/** Performs a sanity check on the IPD to ensure that it is not too small, big, or reversed.
@param viewmatrix View matrix for the viewportID
@param viewportID The viewportID for this particular view matrix.
*/
static void viewmat_validate_ipd(float viewmatrix[16], int viewportID)
{
// First, if viewportID=0, save the matrix so we can do the check when we are called with viewportID=1.
static float viewmatrix0[16];
static long viewmatrix0time;
if(viewportID == 0)
{
mat4f_copy(viewmatrix0, viewmatrix);
viewmatrix0time = kuhl_microseconds();
return;
}
// If rendering viewportID == 1, and if there are two viewports,
// assume that we are running in a stereoscopic configuration and
// validate the IPD value.
if(viewportID == 1 && viewports_size == 2)
{
float flip = 1;
/* In most cases, viewportID=0 is the left eye. However,
* Oculus may cause this to get swapped. */
if(viewmat_viewport_to_eye(0) == VIEWMAT_EYE_RIGHT)
flip = -1;
// Get the position matrix information
float pos1[4], pos2[4];
mat4f_getColumn(pos1, viewmatrix0, 3); // get last column
mat4f_getColumn(pos2, viewmatrix, 3); // get last column
// Get a vector between the eyes
float diff[4];
vec4f_sub_new(diff, pos1, pos2);
vec4f_scalarMult_new(diff, diff, flip); // flip vector if necessary
/* This message may be triggered if a person is moving quickly
* and/or when the FPS is low. This happens because the
* position/orientation of the head changed between the
* rendering of the left and right eyes. */
float ipd = diff[0];
long delay = kuhl_microseconds() - viewmatrix0time;
if(ipd > .07 || ipd < .05)
{
msg(MSG_WARNING, "IPD=%.4f meters, delay=%ld us (IPD validation failed; occasional messages are OK!)\n", ipd, delay);
}
// msg(MSG_INFO, "IPD=%.4f meters, delay=%ld us\n", ipd, delay);
}
}
void display()
{
/* If we are using DGR, send or receive data to keep multiple
* processes/computers synchronized. */
dgr_update();
/* Get current frames per second calculations. */
float fps = kuhl_getfps(&fps_state);
if(dgr_is_enabled() == 0 || dgr_is_master())
{
// If DGR is being used, only display dgr counter if we are
// the master process.
// Check if FPS value was just updated by kuhl_getfps()
if(fps_state.frame == 0)
{
char label[1024];
snprintf(label, 1024, "FPS: %0.1f", fps);
/* Delete old label if it exists */
if(fpsLabel != 0)
glDeleteTextures(1, &fpsLabel);
/* Make a new label */
float labelColor[3] = { 1,1,1 };
float labelBg[4] = { 0,0,0,.3 };
/* Change the last parameter (point size) to adjust the
* size of the texture that the text is rendered in to. */
fpsLabelAspectRatio = kuhl_make_label(label,
&fpsLabel,
labelColor, labelBg, 24);
if(fpsLabel != 0)
kuhl_geometry_texture(&labelQuad, fpsLabel, "tex", 1);
}
}
/* Ensure the slaves use the same render style as the master
* process. */
dgr_setget("style", &renderStyle, sizeof(int));
/* Render the scene once for each viewport. Frequently one
* viewport will fill the entire screen. However, this loop will
* run twice for HMDs (once for the left eye and once for the
* right. */
viewmat_begin_frame();
for(int viewportID=0; viewportID<viewmat_num_viewports(); viewportID++)
{
viewmat_begin_eye(viewportID);
/* Where is the viewport that we are drawing onto and what is its size? */
int viewport[4]; // x,y of lower left corner, width, height
viewmat_get_viewport(viewport, viewportID);
glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
/* Clear the current viewport. Without glScissor(), glClear()
* clears the entire screen. We could call glClear() before
* this viewport loop---but on order for all variations of
* this code to work (Oculus support, etc), we can only draw
* after viewmat_begin_eye(). */
glScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
glEnable(GL_SCISSOR_TEST);
glClearColor(.2,.2,.2,0); // set clear color to grey
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
glDisable(GL_SCISSOR_TEST);
glEnable(GL_DEPTH_TEST); // turn on depth testing
kuhl_errorcheck();
/* Turn on blending (note, if you are using transparent textures,
the transparency may not look correct unless you draw further
items before closer items.). */
glEnable(GL_BLEND);
glBlendEquationSeparate(GL_FUNC_ADD, GL_FUNC_ADD);
glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO);
/* Get the view or camera matrix; update the frustum values if needed. */
float viewMat[16], perspective[16];
viewmat_get(viewMat, perspective, viewportID);
glUseProgram(program);
kuhl_errorcheck();
/* Send the perspective projection matrix to the vertex program. */
glUniformMatrix4fv(kuhl_get_uniform("Projection"),
1, // number of 4x4 float matrices
0, // transpose
perspective); // value
float modelMat[16];
get_model_matrix(modelMat);
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"), renderStyle);
// Copy far plane value into vertex program so we can render depth buffer.
