void
My_TestGLDrawing::
DrawScene(PickParam const * pickParam)
{
int width = GetWidth(), height = GetHeight();
GfMatrix4d viewMatrix = GetViewMatrix();
GfFrustum frustum = GetFrustum();
GfVec4d viewport(0, 0, width, height);
if (pickParam) {
frustum = frustum.ComputeNarrowedFrustum(
GfVec2d((2.0 * pickParam->location[0]) / width - 1.0,
(2.0 * (height-pickParam->location[1])) / height - 1.0),
GfVec2d(1.0 / width, 1.0 / height));
viewport = pickParam->viewport;
}
GfMatrix4d projMatrix = frustum.ComputeProjectionMatrix();
_delegate->SetCamera(viewMatrix, projMatrix);
glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
HdTaskSharedPtrVector tasks;
SdfPath renderSetupTask("/renderSetupTask");
SdfPath renderTask("/renderTask");
tasks.push_back(_delegate->GetRenderIndex().GetTask(renderSetupTask));
tasks.push_back(_delegate->GetRenderIndex().GetTask(renderTask));
HdxRenderTaskParams param
= _delegate->GetTaskParam(
renderSetupTask, HdTokens->params).Get<HdxRenderTaskParams>();
param.enableIdRender = (pickParam != NULL);
param.viewport = viewport;
_delegate->SetTaskParam(renderSetupTask, HdTokens->params, VtValue(param));
glEnable(GL_DEPTH_TEST);
glBindVertexArray(vao);
_engine.Execute(_delegate->GetRenderIndex(), tasks);
glBindVertexArray(0);
}
SdfPath
My_TestGLDrawing::PickScene(int pickX, int pickY,
int * outInstanceIndex,
int * outElementIndex)
{
int width = 128;
int height = 128;
GlfDrawTargetRefPtr drawTarget = GlfDrawTarget::New(GfVec2i(width, height));
drawTarget->Bind();
drawTarget->AddAttachment(
"primId", GL_RGBA, GL_UNSIGNED_BYTE, GL_RGBA8);
drawTarget->AddAttachment(
"instanceId", GL_RGBA, GL_UNSIGNED_BYTE, GL_RGBA8);
drawTarget->AddAttachment(
"elementId", GL_RGBA, GL_UNSIGNED_BYTE, GL_RGBA8);
drawTarget->AddAttachment(
"depth", GL_DEPTH_COMPONENT, GL_FLOAT, GL_DEPTH_COMPONENT32F);
drawTarget->Unbind();
drawTarget->Bind();
GLenum drawBuffers[] = {
GL_COLOR_ATTACHMENT0,
GL_COLOR_ATTACHMENT1,
GL_COLOR_ATTACHMENT2
};
glDrawBuffers(3, drawBuffers);
glEnable(GL_DEPTH_TEST);
GLfloat clearColor[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
glClearBufferfv(GL_COLOR, 0, clearColor);
glClearBufferfv(GL_COLOR, 1, clearColor);
GLfloat clearDepth[1] = { 1.0f };
glClearBufferfv(GL_DEPTH, 0, clearDepth);
PickParam pickParam;
pickParam.location = GfVec2d(pickX, pickY);
pickParam.viewport = GfVec4d(0, 0, width, height);
DrawScene(&pickParam);
drawTarget->Unbind();
GLubyte primId[width*height*4];
glBindTexture(GL_TEXTURE_2D,
drawTarget->GetAttachments().at("primId")->GetGlTextureName());
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, primId);
GLubyte instanceId[width*height*4];
glBindTexture(GL_TEXTURE_2D,
drawTarget->GetAttachments().at("instanceId")->GetGlTextureName());
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, instanceId);
GLubyte elementId[width*height*4];
glBindTexture(GL_TEXTURE_2D,
drawTarget->GetAttachments().at("elementId")->GetGlTextureName());
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, elementId);
GLfloat depths[width*height];
glBindTexture(GL_TEXTURE_2D,
drawTarget->GetAttachments().at("depth")->GetGlTextureName());
glGetTexImage(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, GL_FLOAT, depths);
double zMin = 1.0;
int zMinIndex = -1;
for (int y=0, i=0; y<height; y++) {
for (int x=0; x<width; x++, i++) {
if (depths[i] < zMin) {
zMin = depths[i];
zMinIndex = i;
}
}
}
bool didHit = (zMin < 1.0);
SdfPath result;
if (didHit) {
int idIndex = zMinIndex*4;
result = _delegate->GetRenderIndex().GetRprimPathFromPrimId(
HdxRenderSetupTask::DecodeIDRenderColor(&primId[idIndex]));
if (outInstanceIndex) {
*outInstanceIndex = HdxRenderSetupTask::DecodeIDRenderColor(
&instanceId[idIndex]);
}
if (outElementIndex) {
*outElementIndex = HdxRenderSetupTask::DecodeIDRenderColor(
&elementId[idIndex]);
}
}
return result;
}
