void drawOrientedWireSphere(float r, const Matrix4& basis)
{
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glMultMatrix(basis);
drawWireSphere(r);
glPopMatrix();
}
void drawSphereNormals() {
//Draw the sphere.
drawWireSphere();
//Draw the normals.
glVertexPointer(3, GL_FLOAT, 0, sphereNormalsV);
glColorPointer(3, GL_FLOAT, 0, sphereNormalsC);
for (int i = 0; i < SECTIONS * SECTIONS; i++)
glDrawArrays(GL_LINES, i * 2, 3);
}
void display() {
//Clear buffers and set the transformation matrix to the identity matrix.
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
//Increment global angle variables (take FPS into account).
a += 90 / FPS; b += 90 / FPS; c += 90 / FPS; d += 90 / FPS;
a %= 360; b %= 360; c %= 360; d %= 360;
//Draw scene depending on program state.
switch (state) {
case 1:
rotateY(a);
rotateZ(a);
drawWireSphere();
break;
case 2:
rotateX(20);
rotateY(b);
drawWireCone();
break;
case 3:
rotateY(a);
rotateZ(a);
drawSphereNormals();
break;
case 4:
rotateY(d);
drawShadedSphere();
break;
case 5: drawAnimation();
break;
}
//Swap buffers.
SDL_GL_SwapBuffers();
}
void drawAnimation() {
//Rotate the SphereNormals display in the x-axis.
scale(0.35, 0.35, 0.35);
rotateX(a);
rotateZ(a);
translate(0, 0, 4);
drawSphereNormals();
glLoadIdentity();
//Rotate the WireCone drawing in the y-axis.
scale(0.35, 0.35, 0.35);
rotateY(b);
rotateX(b);
translate(4, 0, 0);
drawWireCone();
glLoadIdentity();
//Rotate the WireSphere drawing the the z-axis.
scale(0.35, 0.35, 0.35);
rotateZ(c);
rotateY(c);
translate(0, 4, 0);
drawWireSphere();
glLoadIdentity();
//Rotate the ShadedSphere drawing (on the spot) through the x-, y- and z- axis.
scale(0.35, 0.35, 0.35);
rotateY(d);
drawShadedSphere();
glLoadIdentity();
//Reset the camera to orthographic.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2, 2, -2, 2, 2, -2);
glMatrixMode(GL_MODELVIEW);
}
