From d486282bb6baedd1b4f1af153556b4a6b54b0cbd Mon Sep 17 00:00:00 2001
From: Nate Morrical <natemorrical@gmail.com>
Date: Mon, 15 May 2023 15:39:41 -0600
Subject: [PATCH 1/2] adding some controls to override default number of ray
 payload registers

---
 owl/Context.cpp            | 14 ++++++++++++++
 owl/Context.h              |  6 ++++++
 owl/DeviceContext.cpp      |  2 +-
 owl/impl.cpp               |  7 +++++++
 owl/include/owl/owl_host.h |  6 ++++++
 5 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/owl/Context.cpp b/owl/Context.cpp
index 72f657d2..76174e04 100644
--- a/owl/Context.cpp
+++ b/owl/Context.cpp
@@ -596,6 +596,20 @@ namespace owl {
     } 
   }
 
+  void Context::setNumPayloadValues(size_t numPayloadValues)
+  {
+    if (numPayloadValues > 32)
+      OWL_RAISE
+        ("a payload count > 32 isnt' currently supported in OWL; "
+         "please see comments on owlSetNumPayloadValues() (owl/owl_host.h)");
+
+    for (auto device : getDevices()) {
+      assert("check programs have not been built"
+             && device->allActivePrograms.empty());
+    }
+    this->numPayloadValues = (int)numPayloadValues;
+  }
+
   void Context::enableMotionBlur()
   {
     motionBlurEnabled = true;
diff --git a/owl/Context.h b/owl/Context.h
index 5c904a3d..5dcb7da8 100644
--- a/owl/Context.h
+++ b/owl/Context.h
@@ -116,6 +116,9 @@ namespace owl {
        to ClosestHit programs.  Default 2.  Has no effect once programs are built.*/
     void setNumAttributeValues(size_t numAttributeValues);
 
+    /* Set number of payload registers for passing data between raygen and raytracing 
+        programs.  Default 2.  Has no effect once programs are built.*/
+    void setNumPayloadValues(size_t numPayloadValues);
 
     // ------------------------------------------------------------------
     // internal mechanichs/plumbling that do the actual work
@@ -322,6 +325,9 @@ namespace owl {
     /* Number of attributes for writing data between Intersection and ClosestHit */
     int numAttributeValues = 2;
 
+    /* Number of payload registers for writing data between raygen and raytracing programs */
+    int numPayloadValues = 2;
+
     /*! a set of dummy (ie, empty) launch params. allows us for always
       using the same launch code, *with* launch params, even if th
       user didn't specify any during launch */
diff --git a/owl/DeviceContext.cpp b/owl/DeviceContext.cpp
index 92e08b43..7cdcd0ee 100644
--- a/owl/DeviceContext.cpp
+++ b/owl/DeviceContext.cpp
@@ -309,7 +309,7 @@ namespace owl {
       break;
     }
     pipelineCompileOptions.usesMotionBlur     = parent->motionBlurEnabled;
-    pipelineCompileOptions.numPayloadValues   = 2;
+    pipelineCompileOptions.numPayloadValues = parent->numPayloadValues;
     pipelineCompileOptions.numAttributeValues = parent->numAttributeValues;
     pipelineCompileOptions.exceptionFlags     = OPTIX_EXCEPTION_FLAG_NONE;
     pipelineCompileOptions.pipelineLaunchParamsVariableName = "optixLaunchParams";
diff --git a/owl/impl.cpp b/owl/impl.cpp
index 9a8e0c83..ed81642c 100644
--- a/owl/impl.cpp
+++ b/owl/impl.cpp
@@ -110,6 +110,13 @@ owlContextSetNumAttributeValues(OWLContext _context, size_t numAttributeValues)
   checkGet(_context)->setNumAttributeValues(numAttributeValues);
 }
 
+OWL_API void
+owlContextSetNumPayloadValues(OWLContext _context, size_t numPayloadValues)
+{
+  LOG_API_CALL();
+  checkGet(_context)->setNumPayloadValues(numPayloadValues);
+}
+
 OWL_API void
 owlContextSetBoundLaunchParamValues(OWLContext _context,
                                     const OWLBoundValueDecl *_boundValues,
diff --git a/owl/include/owl/owl_host.h b/owl/include/owl/owl_host.h
index 59a770a4..78087e53 100644
--- a/owl/include/owl/owl_host.h
+++ b/owl/include/owl/owl_host.h
@@ -401,6 +401,12 @@ OWL_API void
 owlContextSetNumAttributeValues(OWLContext context,
                                 size_t numAttributeValues);
 
+/* Set number of payload registers for passing data between raygen programs and 
+   closesthit / anyhit / miss programs.  Default 2.  Has no effect once programs are built.*/
+OWL_API void
+owlContextSetNumPayloadValues(OWLContext context,
+                                size_t numPayloadValues);
+
 /*! tells OptiX to specialize the values of certain launch parameters
   when compiling modules, and ignore their values at launch.
   See section 6.3.1 of the OptiX 7.2 programming guide.

From 488f10b33af219e299212271415b71d5de674d0b Mon Sep 17 00:00:00 2001
From: Nate Morrical <natemorrical@gmail.com>
Date: Mon, 15 May 2023 15:41:51 -0600
Subject: [PATCH 2/2] small spacing change

---
 owl/DeviceContext.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/owl/DeviceContext.cpp b/owl/DeviceContext.cpp
index 7cdcd0ee..14f2f048 100644
--- a/owl/DeviceContext.cpp
+++ b/owl/DeviceContext.cpp
@@ -309,7 +309,7 @@ namespace owl {
       break;
     }
     pipelineCompileOptions.usesMotionBlur     = parent->motionBlurEnabled;
-    pipelineCompileOptions.numPayloadValues = parent->numPayloadValues;
+    pipelineCompileOptions.numPayloadValues   = parent->numPayloadValues;
     pipelineCompileOptions.numAttributeValues = parent->numAttributeValues;
     pipelineCompileOptions.exceptionFlags     = OPTIX_EXCEPTION_FLAG_NONE;
     pipelineCompileOptions.pipelineLaunchParamsVariableName = "optixLaunchParams";