void displayCallback( ){
const float centerPosition[] = {0.0, 0.0, 0.0};
float viewingTransform[16];
float modelingTransform[16];
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
myLookAt( viewingTransform,
eyePosition[0], eyePosition[1], eyePosition[2],
centerPosition[0], centerPosition[1], centerPosition[2],
upVector[0], upVector[1], upVector[2], camZ
);
// Set light & material properties for the teapot;
// lights are transformed by current modelview matrix
// such that they are positioned correctly in the scene.
matMultVec4f( light0, light0_position, viewingTransform );
matMultVec4f( light1, light1_position, viewingTransform );
matMultVec4f( light2, light2_position, viewingTransform );
matMultVec4f( light3, light3_position, viewingTransform );
shaderProgram_A->activate( );
activateUniforms_A( );
glLoadIdentity( );
glMultMatrixf(viewingTransform);
myScalef(modelingTransform,
teapotScale_A[0], teapotScale_A[1], teapotScale_A[2]);
glMultMatrixf(modelingTransform);
myTranslatef(modelingTransform,
teapotTranslation_A[0],
teapotTranslation_A[1],
teapotTranslation_A[2]);
glMultMatrixf(modelingTransform);
_glutSolidTeapot(1.3);
shaderProgram_B->activate( );
activateUniforms_B( );
glLoadIdentity( );
glMultMatrixf(viewingTransform);
myTranslatef(modelingTransform,
teapotTranslation_B[0],
teapotTranslation_B[1],
teapotTranslation_B[2]);
glMultMatrixf(modelingTransform);
_glutSolidTeapot(1.3);
glutSwapBuffers();
}
void DrawGLScene(void)
{
double stretch,height,position,rotation;
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
glLoadIdentity();
gluLookAt(5.0, 5.0, 20.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
position=cos((double)frame*speed)*2;
height=fabs(sin((double)frame*speed)*10)+1;
rotation=cos((double)frame*speed)*90;
stretch=1+0.3*sin((double)frame*speed/2);
if(useMyTransformations) {
if(doTranslate) myTranslatef(position,height-5,0.0);
if(doRotate) myRotatef(rotation,0.2,0.6,0.77);
if(doScale) myScalef(1/sqrt(stretch),stretch,1/sqrt(stretch));
} else {
if(doTranslate) glTranslatef(position,height-5,0.0);
if(doRotate) glRotatef(rotation,0.2,0.6,0.77);
if(doScale) glScalef(1/sqrt(stretch),stretch,1/sqrt(stretch));
}
//drawCube();
drawTeapot();
frame++;
glutSwapBuffers();
}
void drawPolys(void) {
myMatrixMode(GL_MODELVIEW);
myScalef(50.0,50.0);
drawHouse();
myPopMatrix();
myTranslatef(-50.0,0.0);
myScalef(30.0,30.0);
drawHouse();
myPopMatrix();
myTranslatef(0.0,-100.0);
myScalef(40.0,40.0);
drawHouse();
glFlush();
}
void myLookAt(GLfloat *matrix,
GLdouble eyeX, GLdouble eyeY, GLdouble eyeZ,
GLdouble centerX, GLdouble centerY, GLdouble centerZ,
GLdouble upX, GLdouble upY, GLdouble upZ){
// Please implement this function.
