float * getOpenGLDepthFromOSPPerspective(OSPFrameBuffer frameBuffer,
const osp::vec2i &frameBufferSize)
{
// compute fovy, aspect, zNear, zFar from OpenGL projection matrix
// this assumes fovy, aspect match the values set on the OSPRay perspective camera!
GLdouble glProjectionMatrix[16];
glGetDoublev(GL_PROJECTION_MATRIX, glProjectionMatrix);
const double m0 = glProjectionMatrix[0];
const double m5 = glProjectionMatrix[5];
const double m10 = glProjectionMatrix[10];
const double m14 = glProjectionMatrix[14];
const double k = (m10 - 1.0f) / (m10 + 1.0f);
const double fovy = 2. * atan(1.0f / m5) * 180./M_PI;
const double aspect = m5 / m0;
const double zNear = (m14 * (1.0f - k)) / (2.0f * k);
const double zFar = k * zNear;
// get camera direction and up vectors from model view matrix
// again, this assumes these values match those set on the OSPRay camera!
GLdouble glModelViewMatrix[16];
glGetDoublev(GL_MODELVIEW_MATRIX, glModelViewMatrix);
const ospray::vec3f cameraUp( glModelViewMatrix[1], glModelViewMatrix[5], glModelViewMatrix[9]);
const ospray::vec3f cameraDir(-glModelViewMatrix[2], -glModelViewMatrix[6], -glModelViewMatrix[10]);
// map OSPRay depth buffer from provided frame buffer
const float *ospDepthBuffer = (const float *)ospMapFrameBuffer(frameBuffer, OSP_FB_DEPTH);
// get OpenGL depth from OSPRay depth
float *glDepth
= getOpenGLDepthFromOSPPerspective(fovy, aspect, zNear, zFar,
(osp::vec3f&)cameraDir, (osp::vec3f&)cameraUp,
ospDepthBuffer, frameBufferSize);
// unmap OSPRay depth buffer
ospUnmapFrameBuffer(ospDepthBuffer, frameBuffer);
return glDepth;
}
void GLFWOSPRayWindow::display()
{
// clock used to compute frame rate
static auto displayStart = std::chrono::high_resolution_clock::now();
if (showUi && uiCallback) {
ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize;
ImGui::Begin(
"Tutorial Controls (press 'g' to hide / show)", nullptr, flags);
uiCallback();
ImGui::End();
}
// if a display callback has been registered, call it
if (displayCallback) {
displayCallback(this);
}
// render OSPRay frame
ospRenderFrame(framebuffer, renderer, OSP_FB_COLOR | OSP_FB_ACCUM);
// map OSPRay frame buffer, update OpenGL texture with its contents, then
// unmap
uint32_t *fb = (uint32_t *)ospMapFrameBuffer(framebuffer, OSP_FB_COLOR);
glBindTexture(GL_TEXTURE_2D, framebufferTexture);
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGBA,
windowSize.x,
windowSize.y,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
fb);
ospUnmapFrameBuffer(fb, framebuffer);
// clear current OpenGL color buffer
glClear(GL_COLOR_BUFFER_BIT);
// render textured quad with OSPRay frame buffer contents
glBegin(GL_QUADS);
glTexCoord2f(0.f, 0.f);
glVertex2f(0.f, 0.f);
glTexCoord2f(0.f, 1.f);
glVertex2f(0.f, windowSize.y);
glTexCoord2f(1.f, 1.f);
glVertex2f(windowSize.x, windowSize.y);
glTexCoord2f(1.f, 0.f);
glVertex2f(windowSize.x, 0.f);
glEnd();
if (showUi && uiCallback) {
ImGui::Render();
}
// swap buffers
glfwSwapBuffers(glfwWindow);
// display frame rate in window title
auto displayEnd = std::chrono::high_resolution_clock::now();
auto durationMilliseconds =
std::chrono::duration_cast<std::chrono::milliseconds>(displayEnd -