float f[6]; // left, right, bottom, top, near>0, far>0
projmat_get_frustum(f, viewport[2], viewport[3]);
glUniform1f(kuhl_get_uniform("farPlane"), f[5]);
kuhl_errorcheck();
kuhl_geometry_draw(modelgeom); /* Draw the model */
kuhl_errorcheck();
if(showOrigin)
{
/* Save current line width */
GLfloat origLineWidth;
glGetFloatv(GL_LINE_WIDTH, &origLineWidth);
glLineWidth(4); // make lines thick
/* Object coordinate system origin */
kuhl_geometry_draw(origingeom); /* Draw the origin marker */
/* World coordinate origin */
mat4f_copy(modelview, viewMat);
glUniformMatrix4fv(kuhl_get_uniform("ModelView"),
1, // number of 4x4 float matrices
0, // transpose
modelview); // value
kuhl_geometry_draw(origingeom); /* Draw the origin marker */
/* Restore line width */
glLineWidth(origLineWidth);
}
if(dgr_is_enabled() == 0 || dgr_is_master())
{
/* The shape of the frames per second quad depends on the
* aspect ratio of the label texture and the aspect ratio of
* the window (because we are placing the quad in normalized
* device coordinates). */
int windowWidth, windowHeight;
viewmat_window_size(&windowWidth, &windowHeight);
float windowAspect = windowWidth / (float)windowHeight;
float stretchLabel[16];
mat4f_scale_new(stretchLabel, 1/8.0 * fpsLabelAspectRatio / windowAspect, 1/8.0, 1);
/* Position label in the upper left corner of the screen */
float transLabel[16];
mat4f_translate_new(transLabel, -.9, .8, 0);
mat4f_mult_mat4f_new(modelview, transLabel, stretchLabel);
glUniformMatrix4fv(kuhl_get_uniform("ModelView"), 1, 0, modelview);
/* Make sure we don't use a projection matrix */
float identity[16];
mat4f_identity(identity);
glUniformMatrix4fv(kuhl_get_uniform("Projection"), 1, 0, identity);
/* Don't use depth testing and make sure we use the texture
* rendering style */
glDisable(GL_DEPTH_TEST);
glUniform1i(kuhl_get_uniform("renderStyle"), 1);
kuhl_geometry_draw(&labelQuad); /* Draw the quad */
glEnable(GL_DEPTH_TEST);
kuhl_errorcheck();
}
glUseProgram(0); // stop using a GLSL program.
} // finish viewport loop
viewmat_end_frame();
/* Update the model for the next frame based on the time. We
* convert the time to seconds and then use mod to cause the
* animation to repeat. */
int time = glutGet(GLUT_ELAPSED_TIME);
dgr_setget("time", &time, sizeof(int));
kuhl_update_model(modelgeom, 0, ((time%10000)/1000.0));
/* Check for errors. If there are errors, consider adding more
* calls to kuhl_errorcheck() in your code. */
kuhl_errorcheck();
//kuhl_video_record("videoout", 30);
/* Ask GLUT to call display() again. We shouldn't call display()
* ourselves recursively because it will not leave time for GLUT
* to call other callback functions for when a key is pressed, the
* window is resized, etc. */
glutPostRedisplay();
}
