In this chapter, you learn what is input and output devices. The keyboard is presented and different keyboard types are described. You are introduced to various pointing devices, such as the mouse, trackball, touchpad, pointing stick, joystick, touchscreen, and pen input. Scanners and reading devices, including optical scanners, optical readers, magnetic ink character recognition readers, and data collection devices are explained,. | Computer Graphics Lecture 26 Fasih ur Rehman Last Class Shading Phong Reflection Model Today’s Agenda Examples Matrix Multiplication void matrixMul(float P[1][3],float T[3][3]) { int i,j,k; //Initialize Matrix P1 with Zero for(i=0;i<3;i++) P1[0][i]=0; /*Mutiply T with P and store the result in P1 */ for(k=0;k<1;k++) for(i=0;i<3;i++) for(j=0;j<3;j++) P1[k][i]+=P[k][j]*T[j][i]; } Matrix Identity void matrixIdentity(float T[3][3]) { int i,j; /* Make matrix T as Identity Matrix by Storing 1 in the left diagonal positions of Matrix T and store 0 in other positions */ for(i=0;i<3;i++) { for(j=0;j<3;j++) { if(i==j) T[i][j]=1; else T[i][j]=0; } } } Translation void translate_point(int x,int y,int tx,int ty) //Translate a point by translation factors tx,ty { float T[3][3]; matrixIdentity(T); T[2][0]=tx; T[2][1]=ty; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,T); } Rotation void rotate_point(int x,int y,float angle) // Rotate a point by given angle { float R[3][3]; float radian; . | Computer Graphics Lecture 26 Fasih ur Rehman Last Class Shading Phong Reflection Model Today’s Agenda Examples Matrix Multiplication void matrixMul(float P[1][3],float T[3][3]) { int i,j,k; //Initialize Matrix P1 with Zero for(i=0;i<3;i++) P1[0][i]=0; /*Mutiply T with P and store the result in P1 */ for(k=0;k<1;k++) for(i=0;i<3;i++) for(j=0;j<3;j++) P1[k][i]+=P[k][j]*T[j][i]; } Matrix Identity void matrixIdentity(float T[3][3]) { int i,j; /* Make matrix T as Identity Matrix by Storing 1 in the left diagonal positions of Matrix T and store 0 in other positions */ for(i=0;i<3;i++) { for(j=0;j<3;j++) { if(i==j) T[i][j]=1; else T[i][j]=0; } } } Translation void translate_point(int x,int y,int tx,int ty) //Translate a point by translation factors tx,ty { float T[3][3]; matrixIdentity(T); T[2][0]=tx; T[2][1]=ty; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,T); } Rotation void rotate_point(int x,int y,float angle) // Rotate a point by given angle { float R[3][3]; float radian; radian=()*angle; matrixIdentity(R); R[0][0]=cos(radian); R[1][0]=-1*sin(radian); R[2][0]=0; R[0][1]=sin(radian); R[1][1]=cos(radian); R[2][1]=0; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,R); } Scale void scale_point(int x,int y,float sx,float sy) /* Scale a point by scaling factors sx,sy and with respect to some fixed point */ { float S[3][3]; matrixIdentity(S); S[0][0]=sx; S[2][0]=0; S[1][1]=sy; S[2][1]=0; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,S); } Reflect void reflect_point_X(int x,int y) { float R[3][3]; matrixIdentity(R); R[1][1]=-1; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,R); } Shear void shear_point_Y(int x,int y,float shy) { float R[3][3]; matrixIdentity(R); R[0][1]=shy; P[0][0]=x; P[0][1]=y; P[0][2]=1; matrixMul(P,R); } Summary Examples References Fundamentals of Computer Graphics Third Edition by Peter Shirley and Steve Marschner Interactive Computer Graphics, A Top-down Approach with OpenGL (Sixth Edition) by Edward Angel. .
