OpenGL 繪製一個三角形帶（Triangle Strip）

Homework1：繪製一個三角形

#define _STDCALL_SUPPORTED
#define _M_IX86
#define GLUT_DISABLE_ATEXIT_HACK
#define GLUT_NO_WARNING_DISABLE

#include <GL/gl.h>
#include <GL/glut.h>

void myDisplay(void)
{
   glClearColor(0.75f,0.75f,0.75f,1.0f);
   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
   glBegin(GL_TRIANGLES);
       glColor3f(1.0,0.0,1.0);
       glVertex3f(-0.8,-0.6,0);

       glColor3f(0.0,0.9,0.0);
       glVertex3f(0.8,-0.6,0);

       glColor3f(0.0,0.0,1.0);
       glVertex3f(0,0.7,0);
   glEnd();
   glFlush();
}

int main(int argc, char *argv[])
{
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
   glutInitWindowPosition(100, 100);
   glutInitWindowSize(400, 400);
   glutCreateWindow("Homework1.1(A Triangle)");
   glutDisplayFunc(&myDisplay);
   glutMainLoop();
   return 0;
}

執行結果如下

Homework2：

使用GL_TRIANGLE_STRIP，代碼如下

#define _STDCALL_SUPPORTED
#define _M_IX86
#define GLUT_DISABLE_ATEXIT_HACK
#define GLUT_NO_WARNING_DISABLE

#include <GL/gl.h>
#include <GL/glut.h>


const float top = 0.7 , bottom = -0.6 , left = -0.9 ,width = 0.2;
//頂點
struct Vertex{
     float x,y,z;
};

void myDisplay(void)
{
   Vertex v[10];
   for(int i = 0; i < 10; i++){
      v[i].x = left + width*i;
      v[i].y = i%2*top + ((i+1)%2)*bottom;
      v[i].z = 1.0;
   }
   glClearColor(0.01f,0.01f,0.01f,0.0f);//背景顏色
   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
   glBegin(GL_TRIANGLE_STRIP);
       for(int i = 0; i < 10; i++){
          glColor3f(0.1+i*0.1,0.9-i*0.1,0.1+i*0.1);
          glVertex3f(v[i].x,v[i].y,v[i].z);//此處不能使用glVertex3fv 原因在於其參數應爲const類型
       }
   glEnd();
   glLineWidth(3); //設置線寬
   glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);//使用線框模式，默認爲GL_full
   glFlush();
}

int main(int argc, char *argv[])
{
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
   glutInitWindowPosition(20, 50);
   glutInitWindowSize(1200, 400);
   glutCreateWindow("Homework1.2(A single Triangle Strip)");
   glutDisplayFunc(&myDisplay);
   glutMainLoop();
   return 0;
}

效果圖如下：

Homework3：多個Triangle_Strip 可形成三角網，代碼如下（省略main函數）

const float top = 0.8 , left = -0.9 ,width = 0.2,height = 0.3;
const int colum = 20,row =5;
//頂點
struct Vertex{
     float x,y,z;
};

void myDisplay(void)
{
   Vertex v[row][colum];
   for(int i = 0; i < row; i++){
      for(int j = 0; j < colum; j++){
        v[i][j].x = left + (j/2)*width;
        v[i][j].y = j%2*(top-height*i) + ((j+1)%2)*(top-(i+1)*height);
        v[i][j].z = 1.0;
      }
   }

   glClearColor(0.01f,0.01f,0.01f,0.0f);//背景顏色
   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

      for(int i = 0; i < row; i++){
           glBegin(GL_TRIANGLE_STRIP);
           for(int j = 0; j < colum; j++){
           glColor3f(0.05+j*0.05,0.9-j*0.05,0.05+j*0.05);
           glVertex3f(v[i][j].x,v[i][j].y,v[i][j].z);
           }
           glEnd();
       }

   glLineWidth(3); //設置線寬
   glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);//使用線框模式，默認爲GL_full
   glFlush();
}

效果如下