
#include <gl/glaux.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
GLUquadricObj *g_text;//贴图指针

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 LoadT8(char *filename, GLuint &texture)
{
	AUX_RGBImageRec *pImage = NULL;
	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
	free(pImage->data);//释放位图内存
	free(pImage);
	return true;
}

void renderScene(void)
{
	static float i = 0;
	i += 0.01f;
	if (i > 360) i = 0;
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();

	glTranslatef(0, 0, -1.5);
	glRotatef(i, 1, 1, 1);
	Box(0.3f, 0.3f, 0.3f);

	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口大小
	gluPerspective(45, ratio, 1, 1000);// 设置正确的投影矩阵
	glMatrixMode(GL_MODELVIEW);//下面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);//设置观测点
}
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");
	glutDisplayFunc(renderScene);
	glutIdleFunc(renderScene); //指定程序空闲时调用函数
	glutReshapeFunc(changeSize); //指定窗口形状变化时的回调函数
	glEnable(GL_DEPTH_TEST);

	g_text = gluNewQuadric(); //申请贴图缓存
	LoadT8("1.bmp", g_bmp[0]);
	glutMainLoop();
	return 0;
}

图片如下 1.bmp