openGL 深度測試

// depthTest.cpp : 定義控制檯應用程序的入口點。
//


#include "stdafx.h"

#include<glew.h>
#include <glut.h>



#pragma comment(lib, "glew32.lib")
#pragma   comment(   lib, "glut32.lib ")


#define BUFFER_OFFSET(bytes) ((GLubyte*) NULL + (bytes))
#define VERTICES 0
#define INDICES 1
#define NUM_BUFFERS 2
GLuint buffers[NUM_BUFFERS];

#define  FACE_CNT 2

GLuint ids[FACE_CNT] = { 0 };

GLuint framebuffer = 0;
GLuint renderbuffer =0;

int height = 512;
int width = 512;

void changeSize(int w, int h)
{
glViewport(0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (double)w / (double)h, 1, 30);
gluLookAt(0, 0, 5, 0, 0, 0, 0, 1, 0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);//一定得加

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glRotatef(30.0f, 1.0f, 1.0f, 0.0f);

glBegin(GL_TRIANGLES);

//第一個三角形
glColor3f(0.f, 0.0f, 1.0f); //blue
glVertex3f(1.0f, 0.5f, 0.50f);
glVertex3f(-0.5f, 1.0f, 0.50f);
glVertex3f(-1.0f, -1.0f, 0.50f);

//第二個三角形
glColor3f(1.0f, 0.0f, 0.0f); //red
glVertex3f(1.0f, 1.0f, -0.5f);
glVertex3f(-1.0f, 1.0f, -0.5f);
glVertex3f(-1.0f, -1.0f, -0.5f);

glEnd();

glutSwapBuffers();

}

void init(void)
{
glewInit();
glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set background color to black and opaque
//glClearDepth(1.0f);                   // Set background depth to farthest
glEnable(GL_DEPTH_TEST);   // Enable depth testing for z-culling
glDepthFunc(GL_LESS);    // Set the type of depth-test

}

int main(int argc, char* argv[])
{
glutInit(&argc, argv);

glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
glutInitWindowSize(width, height);
glutCreateWindow("Buffer Demo");

glutReshapeFunc(changeSize);
glutDisplayFunc(display);

init();

glutMainLoop();

return 0;

}