opengl編程指南樣本程式2-15完整代碼

#include "stdafx.h"
#include <windows.h>
#include <GL/glew.h>
#include<GL/glut.h>
#define FREEGLUT_STATIC
#include <GL/freeglut.h>
#pragma comment(linker, "/NODEFAULTLIB:libc.lib")
#define BUFFER_OFFSET(offset) ((const GLubyte *)NULL + (offset))

#define XStart -0.8
#define XEnd 0.8
#define YStart -0.8
#define YEnd 0.8
#define NumXPoints 11
#define NumYPoints 11
#define NumPoints (NumXPoints * NumYPoints)
#define NumPointsPerStrip (2 * NumXPoints)
#define NumStrips (NumYPoints - 1)
#define RestartIndex 0xffff
GLfloat color[6][3]={
 {1.0,1.0,1.0},{1.0,0.0,0.0},{1.0,1.0,0.0},
 {0.0,1.0,0.0},{0.0,1.0,1.0},{0.0,0.0,1.0}
};
void init(){
 GLuint vbo, ebo;
 GLfloat* vertices = 0;
 GLushort* indices = 0;
 glGenBuffers(1, &vbo);
 glBindBuffer(GL_ARRAY_BUFFER, vbo);
 glBufferData(GL_ARRAY_BUFFER, 6 * NumPoints * sizeof(GLfloat), NULL, GL_STATIC_DRAW);
 vertices = (GLfloat*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
 if(vertices == NULL){
  exit(EXIT_FAILURE);
 }
 else{
  int i;
  int j;
  GLfloat dx = (GLfloat)(XEnd - XStart) / (NumXPoints - 1);
  GLfloat dy = (GLfloat)(YEnd - YStart) / (NumYPoints - 1);
  GLfloat* tmp = vertices;
  int n = 0;
  for(j = 0; j < NumYPoints; ++j){
   GLfloat y = (GLfloat)(YStart + j * dy);
   for(i = 0; i < NumXPoints; ++i){
    GLfloat x = (GLfloat)(XStart + i * dx);
    *tmp++ = color[(i+j)%6][0];
    *tmp++ = color[(i+j)%6][1];
    *tmp++ = color[(i+j)%6][2];
    *tmp++ = x;
    *tmp++ = y;
    *tmp++ = 0;
   }
  }
  glUnmapBuffer(GL_ARRAY_BUFFER);
  glVertexPointer(3, GL_FLOAT, 6 * sizeof(GLfloat), BUFFER_OFFSET(3 * sizeof(GLfloat)));
  glColorPointer(3, GL_FLOAT, 6 * sizeof(GLfloat), BUFFER_OFFSET(0));
  glEnableClientState(GL_VERTEX_ARRAY);
  glEnableClientState(GL_COLOR_ARRAY);
  //glInterleavedArrays(GL_C3F_V3F, 0, 0);
 }
 
 glGenBuffers(1, &ebo);
 glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
 glBufferData(GL_ELEMENT_ARRAY_BUFFER, NumStrips * (NumPointsPerStrip + 1) * sizeof(GLushort), NULL, GL_STATIC_DRAW);
 indices = (GLushort*)glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY);
 if(indices == NULL){
  exit(EXIT_FAILURE);
 }
 else{
  int i;
  int j;
  GLushort* index = indices;
  for(j = 0; j < NumStrips; ++j){
   GLushort bottomRow = j * NumYPoints;
   GLushort topRow = bottomRow + NumYPoints;
   for(i = 0; i < NumXPoints; ++i){
    *index++ = topRow + i;
    *index++ = bottomRow + i;
   }
   *index++ = RestartIndex;
  }
  glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
 }
 glPrimitiveRestartIndex(RestartIndex);
 glEnable(GL_PRIMITIVE_RESTART);
}

void display(){
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 glColor3f(1, 1, 1);
 glDrawElements(GL_TRIANGLE_STRIP, NumStrips * (NumPointsPerStrip + 1), GL_UNSIGNED_SHORT, BUFFER_OFFSET(0));
 glutSwapBuffers();
}
void reshape(int w, int h){
 glViewport(0, 0, w, h);
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 gluOrtho2D(0.0, w, 0.0, h);
}
void keyboardfunc(unsigned char key, int x, int y){
 //std::cout << key << x << y << std::endl;
}
void mouse(int button, int state, int x, int y){
 switch (button)
 {
 case GLUT_LEFT_BUTTON:
  if(state == GLUT_DOWN){
   glutIdleFunc(NULL);
  }
  break;
 case GLUT_RIGHT_BUTTON:
  if(state == GLUT_DOWN){
   glutIdleFunc(NULL);
  }
  break;
 default:
  break;
 }
}
void move(int x, int y){
 //std::cout << x << y << std::endl;
}
int main(int argc, char** argv){
 glutInit(&argc, argv);
 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
 glutInitWindowSize(250, 250);
 glutInitWindowPosition(100, 100);
 glutInitContextVersion(3, 0);
 glutCreateWindow("hello");
 glewInit();
 init();
 glutDisplayFunc(display);
 //glutReshapeFunc(reshape);
 glutMouseFunc(mouse);
 //glutMotionFunc(move);
 //glutKeyboardFunc(keyboardfunc);
 glutMainLoop();
 return 0;
}