GLdouble gaze[3] = { centerX - eyeX, centerY - eyeY, centerZ - eyeZ };
GLdouble up[3] = { upX, upY, upZ };
GLdouble normGaze[3];
double gazeLength;
GLdouble normUp[3];
double upLength;
GLdouble right[3];
GLdouble normRight[3];
double rightLength;
GLfloat translate[16];
GLfloat modelView[16];
gazeLength = sqrt(SQR(gaze[0]) + SQR(gaze[1]) + SQR(gaze[2]));
for (int i = 0; i < 3; i++)
{
normGaze[i] = gaze[i] / gazeLength;
}
upLength = sqrt(SQR(up[0]) + SQR(up[1]) + SQR(up[2]));
for (int i = 0; i < 3; i++)
{
normUp[i] = up[i] / upLength;
}
right[0] = normGaze[1] * normUp[2] - normGaze[2] * normUp[1];
right[1] = normGaze[2] * normUp[0] - normGaze[0] * normUp[2];
right[2] = normGaze[0] * normUp[1] - normGaze[1] * normUp[0];
rightLength = sqrt(SQR(right[0]) + SQR(right[1]) + SQR(right[2]));
for (int i = 0; i < 3; i++)
{
normRight[i] = right[i] / rightLength;
}
modelView[0] = normRight[0]; modelView[4] = normRight[1]; modelView[8] = normRight[2]; modelView[12] = 0;
modelView[1] = normUp[0]; modelView[5] = normUp[1]; modelView[9] = normUp[2]; modelView[13] = 0;
modelView[2] = -normGaze[0]; modelView[6] = -normGaze[1]; modelView[10] = -normGaze[2]; modelView[14] = 0;
modelView[3] = 0; modelView[7] = 0; modelView[11] = 0; modelView[15] = 1;
myTranslatef(translate, -eyeX, -eyeY, -eyeZ);
matrixMult(matrix, modelView, translate);
}
void myLookAt(GLfloat *matrix,
GLfloat eyeX, GLfloat eyeY, GLfloat eyeZ,
GLfloat centerX, GLfloat centerY, GLfloat centerZ,
GLfloat upX, GLfloat upY, GLfloat upZ){
GLfloat normGaze[3]; // will hold the normalized gaze vector
GLfloat normUp[3]; // will hold the normalized up vector
GLfloat normRight[3]; // will hold the normalized right vector
GLfloat right[3]; // will hold the right vector
GLfloat modelView[16]; // will hold the pre-translated model view matrix
GLfloat translate[16]; // will hold the translate matrix
GLfloat gaze[] = { centerX - eyeX, centerY - eyeY, centerZ - eyeZ }; // holds the gaze vector
GLfloat up[] = { upX, upY, upZ }; // holds the up vector
float gazeLength;
float upLength;
float rightLength;
gazeLength = sqrt(SQR(gaze[0]) + SQR(gaze[1]) + SQR(gaze[2])); // find the length of the gaze vector
for (int i = 0; i < 3; i++) // normalize the gaze vector
{
normGaze[i] = gaze[i] / gazeLength;
}
upLength = sqrt(SQR(up[0]) + SQR(up[1]) + SQR(up[2])); // find the length of the up vector
for (int i = 0; i < 3; i++) // normalize the up vector
{
normUp[i] = up[i] / upLength;
}
// cross the normalized gaze vector with the normalized up vector to get the right vector
right[0] = normUp[2] * normGaze[1] - normUp[1] * normGaze[2];
right[1] = normUp[0] * normGaze[2] - normUp[2] * normGaze[0];
right[2] = normUp[1] * normGaze[0] - normUp[0] * normGaze[1];
rightLength = sqrt(SQR(right[0]) + SQR(right[1]) + SQR(right[2])); // find the length of the right vector
for (int i = 0; i < 3; i++) // normalize the right vector because I can
{
normRight[i] = right[i] / rightLength;
}
// create the model view matrix
matrix[0] = normRight[0]; matrix[4] = normRight[1]; matrix[8] = normRight[2]; matrix[12] = 0;
matrix[1] = normUp[0]; matrix[5] = normUp[1]; matrix[9] = normUp[2]; matrix[13] = 0;
matrix[2] = -normGaze[0]; matrix[6] = -normGaze[1]; matrix[10] = -normGaze[2]; matrix[14] = 0;
matrix[3] = 0; matrix[7] = 0; matrix[11] = 0; matrix[15] = 1;
myTranslatef(matrix, -eyeX, -eyeY, -eyeZ); // translate the camera to be at (eyeX, eyeY, eyeZ)
}