Файл: Геометрическое моделирование и компьютерная графика.docx

ВВЕДЕНИЕ

На данной лабораторной работе мы будем рассматривать вращение объемных фигур, используемые функции и классы, а также принципы построения сплайнов и виды сплайнов.

ХОД РАБОТЫ

Задание 1. Изображение вращающегося куба. Написан код для изображения вращающегося при помощи мыши куба с удаленными гранями и закраской

Код программы:

const int WIDTH = 400; const int HEIGHT = 300;

float v11, v12, v13, v21, v22, v23, v31, v32, v33, v43; float rho = 300., thetta = 75., phi = 30., ScreenDist = 500.; float A, B, C, D, An, Bn, Cn;

float xt[3], yt[3], zt[3]; float Al, Bl, Cl;

float alpha;

float th, ph, costh, cosph, sinth, sinph; float factor = atan(1.0) / 45.; PAINTSTRUCT ps;

static HBRUSH hBrush;

---

class TFPoint

{

public:

float X; float Y; float Z;

};

TFPoint CubePoints[] =

{

{-50,-50, -50},

{ 50,-50, -50},

{ 50, 50, -50},

{-50, 50, -50},

{-50, 50, 50},

{-50,-50, 50},

{ 50,-50, 50},

{ 50, 50, 50}

};

int Gran[6][4] =

{

{0,3,4,5},

{0,5,6,1},

{2,7,4,3},

{7,6,5,4},

{0,1,2,3},

{2,1,6,7}

};

void VidMatCoeff(float rho, float thetta, float phi)
{

th = thetta * factor; ph = phi * factor;

costh = cos(th); sinth = sin(th); cosph = cos(ph); sinph = sin(ph); v11 = -sinth; v12 = -cosph * costh; v13 = -sinph * costh;

v21 = costh; v22 = -cosph * sinth; v23 = -sinph * sinth; v31 = 0.; v32 = sinph; v33 = -cosph;

v43 = rho;

}

POINT Perspective(float x, float y, float z)

{

POINT point; float xe, ye, ze;

VidMatCoeff(rho, thetta, phi); xe = v11 * x + v21 * y;

ye = v12 * x + v22 * y + v32 * z;

ze = v13 * x + v23 * y + v33 * z + v43; point.x = ScreenDist * xe / ze + 700.; point.y = ScreenDist * ye / ze + 400.; return point;

}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)

{

POINT point1[4]; HDC hdc;

int sx, sy, xPos, yPos, zDelta; switch (message)

{

case WM_DESTROY: PostQuitMessage(0);

break;

case WM_MOUSEMOVE:

sx = LOWORD(lParam); sy = HIWORD(lParam);

thetta += ((sx % 180) - 90) / 10;

phi += ((sy % 180) - 90) / 10;

InvalidateRect(hWnd, NULL, TRUE); break;

case WM_MOUSEWHEEL:

zDelta = (int)wParam; ScreenDist -= zDelta / 1000000.;
InvalidateRect(hWnd, NULL, TRUE);

break;

case WM_PAINT:

hdc = BeginPaint(hWnd, &ps);

th = thetta * factor;

---

ph = phi * factor;

costh = cos(th); sinth = sin(th); cosph = cos(ph); sinph = sin(ph); A = rho * sinph * costh; B = rho * sinph * sinth; C = rho * cosph; Al = A / (sqrt(A * A + B * B + C * C));

Bl = B / (sqrt(A * A + B * B + C * C)); Cl = C / (sqrt(A * A + B * B + C * C)); for (int i = 0; i < 6; i++)

{

for (int j = 0; j < 3; j++)

{

xt[j] = CubePoints[Gran[i][j]].X;

yt[j] = CubePoints[Gran[i][j]].Y;

zt[j] = CubePoints[Gran[i][j]].Z;

}

{

point1[j] = Perspective(CubePoints[Gran[i][j]].X, CubePoints[Gran[i][j]].Y,

CubePoints[Gran[i][j]].Z);

}

D = point1[0].x * (point1[1].y - point1[2].y) -

point1[1].x * (point1[0].y - point1[2].y) +

point1[2].x * (point1[0].y - point1[1].y); if (D < 0)

