/** Draw a object at the location and orientation of the tracked vrpn object */
void drawObject(const int objectIndex, float viewMat[16])
{
const char *vrpnObject = global_argv[objectIndex];
const float scaleFactor = .5;
float pos[4], orient[16];
vrpn_get(vrpnObject, NULL, pos, orient);
float modelMat[16],translate[16],scale[16];
mat4f_scale_new(scale, scaleFactor, scaleFactor, scaleFactor);
mat4f_translateVec_new(translate, pos);
mat4f_mult_mat4f_many(modelMat, translate, orient, scale, NULL);
float modelview[16];
mat4f_mult_mat4f_new(modelview, viewMat, modelMat); // modelview = view * model
/* Send the modelview matrix to the vertex program. */
glUniformMatrix4fv(kuhl_get_uniform("ModelView"),
1, // number of 4x4 float matrices
0, // transpose
modelview); // value
glUniform1i(kuhl_get_uniform("renderStyle"), 2);
kuhl_errorcheck();
kuhl_geometry_draw(modelgeom); /* Draw the model */
kuhl_errorcheck();
/* Transparency of labels may not appear right because we aren't
* sorting them by depth. */
float labelScale[16];
mat4f_scale_new(labelScale, 1, 1/labelAspectRatio[objectIndex-1], 1);
mat4f_mult_mat4f_new(modelview, modelview, labelScale);
glUniformMatrix4fv(kuhl_get_uniform("ModelView"), 1, 0, modelview);
glUniform1i(kuhl_get_uniform("renderStyle"), 1);
kuhl_geometry_texture(&quad, label[objectIndex-1], "tex", 1);
kuhl_geometry_draw(&quad);
#if 0
printf("%s is at\n", vrpnObject);
vec3f_print(pos);
mat4f_print(orient);
#endif
}
/** Get view and projection matrices appropriate for the Oculus HMD */
static void viewmat_get_hmd_oculus(float viewmatrix[16], float projmatrix[16], int viewportID)
{
#ifndef MISSING_OVR
/* Oculus recommends the order that we should render eyes. We
* assume that smaller viewportIDs are rendered first. So, we need
* to map the viewportIDs to the specific Oculus HMD eye. The
* "eye" variable will be set to either ovrEye_Left (if we are
* rendering the left eye) or ovrEye_Right (if we are rendering
* the right eye). */
ovrEyeType eye = hmd->EyeRenderOrder[viewportID];
/* Oculus doesn't provide us with easy access to the view
* frustum information. We get the projection matrix directly
* from libovr. */
ovrMatrix4f ovrpersp = ovrMatrix4f_Projection(hmd->DefaultEyeFov[eye], 0.5, 500, 1);
mat4f_setRow(projmatrix, &(ovrpersp.M[0][0]), 0);
mat4f_setRow(projmatrix, &(ovrpersp.M[1][0]), 1);
mat4f_setRow(projmatrix, &(ovrpersp.M[2][0]), 2);
mat4f_setRow(projmatrix, &(ovrpersp.M[3][0]), 3);
float offsetMat[16], rotMat[16], posMat[16], initPosMat[16];
mat4f_identity(offsetMat); // Viewpoint offset (IPD, etc);
mat4f_identity(rotMat); // tracking system rotation
mat4f_identity(posMat); // tracking system position
mat4f_identity(initPosMat); // camera starting location
/* Construct posMat and rotMat matrices which indicate the
* position and orientation of the HMD. */
if(viewmat_vrpn_obj) // get position from VRPN
{
/* Get the offset for the left and right eyes from
* Oculus. If you are using a separate tracking system, you
* may also want to apply an offset here between the tracked
* point and the eye location. */
mat4f_translate_new(offsetMat,
eye_rdesc[eye].HmdToEyeViewOffset.x, // left & right IPD offset
eye_rdesc[eye].HmdToEyeViewOffset.y, // vertical offset
eye_rdesc[eye].HmdToEyeViewOffset.z); // forward/back offset
float pos[3] = { 0,0,0 };
vrpn_get(viewmat_vrpn_obj, NULL, pos, rotMat);
mat4f_translate_new(posMat, -pos[0], -pos[1], -pos[2]); // position
viewmat_fix_rotation(rotMat);
}
else // get position from Oculus tracker
{
pose[eye] = ovrHmd_GetHmdPosePerEye(hmd, eye);
mat4f_translate_new(posMat, // position (includes IPD offset)
-pose[eye].Position.x,
-pose[eye].Position.y,
-pose[eye].Position.z);
mat4f_rotateQuat_new(rotMat, // rotation
pose[eye].Orientation.x,
pose[eye].Orientation.y,
pose[eye].Orientation.z,
pose[eye].Orientation.w);
// Starting point:
// Translate the world based on the initial camera position
// specified in viewmat_init(). You may choose to initialize the
// camera position with y=1.5 meters to approximate a normal
// standing eyeheight.
float initPosVec[3];
vec3f_scalarMult_new(initPosVec, oculus_initialPos, -1.0f);
mat4f_translateVec_new(initPosMat, initPosVec);
// TODO: Could also get eyeheight via ovrHmd_GetFloat(hmd, OVR_KEY_EYE_HEIGHT, 1.65)
}
mat4f_transpose(rotMat); /* orientation sensor rotates camera, not world */
// viewmatrix = offsetMat * rotMat * posMat * initposmat
mat4f_mult_mat4f_new(viewmatrix, offsetMat, rotMat); // offset is identity if we are using Oculus tracker
mat4f_mult_mat4f_new(viewmatrix, viewmatrix, posMat);
mat4f_mult_mat4f_new(viewmatrix, viewmatrix, initPosMat);
if(0)
{
printf("ViewportID=%d; eye=%s\n", viewportID, eye == ovrEye_Left ? "left" : "right");
printf("Eye offset according to OVR (only used if VRPN is used): ");
mat4f_print(offsetMat);
printf("Rotation sensing (from OVR or VRPN): ");
mat4f_print(rotMat);
printf("Position tracking (from OVR or VRPN): ");
mat4f_print(posMat);
printf("Initial position (from set in viewmat_init()): ");
mat4f_print(initPosMat);
printf("Final view matrix: ");
mat4f_print(viewmatrix);
}
#else
/* We shouldn't ever get here, but we'll generate a generic view
* and projection matrix just in case... */
mat4f_lookat_new(viewmatrix,
0,1.55,0,
0,1.55,-1,
0,1,0);
mat4f_perspective_new(projmatrix, 50, 1, 0.5, 500);
#endif
}