1. 参数定义的House
2. a flurry of filled rectangles
3. Sierpinski曲线
含有鼠标和键盘响应函数onmouse和onkeyboard。
/************************************************************************/
/* CreateTime:2013-2-18
**Author:@Rachel Zhang
**Discription: Draw Parameter House, Flurry and Sierpinski
**3rd-party:OpenGL*/
/************************************************************************/
#include "GL/glut.h"
#include "stdlib.h"
#include <iostream>
using namespace std;
#define screenHeight 480
class GLintPoint{
public:
GLint x, y;
};
// Create a number between 0 and m(a number which will be given)
// the input m must be less than 32767 according to P49 in <Computer Graphics Using OpenGL>
int random(int m)
{
return rand()%m;
}
void drawDot (GLint x, GLint y)
{
glPointSize(3);
glBegin(GL_POINTS);
glVertex2i(x,y);
glEnd();
}
typedef struct
{
GLfloat r, g, b;
} GLfloatRGBColour;
GLfloatRGBColour colour[8] = { {0.0f, 0.0f, 0.0f}, {0.0f, 0.0f, 1.0f},
{0.0f, 1.0f, 0.0f}, {1.0f, 0.0f, 0.0f},
{0.0f, 1.0f, 1.0f}, {1.0f, 0.0f, 1.0f},
{1.0f, 1.0f, 0.0f}, {1.0f, 1.0f, 1.0f}};
void setPenColour(GLfloatRGBColour newColour)
{
glColor3f(newColour.r, newColour.g, newColour.b);
}
/************************************************************************/
/* Draw Functions */
/************************************************************************/
void parameterizedHouse(GLintPoint peak, GLint width, GLint height)
// the top of house is at the peak; the size of house is given
// by height and width
{
glBegin(GL_LINE_LOOP);
glVertex2i(peak.x, peak.y); // draw shell of house
glVertex2i(peak.x + width / 2, peak.y - 3 * height /8);
glVertex2i(peak.x + width / 2, peak.y - height);
glVertex2i(peak.x - width / 2, peak.y - height);
glVertex2i(peak.x - width / 2, peak.y - 3 * height /8);
glEnd();
}
void drawFlurry(int num, int Width, int Height)
// draw num random rectangles in a Width by Height rectangle
{
for (int i = 0; i < num; i++)
{
GLint x1 = random(Width); // place corner randomly
GLint y1 = random(Height);
GLint x2 = random(Width); // pick the size so it fits
GLint y2 = random(Height);
GLfloat lev = random(10)/10.0; // random value, in range 0 to 1
glColor3f(lev,lev,lev); // set the gray level
glRecti(x1, y1, x2, y2); // draw the rectangle
}
glFlush();
}
void drawSierpinski(GLintPoint corner[3])
{
int i, index, tcolour=0;
GLintPoint point;
point = corner[random(3)];
drawDot(point.x, point.y);
for (i = 0; i < 1000; i++)
{
index = random(3);
point.x = (point.x + corner[index].x)/2;
point.y = (point.y + corner[index].y)/2;
tcolour = (++tcolour)%7; // col = (col + 1) mod 7;
setPenColour(colour[tcolour]);
drawDot(point.x, point.y);
}
}
/************************************************************************/
/* Mouse Listener and keyboard Listener */
/************************************************************************/
void myMouse(int button, int state, int x, int y)
{
static GLintPoint corners[3];
static int numCorners;
if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
{
corners[numCorners].x = x;
corners[numCorners].y = screenHeight - y - 1;
if (++numCorners == 3)
{
drawSierpinski(corners);
numCorners = 0;
}
}
else if (button==GLUT_RIGHT_BUTTON)
glClear(GL_COLOR_BUFFER_BIT);
glFlush();
}
void onKeyBoard(unsigned char key,int mousex, int mousey)
{
switch (key)
{
case 'q':
exit(0);
case 'r':
static GLintPoint corners[3];
for (int i=0;i<3;i++)
{
corners[i].x = random(640);
corners[i].y = random(screenHeight);
}
drawSierpinski(corners);
default:
break;
}
}