{

hBrush = CreateSolidBrush(RGB((1 - alpha) * 255, (1 - alpha) * 255, (1

---

- alpha) * 255));

SelectObject(hdc, hBrush); Polygon(hdc, point1, 4);

}

}

EndPaint(hWnd, &ps);
break;

default:

return DefWindowProc(hWnd, message, wParam, lParam);

}

return 0;

}

Результат работы программы:

Рис.1-вращающийсякуб

Задание 2. Приложение «Кривая Безье». Написан код приложения «Кривая Безье»

Код программы:

#include #include

#define _USE_MATH_DEFINES #include

#include

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

TCHAR WinName[] = _T("MainFrame");

int APIENTRY WinMain(HINSTANCE This, HINSTANCE Prev, LPSTR cmd, int

mode)

{

HWND hWnd; MSG msg; WNDCLASS wc;

wc.hInstance = This; wc.lpszClassName = WinName; wc.lpfnWndProc = WndProc;

wc.style = CS_HREDRAW | CS_VREDRAW; wc.hIcon = LoadIcon(NULL, IDI_APPLICATION); wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.lpszMenuName = NULL;

wc.cbClsExtra = 0;

wc.cbWndExtra = 0;

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); if (!RegisterClass(&wc)) return 0;

hWnd = CreateWindow(WinName, _T("Каркас Windows-приложения"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,

CW_USEDEFAULT,

CW_USEDEFAULT, CW_USEDEFAULT, HWND_DESKTOP, NULL, This,

NULL);

ShowWindow(hWnd, mode);

while (GetMessage(&msg, NULL, 0, 0))

{

TranslateMessage(&msg); DispatchMessage(&msg);

}
return 0;

}

static int sx, sy;

const int SCALE = 1000; const int MARK = 4;

void DcInLp(POINT& point)

{

point.x = point.x * SCALE / sx;

point.y = SCALE - point.y * SCALE / sy;

}

void transform(HDC& hdc)

{

SetMapMode(hdc, MM_ANISOTROPIC); SetWindowExtEx(hdc, SCALE, -SCALE, NULL); SetViewportExtEx(hdc, sx, sy, NULL); SetViewportOrgEx(hdc, 0, sy, NULL);

}

PAINTSTRUCT ps;

static HPEN hDash, hBezier; static HBRUSH hRect, hSel; static POINT pt[20];

static POINT point; RECT rt;

static int count, index; static bool capture;

int i; std::ifstream in; std::ofstream out;

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)

{

HDC hdc;

switch (message)

{

case WM_DESTROY: DeleteObject(hDash); DeleteObject(hBezier); DeleteObject(hRect); DeleteObject(hSel); out.open("dat.txt");

for (i = 0; i < count; i++) out << pt[i].x << '\t' << pt[i].y <<

'\n'; out.close();
break; case WM_CREATE:

in.open("dat.txt");

if (in.fail())

{

MessageBox(hWnd, _T("Файл dat.txt не найден"),

_T("Открытие файла"), MB_OK | MB_ICONEXCLAMATION);

PostQuitMessage(0); return 1;

}

for (count = 0; in >> pt[count].x; count++) in >> pt[count].y; in.close();

hDash = CreatePen(PS_DASH, 1, 0);

hBezier = CreatePen(PS_SOLID, 4, RGB(0, 0,

255)); hRect = CreateSolidBrush(RGB(128, 0, 128));

hSel = CreateSolidBrush(RGB(255, 0, 0)); break;

case WM_SIZE:

sx = LOWORD(lParam); sy = HIWORD(lParam); break;

case WM_LBUTTONDOWN:

point.x = LOWORD(lParam); point.y = HIWORD(lParam); DcInLp(point);

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

{

SetRect(&rt, pt[i].x - MARK, pt[i].y -

MARK, pt[i].x + MARK, pt[i].y + MARK);

if (PtInRect(&rt, point))

{

index = i; capture = true;

hdc = GetDC(hWnd); transform(hdc); FillRect(hdc, &rt, hSel); ReleaseDC(hWnd, hdc); SetCapture(hWnd); return 0;

