From e81487ae08a658811a0104ead4764ad71b449074 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Lemaire?= <michael@thunderk.net>
Date: Fri, 16 Oct 2015 00:14:54 +0200
Subject: [PATCH] Added safety offset on lighting

This avoids shadow algorithm to hit the surface it is currently checking
---
 src/render/software/GodRaysSampler.cpp  |  1 +
 src/render/software/LightStatus.cpp     |  8 +++++++-
 src/render/software/LightStatus.h       | 10 ++++++++++
 src/render/software/LightingManager.cpp |  8 +++++++-
 src/render/software/LightingManager.h   |  9 +++++++--
 5 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/src/render/software/GodRaysSampler.cpp b/src/render/software/GodRaysSampler.cpp
index 39c6e67..4233cd6 100644
--- a/src/render/software/GodRaysSampler.cpp
+++ b/src/render/software/GodRaysSampler.cpp
@@ -110,6 +110,7 @@ Color GodRaysSampler::getRawLight(const Vector3 &location, bool filtered) const
     if (lighting)
     {
         LightStatus status(lighting, location, *camera_location, filtered);
+        status.setSafetyOffset(0.0);  // Not a hard surface, safety offset not needed
         lighting->fillStatus(status, location);
         return status.getSum();
     }
diff --git a/src/render/software/LightStatus.cpp b/src/render/software/LightStatus.cpp
index 31555d1..e06baa5 100644
--- a/src/render/software/LightStatus.cpp
+++ b/src/render/software/LightStatus.cpp
@@ -7,6 +7,7 @@
 
 LightStatus::LightStatus(LightingManager *manager, const Vector3 &location, const Vector3 &eye, bool filtered)
 {
+    this->safety_offset = -0.0000001;
     this->max_power = 0.0;
     this->manager = manager;
     this->location = location;
@@ -25,7 +26,7 @@ void LightStatus::pushComponent(LightComponent component)
             return;
         }
 
-        if (manager->alterLight(component, location))
+        if (manager->alterLight(component, location.add(component.direction.scale(safety_offset))))
         {
             if (power > max_power)
             {
@@ -64,3 +65,8 @@ Color LightStatus::getSum() const
 
     return final;
 }
+
+void LightStatus::setSafetyOffset(double safety_offset)
+{
+    this->safety_offset = -safety_offset;
+}
diff --git a/src/render/software/LightStatus.h b/src/render/software/LightStatus.h
index 0f0d7c2..6de1251 100644
--- a/src/render/software/LightStatus.h
+++ b/src/render/software/LightStatus.h
@@ -29,7 +29,17 @@ public:
      */
     Color getSum() const;
 
+    /**
+     * Set the safety offset for this status.
+     *
+     * The offset is used to not hit the surface we are currently working on immediately.
+     * It adds a small vector toward the light at the start of shadow casting.
+     * This number should remain very small to not produce precision errors.
+     */
+    void setSafetyOffset(double safety_offset);
+
 private:
+    double safety_offset;
     double max_power;
     LightingManager* manager;
     Vector3 location;
diff --git a/src/render/software/LightingManager.cpp b/src/render/software/LightingManager.cpp
index bb0bb96..5b087a2 100644
--- a/src/render/software/LightingManager.cpp
+++ b/src/render/software/LightingManager.cpp
@@ -10,6 +10,7 @@
 LightingManager::LightingManager()
 {
     specularity = true;
+    filtering = true;
 }
 
 int LightingManager::getStaticLightsCount() const
@@ -81,7 +82,7 @@ void LightingManager::unregisterFilter(LightFilter *filter)
 
 bool LightingManager::alterLight(LightComponent &component, const Vector3 &location)
 {
-    if (component.altered)
+    if (filtering and component.altered)
     {
         for (auto filter:filters)
         {
@@ -105,6 +106,11 @@ void LightingManager::setSpecularity(bool enabled)
     specularity = enabled;
 }
 
+void LightingManager::setFiltering(bool enabled)
+{
+    filtering = enabled;
+}
+
 Color LightingManager::applyFinalComponent(const LightComponent &component, const Vector3 &eye, const Vector3 &location, const Vector3 &normal, const SurfaceMaterial &material)
 {
     Color result, light_color;
diff --git a/src/render/software/LightingManager.h b/src/render/software/LightingManager.h
index f4c2544..49cf1ae 100644
--- a/src/render/software/LightingManager.h
+++ b/src/render/software/LightingManager.h
@@ -77,6 +77,11 @@ public:
      */
     void setSpecularity(bool enabled);
 
+    /**
+     * Enable or disable the filtering (shadows).
+     */
+    void setFiltering(bool enabled);
+
     /**
      * Apply a final component on a surface material.
      */
@@ -93,11 +98,11 @@ public:
     Color apply(const Vector3 &eye, const Vector3 &location, const Vector3 &normal, const SurfaceMaterial &material);
 
 private:
-    int specularity;
+    bool specularity;
+    bool filtering;
     std::vector<LightComponent> static_lights;
     std::vector<LightFilter *> filters;
     std::vector<LightSource *> sources;
-
 };
 
 }