Function Category

Command Syntax

Description

Initialization and Window Control

initgraph(width, height)

Initialize the graphics window with width width and height height

initgraph(width, height, SHOWCONSOLE)

Initialize the window and show the console

closegraph()

Close the graphics window and release resources

cleardevice()

Clear the window and fill the background color

setbkcolor(color)

Set the background color, parameter is a color constant (e.g., WHITE, RGB (r,g,b))

Basic Drawing

Color Settings

setlinecolor(color)

Set the line color

setfillcolor(color)

Set the fill color

settextcolor(color)

Set the text color

Line Drawing

line(x1, y1, x2, y2)

Draw a line from (x1,y1) to (x2,y2).

rectangle(x1, y1, x2, y2)

Draw a rectangle border

ellipse(x1, y1, x2, y2)

Draw an ellipse (bounding rectangle is (x1,y1)-(x2,y2)).

circle(x, y, r)

Draw a circle (center at (x,y), radius r).

Fill Shapes

solidrectangle(x1, y1, x2, y2)

Draw a solid rectangle

fillellipse(x1, y1, x2, y2)

Draw a solid ellipse

fillcircle(x, y, r)

Draw a solid circle

Text Drawing

outtextxy(x, y, “Text“)

Draw text at (x,y) (default font)

drawtext(“Text“, &rect, format)

Draw text according to specified area and format (e.g., DT_CENTER for centering)

setfont(size, weight, “font name“)

Set font style (e.g., setfont(24, 0, “Microsoft YaHei”)).

Images and Pixels

putpixel(x, y, color)

Draw a single pixel at (x,y).

loadimage(&img, “image path“)

Load an image into an IMAGE object

putimage(x, y, &img)

Display an image at (x,y) (top-left aligned)

Interactive Operations

Mouse Messages

peekmessage(&msg)

Check and retrieve messages (non-blocking)

msg.message == WM_LBUTTONDOWN

Left mouse button click event, coordinates are msg.x and msg.y

Keyboard Messages

_kbhit()

Check if a key is pressed (non-blocking)

_getch()

Get the key value (blocking)

msg.vkcode == VK_ESCAPE

Capture special keys like ESC (requires ExMessage)

Other Common Functions

Sleep(ms)

Pause for ms milliseconds (requires <windows.h>).

getwidth() / getheight()

Get window width / height

setlinestyle(style, width)

Set line style (e.g., setlinestyle(PS_SOLID, 3) for a 3-pixel solid line).

#include <graphics.h>

#include <tchar.h>

#include <conio.h>

#include <time.h>

#include <vector>

#include <cmath> // Include this header to use math functions like sin and cos

#define PI 3.1416

// Firework particle structure

struct FireworkParticle {

int x, y; // Position

int vx, vy; // Velocity

COLORREF color; // Color

int life; // Life span

int maxLife; // Maximum life span

};

// Peace dove drawing function

void drawPeaceDove(int x, int y, int size, bool holdingOlive = false)

{

setfillcolor(WHITE);

setlinecolor(LIGHTGRAY);

// Body

ellipse(x, y, x + size*0.8, y + size*0.6);

// Head

circle(x + size*0.7, y + size*0.2, size*0.2);

// Beak

setlinecolor(BLACK);

line(x + size*0.85, y + size*0.2, x + size*0.95, y + size*0.18);

// Wings

POINT wingPoints[3] = {

{x + size*0.2, y + size*0.1},

{x – size*0.3, y – size*0.2},

{x + size*0.1, y + size*0.4}

};

fillpolygon(wingPoints, 3);

// Tail

POINT tailPoints[3] = {

{x, y + size*0.3},

{x – size*0.4, y + size*0.5},

{x – size*0.2, y + size*0.2}

};

fillpolygon(tailPoints, 3);

// Eyes

setfillcolor(BLACK);

solidcircle(x + size*0.8, y + size*0.18, size*0.05);

// Olive branch

if (holdingOlive)

{

setlinecolor(GREEN);

setfillcolor(GREEN);