}

}

break;

case WM_LBUTTONUP:
if (capture)

{

}

break;

ReleaseCapture(); capture = false;

case WM_MOUSEMOVE:

if (capture)

{

}

break;

point.x = LOWORD(lParam); point.y = HIWORD(lParam); DcInLp(point);

pt[index] = point; InvalidateRect(hWnd, NULL, TRUE);

case WM_PAINT:

hdc = BeginPaint(hWnd, &ps); transform(hdc); SelectObject(hdc, hDash); Polyline(hdc, pt, count); SelectObject(hdc, hBezier); PolyBezier(hdc, pt, count);

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

{

SetRect(&rt, pt[i].x - MARK, pt[i].y - MARK,

pt[i].x + MARK, pt[i].y + MARK);

FillRect(hdc, &rt, hRect);

}

break; default:

return DefWindowProc(hWnd, message, wParam, lParam);

}

return 0;

}

Результат работы программы:

Рис.2-криваяБезье

Задание 3. Построение кривой B-сплайна.

Написан код для построения кривой B-сплайна

Код программы:

#include #include

#define _USE_MATH_DEFINES #include

#include

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

TCHAR WinName[] = _T("MainFrame");

int APIENTRY WinMain(HINSTANCE This, HINSTANCE Prev, LPSTR cmd, int

mode)

{

HWND hWnd; MSG msg; WNDCLASS wc;

wc.hInstance = This; wc.lpszClassName = WinName;

wc.lpfnWndProc = WndProc;

wc.style = CS_HREDRAW | CS_VREDRAW; wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.lpszMenuName = NULL;

wc.cbClsExtra = 0;

wc.cbWndExtra = 0;

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); if (!RegisterClass(&wc)) return 0;

hWnd = CreateWindow(WinName, _T("Каркас Windows-приложения"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT,

CW_USEDEFAULT,

CW_USEDEFAULT, CW_USEDEFAULT, HWND_DESKTOP, NULL, This,

NULL);

ShowWindow(hWnd, mode);

while (GetMessage(&msg, NULL, 0, 0))

{

TranslateMessage(&msg); DispatchMessage(&msg);

}

return 0;

}

const int WIDTH = 400; const int HEIGHT = 300;

float v11, v12, v13, v21, v22, v23, v31, v32, v33, v43; float rho = 300., thetta = 75., phi = 30., ScreenDist = 500.; float A, B, C, D, An, Bn, Cn;

float xt[3], yt[3], zt[3]; float Al, Bl, Cl; float alpha;

float th, ph, costh, cosph, sinth, sinph; float factor = atan(1.0) / 45.; static int sx, sy;

const int SCALE = 1000; //размер логического окна

const int MARK = 4; //размер прямоугольного маркера точек

void DcInLp(POINT& point)

{

point.x = point.x * SCALE / sx;

point.y = SCALE - point.y * SCALE / sy;

}

void transform(HDC& hdc)

{

SetMapMode(hdc, MM_ANISOTROPIC);

SetWindowExtEx(hdc, SCALE, -SCALE, NULL);
SetViewportExtEx(hdc, sx, sy, NULL); SetViewportOrgEx(hdc, 0, sy, NULL);

}

void PolyBSplayn(HDC hdc, POINT pt[], int count)

{

float a0, a1, a2, a3, b0, b1, b2, b3, t; int first = -1, X, Y, eps = 20;

for (int i = 1; i <= count - 1; i++) {

MoveToEx(hdc, pt[i].x - eps, pt[i].y - eps, NULL);

LineTo(hdc, pt[i].x + eps, pt[i].y + eps); MoveToEx(hdc, pt[i].x + eps, pt[i].y + eps, NULL); LineTo(hdc, pt[i].x - eps, pt[i].y - eps);

}

for (int i = 1; i <= count - 2; i++)

