計算機圖形學(xué)實驗五：圖形變換

1、貴州大學(xué)實驗報告學(xué)院：計算機科學(xué)與技術(shù) 專業(yè)： 計算機科學(xué)與技術(shù) 班級：計科131姓名學(xué)號實驗組實驗時間指導(dǎo)教師黃初華成績實驗項目名稱圖形變換實驗?zāi)康膶嶒災(zāi)康耐ㄟ^本實驗，使學(xué)生了解并掌握在光柵顯示系統(tǒng)中直線的生成和顯示算法，熟悉相關(guān)開發(fā)平臺。為后繼實驗打下基礎(chǔ)。實驗要求對于設(shè)計性實驗，應(yīng)根據(jù)“由學(xué)生自行設(shè)計實驗方案并加以實現(xiàn)的實驗”內(nèi)涵要求，注意省略由學(xué)生自主設(shè)計的“實驗方案”。根據(jù)本實驗的特點、要求和具體條件，采用“以學(xué)生自主訓(xùn)練為主的開放模式組織教學(xué)，還是采用集中授課形式”，須加以明確。實驗原理標(biāo)準(zhǔn)齊次坐標(biāo)(x,y,1) 二維變換的矩陣表示平移變換旋轉(zhuǎn)變換放縮變換l 平移變換只改變圖形的位

2、置，不改變圖形的大小。l 旋轉(zhuǎn)變換不改變圖形的形狀l 放縮變換引起圖形形狀的變化。復(fù)合變換結(jié)果與變換的順序有關(guān)（矩陣乘法不可交換實驗環(huán)境硬件平臺：PC軟件(推薦)：Windows平臺，Visual stdio2013,openGL實驗步驟實驗步驟1. 掌握算法原理；2. 依據(jù)算法，編寫源程序并進行調(diào)試；3. 對運行結(jié)果進行保存與分析；4. 把源程序以文件的形式提交；5. 按格式書寫實驗報告。實驗內(nèi)容#include"stdafx.h"#include <glut.h>#include <stdlib.h>#include <math.h>

3、GLsizei winWidth = 600, winHeight = 600;GLfloat xwcMin = 0.0, xwcMax = 225.0;GLfloat ywcMin = 0.0, ywcMax = 225.0;class wcPt2Dpublic:GLfloat x, y;typedef GLfloat Matrix3x333;Matrix3x3 matComposite;const GLdouble pi = 3.14159;void init(void)glClearColor(1.0, 1.0, 1.0, 0.0);void matrix3x3SetIdentity(M

4、atrix3x3 matIdent3x3)GLint row, col;for (row = 0; row<3; row+)for (col = 0; col<3; col+)matIdent3x3rowcol = (row = col);/生成1,0,00,1,00,0,1void matrix3x3PreMultiply(Matrix3x3 m1, Matrix3x3 m2)GLint row, col;Matrix3x3 matTemp;for (row = 0; row<3; row+)for (col = 0; col<3; col+)matTemprowco

5、l = m1row0 * m20col + m1row1 * m21col + m1row2 * m22col;for (row = 0; row<3; row+)for (col = 0; col<3; col+)m2rowcol = matTemprowcol;void translate2D(GLfloat tx, GLfloat ty)/平移Matrix3x3 matTransl;matrix3x3SetIdentity(matTransl);matTransl02 = tx;matTransl12 = ty;matrix3x3PreMultiply(matTransl,

6、matComposite);void rotate2D(wcPt2D pivotPt, GLfloat theta)/旋轉(zhuǎn)Matrix3x3 matRot;matrix3x3SetIdentity(matRot);matRot00 = cos(theta);matRot01 = -sin(theta);matRot02 = pivotPt.x*(1 - cos(theta) + pivotPt.y*sin(theta);matRot10 = sin(theta);matRot11 = cos(theta);matRot312 = pivotPt.x*(1 - cos(theta) - pivo

7、tPt.y*sin(theta);matrix3x3PreMultiply(matRot, matComposite);void scale2D(GLfloat sx, GLfloat sy, wcPt2D fixedPt)/縮放Matrix3x3 matScale;matrix3x3SetIdentity(matScale);matScale00 = sx;matScale02 = (1 - sx)*fixedPt.x;matScale11 = sy;matScale12 = (1 - sy)*fixedPt.y;matrix3x3PreMultiply(matScale, matCompo

8、site);void transformVerts2D(GLint nVerts, wcPt2D * verts)/組合變化后的矩陣GLint k;GLfloat temp;for (k = 0; k<nVerts; k+)temp = matComposite00 * vertsk.x + matComposite01 * vertsk.y + matComposite02;vertsk.y = matComposite10 * vertsk.x + matComposite11 * vertsk.y + matComposite12;vertsk.x = temp;void tria

9、ngle(wcPt2D*verts)GLint k;glBegin(GL_TRIANGLES);for (k = 0; k<3; k+)glVertex2f(vertsk.x, vertsk.y);glEnd();void displayFcn(void)GLint nVerts = 3;wcPt2D verts3 = 50.0, 25.0 , 150.0, 25.0 , 100.0, 100.0 ;wcPt2D centroidPt;GLint k, xSum = 0, ySum = 0;for (k = 0; k<nVerts; k+)xSum += vertsk.x;ySum

10、 += vertsk.y;centroidPt.x = GLfloat(xSum) / GLfloat(nVerts);centroidPt.y = GLfloat(ySum) / GLfloat(nVerts);wcPt2D pivPt, fixedPt;pivPt = centroidPt;fixedPt = centroidPt;GLfloat tx = 0.0, ty = 100.0;GLfloat sx = 0.5, sy = 0.5;GLdouble theta = pi / 2.0;glClear(GL_COLOR_BUFFER_BIT);glColor3f(0.0, 0.0,

11、1.0);triangle(verts);/三角形matrix3x3SetIdentity(matComposite);scale2D(sx, sy, fixedPt);/縮小transformVerts2D(nVerts, verts);glColor3f(1.0, 0.0, 0.0);triangle(verts);matrix3x3SetIdentity(matComposite);rotate2D(pivPt, theta);/旋轉(zhuǎn)90transformVerts2D(nVerts, verts); glColor3f(1.0, 0.0, 0.0);triangle(verts);ma

12、trix3x3SetIdentity(matComposite);translate2D(tx, ty);/平移transformVerts2D(nVerts, verts); glColor3f(1.0, 0.0, 0.0);triangle(verts);matrix3x3SetIdentity(matComposite);transformVerts2D(nVerts, verts);glColor3f(1.0, 0.0, 0.0);triangle(verts);glFlush();void winReshapeFcn(GLint newWidth, GLint newHeight)g

13、lMatrixMode(GL_PROJECTION);gluOrtho2D(xwcMin, xwcMax, ywcMin, ywcMax);glClear(GL_COLOR_BUFFER_BIT);void main(int argc, char* argv)glutInit(&argc, argv);glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);glutInitWindowPosition(50, 50);glutInitWindowSize(winWidth, winHeight);glutCreateWindow("Geometr