From 7aacbd27b9fd5124de2e8aaf81d197ce962aed9b Mon Sep 17 00:00:00 2001
From: Russ Taylor <russ@reliasolve.com>
Date: Sat, 10 Jun 2017 21:19:00 -0400
Subject: [PATCH] Enable specification of the number of desired triangles in
 the generated distortion mesh in the configuration file.

---
 osvr/RenderKit/DistortionParameters.cpp       |  1 +
 osvr/RenderKit/RenderManagerBase.cpp          |  1 -
 osvr/RenderKit/osvr_display_configuration.cpp | 10 ++++++++++
 osvr/RenderKit/osvr_display_configuration.h   |  4 ++++
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/osvr/RenderKit/DistortionParameters.cpp b/osvr/RenderKit/DistortionParameters.cpp
index e03e3af..6b44c43 100644
--- a/osvr/RenderKit/DistortionParameters.cpp
+++ b/osvr/RenderKit/DistortionParameters.cpp
@@ -35,6 +35,7 @@ namespace osvr {
     OSVR_RENDERMANAGER_EXPORT DistortionParameters::DistortionParameters(
       OSVRDisplayConfiguration& osvrParams,
       size_t eye) : DistortionParameters() {
+      m_desiredTriangles = osvrParams.getDesiredDistortionTriangleCount();
       if (osvrParams.getDistortionType() ==
         OSVRDisplayConfiguration::RGB_SYMMETRIC_POLYNOMIALS) {
         m_type = rgb_symmetric_polynomials;
diff --git a/osvr/RenderKit/RenderManagerBase.cpp b/osvr/RenderKit/RenderManagerBase.cpp
index 22ab333..62aa13f 100644
--- a/osvr/RenderKit/RenderManagerBase.cpp
+++ b/osvr/RenderKit/RenderManagerBase.cpp
@@ -2160,7 +2160,6 @@ namespace renderkit {
         // @todo Remove once we get a general polynomial from Core.
         for (size_t i = 0; i < p.m_displayConfiguration->getEyes().size(); i++) {
           DistortionParameters distortion(*p.m_displayConfiguration, i);
-          distortion.m_desiredTriangles = 200 * 64;
           p.m_distortionParameters.push_back(distortion);
         }
 
diff --git a/osvr/RenderKit/osvr_display_configuration.cpp b/osvr/RenderKit/osvr_display_configuration.cpp
index 0e07272..cd2f36d 100644
--- a/osvr/RenderKit/osvr_display_configuration.cpp
+++ b/osvr/RenderKit/osvr_display_configuration.cpp
@@ -530,6 +530,11 @@ void OSVRDisplayConfiguration::parse(const std::string& display_description) {
     {
         auto const& distortion = hmd["distortion"];
 
+        /// Find out how many desired triangles, if this is specified.
+        /// If not specified, set to a default.
+        m_distortionDesiredTriangleCount =
+          distortion.get("desired_triangle_count", 200 * 64).asInt();
+
         /// We will detect distortion type based on either the explicitly
         /// specified string or the presence of essential object members.
         m_distortionTypeString = distortion["type"].asString();
@@ -783,6 +788,11 @@ OSVRDisplayConfiguration::getDistortionPolynomalBlue() const {
     return m_distortionPolynomialBlue;
 }
 
+int OSVR_RENDERMANAGER_EXPORT
+OSVRDisplayConfiguration::getDesiredDistortionTriangleCount() const {
+    return m_distortionDesiredTriangleCount;
+}
+
 std::vector<OSVRDisplayConfiguration::EyeInfo> const&
 OSVRDisplayConfiguration::getEyes() const {
     return m_eyes;
diff --git a/osvr/RenderKit/osvr_display_configuration.h b/osvr/RenderKit/osvr_display_configuration.h
index b4b7fc3..39f3700 100644
--- a/osvr/RenderKit/osvr_display_configuration.h
+++ b/osvr/RenderKit/osvr_display_configuration.h
@@ -132,6 +132,9 @@ class OSVRDisplayConfiguration {
     std::vector<float> const& getDistortionPolynomalBlue() const;
     ///@}
 
+    /// Returns the desired number of triangles in the constructed distortion mesh.
+    int OSVR_RENDERMANAGER_EXPORT getDesiredDistortionTriangleCount() const;
+
     /// Structure holding the information for one eye.
     class EyeInfo {
       public:
@@ -186,6 +189,7 @@ class OSVRDisplayConfiguration {
     std::vector<float> m_distortionPolynomialRed;
     std::vector<float> m_distortionPolynomialGreen;
     std::vector<float> m_distortionPolynomialBlue;
+    int m_distortionDesiredTriangleCount;
 
     // Rendering
     double m_rightRoll = 0.;