displayStart);
displayStart = displayEnd;
const float frameRate = 1000.f / float(durationMilliseconds.count());
std::stringstream windowTitle;
windowTitle << "OSPRay: " << std::setprecision(3) << frameRate << " fps";
glfwSetWindowTitle(glfwWindow, windowTitle.str().c_str());
}
void FrameBuffer::unmap(const void *mem)
{
ospUnmapFrameBuffer(mem, ospFrameBuffer);
}
int main(int ac, const char **av) {
// image size
osp_vec2i imgSize;
imgSize.x = 1024; // width
imgSize.y = 768; // height
// camera
float cam_pos[] = {0.f, 0.f, 0.f};
float cam_up [] = {0.f, 1.f, 0.f};
float cam_view [] = {0.1f, 0.f, 1.f};
// triangle mesh data
float vertex[] = { -1.0f, -1.0f, 3.0f, 0.f,
-1.0f, 1.0f, 3.0f, 0.f,
1.0f, -1.0f, 3.0f, 0.f,
0.1f, 0.1f, 0.3f, 0.f };
float color[] = { 0.9f, 0.5f, 0.5f, 1.0f,
0.8f, 0.8f, 0.8f, 1.0f,
0.8f, 0.8f, 0.8f, 1.0f,
0.5f, 0.9f, 0.5f, 1.0f };
int32_t index[] = { 0, 1, 2,
1, 2, 3 };
// initialize OSPRay; OSPRay parses (and removes) its commandline parameters, e.g. "--osp:debug"
ospInit(&ac, av);
// create and setup camera
OSPCamera camera = ospNewCamera("perspective");
ospSetf(camera, "aspect", imgSize.x/(float)imgSize.y);
ospSet3fv(camera, "pos", cam_pos);
ospSet3fv(camera, "dir", cam_view);
ospSet3fv(camera, "up", cam_up);
ospCommit(camera); // commit each object to indicate modifications are done
// create and setup model and mesh
OSPGeometry mesh = ospNewGeometry("triangles");
OSPData data = ospNewData(4, OSP_FLOAT3A, vertex, 0); // OSP_FLOAT3 format is also supported for vertex positions (currently not on MIC)
ospCommit(data);
ospSetData(mesh, "vertex", data);
data = ospNewData(4, OSP_FLOAT4, color, 0);
ospCommit(data);
ospSetData(mesh, "vertex.color", data);
data = ospNewData(2, OSP_INT3, index, 0); // OSP_INT4 format is also supported for triangle indices
ospCommit(data);
ospSetData(mesh, "index", data);
ospCommit(mesh);
OSPModel world = ospNewModel();
ospAddGeometry(world, mesh);
ospCommit(world);
// create and setup renderer
OSPRenderer renderer = ospNewRenderer("scivis"); // choose Scientific Visualization renderer
ospSet1f(renderer, "aoWeight", 1.0f); // with full Ambient Occlusion
ospSet1i(renderer, "aoSamples", 1);
ospSetObject(renderer, "model", world);
ospSetObject(renderer, "camera", camera);
ospCommit(renderer);
// create and setup framebuffer
OSPFrameBuffer framebuffer = ospNewFrameBuffer(&imgSize, OSP_FB_SRGBA, OSP_FB_COLOR | /*OSP_FB_DEPTH |*/ OSP_FB_ACCUM);
ospFrameBufferClear(framebuffer, OSP_FB_COLOR | OSP_FB_ACCUM);
// render one frame
ospRenderFrame(framebuffer, renderer, OSP_FB_COLOR | OSP_FB_ACCUM);
// access framebuffer and write its content as PPM file
const uint32_t * fb = (uint32_t*)ospMapFrameBuffer(framebuffer, OSP_FB_COLOR);
writePPM("firstFrameC.ppm", &imgSize, fb);
ospUnmapFrameBuffer(fb, framebuffer);
// render 10 more frames, which are accumulated to result in a better converged image
for (int frames = 0; frames < 10; frames++)
ospRenderFrame(framebuffer, renderer, OSP_FB_COLOR | OSP_FB_ACCUM);
fb = (uint32_t*)ospMapFrameBuffer(framebuffer, OSP_FB_COLOR);
writePPM("accumulatedFrameC.ppm", &imgSize, fb);
ospUnmapFrameBuffer(fb, framebuffer);
return 0;
}