// Branch

line(x – size*0.2, y + size*0.2, x – size*0.5, y + size*0.1);

// Leaves

POINT leaf1[3] = {

{x – size*0.35, y + size*0.05},

{x – size*0.45, y – size*0.05},

{x – size*0.55, y + size*0.05}

};

fillpolygon(leaf1, 3);

POINT leaf2[3] = {

{x – size*0.35, y + size*0.15},

{x – size*0.45, y + size*0.25},

{x – size*0.55, y + size*0.15}

};

fillpolygon(leaf2, 3);

}

}

// Initialize firework particles

void initFirework(std::vector<FireworkParticle>& particles, int x, int y)

{

int count = rand() % 50 + 80; // Number of particles

for (int i = 0; i < count; i++)

{

FireworkParticle p;

p.x = x;

p.y = y;

// Random speed and angle

double angle = 2 * PI * rand() / RAND_MAX;

int speed = rand() % 5 + 2;

p.vx = (int)(speed * cos(angle));

p.vy = (int)(speed * sin(angle));

// Random color (bright color)

int r = 180 + rand() % 75;

int g = 150 + rand() % 105;

int b = 150 + rand() % 105;

p.color = RGB(r, g, b);

p.life = 0;

p.maxLife = rand() % 20 + 30; // Life span

particles.push_back(p);

}

}

// Update and draw fireworks

void updateAndDrawFireworks(std::vector<FireworkParticle>& particles)

{

for (size_t i = 0; i < particles.size(); )

{

FireworkParticle& p = particles[i];

// Update position

p.x += p.vx;

p.y += p.vy;

// Affected by gravity

p.vy += 0.1;

// Update life span

p.life++;

// Calculate opacity (changes with life span)

int alpha = 255 * (1 – (float)p.life / p.maxLife);

if (alpha < 0) alpha = 0;

// Set color (with opacity)

COLORREF color = p.color;

int r = GetRValue(color);

int g = GetGValue(color);

int b = GetBValue(color);

setfillcolor(RGB(r * alpha / 255, g * alpha / 255, b * alpha / 255));

// Draw particle

solidcircle(p.x, p.y, 2);

// Remove particles whose life span has ended

if (p.life >= p.maxLife)

{

particles.erase(particles.begin() + i);

}

else

{

i++;

}

}

}

int main()

{

srand((unsigned int)time(NULL));

initgraph(800, 600);

SetWindowText(GetHWnd(), “Commemoration of the 80th Anniversary of the Victory of the Anti-Japanese War – Doves of Peace and Fireworks”);

std::vector<FireworkParticle> fireworks;

int fireworkTimer = 0;

while (true)

{

// Red background

setbkcolor(RGB(180, 20, 30));

cleardevice();

// Timed firework launch

fireworkTimer++;

if (fireworkTimer >= 60) // Launch approximately once per second

{

int x = rand() % 600 + 100;

int y = rand() % 200 + 50;

initFirework(fireworks, x, y);

fireworkTimer = 0;

}

// Update and draw fireworks

updateAndDrawFireworks(fireworks);

// Draw doves of peace

drawPeaceDove(500, 200, 80, true); // Holding olive branch

drawPeaceDove(650, 300, 60);

drawPeaceDove(450, 400, 70);

drawPeaceDove(300, 280, 50);

// Commemorative text

settextcolor(YELLOW);

settextstyle(30, 0, _T(“SimHei”));

outtextxy(80, 480, _T(“Commemoration of the 80th Anniversary of the Victory of the Anti-Japanese War and the World Anti-Fascist War”));

settextstyle(24, 0, _T(“SimSun”));

outtextxy(280, 530, _T(“Cherish Peace, Oppose War”));

// Exit prompt

settextcolor(WHITE);

settextstyle(16, 0, _T(“SimSun”));

outtextxy(320, 570, _T(“Press ESC to exit”));

// Delay refresh

Sleep(30);

// Check for exit

if (_kbhit() && _getch() == 27) // ESC key

break;

}

closegraph();

return 0;

}