From 9a913ac95be9493460da038672aa3043093f00bb Mon Sep 17 00:00:00 2001
From: Ben Visness <bvisness@gmail.com>
Date: Fri, 21 May 2021 12:04:17 -0500
Subject: [PATCH] Expose NaNs in our tests

oops
---
 test/HandmadeTest.h             |  5 +++--
 test/categories/QuaternionOps.h | 39 +++++++++++++++++++++++++++------
 2 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/test/HandmadeTest.h b/test/HandmadeTest.h
index c142e11..89428cf 100644
--- a/test/HandmadeTest.h
+++ b/test/HandmadeTest.h
@@ -58,6 +58,7 @@
 #define HANDMADETEST_H
 
 #include <float.h>
+#include <math.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -152,7 +153,7 @@ INITIALIZER(_HMT_COVERCASE_FUNCNAME_INIT(name)) { \
     _HMT_CASE_START(); \
     float actual = (_actual); \
     float diff = actual - (_expected); \
-    if (diff < -FLT_EPSILON || FLT_EPSILON < diff) { \
+    if (isnan(actual) || diff < -FLT_EPSILON || FLT_EPSILON < diff) { \
         _HMT_CASE_FAIL(); \
         printf("Expected %f, got %f", (_expected), actual); \
     } \
@@ -162,7 +163,7 @@ INITIALIZER(_HMT_COVERCASE_FUNCNAME_INIT(name)) { \
     _HMT_CASE_START(); \
     float actual = (_actual); \
     float diff = actual - (_expected); \
-    if (diff < -(_epsilon) || (_epsilon) < diff) { \
+    if (isnan(actual) || diff < -(_epsilon) || (_epsilon) < diff) { \
         _HMT_CASE_FAIL(); \
         printf("Expected %f, got %f", (_expected), actual); \
     } \
diff --git a/test/categories/QuaternionOps.h b/test/categories/QuaternionOps.h
index a373106..235c783 100644
--- a/test/categories/QuaternionOps.h
+++ b/test/categories/QuaternionOps.h
@@ -66,14 +66,39 @@ TEST(QuaternionOps, NLerp)
 
 TEST(QuaternionOps, Slerp)
 {
-    hmm_quaternion from = HMM_Quaternion(0.0f, 0.0f, 0.0f, 1.0f);
-    hmm_quaternion to = HMM_Quaternion(0.5f, 0.5f, -0.5f, 0.5f);
+    // Normal operation
+    {
+        hmm_quaternion from = HMM_Quaternion(0.0f, 0.0f, 0.0f, 1.0f);
+        hmm_quaternion to = HMM_Quaternion(0.5f, 0.5f, -0.5f, 0.5f);
 
-    hmm_quaternion result = HMM_Slerp(from, 0.5f, to);
-    EXPECT_FLOAT_EQ(result.X, 0.28867513f);
-    EXPECT_FLOAT_EQ(result.Y, 0.28867513f);
-    EXPECT_FLOAT_EQ(result.Z, -0.28867513f);
-    EXPECT_FLOAT_EQ(result.W, 0.86602540f);
+        hmm_quaternion result = HMM_Slerp(from, 0.5f, to);
+        EXPECT_FLOAT_EQ(result.X, 0.28867513f);
+        EXPECT_FLOAT_EQ(result.Y, 0.28867513f);
+        EXPECT_FLOAT_EQ(result.Z, -0.28867513f);
+        EXPECT_FLOAT_EQ(result.W, 0.86602540f);
+    }
+
+    // Same quat twice
+    {
+        hmm_quaternion q = HMM_Quaternion(0.5f, 0.5f, 0.5f, 1.0f);
+
+        hmm_quaternion result = HMM_Slerp(q, 0.5f, q);
+        EXPECT_FLOAT_EQ(result.X, 0.5f);
+        EXPECT_FLOAT_EQ(result.Y, 0.5f);
+        EXPECT_FLOAT_EQ(result.Z, 0.5f);
+        EXPECT_FLOAT_EQ(result.W, 1.0f);
+    }
+
+    // Identity quat twice
+    {
+        hmm_quaternion q = HMM_Quaternion(0.0f, 0.0f, 0.0f, 1.0f);
+
+        hmm_quaternion result = HMM_Slerp(q, 0.5f, q);
+        EXPECT_FLOAT_EQ(result.X, 0.0f);
+        EXPECT_FLOAT_EQ(result.Y, 1.0f);
+        EXPECT_FLOAT_EQ(result.Z, 0.0f);
+        EXPECT_FLOAT_EQ(result.W, 1.0f);
+    }
 }
 
 TEST(QuaternionOps, QuatToMat4)