OpenGL地形生成

我试图从顶点网格制作地形，我有一个bug，只是找不到它。我坚持了3个小时。我使用c++和opengl。我计划使用一个混合贴图纹理和高度贴图稍后。总之，下面是代码:

应该是这样的:http://postimg.org/image/9431kcvy7/

是这样的:http://postimg.org/image/xxsoesqkp/

你可以看到三角形被一个1单位的矩形隔开看起来所有底部的点形成一个三角形点的坐标是(0,0,0)

我知道这个问题看起来很容易解决，但是我已经浪费了3个小时的时间。请帮助:)

Map.h

#ifndef MAP_H
#define MAP_H
#include <string>
#include <vector>
#include <iostream>
#include <fstream>
#include <SFML/OpenGL.hpp>
#include <SFML/Graphics.hpp>
#include <windows.h>
using namespace std;
struct coordinate{
    float x,y,z;
};
struct face{
    int v[3];
    int n[3];
};
struct uv{
    float x;
    float y;
};

class Map
{
    private:
        int mapX,mapY;
        vector<coordinate> vertex;
        vector<uv>textureCoordinates;
        vector<coordinate>normals;
        vector< vector<face> > faces;
        string fileNameString;
        sf::Image image[5];
        sf::Color faceColor,blendPixel,p0,p1,p2;
        sf::Image texture;
        sf::Uint8 pixels[256*256*4];
        unsigned int imageID[3],textureID;
    public:
        void load(const char *fileName);
        void draw();
};
#endif // MAP_H

和Map.cpp

#include "Map.h"
#define blendMap 3
#define heightMap 4
void Map::load(const char *fileName)
{
    int i,j;
    fileNameString=fileName;
    vector<face> F;
    coordinate v;
    face f;
    image[0].loadFromFile(fileNameString+"/0.png");
    image[1].loadFromFile(fileNameString+"/1.png");
    image[2].loadFromFile(fileNameString+"/2.png");
    image[blendMap].loadFromFile(fileNameString+"/blendMap.png");
    image[heightMap].loadFromFile(fileNameString+"/heightMap.png");
    mapX=image[blendMap].getSize().x;
    mapY=image[blendMap].getSize().y;
    for(i=-mapY/2;i<mapY/2;i++)
        for(j=-mapX/2;j<mapX/2;j++)
        {
            v.x=j*0.5;
            v.z=i*0.5;
            vertex.push_back(v);
        }
    for(i=0;i<mapY-1;i++)
    {
        for(j=0;j<2*(mapX-1);j++)
            F.push_back(f);
        faces.push_back(F);
    }
    for(i=0;i<mapY-1;i++)
        for(j=0;j<(mapX-1)*2;j+=2)
        {
            faces[i][j].v[0]=i*mapX+j;
            faces[i][j].v[1]=i*mapX+j+1;
            faces[i][j].v[2]=(i+1)*mapX+j;
            faces[i][j+1].v[0]=i*mapX+j+1;
            faces[i][j+1].v[1]=(i+1)*mapX+j+1;
            faces[i][j+1].v[2]=(i+1)*mapX+j;
        }
    for(i=0;i<mapX*mapY;i++)
        {
            color=image[heightMap].getPixel(i/mapX,i%mapX);
            vertex[i].y=0;//(float)color.r/25.5-10;
        }
}
void Map::draw()
{
    unsigned int i,j;
    for(i=0;i<mapY-1;i++)
        for(j=0;j<(mapX-1)*2;j+=2)
        {
            glBindTexture(GL_TEXTURE_2D,imageID[0]);
            glBegin(GL_TRIANGLES);
                glTexCoord2f (0,0);
                glVertex3f(vertex[faces[i][j].v[0]].x , vertex[faces[i][j].v[0]].y , vertex[faces[i][j].v[0]].z);
                glTexCoord2f (1,0);
                glVertex3f(vertex[faces[i][j].v[1]].x , vertex[faces[i][j].v[1]].y , vertex[faces[i][j].v[1]].z);
                glTexCoord2f (0,1);
                glVertex3f(vertex[faces[i][j].v[2]].x , vertex[faces[i][j].v[2]].y , vertex[faces[i][j].v[2]].z);
                glTexCoord2f (0,0);
                glVertex3f(vertex[faces[i][j+1].v[0]].x , vertex[faces[i][j+1].v[0]].y , vertex[faces[i][j+1].v[0]].z);
                glTexCoord2f (1,0);
                glVertex3f(vertex[faces[i][j+1].v[1]].x , vertex[faces[i][j+1].v[1]].y , vertex[faces[i][j+1].v[1]].z);
                glTexCoord2f (0,1);
                glVertex3f(vertex[faces[i][j+1].v[2]].x , vertex[faces[i][j+1].v[2]].y , vertex[faces[i][j+1].v[2]].z);
            glEnd();
        }
}

for(i=-mapY/2;i<mapY/2;i++)

for(i = 0; i < mapY; i++)
    for(j = 0; j < mapX; j++)
    {
        v.x = j * 0.5 - mapY / 2.0;
        v.z = i * 0.5 - mapX / 2.0;
        vertex.push_back(v);
    }

for(j=0;j<(mapX-1)*2;j+=2)

for(j = 0; j <= (mapX - 1) * 2; j += 2)