{

a3 = (-pt[i - 1].x + 3 * (pt[i].x - pt[i + 1].x) + pt[i + 2].x) / 6.0;

b3 = (-pt[i - 1].y + 3 * (pt[i].y - pt[i + 1].y) + pt[i + 2].y) / 6.0;

a2 = (pt[i - 1].x - 2 * pt[i].x + pt[i + 1].x) / 2.0;

b2 = (pt[i - 1].y - 2 * pt[i].y + pt[i + 1].y) / 2.0;

a1 = (pt[i + 1].x - pt[i - 1].x) / 2.0;

b1 = (pt[i + 1].y - pt[i - 1].y) / 2.0;

a0 = (pt[i - 1].x + 4 * pt[i].x + pt[i + 1].x) / 6.0;

b0 = (pt[i - 1].y + 4 * pt[i].y + pt[i + 1].y) / 6.0; for (int j = 0; j <= 30; j++)

{

t = (float)j / 30.;

X = ((a3 * t + a2) * t + a1) * t + a0; Y = ((b3 * t + b2) * t + b1) * t + b0; if (first)

{

first = 0; MoveToEx(hdc, X, Y, NULL);

}

else LineTo(hdc, X, Y);

}

}

}

static HPEN hDash, hBezier; static HBRUSH hRect, hSel; static POINT pt[20];

static POINT point; RECT rt;

static int count, index; static bool capture;

int i; std::ifstream in; std::ofstream out;

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)

{

PAINTSTRUCT ps;

HDC hdc;

switch (message)

{

case WM_CREATE:

in.open("dat.txt");

if (in.fail())

{

MessageBox(hWnd, _T("Файл dat.txt не найден"),

_T("Открытие файла"), MB_OK | MB_ICONEXCLAMATION);

PostQuitMessage(0); return 1;

}

for (count = 0; in >> pt[count].x; count++) in >> pt[count].y;

in.close();

hDash = CreatePen(PS_DASH, 1, 0);

hBezier = CreatePen(PS_SOLID, 4, RGB(0, 0, 255));

hRect = CreateSolidBrush(RGB(128, 0, 128));

hSel = CreateSolidBrush(RGB(255, 0, 0)); break;

case WM_SIZE:

sx = LOWORD(lParam); sy = HIWORD(lParam); break;

case WM_LBUTTONDOWN:

point.x = LOWORD(lParam); point.y = HIWORD(lParam);
DcInLp(point);

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

{
SetRect(&rt, pt[i].x - MARK, pt[i].y - MARK, pt[i].x +

MARK,

pt[i].y + MARK);

if (PtInRect(&rt, point))

{

}

}

break;

index = i; capture = true;

hdc = GetDC(hWnd); transform(hdc); FillRect(hdc, &rt, hSel);

ReleaseDC(hWnd, hdc); SetCapture(hWnd);

return 0;

case WM_LBUTTONUP:

if (capture)

{

}

break;

ReleaseCapture(); capture = false;

case WM_MOUSEMOVE:

if (capture)

{

}

break;

point.x = LOWORD(lParam); point.y = HIWORD(lParam); DcInLp(point);

pt[index] = point; InvalidateRect(hWnd, NULL, TRUE);

case WM_PAINT:

hdc = BeginPaint(hWnd, &ps); transform(hdc); SelectObject(hdc, hDash); Polyline(hdc, pt, count); SelectObject(hdc, hBezier); PolyBSplayn(hdc, pt, count); for (i = 0; i < count; i++)

{

SetRect(&rt, pt[i].x - MARK, pt[i].y - MARK, pt[i].x + MARK, pt[i].y + MARK);

FillRect(hdc, &rt, hRect);

}

break;

case WM_DESTROY: PostQuitMessage(0); DeleteObject(hDash); DeleteObject(hBezier); DeleteObject(hRect); DeleteObject(hSel); out.open("dat.txt");

for (i = 0; i < count; i++) out << pt[i].x << '\t' << pt[i].y << '\n'; out.close();

PostQuitMessage(0); break;

default: return DefWindowProc(hWnd, message, wParam, lParam);

}

return 0;

}
Результат работы программы:

ВЫВОД

Рис.3-криваяB-сплайна

Сегодня мы рассмотрели вращение объемных фигур, построение сплайнов, виды сплайнов. Изобразили вращающийся при помощи мыши куб с удалёнными гранями и закраской, «Кривая Безье». По примеру кода «Безье» адаптировали код программы, написанной в MS-DOS для построения В-сплайна.

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