From 5924fa78ea5d93bc80a0505380c0526291e8fffe Mon Sep 17 00:00:00 2001
From: codereader <greebo@angua.at>
Date: Tue, 23 Mar 2021 07:11:27 +0100
Subject: [PATCH] #5571: Fix table lookup implementation (clamped)

---
 radiantcore/shaders/TableDefinition.cpp |  4 +--
 test/Materials.cpp                      | 46 +++++++++++++++++++++----
 test/resources/tdm/materials/tables.mtr |  2 ++
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/radiantcore/shaders/TableDefinition.cpp b/radiantcore/shaders/TableDefinition.cpp
index 3532cc1788..0a35b268d7 100644
--- a/radiantcore/shaders/TableDefinition.cpp
+++ b/radiantcore/shaders/TableDefinition.cpp
@@ -38,11 +38,11 @@ float TableDefinition::getValue(float index)
 	{
 		if (index > 1.0f) 
 		{
-			index = 1.0f - 1.0f / numValues;
+			return _values[numValues - 1];
 		}
 		else if (index < 0.0f) 
 		{
-			index = 0.0f;
+			return _values[0];
 		}
 
 		// Map the index to the [0..N-1] interval
diff --git a/test/Materials.cpp b/test/Materials.cpp
index 5cf84147a1..9035d0df50 100644
--- a/test/Materials.cpp
+++ b/test/Materials.cpp
@@ -110,11 +110,20 @@ TEST_F(MaterialsTest, IdentifyAmbientLight)
     EXPECT_FALSE(nonLight->isAmbientLight());
 }
 
-TEST_F(MaterialsTest, MaterialTableLookup)
+void performLookupTests(const ITableDefinition::Ptr& table, const std::vector<std::pair<float, float>>& testCases)
+{
+    for (auto testcase : testCases)
+    {
+        EXPECT_NEAR(table->getValue(testcase.first), testcase.second, TestEpsilon) << "Lookup failed: "
+            << table->getName() << "[" << testcase.first << "] = " << table->getValue(testcase.first) << ", but should be " << testcase.second;
+    }
+}
+
+TEST_F(MaterialsTest, MaterialTableLookupNonSnapped)
 {
     auto table = GlobalMaterialManager().getTable("sinTable");
 
-    constexpr std::pair<float, float> testCases[]
+    std::vector<std::pair<float, float>> testCases
     {
       {  -9.400000f, -0.587745f },
       {  -1.000000f,  0.000000f },
@@ -135,11 +144,36 @@ TEST_F(MaterialsTest, MaterialTableLookup)
       { 100.230003f,  0.992086f }
     };
 
-    for (auto testcase : testCases)
+    performLookupTests(table, testCases);
+}
+
+TEST_F(MaterialsTest, MaterialTableLookupClamped)
+{
+    auto table = GlobalMaterialManager().getTable("clampTest");
+
+    std::vector<std::pair<float, float>> testCases
     {
-        EXPECT_NEAR(table->getValue(testcase.first), testcase.second, TestEpsilon) << "Lookup failed: "
-            << table->getName() << "[" << testcase.first << "] = " << table->getValue(testcase.first) << ", but should be " << testcase.second;
-    }
+        {  -9.400000f, 1.000000f },
+        {  -1.000000f, 1.000000f },
+        {  -0.355500f, 1.000000f },
+        {  -0.000025f, 1.000000f },
+        {   0.000000f, 1.000000f },
+        {   0.000025f, 1.000000f },
+        {   0.050000f, 1.000000f },
+        {   0.250000f, 1.000000f },
+        {   0.332200f, 1.000000f },
+        {   0.700020f, 1.000000f },
+        {   0.910000f, 0.809999f },
+        {   0.999980f, 0.000180f },
+        {   1.000000f, 0.000000f },
+        {   1.002000f, 0.000000f },
+        {   1.800000f, 0.000000f },
+        {   2.300000f, 0.000000f },
+        {  60.500000f, 0.000000f },
+        { 100.230003f, 0.000000f },
+    };
+
+    performLookupTests(table, testCases);
 }
 
 TEST_F(MaterialsTest, MaterialRotationEvaluation)
diff --git a/test/resources/tdm/materials/tables.mtr b/test/resources/tdm/materials/tables.mtr
index 253139c31d..0a6f396d37 100644
--- a/test/resources/tdm/materials/tables.mtr
+++ b/test/resources/tdm/materials/tables.mtr
@@ -65,3 +65,5 @@ table cosTable { {
 0.831470, 0.844854, 0.857729, 0.870087, 0.881921, 0.893224, 0.903989, 0.914210, 
 0.923880, 0.932993, 0.941544, 0.949528, 0.956940, 0.963776, 0.970031, 0.975702, 
 0.980785, 0.985278, 0.989177, 0.992480, 0.995185, 0.997290, 0.998795, 0.999699 } }
+
+table clampTest { clamp { 1, 1, 1, 1, 1, 1, 1, 1, 1, 0 } }